Skip to main content
NCBI home page
Wiley Open Access Collection logoLink to Wiley Open Access Collection
. 2025 Feb 7;39(3):559–575. doi: 10.1111/mve.12795

Citizen scientists mapping the United Kingdom's and Republic of Ireland's flat flies (louse flies) (Diptera: Hippoboscidae) reveal a vector's range shift

Denise C Wawman 1,✉
PMCID: PMC12323749  PMID: 39921336

Abstract

Changes in climate may cause changes in the ranges, phenology and interactions of insects with other species and lead parasites to switch host species. A study of louse (flat) flies in the United Kingdom, Republic of Ireland and Isle of Man, in which licensed bird ringers acting as citizen scientists collected ectoparasites that left birds during ringing, showed recent range shifts of several species. The Common or Bird Louse Fly Ornithomya avicularia (Linnaeus, 1758), a vector of Haemoproteus sp. and trypanosomes, has undergone a major northwards range expansion of over 300 km in the United Kingdom (UK) since the 1960s. The Finch Louse Fly Ornithomya fringillina (Curtis, 1836) has also expanded its range over 300 km northwards and 400 km westwards into the Island of Ireland, and the Swallow Louse Fly Ornithomya biloba (Dufour, 1827) is now established in Wales and Southern England. The Grouse Louse Fly Ornithomya chloropus (Bergroth, 1901) has undergone a range contraction at lower altitudes and on the southern edge of its range. Other species of louse fly were detected: Crataerina pallida (Latreille, 1812), Stenepteryx hirundinis (Linnaeus, 1758), Pseudolynchia garzettae (Rondani, 1879) and Icosta minor (Bigot, 1858). Some generalist species have shifted their phenology, whereas the more specialist nest parasites of migrant birds have not, as the arrival and breeding dates of their hosts have not changed. The range changes of the generalist species of these ectoparasites may have implications for bird health, especially if they switch to new host species as their ranges shift.

Keywords: birds, climate change, ectoparasites, modelling, prediction, range shift, vectors

  • The Common or Bird Louse Fly Ornithomya avicularia, a vector of Haemoproteus sp. and trypanosomes, has undergone a major northwards range expansion in the United Kingdom since the 1960s.

  • The Finch Louse Fly Ornithomya fringillina has also expanded its range northwards and westwards, and the Swallow Louse Fly Ornithomya biloba is now established in Wales and Southern England.

  • The range of the Grouse Louse Fly Ornithomya chloropus is contracting at lower altitudes at the southern edge of its range.

graphic file with name MVE-39-559-g005.jpg

INTRODUCTION

Changes in climate, such as those in temperature and seasonality, may affect the ranges, phenology and interactions of insects with other species (Harvey et al., 2023). Range changes are often related to physiological constraints such as thermal limits (Weaving et al., 2023), as well as changes in interactions with other species, in both food webs, with effects on their ability to find suitable food (Bartley et al., 2019), and with competitors (Gilman et al., 2010). While generalist species may be able to change their position in a food web quickly (Bartley et al., 2019), specialist species are generally slower to adapt (Menéndez et al., 2006). Nonstandardised methods of historic data collection complicate the analyses of range shifts (Guzman et al., 2021), but there are few long‐term datasets for parasitic arthropods, even for species such as ticks that are known to be important disease vectors (Nuttall, 2021).

The Hippoboscidae are a family of haematophagous ectoparasites of birds and mammals. The species found on birds are known as louse flies in most of the world but are often referred to as flat flies in the United Kingdom (UK), Republic of Ireland (ROI) and Isle of Man (Hutson, 1984), an area collectively historically referred to as the British Isles, and referred to hereafter as ‘the region’. In the UK, there are eight breeding species of flat fly (Hutson, 1984; Wawman, 2024), three of these are generalists, although with some niche separation according to host size and local environmental factors (Hill, 1962a; Lehikoinen et al., 2021). These three generalists are in the genus Ornithomya species group ‘a’: O. avicularia (Linnaeus, 1758), O. chloropus (Bergroth, 1901) and O. fringillina (Curtis, 1836) (Dick, 2018). A fourth member of the genus, the relatively recent UK colonist, O. biloba (Dufour, 1827), is in group ‘b’ and has a preference for Swallow Hirundo rustica (Linnaeus 1758) as its main host but can be found on other hirundines (Wawman, 2024). Another two fully flighted species have bred in the UK, Pseudolynchia canariensis (Macquart 1839), on feral pigeons Columba livia domestica (Gmelin, 1789), and P. garzettae (Rondani, 1879) on Nightjar Caprimulgus europaeus (Linnaeus, 1758) (Wawman, 2024). A further two species are flightless nest parasites: Crataerina pallida (Latreille, 1812) prefers to parasitise Swift Apus apus (Linnaeus 1758) but may be found on hirundines, and Stenepteryx hirundinis (Linnaeus, 1758) (Crataerina hirundinis [Linnaeus, 1758]) is found on hirundines, especially on the House Martin Delichon urbicum (Linnaeus, 1758) (Hutson, 1984). In Ireland, only five species of louse fly are known to breed: O. avicularia, O. chloropus, O. fringillina, C. pallida and S. hirundinis (O'Connor & Sleeman, 1987; Smiddy & Sleeman, 2004).

Louse flies reproduce by adenotrophic viviparity. Fertilised eggs are released one at a time into the female's uterus, where the larvae hatch and are fed from a special milk gland. When a third instar larva is mature, parturition occurs and the larva's exoskeleton hardens to form a puparium (Baker, 1967). Flightless females in the genera Crataerina and Stenepteryx leave their avian hosts to deposit their larvae in their hosts’ nests (Hutson, 1984). Females capable of flight in the genus Ornithomya may give birth while on their hosts or leave them when they are resting to find a suitable site to larviposit (Corbet, 1956; Hutson, 1984), and female P. canariensis, kept on captive domestic pigeons, were observed to deposit their larvae away from both their hosts and their nest material in darkened corners or under objects (Coatney, 1931). The well‐established species in the region undergo a winter diapause (Corbet, 1956; Hill, 1963; Walker & Rotherham, 2010b), but the recent UK colonists (Wawman, 2024) have shorter lifecycles: P. canariensis emerges from puparia after only 25–31 days when kept at ‘laboratory temperatures’ (Coatney, 1931); O. biloba has both diapausing and non‐diapausing generations (Kennedy et al., 1975).

Adults, and thus the eggs and larvae inside females, are protected against environmental extremes when on their homeothermic avian hosts but free‐flying adults and overwintering puparia may be exposed to harmful temperature, humidity and precipitation. The ability of flighted adults to find hosts maybe affected by wind speed, and in Poland, counts of the ked Lipoptena fortisetosa (Maa, 1965) were negatively correlated with increasing wind speed (Gałęcki et al., 2020). In common with the Hippoboscids found on birds, the puparia of the Deer Ked Lipoptena cervi (Linnaeus, 1758) undergo a winter diapause off their hosts and have been shown to freeze at −26°C during diapause, −20°C as developing puparia and −21°C as adults (Harkonen et al., 2012). High temperatures (20°C) during the winter diapause cause a deterioration in the immune‐based encapsulation response of diapausing L. cervi (Kaunisto et al., 2015). Little is known about the thermal tolerance of louse flies in the region but prolonged temperatures of 13°C or lower, or over 37°C were lethal to the puparia of P. canariensis, and colony survival was best between 24.6 and 30°C (Klei & Degiusti, 1975). Adult C. pallida successfully emerge from puparia in greater numbers at temperatures of 27–36°C—the temperature range in Swift nests during incubation—although smaller numbers emerged at lower temperatures, and none emerged when they were kept at 4–14°C to simulate winter temperatures (Walker & Rotherham, 2010a).

Thompson reported the presence of S. hirundinis in the British Isles from May to October, with numbers reaching a peak in June and C. pallida from June to August with maximum numbers in July (Thompson, 1953). Unfortunately, he did not distinguish between O. chloropus and O. fringillina, but he reported O. avicularia as mainly present from May to September, with a few flies in October, and November, and a peak in August (Thompson, 1954), and Hill reported this species as present from June to late November with a peak in August (Hill, 1963). Ornithomya fringillina was found from early July to late September at several sites, and O. chloropus (reported as O. lagopodis [Sharp, 1907]) was seen from July to September in Fair Isle (Hill, 1963). Corbet reported O. chloropus (as O. fringillina before the Ornithomya species were revised and the specimens reviewed [Hill, 1962b]) as present from June to mid‐August, and occasionally as late as October on Fair Isle (Corbet, 1956).

Hill reported that O. avicularia was, other than accidental records on migrant hosts from Scandinavia, absent from Scotland and the surrounding islands (Hill, 1962a). Whereas earlier authors (Smart, 1939) believed that O. fringillina was rare and restricted to south and south‐east England, Hill reported it as far north as Lancashire, with a continental distribution only as far north as Southern Sweden and Denmark (Hill, 1962a). Ornithomya fringillina was first reliably identified from the Island of Ireland in 1982 (Smiddy & Sleeman, 2004). Ornithomya chloropus was distributed in areas favoured by the Red Grouse Lagopus lagopus scotica (Latham, 1787), on higher ground bounded by a line that, in the early 1960s, correlated with the ‘61°F July isotherm’ (~16°C) and suggested it was a glacial phase survivor, whereas O. fringillina's and O. avicularia's distributions suggested that they were post‐glacial invaders (Hill, 1962a). Other earlier research on the distribution of Ornithomya spp. in the region (Thompson, 1954) cannot be compared with records using the current taxonomy because only two species of Ornithomya were recognised, instead of three. Suitable avian hosts of the generalist species are present throughout the UK and are unlikely to restrict their ranges.

