An inexpensive artificial snake hibernaculum built using readily available plumbing supplies

Abstract

Artificial snake hibernacula are anthropogenic structures used by snakes in temperate zones to survive harsh winter conditions. Artificial hibernacula can be intentionally created for various purposes including herpetoculture, research, habitat enhancement and conservation, or to offset development impacts. Here we present a design for an artificial snake hibernaculum for research use that was convenient (manually installed) and cost-effective ($91 CAD ea.). The hibernaculum was made of HDPE and ABS plumbing hardware, and measured ∼160 cm long by ∼10 cm wide. Our design was multi-chambered, descended to the groundwater table, and was modelled after the burrowing crayfish burrows used as overwinter refugia by snakes in our study area. Installation was completed using a manual soil auger in areas with soil depths of ∼115 cm. Removable components would allow easy ingress and egress of snakes, and threaded caps would facilitate monitoring via borescope camera. Dataloggers were used in 4 unoccupied hibernacula during one hibernation period, and results demonstrated that hibernacula supported a low mean air temperature and a high mean relative humidity. The hibernacula also provided a substantial buffer against extreme outside temperature and humidity. Further testing may demonstrate the suitability of our hibernaculum design for herpetoculture or conservation purposes.

• •Installed using a manual soil auger in areas with soil depths of ∼115 cm
• •Removable components allow for safe and easy ingress/egress of wild-caught or captive-reared snakes
• •Removable cap and simplified shape facilitate health monitoring of snakes via borescope camera

Graphical abstract

Specifications table

Subject area:	Agricultural and Biological Sciences
More specific subject area:	Conservation Biology
Name of your method:	Artificial Snake Hibernaculum (ASH)
Name and reference of original method:	“Artificial burrow”: Péchy, T., B. Halpern, E. Sós, and C. Walzer. 2015. Conservation of the Hungarian meadow viper Vipera ursinii rakosiensis. International Zoo Yearbook 49:89-103.
Resource availability:	Armtec: armtec.com; Carriff: carriff.com; Normandy Products Company: normandyproducts.com; AMD Inc.: ams-samplers.com; RELN Intl.: relnproducts.com; Thermochron: thermochron.com.au

Method details

Overview

Artificial snake hibernacula are anthropogenic structures used by snakes in temperate zones to survive harsh winter conditions. These features can be unintentionally created whenever built structures, such as building ruins, old dumping sites, underground infrastructure and equipment, or abandoned mine shafts are incidentally adopted as hibernacula by wild animals (e.g., [[1], [2], [3]]). Alternatively, artificial snake hibernacula can be intentionally created for various reasons including herpetoculture [4], research [[5], [6], [7], [8]], habitat enhancement and conservation [9], or to offset development impacts [[10], [11]]. As a result, artificial hibernacula designs can vary widely in terms of their installation location (outdoors vs. indoors), size, and cost, up to an including those large enough to house hundreds of snakes and requiring the use of heavy construction machinery at the cost of tens of thousands of dollars [11].

Here we present a convenient and inexpensive design for an artificial snake hibernaculum (ASH) used for research that measured ∼160 cm long by ∼10 cm wide when fully assembled and installed (Figs. 1, 2). Replication in quantity was facilitated by the relatively low per unit cost of the ASH assembly (∼$91 CAD each; Table 1) and the ability to install it manually, when compared to alternatives (see Additional information). We uniquely constructed our design primarily out of inexpensive, durable, safe, and widely available HDPE (High Density PolyEthylene) and ABS (Acrylonitrile Butadiene Styrene) plumbing pipes and fittings [12]. However, we drew inspiration from artificial hibernacula used in other studies that were made with other materials (frost-proof terracotta: [13]; Acrylic: A. Yagi, 8Trees Inc., personal communication). We acknowledge a variety of reasons for creating artificial snake hibernacula, and suspect our design may be suitable for additional applications with further study (see Additional information), however, our goal here was to develop an accessible design specifically for research purposes that was easy to duplicate, conducive to modification, and convenient to repair in the North American context.

Fig. 1.

An assembly diagram of the artificial snake hibernaculum design. Each component is labelled in the diagram with a letter, corresponding to the parts list below. The fully assembled outer sleeve is ∼150 cm long (exact length will depend on the brand of HDPE end cap used). The fully assembled inner housing is ∼140 cm long (exact length will depend on how accurately pipe sections are measured and cut). See “Detailed assembly and installation” subsection for a description of the outer sleeve and inner housing, including design, construction and installation. See “Overview” subsection for a description of the removable bottom chamber.

