Table 1.
Overview of age determination studies on hedgehogs, including the present study. * signifies that individuals of the age group 0–1 year have been omitted from the calculation of mean age. A blank field indicates missing data. Measures of age are presented in years. Brockie [47]: Detailed information was limited. One hundred forty-three individuals, 11% (n = 16) over 18 months (counted as 1-year-olds) and 7 over 2.5 years counted as 2-year-olds. The mean value is based on 120 individuals of 0–1 years, 16 individuals of 1–2 years, and 7 individuals of 2–3 years. Brockie [47] estimated that average life expectancy from birth was around 18 months. Brockie [64] estimated that the life expectancy was less than 2.7 years and probably closer to 2 years. Calculating the life expectancy excluding the individuals below 1 year of age, the mean is 2.7 years. When including individuals younger than 1 year of age, the mean is 1.8 years.
| Author | Country | Technique | Period | Sample Size | Mean Age | Age Span | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Female | Male | Total | Female | Male | Total | ||||||
| Brockie [47] | New Zealand | Tooth abrasions | 143 | 0.4 (see table text) | 0–2 | ||||||
| Brockie [64] | New Zealand | Mandible (periosteal growth lines) | 83 | <2.7* or 1.8 (see table text) | 0–7 | ||||||
| Dickman [48] | United Kingdom | Mandible (periosteal growth lines) | 1982–84 | 87 | 3.3* | 1–8 | |||||
| Döpke [49] | Germany | Mandible (periosteal growth lines) | 1980–2001 | 32 | 34 | 66 | 0.8 | 1.7 | 1.2 | 0–6 | |
| Haigh, Kelly, Butler and O’Riordan [50] | Ireland | Mandible (periosteal growth lines) | 2008–2011 | 31 | 46 | 83 (6 of unknown sex) | 2.1 | 1.9 | 1.9 | 0–9 | |
| Heddergott [51] | Thüringen, Germany | Tooth growth lines | 1993–2002 | 81 | 99 | 185 (5 of unknown sex) | 2.5 | 2.1 | 2.3* | 1–7 | |
| Heddergott [52] | Harz, Germany | Tooth growth lines | 1997–2002 | 49 | 57 | 106 | 1.6 | 1.5 | 1.5* | 1–4 | |
| Heddergott [53] | Germany, Saalfeld-Rudolstadt (Thüringen) |
Tooth growth lines | 1992–2003 | 44 | 37 | 81 | 1.9 | 2.5 | 2.2* | 1–8 | |
| Heddergott and Müller [54] | Germany, Osthessen | Tooth growth lines | 1980–2006 | 62 | 61 | 124 | 1.9 | 1.7 | 1.8* | 1–6 | |
| Heddergott, Steinbach and Heddergott [55] | Germany, Heilbad Heiligenstadt (Thüringen) | Tooth growth lines | 1998–2004 | 62 | 51 | 113 | 2.2 | 2.5 | 2.3* | 1–7 | |
| Heyne [56] | Germany | Tooth abrasions+ Tooth growth lines | 1981–89 | 62 | 2* | 1–5 | |||||
| Kristoffersson [58] | Finland | Mandible (periosteal growth lines) | 1960–61 | 67 | 2.7* (individuals < 500 g excluded) | 1–7 | |||||
| Scott-Hayward [68] | Uists, Outer Hebrides, UK | Mandible (periosteal growth lines) | 66 | 2.6* | 1–6 | ||||||
| Morris [36], Morris [41], Morris [60] | Southern England, United Kingdom | Mandible (periosteal growth lines) | 1965–68 | 102 | 127 | 244 (15 of unknown sex) | 1.7 | 0–6 | |||
| Neuschulz and Schubert [60] | Dresden-Bühlau, Germany | Capture-mark-recapture | 1984–89 | 125 (60 adults and 65 juveniles marked, 53 recaptured over 5 years) | 2.1* | 1–6 | |||||
| Parkes [65] | Manawatu, New Zealand | Capture-mark-recapture + calculation using a formula [66] | 1970–1971 | 144 (73 juveniles) | 2.0 | ||||||
| Rasmussen et al. 2023 (present study) | Denmark | Mandible (periosteal growth lines) | 2016 | 109 | 177 | 388 (101 of unknown sex) | 1.6 | 2.2 (1.6 for unknown sex) | 1.8 | 0–16 | |
| Rautio, Kunnasranta, Valtonen, Ikonen, Hyvarinen, Holopainen and Kukkonen [61] | Finland | Mandible (periosteal growth lines) | 2004–2005 | 31 | 34 | 65 | 1.5 | 1.7 | 1.6 | 0–7 | |
| Reeve, Love and Shore [42] | United Kingdom | Mandible (periosteal growth lines) | 1988–89 | 68 | 1.6 | 0–7 | |||||
| Skoudlin [62] | Czech republic | Tooth abrasions | 43 | 63 | 106 | 2.5* | 1–5 | ||||
| Skoudlin [63] | Czech republic, Bohemina and Moravia | Tooth abrasions | 215 | 2.1 | 0–6 | ||||||