Thompson suggested that C. pallida and S. hirundinis would be found throughout the breeding ranges of their hosts, although he had no records from collectors in Scotland and northern England for C. pallida or for the northern half of Scotland for S. hirundinis (Thompson, 1953). Ornithomya biloba was first recorded as a vagrant in the UK in 1964, with only four records up until 2007 (Lloyd‐Evans, 1967; Wawman, 2024). Its main host, the Barn Swallow, is also found throughout the UK, with the exception of Central London and the highest parts of the Scottish Highlands (Balmer et al., 2013).

Changes in the ranges of UK Hippoboscidae are expected with climate change, as many species of insect have expanded their ranges towards higher latitudes (Harvey et al., 2023) and range shifts have been seen in other Hippoboscids in Europe. For example, Lipoptena fortisetosa expanded its range northwards from the Czech republic, where it was first found in 1967, to reach Estonia in 2014 (Kurina et al., 2019), and L. cervi invaded Northern Europe to reach Finland (Kaunisto et al., 2011).

Parasite range changes may have consequences for its hosts, especially when it is a competent vector of microparasites. As a group, the Hippoboscidae are known to harbour a range of disease causing organisms although in many cases, their status as vectors is not proven (Bezerra‐Santos & Otranto, 2020). Of the long established UK species, O. avicularia is a proven vector of Haemoproteus spp. (Baker, 1963) and trypanosomes in the UK, although the latter was only transmitted if the flies were ingested by the host (Baker, 1956). Several studies have also suggested that Leucocytozoon sp. may be transmitted by Ornithomya spp. that are present in the UK, but having carefully reviewed all available evidence, Baker felt that it was not conclusive (Baker, 1967). In other countries, trypanosomes have been detected in O. avicularia, O. chloropus and O. fringillina but not in C. pallida (Santolíková et al., 2022) and several species of Babesia have been detected in O. avicularia (Čisovská Bazsalovicsová et al., 2023). Of the recent UK colonists, P. canariensis is a vector of Haemoproteus columbae (Baker, 1967; Cepeda et al., 2019) and trypanosomes were detected in 18.7% of O. biloba in a study in Czechia (Santolíková et al., 2022). Babesia canis has also been detected in O. biloba (Čisovská Bazsalovicsová et al., 2023). Rickettsia belii and Rickettsia monacensis have been detected in C. pallida (Cerutti et al., 2018), but a study failed to detect Haemoproteus spp. in either this fly or its host the Swift in Italy (Ilahiane et al., 2023).

The Mapping the UK's Flat Flies Project is an ongoing citizen science project in which licensed British Trust for Ornithology (BTO) bird ringers are asked to collect flat flies that leave birds during their normal ringing sessions, with the aim of determining which species are present in the region, their geographical and host ranges, and the phenology of the species. It has expanded to include Hippoboscidae of all species, across the region made up of the UK, ROI and Isle to Man. This paper considers the geographical ranges and phenology of the louse fly species as revealed by data collected from June 2020 to May 2024. The presence of new species breeding in the UK has been previously discussed (Wawman, 2024), and the host–parasite associations revealed will be the topic of a further study.

METHODS

The Mapping the UK's Flat Flies Project began as a small pilot study in 2020 and is an ongoing study run as part of the UK Hippoboscidae and Nycteribiidae Recording Scheme. BTO volunteer bird ringers were recruited via social media groups, articles in the BTO's ‘Lifecycle’ magazine and personal communications and were asked to collect louse flies that were seen leaving birds during their normal ringing activities, as current UK animal welfare regulations prevent the use of methods such as ‘dust‐ruffling’ using insecticidal powders (Walther & Clayton, 1997) or a Fair Isle Apparatus (Williamson, 1954). Participants were sent recording forms, tubes and 70% ethanol and asked to return any flies with the metadata at the end of the season.

Volunteers were asked to collect the following metadata: site name, Ordnance Survey Grid Reference, altitude and, if known, the host species, the number of flies both seen on and collected from each host and its age, sex and moult status, using BTO ringing codes (Redfern & Clark, 2001).

Keds were collected by bird ringers, entomologists and interested members of the public, via both the main mapping project and the national recording scheme.

The flies were identified to species, under a binocular microscope, following a published key and descriptions of flat flies in the British Isles (Hutson, 1984). Additional information for rarer species was sourced from a range of publications (Hutson, 1981a; Maa, 1964, 1966, 1969; Maa & Petersen, 1987).

The grid references and site altitudes supplied in the metadata, that were used for the initial analyses, were checked on the website Curaera (www.cucaera.co.uk/grp last accessed 27 May 2024).

The data were analysed in R version 4.2.1 (R Development Core Team, 2022). The packages dplyr (Wickham et al., 2023) and lubridate (Grolemund & Wickham, 2011) were used to process the data prior to analysis. Graphs were made in base R, and basic maps were plotted using packages maps (Becker et al., 2022) and mapdata (Becker et al., 2018), with the package scales (Wickham & Seidel, 2022). Kernel densities were calculated using the packages adehabitatHR (Calenge, 2006) and rgdal (Bivand et al., 2023). Bioclimatic data and species data were formatted into rasters and manipulated in R using the package raster (Hijmans, 2023). The maps of previously published ranges were replotted using the functions on the website MapChart (https://www.mapchart.net/uk.html, last accessed 10th June 2024). Binomial glms, comparing pairs of the Ornithomya sp., and O. chloropus with all the other Ornithomya in the study were run in R (family = binomial, link = cloglog) with the package arm used to validate the models (Gelman & Su, 2022).

Bioclimatic data, for 2022, the middle year of the main study, and most recent year available, were sourced from the HadUK‐Grid data (Met Office et al., 2023). The UK altitude, as the mean altitude for each 1 km2 square, was taken from Intermap (Intermap. NERC Earth Observation Data Centre, 2009), land cover from LCM 2007 (Morton et al., 2011), protected area status from the UNEP‐WCMC and IUCN Protected Planet Report 2020 (UNEP‐WCMC and IUCN, 2020) and calcareous bedrock from the British Geological Survey's parent material model (British Geological Survey, 2024; Lawley & Rawlins, 2014). The bioclimatic and land cover variables were used in the species distribution modelling, and the rationale for their inclusion are shown in Table 1. It was not possible to obtain data on the same grid scale for some of these variables for the ROI and those which were available were on a different spatial grid and geographical projection, so, as the area was only sparsely sampled, these data were not included in the most complex level of modelling.

TABLE 1.

Variables used in the Maxent SDMs and the rationale for choosing them and hypotheses to be tested.

Description Year Source Rationale for inclusion in initial models/hypotheses to be tested Reason for exclusion from final models
Latitude Initial data exploration suggested this was important, frequently found to be important in similar studies
Longitude Initial data exploration suggested this was important, frequently found to be important in similar studies
Altitude (m above sea level) 2009 Intermap (2009) Initial data exploration suggested this was important, frequently found to be important in similar studies
Calcareous bedrock (% cover per square km) 2014 British Geological Survey Soil pH may affect survival of invertebrates, relevant to species where puparia may be on the ground Not found to be relevant
Ground frost annual (number of days) 2022 Met Office HadUK‐Grid Prolonged low temperatures may affect survival more than shorter cold spells, potentially represented by minimum temperatures
Minimum air temperature seasonal (°C) 2022 Met Office HadUK‐Grid May be lower than lower critical thermal range Highly correlated with other temperature measures
Maximum air temperature seasonal (°C) 2022 Met Office HadUK‐Grid May exceed higher critical thermal range
Mean air temperature annual (°C) 2022 Met Office HadUK‐Grid May be a suitable proxy for both maximum and minimum temperature which are likely to be highly correlated and allow a reduction in the number of variables Highly correlated with other temperature measures
Relative humidity annual (hPa) 2022 Met Office HadUK‐Grid Desiccation may decrease survival of puparia
Wind speed at 10 m—annual—(m s−1) 2022 Met Office HadUK‐Grid May affect flighted flies’ ability to find a host
Precipitation seasonal (mm) 2022 Met Office HadUK‐Grid Possibility of puparia drowning, rain may affect flighted species ability to find a host
Urban land cover (% cover per square km) 2007 2007 UKCEH land cover map Some species (Stenepteryx hirundinis, Crataerina pallida and Ornithomya biloba) are associated with hosts that nest in buildings. To check for spatial bias in data. Possible urban heat island effects
Protected area status (proportion per square km) 2020 UNEP‐WCMC and IUCN (2020) To check for spatial bias in data Not found to be relevant
Open in a new tab

Abbreviation: SDM, species distribution modelling.

As bioclimatic data were not available for some smaller islands and coastal areas with less than 50% land within a 1‐km grid square, these were dealt with in one of two ways. Where there was land immediately adjacent to the site (for example, Portland Bird Observatory and Calf of Man Bird Observatory), the bioclimatic data for the most similar adjacent square (north and west respectively) were used. Where there was no adjacent Ordnance Survey Grid Square with available data (for example, Skokholm Bird Observatory), that of the nearest similar land was used (Skomer Island).

Maximum entropy species distribution modelling (Maxent SDM) was performed using the program Maxent version 3.4.1 (Phillips et al., 2024) using the default settings. After removal of highly correlated variables, the best models were chosen on the basis of the area under the receiver operator curve (AUC) and by visual inspection of the maps produced for anomalies. Variables that did not contribute to the model of each species distribution were excluded based on a combination of permutation importance, jackknife plots and response curves. The data were checked for the presence of spatial bias in favour of urban areas, which is known to occur in many citizen science datasets (Bowler et al., 2022; Sumner et al., 2019), and protected areas (Bowler et al., 2022) by modelling the locations of all flies collected against both urban land cover and protected land cover. The maps published here were produced from the mean of five replicates using the final set of variables.