Fig. 2.

Technical illustration of an artificial snake hibernaculum installed in soil showing the approximate relative locations of the frost level, groundwater table and life zone [14] relative to the ground surface. The fully assembled hibernaculum is ∼160 cm long, with ∼125 cm of the inner housing below the ground surface (exact lengths will depend on the brand of HDPE end cap used, and how accurately pipe sections are measured and cut). * indicates approximate location of the datalogger placed during methods validation. Optional monitoring equipment (groundwater well and frost tube) are depicted as being installed ∼1 m and ∼2 m, respectively, from the artificial snake hibernaculum (Fig. 4; [15]).

Table 1.

All necessary components, the required quantity per unit, and their associated costs, to build an artificial snake hibernaculum (ASH). All prices are approximate and provided in Canadian dollars (CAD) in 2022. ABS = Acrylonitrile Butadiene Styrene, HDPE = High Density PolyEthylene. All ABS pipe is cellcore variety.

Component	Unit cost	Ontario sales tax	Total unit cost	# required per ASH	Cost per ASH (CAD)
ABS reducer (8 cm to 4 cm)	4.49	0.58	5.07	8	40.59
Female threaded ABS cleanout adapter (4 cm)	1.79	0.23	2.02	2	4.05
Male threaded ABS cleanout adapter (4 cm)	1.29	0.17	1.46	1	1.46
Male threaded ABS cleanout plug (4 cm)	2.29	0.30	2.59	1	2.59
ABS cap (4 cm)	4.69	0.61	5.30	1	5.30
HDPE drain pipe end-cap (10 cm)	5.23	0.68	5.91	2	11.82
ABS pipe (8 cm; 365 cm length)	47.99	6.24	54.23	0.11 (40 cm)	5.97
ABS pipe (4 cm; 365 cm length)	21.99	2.86	24.85	0.18 (65 cm)	4.47
HDPE drain pipe (10 cm; 305 cm length; solid)	13.99	1.82	15.81	0.50 (150 cm)	7.90
Filter sock for HDPE pipe (Drain-Sleeve; 10 cm x 300 cm)	13.63	1.77	15.49	0.25 (75 cm)	3.85
Soffit screws (#8 or #6, 3/8”; black head; 100 pack)	8.10	1.05	9.15	0.14 (14 screws)	1.28
Lock washers (#10, 3/64” thick; zinc plated; 50 pack)	5.99	0.78	6.77	0.28 (14 washers)	1.90
				Total cost per ASH:	91.17

We also wanted to replicate as much as possible the size, structure, features, and conditions of natural hibernacula in our study area. Thus, our ASH was designed to integrate characteristics of the burrows of semi-terrestrial burrowing crayfish, which are important overwinter refugia for Eastern Massasaugas, and other snakes, because they provide a subterranean structure with access to the water table and shelter from freezing temperatures [[16], [17], [18], [19], [20]]. Burrows made by North American obligate burrowing crayfish share a number of key characteristics which were considered in our design, including burrow width, depth, and angle, the number of entrances and chambers, water access, and light penetration (Table 2; [21], [22], [23], [24], [25], [26], [27], [28], [29], [30]). We also considered that crayfish burrows with one or more chambers can trap small pockets of air when flooded (S. Hasiotis, University of Kansas, personal communication), which may help crayfish survive when water oxygen levels are low (P. Hamr, Independent Contractor, personal communication). Once fully installed, only a few centimeters of the top of our ASH protruded above the ground surface, reminiscent of the mud “chimney” of a terrestrial crayfish burrow.

Table 2.

Comparison of the key characteristics of our artificial snake hibernaculum design (ASH) with characteristics of the burrows of North American obligate burrowing crayfish (e.g., Lacunicambarus nebrascensis [formerly Cambarus Diogenes], Cresarinus fodiens [formerly Fallicambarus fodiens] and Lacunicambarus polychromatus). See Method details for literature cited.

