Daniel Nesbit’s Placement Report

Placement Location

BirdLife International

Placement Dates

Start Date : September 18, 2023
End Date : December 8, 2023


While on placement with BirdLife I carried out an extinction analysis for a number of ‘lost’ species, which have not been recorded for decades or centuries. This analysis was a continuation of the work carried out by Butchart et al. 2018 and based on two models. One incorporates records and surveys, while the other takes into consideration the threats faced by the species. The goal of this analysis was to determine if these species could be reclassified as Extinct or if they should remain Critically Endangered or Critically Endangered (Possibly Extinct). Which is important so we have an up to date understanding of these species and so that conservation funding can be distributed to the most pressing cases or withdrawn if it is too late.

In order to run these models, I first had to compile all the known records of each species. For some this did not take long, Siau Scops-owl (Otus Siaoensis) for example, is known only from the holotype collected in 1866 and a few unconfirmed sound recordings. Whereas Javan Pied Starling (Gracupica jalla) was once one of the commonest birds on Java but has not been seen in the wild for a number of years, despite over 1 million of them being kept in captivity for the songbird trade. I then had to assign each record a best estimate, along with upper and lower bounds, based on the probability that it is a genuine record.

The next component was surveys and to do this successfully I had to get in touch with a variety of ornithologists, birders and conservationists, many of whom had searched for these birds themselves. They provided me with a great deal of information about the surveys that had been carried out in search of these species and I had to estimate the proportion of the species range that had been covered by each survey, the probability of detection had it been there and the probability that the species would have been correctly identified had it been found. For some species survey effort has been extensive, across Vietnam since 2005, there has been more than 700,000 camera trap nights of effort searching for Vietnam Pheasant (Lophura edwardsi) and other exceptionally rare species like Saola (Pseudoryx nghetinhensis). But unfortunately, these have been to no avail.

Lastly, for the threats model I had to estimate the probability that the threats faced by each species had been severe enough to cause local extinctions. I then had to estimate the probability that these threats had acted with such acuity across the entire range of the species. The five Hawaiian species I assessed have faced a panoply of threats, beginning with the arrival of Polynesian settlers who cleared almost all the lowland forests, introduced dogs (Canis familiaris), pigs (Sus scrofa) and Polynesian rats (Rattus exulans) and constructed ceremonial gowns and ornaments made of the feathers of up to 80,000 birds for a single cloak. With the arrival of Europeans more forest was cleared, and a multitude of other non-natives were introduced, including two more species of rats (R. rattus & R. norveigicus), cats (Felis catus), mongooses (Urva auropunctata), and a host of other non-native mammals, birds, insects and plants. However, the most pervasive threats faced by Hawaiian birds are avian malaria and avian pox, spread by an invasive mosquito (Culex quinquefasciatus). Hence the Hawaiian species I assessed scored very highly in the threats model.

During my time at BirdLife I assessed 11 species. Of which, four were uplisted from Critically Endangered (Possibly Extinct) to Extinct. Three were uplisted from Critically Endangered to Critically Endangered (Possibly Extinct) while one remained Critically Endangered (Possibly Extinct) and three remained Critically Endangered.

I had such an incredible time at BirdLife. It was such a pleasure to be surrounded by lovely and likeminded people and I feel as though I was able to fully integrate myself into the team and culture in the David Attenborough Building (where BirdLife is based). I was also lucky enough to see the buildings namesake when he dropped in for a visit. I also had the opportunity to go behind the scenes at The Natural History Museum at Tring when some of my colleagues were carrying out taxonomic research there. I had the chance to see a fraction of the million plus specimens, which represent more than 95% of bird species. It was one of the most amazing experiences to see the sheer diversity of form and function and see birds I’d never even heard of and those I’d always wanted to see. I’m so grateful for my time at BirdLife and feel very lucky to have been able to meaningfully contribute to the important work they carry out.