Flies raised from puparia were excluded from the analysis of phenology as these may have emerged earlier than they would have normally due to being kept indoors.

RESULTS

Total of 3506 Hippoboscids, of 11 species, were received from over 170 individual bird ringers and entomologists, bird observatories and ringing groups up until the date of the analysis in May 2024. These came from 350 10‐km grid squares across the UK, Isle of Man and ROI. The flies were collected over a 22‐year period from 2002 to 2024, with most collected during the main study period from June 2020 to May 2024. The totals included eight species of louse fly and all three UK species of ked. The only UK breeding species that was missing was the Pigeon Louse Fly, P. canariensis, as the BTO bird ringing scheme does not include feral pigeons. The total numbers of each species received are provided in Table 2, with a breakdown of the number of 1‐km and 10‐km grid squares from which they were collected. A map of all the sites at which specimens were collected can be found in the Figure S1.

TABLE 2.

Total number Hippoboscids collected (louse/flat flies and keds), number of 1 km Ordnance Survey gird squares square (UK and Isle of Man) that were included in the Maxent species distribution models and total number of 10 km grid squares (UK, Isle of Man and Republic of Ireland) where each species was reported. Some specimens were only supplied with a 10‐km grid reference. *Icosta minor is a vagrant, while the other species are known to breed in the region. It was not possible to identify one damaged Ornithomya sp. specimen. The keds are included for completeness although they do not form part of the main study of bird parasites and Pseudolynchia canariensis is included to highlight the absence of data from this study.

Species Number of flies Number of 1 km squares (United Kingdom only) Total number of 10 km squares
Louse/flat flies
Swift Louse Fly Crataerina pallida (Latreille, 1812) 60 22 21
Icosta minor (Bigot, 1858)* 1 1 1
Common or Bird Louse Fly Ornithomya avicularia (Linnaeus, 1758) 1438 249 217
Swallow Louse Fly Ornithomya biloba (Dufour, 1827) 30 13 13
Grouse Louse Fly Ornithomya chloropus (Bergroth, 1901) 864 136 103
Finch Louse Fly Ornithomya fringillina (Curtis, 1836) 848 139 123
Ornithomya sp. 1 1 1
Pigeon Louse Fly P. canariensis (Macquart, 1839) 0 0 0
Nightjar Louse Fly Pseudolynchia garzettae (Rondani, 1879) 3 2 2
Martin Louse Fly Stenepteryx hirundinis (Linnaeus, 1758) 155 30 29
Keds
New Forest Fly Hippobosca equina (Linnaeus, 1758) 3 1 2
Deer ked Lipoptena cervi (Linnaeus, 1758) 99 21 18
Sheep Ked Melophagus ovinus (Linnaeus, 1758) 4 2 2
All species 3506 463 350
Open in a new tab

The Maxent SDM showed that there was no evidence of bias favouring records from urban or protected areas (Figure S2) with an AUC of 0.541 (0.5 is random, range 0 to 1.0) for urban landcover, 0.563 for protected area status and 0.604 for both urban and protected areas combined, suggesting that the overall sampling distribution of the study was close to random in relation to both human population density and protected area status. As might be expected, a kernel density plot made from the locations of all individual flies collected in the study (Figure S3) showed that collection was not even across the region, reflecting both differences in collecting effort, including poor coverage over most of the island of Ireland, and the populations of Hippoboscids.

The distributions of each of the six most common species (O. avicularia, O. chloropus, O. fringillina, O. biloba, C. pallida and S. hirundinis) can be seen as a series of plots in Figures 1, 2, 3, 4, 5, 6, which show the location at which specimens were collected, estimates of distribution using kernel densities and Maxent SDMs, together with the previously published distributions (Hill, 1962a) for the generalist Ornithomya spp. Only three specimens of Pseudolynchia garzettae (the UK's and the region's second, third and fourth) and one Icosta minor (the region's and UK's fourth) were received, and this was insufficient to run a Maxent SDM with the number of variables used in the analyses.

FIGURE 1.

FIGURE 1

Open in a new tab

Range of the Common or Bird Louse Fly Ornithomya avicularia (Linnaeus, 1758). (a) Locations of each 10 km square in which O. avicularia was caught during the study. (b) Kernel density plot at 95% predicted probability (dark red), 75% probability and 50% probability of finding O. avicularia at a given location, based entirely on latitude, longitude and presence data. (c) Maxent SDM, red 100% probability of the environmental niche being suitable for O. avicularia, with orange, yellow and green being increasingly lower probabilities of finding it (green 50% and blue 0%). This plot was produced from five iterations of the Maxent SDM using the final list of bioclimatic variables in Table 1 combined with the presence data from the study (AUC = 0.737). (d) Hill's 1962 ranges for the O. avicularia, produced at county level, replotted. The darker red areas are where the species was found: paler areas where he expected it to be present. Note that Hill removed flies found on passage migrant birds from his analysis, whereas they have not been removed from the analyses in this study. AUC, area under the receiver operator curve; SDM, species distribution modelling.

FIGURE 2.

FIGURE 2

Open in a new tab

Range of the Grouse Louse Fly Ornithomya chloropus (Bergroth, 1901). (a) Locations of each 10 km square in which O. chloropus was caught during the study. (b) Kernel density plot at 95% predicted probability (dark red), 75% probability and 50% probability of finding O. chloropus at a given location, based entirely on latitude, longitude and presence data. (c) Maxent SDM, red 100% probability of the environmental niche being suitable for O. chloropus, with orange, yellow and green being increasingly lower probabilities of finding it (green 50% and blue 0%). This plot was produced from five iterations of the Maxent SDM using the final list of bioclimatic variables in Table 1 combined with the presence data from the study (AUC = 0.810). (d) Hill's 1962 ranges for the O. chloropus, produced at county level, replotted. The darker red areas are where the species was found: paler areas where he expected it to be present. Note that Hill removed flies found on passage migrant birds from his analysis, whereas they have not been removed from the analyses in this study. AUC, area under the receiver operator curve; SDM, species distribution modelling.

FIGURE 3.

FIGURE 3

Open in a new tab

Range of the Finch Louse Fly Ornithomya fringillina (Curtis, 1936). (a) Locations of each 10 km square in which O. fringillina was caught during the study. (b) Kernel density plot at 95% predicted probability (dark red), 75% probability and 50% probability of finding O. fringillina at a given location, based entirely on latitude, longitude and presence data. (c) Maxent SDM, red 100% probability of the environmental niche being suitable for O. fringillina, with orange, yellow and green being increasingly lower probabilities of finding it (green 50% and blue 0%). This plot was produced from five iterations of the Maxent SDM using the final list of bioclimatic variables in Table 1 combined with the presence data from the study (AUC = 0.738). (d) Hill's 1962 ranges for the O. fringillina, produced at county level, replotted. The darker red areas are where the species was found: paler areas where he expected it to be present. Note that Hill removed flies found on passage migrant birds from his analysis, whereas they have not been removed from the analyses in this study. AUC, area under the receiver operator curve; SDM, species distribution modelling.

FIGURE 4.

FIGURE 4

Open in a new tab

Range of the Swallow Louse Fly Ornithomya biloba (Dufour, 1827). (a) Locations of each 10 km square in which O. biloba was caught during the study. (b) Kernel density plot at 95% predicted probability (dark red), 75% probability and 50% probability of finding O. biloba at a given location, based entirely on latitude, longitude and presence data. (c) Maxent SDM, red 100% probability of the environmental niche being suitable for O. biloba , with orange, yellow and green being increasingly lower probabilities of finding it (green 50% and blue 0%). This plot was produced from five iterations of the Maxent SDM using the final list of bioclimatic variables in Table 1 combined with the presence data from the study (AUC = 0.805). AUC, area under the receiver operator curve; SDM, species distribution modelling.

FIGURE 5.

FIGURE 5

Open in a new tab

Range of the Swift Louse Fly Crataerina pallida (Latreille, 1812). (a) Locations of each 10 km square in which C. pallida was caught during the study. (b) Kernel density plot at 95% predicted probability (dark red), 75% probability and 50% probability of finding C. pallida at a given location, based entirely on latitude, longitude and presence data. (c) Maxent SDM, red 100% probability of the environmental niche being suitable for C. pallida , with orange, yellow and green being increasingly lower probabilities of finding it (green 50% and blue 0%). This plot was produced from five iterations of the Maxent SDM using the final list of bioclimatic variables in Table 1 combined with the presence data from the study (AUC = 0.807). AUC, area under the receiver operator curve; SDM, species distribution modelling.

FIGURE 6.

FIGURE 6

Open in a new tab

Range of the Martin Louse Fly Stenepteryx hirundinis. (a) Locations of each 10 km square in which S. hirundinis was caught during the study. (b) Kernel density plot at 95% predicted probability (dark red), 75% probability and 50% probability of finding S. hirundinis at a given location, based entirely on latitude, longitude and presence data. (c) Maxent SDM, red 100% probability of the environmental niche being suitable for S. hirundinis, with orange, yellow and green being increasingly lower probabilities of finding it (green 50% and blue 0%). This plot was produced from five iterations of the Maxent SDM using the final list of bioclimatic variables in Table 1 combined with the presence data from the study (AUC = 0.670). AUC, area under the receiver operator curve; SDM, species distribution modelling.