	Crayfish burrows	ASH
Burrow width	0.6–5.1 cm diameter	3.8 cm diameter
Depth	Variable; can exceed 100 cm	Descended to ∼95 cm
Angle	Straight down or slight angle or combination	45° angle
Number of entrance(s)	≤ 4	1
Water access	Descends to water table	Descended to water table
Number of chamber(s)	≥ 1	4; ∼20 cm apart
Terminal chamber	1 large terminal chamber	1 terminal chamber as big as others
Light penetration	Some of the entrances can be capped by clay chimneys, others remain open	Main entrance capped; Small holes drilled in the 10 cm end-cap
Air pockets	Small air pockets trapped in chambers during flood events	Small air pockets trapped in top of chambers during flood events

Finally, it was also important that our ASH design could accommodate safe, hassle-free ingress/egress of snakes, and easy access by researchers for non-invasive monitoring, because we planned to conduct in-situ hibernation of wild-caught Eastern Gartersnakes (Thamnophis sirtalis; see [15]), and later zoo-reared Eastern Massasauga rattlesnakes (Sistrurus catenatus). To this end we incorporated a removable bottom chamber (Fig. 1), which could be capped to allow for safe and contained transport of snakes from elsewhere (e.g., temporary housing ex situ) to the hibernation site. The simple screw-on connection of the bottom chamber to the rest of the inner housing would eliminate the need to handle snakes in the field (see Supplementary material). Also, the top of the assembled hibernaculum was capped with a threaded ABS cleanout plug so that hibernating snakes would be contained and predators would be excluded. The cap could be easily unscrewed to facilitate monitoring of hibernating snakes via borescope camera. We tested our ASH design prior to hibernating live snakes to determine if the internal microclimate (temperature and humidity) was consistent with that of suitable hibernacula in natural conditions ([31]; see Method validation). Our multi-chambered design descended to the groundwater table, allowed groundwater and air entry, provided resting sites at various depths below ground, and was physically sheltered from the elements (Fig. 2), theoretically providing snakes with their specific needs over winter: protection from freezing temperatures, the ability to maintain a relatively cool body temperature, protection from desiccation and predation, and an adequate supply of oxygen [31].

Detailed assembly and installation

Our ASH design was composed of two main parts: a cylindrical outer sleeve, buried at a 45 degree angle to the ground surface; and a removable inner multi-chambered housing that was inserted into the subterranean space maintained by the outer sleeve (Figs. 1, 2). Build and installation time averaged 3.0 and 1.4 person-hours, respectively, per ASH, based on the completion of 18 units.

Outer sleeve design, construction and installation

The outer sleeve was designed so that the inner housing could be removable (Fig. 1). Its function was to maintain a hollow subterranean space that is permeable to groundwater and air flow, and to support the inner housing. We constructed it out of a 150 cm length of 10 cm diameter corrugated and unperforated HDPE drainage pipe (Big ‘O’, Armtec, WGI Westman Group Inc., ON, Canada). We perforated the pipe by drilling 8 mm holes in four equally spaced rows of ten (40 holes total) in the bottom 75 cm of the pipe. We then wrapped the bottom 75 cm of the HDPE pipe in a filter sock (Drain-Sleeve, Carriff Canada, ON, Canada) to prevent debris from entering the outer sleeve. We capped the bottom end of the HDPE pipe with a 10 cm drainage pipe end-cap (Normandy Products Co., PA, USA; Substitution: Armtec, WGI Westman Group Inc., ON, Canada), completing the assembly. Note that not all 10-cm HDPE drainage pipe is manufactured to the exact same internal diameter. To ensure the outer sleeve could accommodate our inner housing (see below), we tested whether an 8 cm to 4 cm ABS reducer slid freely inside of the HDPE pipe before purchase. Further, we determined that our inner housing would not slide freely within pre-perforated 10 cm HDPE pipe.

To install the outer sleeve into the ground, we followed four main steps. Step 1 was to hand bore a ∼155 cm hole at a 45-degree angle into workable, unfrozen soil (corresponding to a vertical soil depth of ∼ 115 cm). The dominant soil type at our installation sites was Berrien Sand [32]. We used a 122 cm (4’) manual soil auger equipped with a two-foot extension rod and a 15 cm (6”) diameter Edelman combination auger head (AMS Inc., ID, USA; Fig. 3). Step 2 was to install the assembled outer sleeve into the hole so that the top lip of the pipe was flush with the soil level (Fig. 4). The inner housing was inserted loosely inside the outer sleeve to increase its rigidity during installation. An effort was made in step 1 to maintain a consistent 45-degree angle while boring, so that the outer sleeve would be installed as straight as possible; A poorly installed outer sleeve may not properly accept the inner housing (see below), rendering insertion and removal unsmooth and difficult. Step 3 was to backfill the remaining gap around the outer sleeve using loose soil from the excavation in step 1 (Fig. 5). An effort was made to pack down the backfilled soil to fill the gap along the entire length of the outer sleeve. The remaining soil was left in a small pile beside the bored hole, and the disturbed area was covered with native organic material (e.g., leaf litter). Step 4 (optional) was to temporarily cap the installed outer sleeve with a removable 10 cm knock-out plug (RELN International, Australia) to prevent debris or equipment from falling in. The plug was easily removed to allow installation of the inner housing (see below).

