The implications for conservation of a major taxonomic revision of the world’s birds

A recent comprehensive revision of the taxonomy that underpins the global IUCN Red List for birds led to an increase of 10.7% (over 1000 species) in the number of recognized bird species. We assessed the implications for conservation of this revision by (1) comparing extinction risk between newly recognized and unrevised species, (2) calculating the extent to which newly recognized species’ ranges are covered by Important Bird and Biodiversity Areas (IBAs) and protected areas, and (3) identifying new hotspots of extinction risk, where high numbers of newly recognized threatened species intersect areas of low protected area coverage. Unexpectedly, newly recognized species derived from taxonomic division (splitting) were on average significantly less threatened in terms of their IUCN global threat categories than species whose taxonomic status remained unchanged, despite their significantly smaller mean range size. Newly recognized species listed as globally threatened had higher average coverage of their ranges by IBAs and protected areas than their pre-revision ‘parents’, although 25 and 21 species had no coverage by IBAs or protected areas respectively. The absolute number of globally threatened species increased slightly overall, particularly in Java and the Philippines, already recognized as hotspots of extinction risk, and in eastern Amazonia, which emerged as a new hotspot of extinction risk. All three regions have low levels of protection and should be prioritized for expansion of the protected area network. Our results suggest that while major taxonomic revisions may lead to an increase in the absolute number of species requiring conservation attention, they do not necessarily lead to a rise in average extinction risk, a decrease in the coverage of species’ ranges by site-level conservation designations or a significant increase in the number of priority areas for conservation investment

Taxonomic status of the extinct Canary Islands Oystercatcher Haematopus meadewaldoi

Mitochondrial genes were sequenced from four specimens of the extinct Canary Islands Oystercatcher Haematopus meadewaldoi and compared with African Oystercatcher Haematopus moquini, Eurasian Oystercatcher Haematopus ostralegus and an old unidentified extralimital ‘black’ oystercatcher specimen from The Gambia. At these loci, H. meadewaldoi was approximately 99.65% identical to multiple Eurasian Oystercatcher samples and in phylogenetic trees fell within the range of genetic variation observed in that species. The mystery Gambian bird was resolved as an extralimital H. moquini. We conclude that H. meadewaldoi was most likely a recently diverged melanistic morph or subspecies of H.ostralegus, although further genomic studies will be required to determine whether there has been a period of isolation followed by introgression

Large avian frugivores in the Philippines show linear responses to improvements in forest quality

Large avian frugivores are important in ecosystem function, but are seriously threatened across the tropics. To conserve them we must understand their habitat needs and the effects of improved forest management on individual species and the community as a whole. We recorded the presence/absence of 18 parrot, pigeon and hornbill species along nearly 500 km of transects at 24 sites in Luzon, Philippines, and used logistic GLMMs to identify bird-habitat associations based on topographical, forest structure and floristic data taken at 1227 habitat plots. We then searched for more complex relationships and thresholds in species responses along forest quality/restoration gradients using GAMMs. Frugivore species richness was highest in forest with large-girthed trees, although some small-scale agricultural disturbance was tolerated or even favoured. Importantly, richness was highest in forests on flat ground, areas which are usually the first to be converted to agriculture. Individual species were positively associated with large trees but responses to floristic gradients were more variable. Very few species had complex relationships with forest quality; for the great majority, the probability of occurrence increased linearly along the forest quality/restoration gradient. While the precise benefits in terms of seed dispersal, and costs of management, at different points along the quality/restoration gradient are likely to be themselves complex, avian frugivores benefit proportionately from step improvements right along the gradient. Thus, any actions to improve forest quality on Luzon, from reforesting the most degraded lands to preventing degradation of relatively healthy forests, are likely to benefit frugivores

Endemic Cyprus Warbler Sylvia melanothorax and colonizing Sardinian Warbler Sylvia melanocephala show different habitat associations

Anthropogenic habitat change and assisted colonization are promoting range expansions of some widespread species with potential consequences for endemic fauna. The recent colonization of Cyprus by breeding Sardinian Warblers Sylvia melanocephala has raised concerns that it might be displacing the closely related and endemic Cyprus Warbler Sylvia melanothorax. Habitat associations of both species were examined using models of abundance within the 95% density kernel of the Sardinian Warbler's range and also outside this range for Cyprus Warbler. Within the Sardinian Warbler's range, the two species were associated with subtly different scrub habitats. Outside the Sardinian Warbler's range, the Cyprus Warbler differed again in its habitat association, but this probably resulted from marked differences in habitat extent and availability in different parts of the island rather than from competitive displacement, as none of the habitat or land-use elements differentially associated with Cyprus Warblers was positively associated with Sardinian Warbler occurrence. This suggests that the Sardinian Warbler has exploited a different niche, rather than displacing the endemic species, and has perhaps benefitted from changing land-use patterns, particularly recent fallows and abandoned agriculture, in contrast to the stronger association of Cyprus Warblers with semi-natural scrub