Ornithomya avicularia (Figure 1) has increased its UK range approximately 300 km northwards, from the 1960s, when it was rarely found north of latitude 55°N, roughly the latitude of the Isle of Man, to reach Inverness, latitude 57.5°N. It was caught in numbers at multiple locations (Figure 1a) in the north of England and Scotland where it was not present in the 1960s (Figure 1d). The kernel density plot (Figure 1b) indicates a range covering most of Great Britain, with a concentration of records from England and Lowland Scotland, but does not take altitude and other bioclimatic variables into account. The Maxent SDM (Figure 1c) predicts suitable bioclimatic niches (shown on the map as green, through yellow, orange and red with increasing probability), corresponding to the sites at which flies were observed. It shows a likely current range throughout the UK, with the exception of the highest ground in England and Wales, and all but the lowest ground in Scotland.

Ornithomya chloropus (Figure 2) may have undergone a slight range contraction at lower altitudes at the southern edge of its range. The few records (Figure 2b) from southern England were mainly on suspected migrant birds near the coast—a set of records that was excluded by Hill (Hill, 1962a) (Figure 2d)—or restricted to higher ground on Dartmoor and Exmoor. Ornithomya chloropus was also detected on breeding birds on Skokholm Island and Lundy Island off the southern coasts of the UK. Ornithomya chloropus has a marked presence along The Pennines—the ridge of hills running north–south in northern England—and is present throughout Scotland. It appears from the map of sites (Figure 2a) and the kernel density plot (Figure 2c) to have been lost from the most southerly part of its former distribution (Figure 2d). The Maxent SDM (Figure 2c) predicts the highest probability of finding areas suitable for O. chloropus (red) is at higher altitudes in Scotland, Wales, northern and southwest England, as well as on islands around the coast.

Ornithomya fringillina, in contrast to O. chloropus (Figure 3), has, like O. avicularia, greatly expanded its UK range. It was mainly restricted to southern England below 54°N, an area south of a line from Blackpool to Leeds, in the 1960s (Figure 3d), but is now seen throughout lowland Scotland to latitude 57.5°N, a distance of over 350 km further north. It has also expanded its range over 400 km westwards into Wales and the ROI. The kernel density plot (Figure 3c) fails to take altitude into account, showing an unlikely distribution over higher ground in Scotland and Wales. The Maxent SDM (Figure 3c) predicts suitable environmental niches present throughout the UK, except at higher altitudes.

Ornithomya biloba (Figure 4) was first recorded as a vagrant in the UK in 1964. Figure 4a shows the location of sites at which it was found; Figure 4b shows the predicted range throughout southern England and all of Wales, south of latitude 53.5°N, using kernel densities; and Figure 4c shows a similar predicted range from a Maxent SDM.

Crataerina pallida (Figure 5) and S. hirundinis (Figure 6) were described in the 1950s as being present throughout the region wherever their hosts were found (Thompson, 1953). The sites at which they were recorded (Figures 5a and 6a) were widely dispersed, with the Maxent SDMs (Figures 5c and 6c) suggesting suitable habitat in all lowland areas of the UK, but showing C. pallida favouring urban areas and S. hirundinis rural areas, in common with their respective preferred avian hosts.

Analyses of the altitude ranges of each species showed that O. chloropus is present at higher altitudes than the other species in the genus Ornithomya (Table 3; Figure 7). None of the other species were seen above 449 m, whereas O. chloropus was seen up to 640 m, and a binomial glm (Figure 7) predicted an increasing probability of finding O. chloropus, rather than other species, as altitude increases with a 100% expectation that a fly would be O. chloropus at 600 m and above. A boxplot of the altitude ranges of all the species can be found in Figure S4.

TABLE 3.

The altitude ranges of the Ornithomya species in metres.

Species Altitude range (m) Mean altitude (m) Median altitude (m)
Ornithomya avicularia 0–449 84.9 64.0
Ornithomya chloropus 0–640 185.1 80.0
Ornithomya fringillina 0–290 74.7 60.0
Ornithomya biloba 2–278 44.6 20.0
O. avicularia + O. fringillina + O. biloba 0–449 80.6 64.0
Open in a new tab

FIGURE 7.

FIGURE 7

Open in a new tab

The probability of finding a species at a given altitude with standard error lines (dotted) from the output of a binomial glm comparing the altitude at which Ornithomya chloropus (top) is found to the that other species in the genus Ornithomya (O. avicularia, O. fringillina and O. biloba ); probability, p < 0.001.

The numbers of flies caught per month, of the six most common species are shown in Figure 8 plotted with the results of previous studies. These show that the peaks in the numbers of both O. avicularia (Figure 8a) and O. chloropus (Figure 8b) now occur a month earlier than previously. Ornithomya fringillina peaks a month later (Figure 8c). Ornithomya biloba is now found throughout the breeding season of its host, rather than as a vagrant on a few early Swallows. The phenology of C. pallida and S. hirundinis appears unchanged from the mid‐20th century.

FIGURE 8.

FIGURE 8

Open in a new tab

The phenology of the UK louse flies. The current study shown in black. With results of previous studies: Thompson (1953, 1954)) in blue, Hill (1963)) in orange, Corbet (1956)) in red, Summers (1975)) in purple, Hutson (1981b)) in green, and Hutson, 1981b) in brown. For most of these studies, only a range is dates and a peak, if one is available, is given, and where this is the case, the months in which the species were reported are plotted as a horizontal line close to zero, with a vertical line to show the reported peak. (a) Ornithomya avicularia, (b) Ornithomya chloropus, (c) Ornithomya fringillina, (d) Ornithomya biloba, (e) Crataerina pallida and (f) Stenepteryx hirundinis.

A comparison of the number of flies of each species in genus Ornithomya seen in this study with that in the 1960s (Hill, 1962a) suggests that O. avicularia may have replaced O. chloropus as the most common species across the UK (Table 4).

TABLE 4.

Comparison of sample sizes of the Ornithomya species between this study and that by Hill (1962a)).

Species Hill (n) Hill (% of total) Current study (n) Current study (% of total)
Ornithomya avicularia 1030 29.2 1438 45.2
Ornithomya chloropus 2082 58.9 864 27.2
Ornithomya fringillina 420 11.9 848 26.7
Ornithomya biloba 0 0 30 0.9
Total 3532 100 3180 100
Open in a new tab

DISCUSSION

The results of this study suggest that the ranges of O. avicularia and O. fringillina have undergone significant northward shift in the 60 years since their ranges were last mapped in the 1960s (Hill, 1962a). Ornithomya avicularia and O. fringillina were both found in significant numbers at sites over 300 km north of their previously published distributions, and Maxent SDMs predicted that there are suitable climatic niches up to the northern tip of Scotland over 100 km beyond their recorded distribution. Ornithomya fringillina has also colonised areas over 400 km west of its previously recorded range, in the island of Ireland, where it was first recorded in 1982 (Smiddy & Sleeman, 2004). There are suitable climatic niches for the recent colonist O. biloba that could allow it to become widely distributed throughout Wales and Southern England. Ornithomya chloropus may have undergone a slight contraction of its range at lower altitudes especially in Yorkshire and around Liverpool and Manchester, and it appears to be less common, but comparisons to this level of accuracy are difficult because Hill's data were only plotted to county level. There was insufficient data, both in terms of published maps and within the current dataset, to thoroughly explore the current ranges of C. pallida and S. hirundinis. The analyses show shifts in the phenology of the three most common species, with O. avicularia and O. chloropus reaching peaks in their populations a month earlier than previously and numbers of O. fringillina peaking a month later. Despite few specimens of C. pallida and S. hirundinis being received their phenology has remained fairly constant. The current study also detected differences in the proportions of the Ornithomya species compared with Hill (1962a), with O. avicularia now the most numerous species, compared with O. chloropus in the past.

Many species have shifted their ranges northwards since the 1960s. For example, over a 25‐year period, there was a mean northwards range shift of 31–61 km in 275 out of the 329 species studied across 16 vertebrate and invertebrate taxa in Great Britain (Hickling et al., 2006). Many of Britain's larger moths (Lepidoptera) have shifted their ranges northwards by over 200 km between the two recording periods 1968–1990 and 1992–2011 (Fox et al., 2013). British dragonflies (Odonata) have shifted their ranges northwards by a mean of 74 km, between recording periods 25 years apart (1960–1970 and 1985–1995) with the northern most edge of the range of the Common Darter Sympetrum striolatum (Charpentier, 1840) moving a further 346 km north (Hickling et al., 2005). Even when the longer duration between the two studies compared in this paper is taken into account, the range shifts suggested by this study would appear to be over a greater distance compared with those of most UK insects. However, other Hippoboscids, have also advanced their ranges northwards at a higher than average rate: Lipoptena fortisetosa advanced its European range from Czechia to Estonia, a distance of over 1000 km between 1967 and 2014 (Kurina et al., 2019), and L. cervi expanded its range northwards by 1000 km in 50 years. While most species of bird in the UK have only shifted their ranges northwards by an estimated 0.76 km per year (Gillings et al., 2015), generalist parasites such as O. avicularia and O. fringillina are not tied to a single host species and can switch hosts to rapidly expand their ranges as conditions permit.

Adult Hippoboscids and their larvae on endothermic hosts, such as Cervids or birds, will be protected from extremes of climate during those phases of their lifecycle, but will be more vulnerable as puparia. The puparia of the nest parasites C. pallida and S. hirundinis are protected from the worst winter weather as they are in the nests of birds, usually within or attached to buildings, but unlike the flighted species, are likely to be slower to colonise a new area as they have to rely entirely on birds or crawling to get to new sites. Flighted species such as the Ornithomya spp. are able to colonise new areas by flying to find a host, but with the exception of O. biloba, which is a nest parasite, are vulnerable to temperature extremes as puparia. This dual advantage may partially explain how quickly O. biloba appears to be colonising the UK.

