Declines and conservation of Himalayan Galliformes

Abstract

The Greater Himalaya has been identified as a key conservation region that supports high levels of biodiversity but has exceptionally high proportions of threatened species. One taxonomic group that is thought to be of particular concern is the bird order Galliformes. The Greater Himalaya is home to 24 species of resident Galliformes with a variety of ecological characteristics, geographical distribution patterns and abundance levels. Our current knowledge of South Asian Galliformes and Himalayan species in particular, contains many gaps. For example, it is suspected that many Himalayan Galliformes have undergone marked population declines but as to what extent they have declined and even the current status of some species is not fully known. There is a similar paucity of knowledge regarding both the distributions of the rarest of Himalayan Galliformes species and how well the current protected area network represents such distributions. Here I provide new insights into the distribution of the rarest Himalayan Galliform, the Critically Endangered Himalayan Quail (Orphrysia superciliosa) by using two proxy species with similar habitat preferences to create an environmental niche model. I show that by calculating an estimate of extinction likelihood, we have good reason to believe that the Himalayan quail to be extant and that recent searches in Nepal would be better targeted in North East India. Moving from single species to multiple species, I then examine long-term population changes across all Himalayan Galliformes by using changes in geographic range size as a proxy. I show that population changes for this suite of species both within and outside the Himalaya can help us to set conservation priorities and baselines. In addition, it can help us to identify species that have undergone large population changes that are not reflected in contemporary IUCN Red List statues. Species with small geographic ranges are currently top priorities for conservation efforts because they are thought to be at a greater risk of extinction. However, because it is also easier to track long term population changes over smaller spatial scales, concern exists that we may have underestimated the declines and therefore the extinction risk of more i widespread species. I show that across the entire Galliformes taxon, geographic range size does not predict the rate of geographic range decline. Finally, I move from population declines across all Galliformes to distributions of Himalayan Galliformes and assess how well the current protected area network represents such species. Using a combination of species distribution modelling and spatial prioritisation software, I show that the current protected area network in the greater Himalayas could be improved to offer better coverage for Himalayan Galliformes. I conclude by discussing the generality of my results and how they can be applied to other taxa and localities. Finally I make a series of recommendations for future Galliformes research and conservation within the Himalaya.