Fig. 3.

Hand boring a 150cm hole at a 45-degree angle into the soil using a 122 cm (4’) hand-auger equipped with a two-foot extension rod and a 15 cm (6”) diameter Edelman combination auger head. The outer sleeve and inner assembly can be seen to the right of the foreground.

Fig. 4.

An assembled outer sleeve before (left), and after (right) installation into a bored hole. The inner housing is sitting loosely inside the outer sleeve to increase its rigidity during installation. The gap between the outer sleeve and the bored hole has not yet been backfilled (right). The graduated white tube used to verify and adjust installation angle can be seen in the foreground (left). Optional monitoring equipment (groundwater well and frost tube) are installed ∼1 m and ∼2 m, respectively, from the artificial snake hibernaculum (left; Fig. 2).

Fig. 5.

The gap around the installed outer sleeve of an artificial snake hibernaculum has been backfilled with native loose sandy soil. The bottom part of the inner housing is in the top right of the figure.

Inner housing design, assembly and installation

The inner housing was designed to replicate the internal structure of burrowing crayfish burrows, which are generally characterized by one to four vertical or angled tunnels descending below the groundwater table and composed of one or more connected chambers ([21]; Table 2). We developed a simplified design comprised of a pattern of four wider chambers with narrower sections of pipe between them connected by a series of reducers to create a multi-chambered structure centred on a single vertical shaft (Figs. 1, 6). We prepared each of the four chamber sections of the inner housing in the same way, each with a 10 cm length of 8 cm diameter ABS pipe and an 8 cm to 4 cm ABS reducer on both ends. To build the top end of the inner housing, we connected a 20 cm length of 4 cm ABS pipe to the top of the first (top) chamber. We then cut a 4 cm hole in the centre of a 10 cm drainage pipe end-cap (Normandy Products Co., PA, USA), perforated it with 3 mm holes equally spaced around its outside perimeter, and inserted the concave side down onto the 20 cm length of 4 cm ABS pipe so that it could slide along the 20 cm pipe section. We capped the top of this pipe with a 4 cm female threaded ABS cleanout and a 4 cm male threaded ABS cleanout plug.

Fig. 6.

The assembled inner housing of an artificial snake hibernaculum, prior to being inserted into the outer sleeve.

We then connected the other chambers together with 4 cm ABS pipe as follows: the first (top) chamber was connected to the second by a 15 cm section of pipe that we perforated with 3 mm holes using an electric drill. The second chamber was also connected to the third in this way. The third chamber was connected to the fourth (bottom) section by an assembly made out of, from superior to inferior, a 7 cm length of pipe that we perforated with 3 mm holes, a male threaded coupling, a female threaded coupling, and a 4 cm length of pipe that we perforated with 3 mm holes. This assembly resulted in ∼15 cm between the third and fourth chambers and allowed for the fourth (bottom) chamber to be removed and capped with a 4 cm male-threaded ABS plug. The bottom of the fourth, and final, chamber was terminated with a 5 cm section of pipe that we perforated with 3 mm holes and a 4 cm ABS end cap.

For extra stability, and to eliminate our exposure to ABS glue off-gassing, we pre-drilled and screwed together all fittings that were connected to a 4 cm ABS pipe with 9.5 mm long screws (# 8), and one spring lock 5.16 mm diameter washer (both from Reliable Fasteners, QC, Canada; Table 1). We found one screw per fitting was sufficient to maintain stability. We chose this length of screw, in combination with a washer, to avoid a sharp metal point protruding into the interior of the hibernaculum, potentially injuring snakes. We did not screw together any 8 cm pipe joints because the protruding screw heads would have prevented the inner housing from sliding into the outer sleeve, and because the larger surface area of these joints was sufficient to prevent them from slipping apart. The completed inner housing (Figs. 6, 7) was then inserted into the outer sleeve in order to complete the hibernaculum assembly (Fig. 8). Our hibernacula were installed in a publicly accessible park so we concealed their protruding tops with leaf litter.

Fig. 7.

The inner housing of an artificial snake hibernaculum being inserted into the outer sleeve.

Fig. 8.