In Scotland, the specimens of the species that were previously thought of as southerly, O. avicularia and O. fringillina, are from coastal areas, not on the hills like O. chloropus that was previously the only species in more northern parts of the UK. Features such as the aspect of a slope or vegetation cover may also produce fine‐scale variation in climatic conditions (de Frenne et al., 2021; Wilson et al., 2015) and areas with suitable microclimates may allow insect species to survive in an otherwise unsuitable area (Minter et al., 2020), as well as allowing some of their bird hosts to achieve a higher reproductive rate (Shutt et al., 2022).

Ornithomya chloropus would appear to have a lower minimum thermal tolerance as it is found at higher altitudes than the other species in the same genus and it may be that it also has a lower maximum thermal tolerance as its range has contracted slightly as temperatures have warmed. A similar effect has been observed with some species of the related tsetse flies Glossina spp. that are undergoing range contraction in Zimbabwe, where the extinction probability of G. morsitans (Westwood, 1851) has been estimated to be a function of temperature (Are & Hargrove, 2020).

Some of the differences in detection of the various species may be due to different sampling methods between the 1960s and the current study. A lot of the results in the older study were from Bird Observatories in the northern half of the UK which may be expected to have more O. chloropus than the other species. Apparent changes in the distributions of the generalist Ornithomya spp. compared with earlier ranges may in part be due to the inclusion of flies on migrating birds in this study, as Hill removed records he considered accidental, that is those where the host was a passage migrant, from his maps (Hill, 1962a). In the current study, all records were used to produce the maps, but most of the O. chloropus on the south coast were on probable migrant species, such as Meadow Pipit Anthus pratensis (Linnaeus, 1758), and this may fully explain their predicted occurrences around The Wash and at other localised sites on the south coast in the Maxent SDM maps.

Another major difference is that the current study relied on the capture of flies that left the birds during routine bird ringing: In the 1960s, sampling was usually done using a knock‐down method, with chloroform in a Fair Isle Apparatus (Williamson, 1954), which would have resulted in the removal and capture of a significantly higher proportion, if not all, of the parasites on each bird. Smaller species of fly were generally reported by volunteers to be harder to catch, when relying solely on just the visual acuity and dexterity of the bird ringer, than the larger ones which were easier to see and move more slowly. Larger flies might also be more easily disturbed than smaller ones when a bird is handled and O. avicularia is the largest of the three generalist species.

The results of this study, compared with earlier studies of UK louse flies, strongly suggest that the phenology of some of the species has changed. Ornithomya avicularia is seen at the same time of year as it was in the 1950s and 1960s (Hill, 1963; Thompson, 1954) as is O. chloropus (Corbet, 1956; Hill, 1963) but numbers of both species now peak a month earlier. It may be that the true peak is even earlier, as many volunteers waited until they started seeing louse flies before asking to join the study, resulting in a delay in the start of collecting at the beginning of the season. Ornithomya fringillina peaks a month later, and this may be due to its range shift to further north or bias in the previous data sets. For the other three species, there is insufficient data from the study to draw robust conclusions, but it would appear that S. hirundinis and C. pallida have a similar phenology to that in the mid‐20th century (Hutson, 1981b; Summers, 1975; Thompson, 1953). While resident host species, for example, Great Tit Parus major (Linnaeus, 1758), are able to track climate changes and advance their laying date (Charmantier et al., 2008), allowing their parasites to also shift their phenology, the dependence of S. hirundinis and C. pallida on migrant hosts limits their seasonality. Hirundines are arriving an average of 10 days earlier than in the 1960s but Swifts have not significantly changed their arrival dates (Newson et al., 2016). Ornithomya biloba is a recent colonist, with only three UK records before 2007, all from Swallows recently arrived from Africa in May and June, whereas now O. biloba breeds in the UK (Wawman, 2024) and is seen from June to October when its host the Swallow is present. However, most of the cited previous studies were small, from single sites or only a few sites, often at Bird Observatories in the northern part of the UK, or used previously published records. It might be possible to produce better comparisons by obtaining all possible original data from publications, museum records and local environmental records centres, but historical data are also biased (Boyd et al., 2022; Guzman et al., 2021; Shirey et al., 2023).

In Fennoscandia, in 2013, the overall prevalence of O. chloropus in Pied Flycatcher Ficedula hypoleuca (Pallas, 1764) nests was found to be 59% (Eeva et al., 2015), whereas, in this study, only one, louse fly, O. chloropus, was collected from a Pied Flycatcher nestling, despite large numbers of Pied Flycatchers being ringed by volunteers, and the author examining over 100 nests for puparia, and monitoring and ringing over 500 broods of Pied Flycatchers in Somerset (Wawman, unpublished data). It may be that by breeding earlier, Pied Flycatchers in the UK miss the peak in louse flies: Pied Flycatchers in Southern Sweden usually start laying eggs in the third week in May (Källander et al., 2017), whereas those in Somerset, UK, may begin laying in late April (Wawman, unpublished data). I hypothesise that O. chloropus is a partial nest parasite as an adaptation to the colder climate in more northerly regions.

As species shift their ranges, species that may not have associated are more likely to do so, and for parasites, this may mean switches in host parasite relationships, bringing the risk of diseases to new hosts. The host–parasite associations of the UK Hippoboscidae found in this study will be the subject of further research, but with known vectors of avian disease amongst them, there is the potential for them to have an impact on avian health.

AUTHOR CONTRIBUTIONS

Denise C. Wawman: Conceptualization; investigation; writing – original draft; methodology; validation; visualization; writing – review and editing; formal analysis; project administration; data curation; resources.

FUNDING INFORMATION

This research received no specific grant from any funding agency, commercial or not‐for‐profit sectors.

CONFLICT OF INTEREST STATEMENT

The author declares no conflicts of interest.

Supporting information

FIGURE S1. All sites from which louse flies (Hippoboscidae) were collected for the avian louse fly study (all flies excluding keds). UK sites are plotted as white squares at 1 km2 resolution and Irish sites in purple.

FIGURE S2. Maps showing the distribution of capture sites for all Hippoboscidae in the study (louse flies and keds), as Maxent model outputs predicting the likelihood of a Hippoboscid in the project being collected at a site, relative to (a) the proportion of urban land‐cover in that 1 km2, (b) the proportion of protected land‐cover and (c) the proportions of both urban and protected land‐cover. Warmer (redder) colours predict a higher probability that a fly will be found at a site. The areas under the receiver operator curve, and the high proportion of green in these maps indicate that the sites are almost randomly distributed with respect to both urban and protected area land‐cover.

FIGURE S3. Kernel densities for all Hippoboscidae in the study. The kernel densities are plotted at 95% predicted probability (dark red), 75% probability and 50% probability of a fly being caught at a given location, during the study, based entirely on latitude, longitude and total count data.

FIGURE S4. Boxplots showing the altitude ranges of all of the species of Hippoboscid received during the study period. Ornithomya chloropus occurs over a wider altitude range than the other Ornithomya sp.

MVE-39-559-s001.pdf (777.7KB, pdf)

ACKNOWLEDGEMENTS

Robin Boyd was acknowledged for his help sourcing the altitude, bedrock and landcover data. Ben C. Sheldon and Adrian L. Smith were thanked for their helpful comments on an earlier draft of this paper. All those who collected Hippoboscids for this project were also acknowledged: Individual licensed bird ringers and entomologists: David Aitken, Anna Alam, Guy Anderson, Dominic Ash, Shane Austin, Louise Bacon, Lee Barber, Richard Barnes, Sam Bayley, John Black, Samuel Bradley, Clare Buckle, George Candelin, Tim Chamberlain, Gary Clewley, Dave Clifton, Alister J. Clunas, Trevor Codlin, Dr Greg Conway, Duerden Cormack, R. H. Creighton, J. E. Crossley, Mark Cutts, Mark Dadds, Stuart Daines, Colin Davison, Fran Daw, Chris W. Dee, Charles Dewhurst, Mike Drew, Jenny Dunn, Jamie Dunning, Rebecca Durrant, Jason Fathers, C. George, Tony Gibson, Ronnie Graham, Mark Grantham, Samuel Gray, David Grieve, Ken Griffin, Lizzie Harper, Alan Heavisides, Ben Herschell, Adam G. Homer, Andy Hood, Jenni Hood, Jo Hood, Kyu Min Huh, Hugh Insley, Alex Inzani FLS, Wendy James, David C. Jardine, Logan Johnson, Helen Jones, Hugh Jones, Jonathan Jones, Nigel R. Jones, Denise Lamsdell, Jo Lashwood, Vince Lea, Kevin Leighton, Rob Lightfoot, Sonya Ludwig, Callum MacGregor, Lydia Martin, Dr C. McGuigan, Bob Medland, Sara Miller, Brian S. Milligan, Ray Morris, Sean Morris, Wayne Morris, Susan Murphy, Luke Nelson, Ellie Ness, Barry O'Mahony, Robin Pearson, Robbie Phillips, D. J. Radford, Graham Rebecca, Liam Reid, Bryn Roberts, Paul Roper, Kirstie H. Ross, P. Roughley, David Scott, Geoff and Jean Sheppard, Carl Soulsbury, Ian Stanbridge, Mark Stanley, E. John Steele, Rachel Steenson, Paul Stevenson, Adrienne Stratford, Dr R. C. Taylor, Y. Townsend, Andy Turner, Jane Turner, N. C. Ward, Colin Wearn, Anthony Wetherhill, Eleanor Wilkins, David Wilkinson, P. S. Woollen, Mick Wright, Tara Wright and Alistair Young. Ringing groups (RG): Belvide RG, Borders RG, BTO Wetland and Marine RG, Clyde RG, East Dales RG, Gordano Valley RG, Gower RG, Isle of Wight RG, Kenfig RG, Llangorse RG, Lundy Field Society, Merseyside RG, Mid‐Wales RG, Northants RG, Northern England Raptor Group, Peak District Raptor Monitoring Group, Rye Bay RG, Shiants Seabird RG, Shropshire RG, Stanford RG, Steyning RG, Tay RG, Watchtree RG and Wicken Fen RG, Bird observatories: Bardsey Bird Observatory, Calf of Man Bird Observatory, Dungeness Bird Observatory, Fair Isle Bird Observatory, Isle of May Bird Observatory RG, Landguard Bird Observatory, Lundy Bird Observatory, Norfolk Ornithologists Association, North Ronaldsay Bird Observatory, Portland Bird Observatory, Sandwich Bay Bird Observatory and Skokholm Bird Observatory. And those who wished to remain anonymous.

