Watchbird January 2022

In parallel, a gene called TGFB2 from the DNA of the cell nucle- us was examined for 31 individual cockatoos, revealing all to be highly similar, which supports conjecture about a possible genet- ic bottleneck. The presence of a unique haplotype for ND2 from the museum specimen indicates that greater genetic diversity may have existed historically for the Philippine Cockatoo. Shrinkage of the distribution and population have probably led to the reduction of genetic diversity, which might limit the ability of the species to adapt to future threats. Thus, there is a compelling need to use genetic techniques in the breeding and reintroduction of the Philippine Cockatoo into its previous distribution, while maintaining efforts to protect and restore habitats and current populations. Rasa and Pandanan Islands constitute an ideal source of founders for any reintroduction of this species else- where in the Philippines. The forest cover on Dumaran Island and other parts of Palawan is heavily depleted, making natural dispersion difficult and necessitating artificial translocation. This is the connection to the oil palm challenge.

Blue - naped Parrot Picture by Blake Matheson/CC BY - NC 2.0

Widespread plantations of oil palms are found in Southern Palawan, and further expansion of plantations in the near future is expected, despite that Palawan is a UNESCO Biosphere Reserve and considered to be the ‘ last ecological frontier ’ of the Philippines. Conversion of forest to oil palm plantation has known negative impacts on biodiversity, and a recent study (Bernardo, 2017) has investigated these effects on bird communi- ties in Aborlan, Palawan, relatively close to Rasa Island and IWPP. The study compared the bird communi- ties in oil palm monoculture and adjacent intact forest.

Of the 78 bird species detected in the study, 55 species were recorded in the primary forest while only 40 species were found in the oil palm plantations. More tellingly, among those 40 species, 23 were open - country birds also found in neighboring open areas. In effect, of the 55 bird species rec- orded in the forest, only 17 forest - adapted species could eke out a living in the oil palm plantations. An index of similari- ty [Morisita Index: 0 (no similarity) to 1 (complete similari- ty)] between the avifaunal communities in the forest and in the oil palm plantations showed the very low value of 0.23. Furthermore, the level of abundance of bird species in oil palm plantations was found to be only 53% of the level of abundance of those found in the forest. Present in the forest but absent from the oil plantations were the Blue - headed Racquet - tail and the Blue - naped Parrot. The Philippine Cockatoo was not recorded at all, but this is be- cause the altitude of study area was too high, given that the Philippine Cockatoo appears to be restricted to lowland pri- mary and secondary forest predominantly below 50 m, in or adjacent to riverine or coastal areas with mangroves. (continued on page 30)

Blue - headed Racquet - tail Parrot

Picture by Peter Widmann KFI; 2 Adapted from Que et al., 2020

AFA Watchbird 29

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