Frequent detection of anticoagulant rodenticides in raptors sampled in Taiwan reflects government rodent control policy.

Anticoagulant rodenticides (ARs) are known to cause extensive secondary exposure in top predators in Europe and North America, but there remains a paucity of data in Asia. In this study, we collected 221 liver samples from 21 raptor species in Taiwan between 2010 and 2018. Most birds were recovered from rescue organizations, but some free-ranging individuals were obtained from bird-strike prevention measures at airports. ARs were detected in 10 species and more than half of the total samples. Common rodent-eating Black-winged Kites (Elanus caeruleus) had the highest prevalence (89.2%) and highest average sum concentration (0.211 ±â€¯0.219 mg/kg), which was similar between free-ranging birds at airports and injured birds from rescue organizations. Scavenging Black Kites (Milvus migrans) and snake-eating Crested Serpent-eagles (Spilornis cheela) had the second highest prevalence or sum concentration, respectively. Seven different AR compounds were detected, of which brodifacoum was the most common and had the highest average concentration, followed by flocoumafen and bromadiolone. The frequency of occurrence in the three most numerous species (Black-winged Kite, Crested Goshawk [Accipiter trivirgatus], and Collared Scops-owl [Otus lettia]) was significantly higher in autumn than summer, which is consistent with the timing of the Taiwanese government's supply of free ARs to farmers. Regional differences in the detection of individual compounds also tended to reflect differences in human population density and use patterns (in agriculture or urban-dominated environments). Clinical poisoning was confirmed in Black Kites with sum concentrations as low as 0.026 mg/kg; however, further study of interspecific differences in AR sensitivity and potential population effects are needed. In addition, continued monitoring remains important given the Taiwanese government has modified their farmland rodent control policy to gradually reduce free AR supplies since 2015.

The Effects of Rainfall, Temperature, and Wind on a Community of Montane Birds in Shei-Pa National Park, Taiwan.

Bruno A. Walther, Jane Ren-Jen Chen, Hui-Shan Lin, and Yuan-Hsun Sun (2017) Montane birds are regularly exposed to extreme weather variations. Taiwan's subtropical montane avifauna (which contains many endemic species) is regularly exposed to large weather fluctuations. From 2010 to 2013, we conducted monthly censuses to study the influence of monthly weather variations on species richness and bird density of a montane bird community (> 3000 m a. s. l.) in Shei-Pa National Park. Censuses were conducted along a trail which traverses four distinct habitats with increasing altitude: bush forest ecotone, post- re grassland, conifer forest, and rocky bushland. The highly variable weather corresponded with large fluctuations in the bird community. We found that lower temperatures had a negative effect on species richness and bird density, and this effect was strongest in the highest elevation habitat, the rocky bushland. Rainfall was positively correlated with bird density, but only explained 15% of the variation, while the effects of wind speed were inconsistent and small. This is the first study to demonstrate such weather effects in Taiwan and probably East Asia. We brie y discuss adaptations to harsh weather conditions in birds which could become a promising future research field for montane birds in Taiwan.