An estimated 10,000 species of bird are scientifically described across the world by the British Trust for Ornithology (BTO, 2022). But unfortunately, many of these species – around 1,500 types of birds – are of conservation concern (BirdLife International, 2022a). The recent “State of the world’s birds” report by BirdLife International (2022b) has shown that 49 percent are in decline globally; therefore, species-specific and habitat-focused conservation action continues to be required.
Birds are, perhaps, the best studied and most well understood group of animals. Their presence on every continent and country and across a wide range of habitats means birds are excellent indicators of the ecological quality of ecosystems. Due to their popularity and strong associations with humans (through bird watching, bird feeding, aviculture and ornithology, for example), birds can help engage people with wider conservation messages. Furthermore, citizen science activities, such as the RSPB’s “Big Garden Birdwatch” (2022), add valuable data to our understanding of population trends and how well certain species are doing.
Integrated species conservation strategies
Collaboration between a wide range of practitioners and stakeholders is key to effective bird conservation – the knowledge and skills of invested parties enhance the efficacy and relevance of conservation action, making such outputs more likely to succeed.
A relatively new initiative from the International Union for Conservation of Nature (IUCN) is the One Plan approach to conservation (CPSG, 2022b). This approach is a sliding scale of management intensity for a species that values all individuals in a population, be they in the wild or captivity. This is an example of “metapopulation management”, where an integrated strategy of management actions includes and benefits all individuals within a population, wherever they are found (Figure 1). Metapopulation management has already been shown to be a useful way of getting stakeholder buy-in for different bird species that require conservation help, for example the greater sage grouse (Centrocercus urophasianus) in Canada (CPSG, 2022a).
Using zoo populations of threatened bird species, such as the southern ground hornbill (Bucorvus leadbeateri) (Figure 1), as a safety net ensures some form of conservation can continue should the wild population crash. These zoo-housed individuals also promote the gravity of the species’ role in its ecosystem, educating people on why they should be protected because of their ecological benefits. Such increased awareness reduces the chances of a crash in wild numbers and promotes the relevance of the zoo bird to its wild cousins and, subsequently, to their conservation action.
Keeping avian conservation sustainable
The sustainability of avicultural practices depends on the integration of wild ecology information into captive care (Rose, 2021). Incorporating information on wild adaptive traits, including key information on behaviour patterns, enables husbandry to be species-specific and ensures that care regimes promote good physical and psychological health (Greenwell and Beilby, 2022).
Many bird species display a wide range of elaborate courtship behaviours (Figure 2):
- flamingos (Phoenicopteriformes) perform synchronised mass courtship dances
- ground hornbills (mentioned above) have a multigenerational cooperative breeding strategy
- some species, such as peafowl (Pavo spp), perform lekking displays where males compete for access to females
Without knowledge of these elaborate reproductive strategies, management techniques and husbandry routines will not cater for them, so breeding success will be hampered. Increasing the number of available mates in flamingo flocks, for example, increases the chances of partners forming, thus promoting nest, egg and chick production (Rose et al., 2022).
Developing a conservation strategy
Using the IUCN Red List as a guide, we can identify species most in need of help and assistance. From there, we can see how health monitoring programmes in zoos should be implemented to ensure long-term population survival. Figure 3 illustrates the different categories of IUCN threat status – with the most imperilled at the top to those doing well at the bottom – and explains the level of conservation management needed for such species.
Species extirpated from the wild require investment in captive facilities (eg aviaries in zoos for captive breeding programmes) to ensure their long-term future. More common species, on the other hand, benefit from an investment in the supplementation of their populations through habitat and ecosystem management that enables populations to maintain high levels of growth and expansion. It is true what they say – that “common species are easier to conserve because they are common”. Therefore, knowledge of their ecological requirements allows habitats to be conserved, which, in turn, keeps the species prevalent and reduces the need for intense species-specific conservation action.
The knowledge of bird behaviour gained from observing populations in the wild benefits the development of ex situ husbandry programmes for captive individuals. Expertise from the zoo, eg design, construction and siting of nest boxes to encourage breeding in new locations (Beilby, 2022), has direct impact on wild populations by evidencing how to augment habitats to improve their quality and usefulness for threatened species at specific times.
Figure 3 compares two species of wildfowl (ducks, geese and swans). At the bottom is the mallard (Anas platyrhynchos), a low concern (LC) species with a worldwide population estimation of 19 million birds (BirdLife International, 2019). The other species (top) is critically endangered (CR), teetering on the brink of extinct in the wild (EW). This is an island endemic – the Laysan duck (Anas laysanensis), which has a maximum estimated global population of 680 individuals (BirdLife International, 2018). Without captive breeding efforts and an integrated conservation strategy involving zoological organisations and private aviculture, the Laysan duck’s future would be even more precarious.
Ultimately, sound bird conservation relies on behavioural ecology information and the application of this knowledge to the reassessment and re-evaluation of housing and husbandry. By encouraging the sharing and dissemination of knowledge from the wild to the zoo and vice versa, captive birds can be kept more appropriately (according to a species’ exact needs). This means that individuals are healthier, less stressed, more robust against illness and, therefore, more viable for breeding and conservation action plans.