Nature calls – does ecology explain abnormal behaviour and breeding problems in captive psittacines?

Psittaciformes are popular pets and aviculture species. However, in captivity they show species variation in susceptibility to problems such as stereotypic behaviours and poor breeding. For example, feather-damaging behaviour (e.g., self-plucking) is prevalent in African grey parrots, Psittacus erithacus, but rare in Senegal parrots, Poicephalus senegalus; while monk parakeets, Myiopsitta monachus, breed readily, yet blue-throated macaws, Ara glaucogularis, do not. Comparing species using phylogenetic comparative methods can unpick fundamental bases of problems; thereby identifying species pre-disposed to be good pets and informing captive breeding management. We investigated relationships between species-typical biological traits proposed to influence welfare, and three welfare-sensitive captive outcomes: feather-damaging behaviour (FDB), other stereotypic behaviours (SB), and hatch rates (HR). Prevalences of FDB and SBs for 53 species (~1,380 birds) were gleaned by surveying pet parrot owners. Captive HRs (chicks hatched/breeding pair/p.a.) for 122 species came from Allen and Johnson (1990 Psittacine Captive Breeding Survey). Using phylogenetic generalised least squares regressions, we assessed effects of the following aspects of species-typical biology on welfare: sociality (maximum group size, communal roosting); foraging effort; ecological flexibility (diet and habitat breadth); intelligence (innovation rate, relative brain volume); and IUCN conservation status. Effortful foraging modes (T3, 34=-2.25, P=0.03, λ=0.88) predicted FDB. Relatively large brain sizes predicted SBs (whole body: T3, 36=2.84, P=0.01, λ=0.29; oral: T3, 37=3.62, P=<0.01, λ=0). More threatened species had lower captive HR (T5, 75=-2.18, P=0.03, λ=0.39). These traits can thus be considered species-level risk factors for poor parrot welfare, providing an evidence-based platform to inspire ways of tackling these problems.