Online supporting material

Species differences in responses to captivity: Stress, Welfare and the Comparative Method’

Georgia J. Mason,

Animal & Poultry Science Dept.,University of Guelph, Guelph, Ontario N1G 2M7

Canada

The relative breeding success of Humboldt’s penguins in zoos

Data collected by Blay & Côté [S1; I. Côté pers. comm.]show that across 13 UK zoos, the mean chick output per breeding pair was 0.53. Chick output/pair in the wild was in contrast 1.34 at a site with minimal human disturbance [S2].

Chamove and colleagues’ analysis of primates’ responses to zoo vistors (S3):

For 12 species, the authors analysed the effects of two variables separately: body weight, and whether arborial or territorial. They found neither to be significant. However, re-analysing their data with a General Linear Model including both factors and their interaction, shows that activity levels when visitors were present were indeed highest in the smallest-bodied species: F1,8 = 6.03, p = 0.04. In contrast whether species with arboreal or terrestrial had no effect (F1,8 = 0.41, p = 0.54), and nor did this interact with body size (F1,8 = 2.33, p = 0.17).

Mettke Hoffman’s study of caged parrots’ responses to novel objects (S4)

Analysing data on responses to novel objects presented in her Table 3, Mann-Whitney U = 0, p = 0.05; median exploration times were 0 minutes for non-self-plucking species (n= 3) and 98 minutes for self-plucking species (n = 6).

Suppementary information for Table 1:

Closely related species with unexplained variation in captive welfare:

Prosimians:

In a 1984 survey [S5], the infant mortality rate of the ring-tailed lemur (Lemur catta) was lower than that for the Black lemur, E. macaco, and this difference was significant (183/872 vs 185/684; chi squared = 7.46, p < 0.01).

More recently, their prevalence of stereotypic behaviour was also assessed [S6]. Data in this publication are presented by genus, but species values were obtained by contacting the lead author (L. Fernandez, pers. comm.). For ring-tailed lemurs, 6% of 174 subjects surveyed showed stereotypic behaviour, compared to55% of 9 subjects surveyed for the Black lemur. This difference again proved to be significant;Fishers exact test p = 0.0002).

Raptors:

All figures are from S7.

Sparrowhawk deaths when kept by falconers, compared to kestrel deaths:

For just their first year in captivity, after being caught from the wild as fledglings only (data in S7’s Table 1) proportions dying were 19 /36 cf. 10/89; chi-squared (with Yates correction) = 25.55, p < 0.0001.

Using one dataset(data in S7’s Table 2), relative proportions dying were 14 /33 cf. 9/85; Chi-squared (with Yates correction) = 13.39, p = 0.0003.

Focussing on birds caught from the wild as immature or mature animals only (i.e. older than fledgling), this species difference was no longer significant, though in part this may reflect low power (8/39 kestrels died, cf. 4/12 sparrowhawks; Fisher exact p = 0.44).

Supplementary references

S1. Blay, N. and Côté, I. M. (2001) Optimal conditions for breeding of captive Humboldt penguins (Spheniscus humboldti): A survey of British zoos. Zoo Biol. 20 545–555

S2. Ellenberg, U. et al. (2006) Physiological and reproductive consequences of human disturbance on Humboldt penguins: the need for species-specific visitor management. Biol. Conserv. 133, 95-106

S3. Chamove, A. S. et al.(1988) Visitors excite primates in zoos. Zoo Biol. 7, 359-369

S4. Mettke, C. (1995) Ecology and environmental enrichment – The example of Parrots. In Research and Captive Propagation (Gansloßer, U. et al., eds.), pp. 257-262, Filander Verlag

S5. Lindberg, D. G. et al. (1984) Primate breeding in zoos: a ten year summary. In One Medicine: A Tribute to Kurt Benirschke. (Ryder, O. A. and Byrd, M. L., eds.), pp. 162-170, Springer-Verlag

S6. Tarou, L.R. et al.(2005) Survey of stereotypic behavior in prosimians. Am. J. Primatol.65, 181-96

S 7. Kenward, R.E. (1974) Mortality and the fate of trained birds of prey. J. Wildl. Manage. 38, 751-756