A fully installed artificial snake hibernaculum. In publicly accessible areas, the protruding top portion can be concealed from view with leaf litter.

Troubleshooting

• •To prevent the installation of ASH in poor quality areas (e.g., flood prone areas, or areas where the water table is too low) potentially resulting in the death of hibernated snakes, a site-selection process can be followed in advance. Although not detailed herein, this process could involve the installation of groundwater and frost monitoring equipment in the direct vicinity of the hibernaculum, or where an ASH is being proposed (Fig. 2; see [15]).
• •To ensure that the outer sleeve will eventually accommodate the inner housing, test whether an 8 cm to 4 cm ABS reducer will slide freely inside the 10 cm HDPE pipe before purchase, and avoid purchasing pre-perforated 10 cm HDPE pipe.
• •To ensure procurement of all necessary components for ASH assembly, and due to variations in stock and manufacturers carried, it may be necessary to frequent more than one local hardware supply store. Additionally, some products may be discontinued or unavailable in certain areas, possibly requiring online ordering or procurement of suitable and snake-safe alternative materials or components. It is outside the scope of this paper to provide an exhaustive list of potential substitutions.
• •To ensure that the inner housing will slide freely within the outer sleeve after installation, take care to maintain a 45-degree angle while boring the hole for the outer sleeve. This can be facilitated by the use of a metre stick or graduated tube (Fig. 4) to periodically verify that the height of the soil auger rod at a given distance from the hole is equal to that distance, and readjust as required. Regardless, it may still be necessary to partially rotate the inner housing while pushing/pulling to ease it in or out of the outer sleeve.
• •To prevent the inner housing from disassembling during repeated insertion and removal events, add a single screw to all 4 cm ABS joints.
• •To reduce the possibility of snake escape during monitoring with a borescope, the threaded ABS cleanout plug at the top of the ASH could be temporarily unscrewed and replaced with a borescope “adapter cap”. The adapter cap could be an ABS cleanout plug with a small hole drilled in its centre, of slightly greater diameter than the camera head of the borescope.

Method validation

Internal temperature and humidity

We monitored the internal temperature and humidity of four ASH during fall/winter of 2018 using a small datalogger (Hygrochron^TM, Thermochron, Australia) placed within ∼20 cm of the opening of each inner housing (Fig. 2). The ASH were installed at the 24 km² Ojibway Prairie Complex and Greater Park Ecosystem in Southwestern Ontario, Canada [33], which is situated within a historical glacial outwash plain with few rocky features or topographical variation, and is dominated by sandy soils [32]. Each datalogger was installed in the upper-most chamber, the equivalent of ∼11 cm below the ground surface (after accounting for the 45° angle of installation). Dataloggers were programmed to sample internal air temperature and humidity every 1 hour from the afternoon of 28 December 2018 to the afternoon of 30 April 2019. Each datalogger recorded 2953 – 2954 samples, after removing aberrant results (n = 70; likely caused by high humidity levels: S. van de Vorstenbosch, On Solution Pty Ltd, personal communication).

We calculated descriptive statistics for the internal temperature and the humidity data (mean, standard deviation, min, max, range) and compared these to the outside ambient temperature and humidity for the same study period, using hourly historical weather data from the Windsor Airport, ∼8.5 km away [34]. The minimum and maximum ambient values (temperature and humidity) were compared to the mean values recoded by the dataloggers for the same date and time to determine the extent to which the ASH buffered outside conditions. We also conducted a one-way ANOVA and a Tukey's post-hoc test to determine if mean temperature or humidity differed between the 4 dataloggers (see Supplementary material).

Temperature and humidity levels within the four ASH monitored from December 2018 to April 2019 were significantly different (p < 0.001; see Supplementary materials), but nonetheless very similar (mean temperature within 1.0 °C; mean humidity within 6.1%; Table 3). The mean internal temperature and humidity based on the combined results of the 4 dataloggers was 2.8 °C (range = -2.0 °C–14.0 °C; SD = 3.4) and 92.6% (range = 67.7%–104.0%; SD = 7.5; Table 3). Although negative temperatures were recorded in the upper ASH chambers, the hibernacula were installed deep enough to provide access to the groundwater, which measures on average 5–6 °C during the winter in our study landscape [15]. Mean internal ASH temperature was buffered from extreme minimum and maximum ambient temperatures by 24.7 °C and 11.0 °C, respectively. Mean internal ASH humidity was buffered from extreme minimum ambient humidity by 70.9%. Furthermore, internal ASH temperature and humidity fluctuated over a much narrower range of values than did ambient conditions (Table 3). Presumably our artificial hibernacula were able to maintain a low mean air temperature, a high mean humidity, and buffered against outside extreme conditions because they descended to the groundwater table, were perforated allowing free flow of water and moisture, and were physically capped at the top keeping moisture in and cold air out.