Wawman, D.C. (2025) Citizen scientists mapping the United Kingdom's and Republic of Ireland's flat flies (louse flies) (Diptera: Hippoboscidae) reveal a vector's range shift. Medical and Veterinary Entomology, 39(3), 559–575. Available from: 10.1111/mve.12795

Associate Editor: Aleksandra Ignjatović Ćupina

DATA AVAILABILITY STATEMENT

The dataset for this study is available at https://doi.org/10.5061/dryad.zs7h44jkh. On completion of the study, the records will be entered into the database on the website iRecord with the other Hippoboscidae and Nycteribiidae Recording Scheme data.

REFERENCES

  1. Are, E.B. & Hargrove, J.W. (2020) Extinction probabilities as a function of temperature for populations of tsetse (Glossina spp.). PLoS Neglected Tropical Diseases, 14(5), 1–19. Available from: 10.1371/journal.pntd.0007769 [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Baker, J.R. (1956) Studies on Trypanosoma avium Danilewsky 1885 II Transmission by Ornithomyia avicularia L. Parasitology, 46(3–4), 321–334. [DOI] [PubMed] [Google Scholar]
  3. Baker, J.R. (1963) Transmission of Haemoproteus sp. of English Wood‐pigeons by Ornithomyia avicularia. The Journal of Protozoology, 10(4), 461–465. [DOI] [PubMed] [Google Scholar]
  4. Baker, J.R. (1967) A review of the role played by the Hippoboscidae (Diptera) as vectors of endoparasites. Journal of Parasitology, 53(2), 412–418 /www.jstor.org/stable/3276603. [PubMed] [Google Scholar]
  5. Balmer, D. , Gillings, S. , Caffrey, B. , Swann, B. , Downie, I. & Fuller, R. (2013) Bird atlas 2007–2011 the breeding and wintering birds of Britain and Ireland, 1st edition. Thetford: British Trust for Ornithology. [Google Scholar]
  6. Bartley, T.J. , McCann, K.S. , Bieg, C. , Cazelles, K. , Granados, M. , Guzzo, M.M. et al. (2019) Food web rewiring in a changing world. Nature Ecology & Evolution, 3(3), 345–354. Available from: 10.1038/s41559-018-0772-3 [DOI] [PubMed] [Google Scholar]
  7. Becker, R.A. , Wilks, A.R. & Brownrigg, R. (2018) mapdata: Extra Map Databases . https://cran.r-project.org/package=mapdata%0A
  8. Becker, R.A. , Wilks, A.R. , Brownrigg, R. , Minka, T.P. & Deckmyn, A. (2022) Maps: draw geographical maps. R Package Version 3.4.1. https://cran.r-project.org/package=maps.
  9. Bezerra‐Santos, M.A. & Otranto, D. (2020) Keds, the enigmatic flies and their role as vectors of pathogens. Acta Tropica, 209, 105521. Available from: 10.1016/j.actatropica.2020.105521 [DOI] [PubMed] [Google Scholar]
  10. Bivand, R. , Keitt, T. & Rowlingson, B. (2023) _rgdal: Bindings for the “Geospatial” Data Abstraction Library_.R package version 1.6–5. https://cran.r-project.org/package=rgdal.
  11. Bowler, D.E. , Callaghan, C.T. , Bhandari, N. , Henle, K. , Benjamin Barth, M. , Koppitz, C. et al. (2022) Temporal trends in the spatial bias of species occurrence records. Ecography, 2022(8), 1–13. Available from: 10.1111/ecog.06219 [DOI] [Google Scholar]
  12. Boyd, R.J. , Powney, G.D. , Burns, F. , Danet, A. , Duchenne, F. , Grainger, M.J. et al. (2022) ROBITT: a tool for assessing the risk‐of‐bias in studies of temporal trends in ecology. Methods in Ecology and Evolution, 13(7), 1497–1507. Available from: 10.1111/2041-210X.13857 [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. British Geological Survey . (2024) Soil Parent Material Model. https://www.ukso.org/static‐maps/parent‐material‐model‐of‐great‐britain.html.
  14. Calenge, C. (2006) The package adehabitat for the R software: a tool for the analysis of space and habitat use by animals. Ecological Modelling, 197, 516–519. [Google Scholar]
  15. Cepeda, A.S. , Lotta‐Arévalo, I.A. , Pinto‐Osorio, D.F. , Macías‐Zacipa, J. , Valkiūnas, G. , Barato, P. et al. (2019) Experimental characterization of the complete life cycle of Haemoproteus columbae, with a description of a natural host‐parasite system used to study this infection. International Journal for Parasitology, 49(12), 975–984. Available from: 10.1016/j.ijpara.2019.07.003 [DOI] [PubMed] [Google Scholar]
  16. Cerutti, F. , Modesto, P. , Rizzo, F. , Cravero, A. , Jurman, I. , Costa, S. et al. (2018) The microbiota of hematophagous ectoparasites collected from migratory birds. PLoS One, 13(8), e0202270. Available from: 10.1371/journal.pone.0202270 [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Charmantier, A. , McCleery, R.H. , Cole, L.R. , Perrins, C. , Kruuk, L.E.B. & Sheldon, B.C. (2008) Adaptive phenotypic plasticity in response to climate change in a wild bird population. Science, 320(5877), 800–803. Available from: 10.1126/science.1157174 [DOI] [PubMed] [Google Scholar]
  18. Čisovská Bazsalovicsová, E. , Víchová, B. , Oboňa, J. , Radačovská, A. , Blažeková, V. & Králová‐Hromadová, I. (2023) Bird louse flies Ornithomya spp. (Diptera: Hippoboscidae) as potential vectors of mammalian babesia and other pathogens. Vector‐Borne and Zoonotic Diseases, 0(0), 1–9. Available from: 10.1089/vbz.2022.0088 [DOI] [PubMed] [Google Scholar]
  19. Coatney, G.R. (1931) On the biology of the pigeon fly, Pseudolynchia maura bigot (Diptera, Hippoboscidae). Parasitology, 23(4), 525–532. Available from: 10.1017/S0031182000013901 [DOI] [Google Scholar]
  20. Corbet, G.B. (1956) The life‐history and host‐relations of a Hippoboscid Fly Ornithomyia fringillina Curtis. The Journal of Animal Ecology, 25(2), 403. Available from: 10.2307/1934 [DOI] [Google Scholar]
  21. de Frenne, P. , Lenoir, J. , Luoto, M. , Scheffers, B.R. , Zellweger, F. , Aalto, J. et al. (2021) Forest microclimates and climate change: importance, drivers and future research agenda. Global Change Biology, 27(11), 2279–2297. Available from: 10.1111/gcb.15569 [DOI] [PubMed] [Google Scholar]
  22. Dick, C.W. (2018) Checklist of the world Hippoboscidae (Diptera: Hippoboscoidea). January . https://www.researchgate.net/publication/322579074_CHECKLIST_OF_WORLD_NYCTERIBIIDAE_DIPTERA_HIPPOBOSCOIDEA.
  23. Eeva, T. , Andersson, T. , Berglund, Å.M.M. , Brommer, J.E. , Hyvönen, R. , Klemola, T. et al. (2015) Species and abundance of ectoparasitic flies (Diptera) in pied flycatcher nests in Fennoscandia. Parasites & Vectors, 8(1), 648. Available from: 10.1186/s13071-015-1267-6 [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Fox, R. , Parsons, M. & Chapman, J. (2013) The state of Britain's larger moths 2013. Butterfly Conservation and Rothamsted Research, Wareham, Dorset, UK, pp. 1–32. http://scholar.google.com/scholar?hl=en&btnG=Search&q=intitle:The+State+of+Britain+?+s+Larger+Moths+2013#1%5Cnhttp://scholar.google.com/scholar?hl=en&btnG=Search&q=intitle:The+State+of+Britain's+Larger+Moths+2013%230.
  25. Gałęcki, R. , Jaroszewski, J. , Xuan, X. & Bakuła, T. (2020) Temporal‐microclimatic factors affect the phenology of Lipoptena fortisetosa in central European forests. Animals, 10(11), 2012. Available from: 10.3390/ani10112012 [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Gelman, A. & Su, Y.‐S. (2022) arm: Data analysis using regression and multilevel/heirachical models. R package version 1.13–1 .
  27. Gillings, S. , Balmer, D.E. & Fuller, R.J. (2015) Directionality of recent bird distribution shifts and climate change in Great Britain. Global Change Biology, 21(6), 2155–2168. Available from: 10.1111/gcb.12823 [DOI] [PubMed] [Google Scholar]
  28. Gilman, S.E. , Urban, M.C. , Tewksbury, J. , Gilchrist, G.W. & Holt, R.D. (2010) A framework for community interactions under climate change. Trends in Ecology & Evolution, 25(6), 325–331. Available from: 10.1016/j.tree.2010.03.002 [DOI] [PubMed] [Google Scholar]
  29. Grolemund, G. & Wickham, H. (2011) Dates and times made easy with lubridate. Journal of Statistical Software, 40(3), 1–25 https://www.jstatsoft.org/v40/i03/. [Google Scholar]
  30. Guzman, L.M. , Johnson, S.A. , Mooers, A.O. & M'Gonigle, L.K. (2021) Using historical data to estimate bumble bee occurrence: variable trends across species provide little support for community‐level declines. Biological Conservation, 257, 109141. Available from: 10.1016/j.biocon.2021.109141 [DOI] [Google Scholar]
  31. Harkonen, L. , Kaitala, A. , Kaunisto, S. & Repo, T. (2012) High cold tolerance through four seasons and all free‐living stages in an ectoparasite. Parasitology, 139(7), 926–933. Available from: 10.1017/S0031182012000091 [DOI] [PubMed] [Google Scholar]
  32. Harvey, J.A. , Tougeron, K. , Gols, R. , Heinen, R. , Abarca, M. , Abram, P.K. et al. (2023) Scientists’ warning on climate change and insects. Ecological Monographs, 93(1), 1–37. Available from: 10.1002/ecm.1553 [DOI] [Google Scholar]
  33. Hickling, R. , Roy, D.B. , Hill, J.K. , Fox, R. & Thomas, C.D. (2006) The distributions of a wide range of taxonomic groups are expanding polewards. Global Change Biology, 12(3), 450–455. Available from: 10.1111/j.1365-2486.2006.01116.x [DOI] [Google Scholar]
  34. Hickling, R. , Roy, D.B. , Hill, J.K. & Thomas, C.D. (2005) A northward shift of range margins in British Odonata. Global Change Biology, 11(3), 502–506. Available from: 10.1111/j.1365-2486.2005.00904.x [DOI] [Google Scholar]
  35. Hijmans, R.J. (2023) Package ‘raster’ R topics documented :Golicher. Josh Greenbe: Duncan Gray . [Google Scholar]
  36. Hill, D.S. (1962a) A study of the distribution and host preferences of three species of Ornithomyia (Diptera: Hippoboscidae). The British Isles, 37(4–6), 37–48. Available from: 10.1111/j.1365-3032.1962.tb00286.x [DOI] [Google Scholar]
  37. Hill, D.S. (1962b) Revision of the British species of Ornithomyia ltreille (Diptera: Hippoboscidae). Proceedings of the Royal Entomological Society of London Series B Taxonomy, 31(1–2), 11–18. Available from: 10.1111/j.1365-3113.1962.tb01163.x [DOI] [Google Scholar]
  38. Hill, D.S. (1963) The life history of the British species of Ornithomya (Diptera: Hippoboscidae). Transactions of the Royal Entomological Society of London, 115(13), 391–407. Available from: 10.1111/j.1365-2311.1963.tb00812.x [DOI] [Google Scholar]
  39. Hutson, A.M. (1981a) A new species of the Ornithomya biloba‐group (Dipt., Hippoboscidae) from crag Martin (Ptyonoprogne rupestris) (Aves, Hirundinidae). Mitteilungen Der Schweiserischen Entomologischen Gesellshaft; Bulletin de La Societe Entomologique Suisse, 54, 157–162 https://www.e-periodica.ch/digbib/view?lang=en&pid=seg-001%3A1981%3A54%3A%3A455#166. [Google Scholar]
  40. Hutson, A.M. (1981b) The population of the louse‐fly, Crataerina pallida (Diptera, Hippoboscidae) on the European swift, Apus apus (Aves, Apodidae). Journal of Zoology, 194, 305–316. [Google Scholar]
  41. Hutson, A.M. (1984) Keds, flat‐flies and bat‐flies: Diptera, Hippoboscidae and Nycteribiidae. Handbooks for the Identification of British Insects, 10(7), 40 https://www.royensoc.co.uk/sites/default/files/Vol10_Part07_Hutson.pdf. [Google Scholar]