Table 3.

Summary of data collected from 4 dataloggers installed in 4 artificial snake hibernacula (ASH) at the Ojibway Prairie Complex and Greater Park Ecosystem, in Windsor, ON, from 28 December 2018 to 30 April 2019. Values are presented for the combined data from 4 dataloggers, and in parentheses the range of those values is presented based on the data from each ASH. Dataloggers were installed in the uppermost chamber of each hibernaculum (Fig. 2). Standard deviation (SD) corresponds to each of the means presented to the left of the SD column. Ambient temperature (temp.) and humidity (hum.) were taken from the Windsor Airport (Government of Canada 2023). Dates indicate the first date of the monitoring period when that particular minimum or maximum value was recorded. For comparison of mean values between the 4 datalogger, and for a summary of additional datalogger data from 2019/20 and 2020/21 seasons see Supplementary material.

	Mean	SD	Min	Max	Range
ASH temp. (°C)	2.8 (2.3 to 3.3)	3.4 (2.9 to 3.9)	-2.0 → 9 Feb 2019 (-2.0 to -0.5)	14.0 → 23 Apr 2019 (10.5 to 14.0)	16.0 (11.0 to 16.0)
Ambient temp. (°C)	0.3	7.7	-24.7 → 31 Jan 2019	22.0 → 8 Apr 2019	46.7
ASH hum. (%)	92.6 (89.5 to 95.6)	7.5 (6.2 to 7.4)	67.7 → 26 Jan 2019 (67.7 to 75.5)	104.0 → 5 Feb 2019 (102.3 to 104.0)	36.3 (28.5 to 36.2)
Ambient hum. (%)	73.7	14.9	24.0 →13 Apr 2019	99.0 → 31 Dec 2018	75.0

Snake locomotion

The ASH inner dimensions and angle of installation (45º) did not impede the ability of gartersnakes of all age classes, including neonates, to move freely up or down the feature [15]. Although not directly tested, the vertical movement of small neonatal snakes might be hindered if hibernacula are installed at a 90º angle from the ground surface.

Conclusion

Purpose-built artificial snake hibernacula provide an important research tool for in-situ hibernation studies because they allow for greater control of the hibernation environment and they facilitate easy observation and monitoring of the animals hibernating within [7]. We presented a convenient and inexpensive design for an artificial snake hibernaculum designed specifically for research (to evaluate habitat suitability of potential reintroduction sites: [15]). During hibernation snakes require shelter from freezing conditions, cold temperatures to minimize wasteful metabolic expenditures, and high relative humidity to protect against desiccation [[6], [31]]. By evaluating internal conditions of 4 hibernacula over the course of one winter (December to April), we demonstrated that these maintained suitable internal conditions for in situ hibernation with a low mean air temperature and a high mean relative humidity. Also, our hibernacula provided a substantial buffer against minimum outside ambient temperatures and humidity in our study landscape. The artificial hibernaculum described herein was not designed or tested as a habitat enhancement tool to replace destroyed natural hibernacula, but further testing may confirm its utility for herpetoculture or conservation purposes (e.g., to provide a hibernation period as environmental enrichment in captivity, or to provide a delayed release as part of a conservation translocation, respectively; Choquette et al. [35]).

Ethics statement

This work did not directly involve animal experiments. For the related research project which did involve animal experiments see Choquette et al. [15].

CRediT authorship contribution statement

Jonathan D. Choquette: Conceptualization, Methodology, Validation, Investigation, Resources, Data curation, Writing – review & editing, Supervision, Project administration, Funding acquisition. Lincoln M. Savi: Conceptualization, Writing – original draft, Visualization. Corentin Fournier: Formal analysis, Investigation, Writing – review & editing, Visualization.

Declaration of competing interest

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:

Jonathan Choquette reports financial support was provided to WPC by Ganawenim Meshkiki and the Eastern Georgian Bay Initiative. Jonathan Choquette (through SCC Ecological) reports a relationship with Blazing Star Environmental, Environment and Climate Change Canada, Gouvernement du Québec, Piroli Construction Inc., and 8Trees Inc. that includes: consulting or advisory.

Data availability

• Data will be made available on request.