  42. Ilahiane, L. , Colominas‐Ciurò, R. , Bize, P. , Boano, G. , Cucco, M. , Ferri, M. et al. (2023) Molecular investigation on infection by haemosporidians in three Western palearctic species of swift (Apodidae) and their ectoparasitic louse flies. Parasitology Research, 122, 1787–1794. Available from: 10.1007/s00436-023-07874-8 [DOI] [PubMed] [Google Scholar]
  43. Intermap . (2009) NERC Earth Observation Data Centre Intermap Technologies (2009): NEXTMap British Digital Terrain (DTM) Model Data. https://catalogue.ceda.ac.uk/uuid/998a28d8a5ed4564863a0daa0f731e8d.
  44. Källander, H. , Hasselquist, D. , Hedenström, A. , Nord, A. , Smith, H.G. & Nilsson, J.Å. (2017) Variation in laying date in relation to spring temperature in three species of tits (Paridae) and pied flycatchers Ficedula hypoleuca in southernmost Sweden. Journal of Avian Biology, 48(1), 83–90. Available from: 10.1111/jav.01287 [DOI] [Google Scholar]
  45. Kaunisto, S. , Härkönen, L. , Niemelä, P. , Roininen, H. & Ylönen, H. (2011) Northward invasion of the parasitic deer ked (Lipoptena cervi), is there geographical variation in pupal size and development duration? Parasitology, 138(3), 354–363. Available from: 10.1017/S0031182010001332 [DOI] [PubMed] [Google Scholar]
  46. Kaunisto, S. , Harkonen, L. , Rantala, M.J. & Kortet, R. (2015) Early‐life temperature modifies adult encapsulation response in an invasive ectoparasite. Parasitology, 142(10), 1290–1296. Available from: 10.1017/S0031182015000591 [DOI] [PubMed] [Google Scholar]
  47. Kennedy, J.A. , Smith, J.R. & Smyth, M. (1975) Diapause in Ornithomya biloba Dufour (Diptera: Hippoboscidae) parasitic on fairy martins in South Australia. The Journal of Parasitology, 61(2), 369. Available from: 10.2307/3279023 [DOI] [PubMed] [Google Scholar]
  48. Klei, T.R. & Degiusti, D.L. (1975) Observations on the bionomics of Pseudolynchia canariensis (Diptera: Hippoboscidae). Parasitology, 70(2), 195–202. Available from: 10.1017/S0031182000049660 [DOI] [PubMed] [Google Scholar]
  49. Kurina, O. , Kirik, H. , Õunap, H. & Õunap, E. (2019) The northernmost record of a blood‐sucking ectoparasite, Lipoptena fortisetosa Maa (Diptera: Hippoboscidae), in Estonia. Biodiversity Data Journal, 7, 1–14. Available from: 10.3897/BDJ.7.e47857 [DOI] [PMC free article] [PubMed] [Google Scholar]
  50. Lawley, R. & Rawlins, B. (2014) User Guide: Soil Parent Material 1 kilometre dataset . https://nora.nerc.ac.uk/id/eprint/509517/1/OR14025.pdf.
  51. Lehikoinen, A. , Pohjola, P. , Valkama, J. , Mutanen, M. & Pohjoismäki, J.L.O. (2021) Promiscuous specialists: host specificity patterns among generalist louse flies. PLoS One, 16(5), e0247698. Available from: 10.1371/journal.pone.0247698 [DOI] [PMC free article] [PubMed] [Google Scholar]
  52. Lloyd‐Evans, L. (1967) Bird parasites. Rye Meads Ringing Group Report, 4, 14–21. [Google Scholar]
  53. Maa, T.C. (1964) On the genus Ornithomya Latreille from Africa (Diptera: Hippoboscidae). Journal of Medical Entomology, I(2), 197–205. [DOI] [PubMed] [Google Scholar]
  54. Maa, T.C. (1966) On the genus Pseudolynchia Bequaert (Dipteria: Hippoboscidae). Pacific Insects Monograph, 10, 125–138 https://pdfs.semanticscholar.org/5e9e/bc24e1e08128b1eadb908ba8148f03c70a73.pdf. [Google Scholar]
  55. Maa, T.C. (1969) Notes on the Hippoboscidae (Diptera), II. Pacific Insects, 20, 237–260. http://scholar.google.com/scholar?hl=en&btnG=Search&q=intitle:NOTES+ON+THE+HIPPOBOSCIDAE+(Diptera). [Google Scholar]
  56. Maa, T.C. & Petersen, B.V. (1987) Hippoboscidae. In: Manual of Nearctic Diptera. Agriculture Canada monograph, No. 28, Vol. 2.  pp. 1271–1281. Biosytematics Research Centre (formerly Institute). Ottawa, Ontario: Research Branch, Agriculture Canada. [Google Scholar]
  57. Menéndez, R. , Megías, A.G. , Hill, J.K. , Braschler, B. , Willis, S.G. , Collingham, Y. et al. (2006) Species richness changes lag behind climate change. Proceedings of the Royal Society B: Biological Sciences, 273(1593), 1465–1470. Available from: 10.1098/rspb.2006.3484 [DOI] [PMC free article] [PubMed] [Google Scholar]
  58. Minter, M. , Dasmahapatra, K.K. , Thomas, C.D. , Morecroft, M.D. , Tonhasca, A. , Schmitt, T. et al. (2020) Past, current, and potential future distributions of unique genetic diversity in a cold‐adapted mountain butterfly. Ecology and Evolution, 10(20), 11155–11168. Available from: 10.1002/ece3.6755 [DOI] [PMC free article] [PubMed] [Google Scholar]
  59. Morton, D. , Rowland, C. , Wood, C. , Meek, L. , Marston, C. , Smith, G. et al. (2011) Countryside survey: final report for LCM2007 – the new UK land cover map. Final report for LCM2007‐the new UK land cover map. Countryside survey technical report no 11/07. www.countrysidesurvey.org.uk.
  60. Newson, S.E. , Moran, N.J. , Musgrove, A.J. , Pearce‐Higgins, J.W. , Gillings, S. , Atkinson, P.W. et al. (2016) Long‐term changes in the migration phenology of UK breeding birds detected by large‐scale citizen science recording schemes. Ibis, 158(3), 481–495. Available from: 10.1111/ibi.12367 [DOI] [Google Scholar]
  61. Nuttall, P.A. (2021) Climate change impacts on ticks and tick‐borne infections. Biologia, 77, 1503–1512. Available from: 10.1007/s11756-021-00927-2 [DOI] [Google Scholar]
  62. O'Connor, J.P. & Sleeman, D.P. (1987) A review of the Irish Hippoboscidae (Insecta:Diptera). Irish Naturalists’ Journal, 22(6), 236–239. [Google Scholar]
  63. Office, M. , Hollis, D. , McCarthy, M. , Kendon, M. & Legg, T. (2023) HadUK‐Grid Gridded Climate Observations on a 1km grid over the UK, v1.2.0.ceda (1836–2022). NERC EDS Centre for Environmental Data Analysis. 10.5285/46f8c1377f8849eeb8570b8ac9b26d86 [DOI]
  64. Phillips, S.J. , Dudík, M. & Schapire, R.E. (2024) Maxent Software Modelling for Spcies Niches and Distributions (Version 3.4.1). https://biodiversityinformatics.amnh.org/open_source/maxent/.
  65. R Development Core Team . (2022) R: a language and environment for statistical computing. (4.2.2). Vienna, Austria: R Foundation for Statistical Computing. https://www.r-project.org/. [Google Scholar]
  66. Redfern, C.P.F. & Clark, J.A. (2001) Ringers' Manual, 4th edition. Thetford: British Trust for Ornithology. [Google Scholar]
  67. Santolíková, A. , Brzoňová, J. , Čepička, I. & Svobodová, M. (2022) Avian louse flies and their trypanosomes: new vectors New Lineages and Host–Parasite Associations. Microorganisms, 10(3), 584. Available from: 10.3390/microorganisms10030584 [DOI] [PMC free article] [PubMed] [Google Scholar]
  68. Shirey, V. , Khelifa, R. , M'Gonigle, L.K. & Guzman, L.M. (2023) Occupancy–detection models with museum specimen data: promise and pitfalls. Methods in Ecology and Evolution, 14(2), 402–414. Available from: 10.1111/2041-210X.13896 [DOI] [Google Scholar]
  69. Shutt, J.D. , Bell, S.C. , Bell, F. , Castello, J. , El Harouchi, M. & Burgess, M.D. (2022) Territory‐level temperature influences breeding phenology and reproductive output in three forest passerine birds. Oikos, 2022(8), 1–13. Available from: 10.1111/oik.09171 [DOI] [Google Scholar]
  70. Smart, J. (1939) Hippoboscidae. Blood‐Sucking Flies, England: Printed by order of the Trustees of the British Museum, 118–124. https://babel.hathitrust.org/cgi/pt?id=umn.319510004583588&view=1up&seq=7&skin=2021. [Google Scholar]
  71. Smiddy, P. & Sleeman, D.P. (2004) Recent Records of Louse‐Flies (Diptera: Hippoboscidae) taken in Ireland recent records of louse‐flies (Diptera: Hippoboscidae) taken in Ireland. Irish Naturalists' Journal, 27(10), 403–404. [Google Scholar]
  72. Summers, R.W. (1975) On the ecology of Crataerina hirundinis (Diptera: Hippoboscidae) in Scotland. Journal of Zoology (London), 175, 557–570. Available from: 10.1111/j.1469-7998.1975.tb01417.x [DOI] [Google Scholar]
  73. Sumner, S. , Bevan, P. , Hart, A.G. & Isaac, N.J.B. (2019) Mapping species distributions in 2 weeks using citizen science. Insect Conservation and Diversity, 12(5), 382–388. Available from: 10.1111/icad.12345 [DOI] [Google Scholar]
  74. Thompson, G.B. (1953) Contributions toward a study of the ectoparasites of British birds and mammals.—No. 1. Annals and magazine of. Natural History, 6(66), 401–425. Available from: 10.1080/00222935308654440 [DOI] [Google Scholar]
  75. Thompson, G.B. (1954) Contributions toward a study of the ectoparasites of British Isles birds and mammals‐No. 2. Annals and Magazine of Natural History, 7, 17–39. [Google Scholar]
  76. UNEP‐WCMC and IUCN . (2020) UNEP‐WCMC and IUCN Protected Planet Report 2020. 10.34892/jg6t-xn70 [DOI]
  77. Walker, M.D. & Rotherham, I.D. (2010a) Temperature affects emergence of Crataerina pallida (Diptera: Hippoboscidae). Journal of Medical Entomology, 47(6), 1235–1237. Available from: 10.1603/ME10125 [DOI] [PubMed] [Google Scholar]
  78. Walker, M.D. & Rotherham, I.D. (2010b) The common swift louse Fly, Crataerina pallida: an ideal species for studying host‐parasite interactions. Journal of Insect Science, 10(193), 1–15. Available from: 10.1673/031.010.19301 [DOI] [PMC free article] [PubMed] [Google Scholar]
  79. Walther, B.A. & Clayton, D.H. (1997) Dust‐ruffling: a simple method for quantifying ectoparasite loads of live birds. Journal of Field Ornithology, 68(4), 509–518. Available from: 10.2307/4514260 [DOI] [Google Scholar]
  80. Wawman, D.C. (2024) Ornithomya biloba, Pseudolynchia garzettae and Pseudolynchia canariensis (Diptera: Hippoboscidae): three new United Kingdom colonists and potential disease vectors. Medical and Veterinary Entomology, 38(2), 160–171. Available from: 10.1111/mve.12703 [DOI] [PubMed] [Google Scholar]
  81. Weaving, H. , Terblanche, J.S. & English, S. (2023) How plastic are upper thermal limits? A comparative study in tsetse (family: Glossinidae) and wider Diptera. Journal of Thermal Biology, 118, 1–10. Available from: 10.1016/j.jtherbio.2023.103745 [DOI] [PMC free article] [PubMed] [Google Scholar]
  82. Wickham, H. , Francois, R. , Henry, L. & Muller, K. (2023) Package ‘dplyr’: A Grammar of Data Manipulation (1.1.2). https://cran.r-project.org/package=dplyr.
  83. Wickham, H. & Seidel, D. (2022) scales: Scale Functions for Visualization (1.2.1). https://cran.r-project.org/package=scales.
  84. Williamson, K. (1954) Fair Isle apparatus for collecting bird ectoparasites. British Birds, 47(1), 234–235 http://phthiraptera.info/content/fair-isle-apparatus-collecting-bird-ectoparasites. [Google Scholar]
  85. Wilson, R.J. , Bennie, J. , Lawson, C.R. , Pearson, D. , Ortúzar‐Ugarte, G. & Gutiérrez, D. (2015) Population turnover, habitat use and microclimate at the contracting range margin of a butterfly. Journal of Insect Conservation, 19(2), 205–216. Available from: 10.1007/s10841-014-9710-0 [DOI] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

FIGURE S1. All sites from which louse flies (Hippoboscidae) were collected for the avian louse fly study (all flies excluding keds). UK sites are plotted as white squares at 1 km2 resolution and Irish sites in purple.

FIGURE S2. Maps showing the distribution of capture sites for all Hippoboscidae in the study (louse flies and keds), as Maxent model outputs predicting the likelihood of a Hippoboscid in the project being collected at a site, relative to (a) the proportion of urban land‐cover in that 1 km2, (b) the proportion of protected land‐cover and (c) the proportions of both urban and protected land‐cover. Warmer (redder) colours predict a higher probability that a fly will be found at a site. The areas under the receiver operator curve, and the high proportion of green in these maps indicate that the sites are almost randomly distributed with respect to both urban and protected area land‐cover.

FIGURE S3. Kernel densities for all Hippoboscidae in the study. The kernel densities are plotted at 95% predicted probability (dark red), 75% probability and 50% probability of a fly being caught at a given location, during the study, based entirely on latitude, longitude and total count data.

FIGURE S4. Boxplots showing the altitude ranges of all of the species of Hippoboscid received during the study period. Ornithomya chloropus occurs over a wider altitude range than the other Ornithomya sp.

MVE-39-559-s001.pdf (777.7KB, pdf)

Data Availability Statement

The dataset for this study is available at https://doi.org/10.5061/dryad.zs7h44jkh. On completion of the study, the records will be entered into the database on the website iRecord with the other Hippoboscidae and Nycteribiidae Recording Scheme data.

Articles from Medical and Veterinary Entomology are provided here courtesy of Wiley

RESOURCES