Conservation of Asian Raptors in the Changing Environment: Continued Need for Local, Regional, and Global Collaborative Strategies

Abstract

Asia, as the largest continent, comprises a wide range of biomes that host more than 230 species of diurnal and nocturnal raptors, with especially high biodiversity toward the equator. In addition, Asia holds numerous endemic and rare species specialized for particular habitats; unfortunately, many of these are threatened and/or understudied. About one quarter of Asia’s raptors are migratory, and migrating raptors provide a significant attraction for tourists and birdwatchers, which contributes to local income generation, and education and research at migratory hotspots and overwintering sites. Such vast migratory movements have been documented at prominent count sites such as Chumphon in Thailand, Tanjung Tuan in Malaysia, and Kenting in Taiwan, thanks to the efforts of many volunteers. Asian raptors serve key ecosystem functions and services, owing to their diverse trophic levels and ecological niches. For example, the Barn Owl (Tyto alba) serves as a biological control agent in many agricultural areas in Southeast Asia. Scavenging vultures in South, Central, and East Asia remove carcasses while simultaneously preventing the spread of diseases. This implies that the absence or changes in raptor populations could potentially lead to adverse cascading effects such as competitive exclusion, intraguild predation, and extirpation or extinction. In Southeast Asia, many raptor habitats are threatened by anthropogenic activities linked to drastic land development and exploitation of natural resources to support the growth of human populations. In addition to habitat loss and degradation, raptors of Asia also face multiple threats ranging from collisions with wind power generation facilities or vehicles, to electrocutions, to secondary poisoning through agrochemicals. Despite the presence of some laws and regulations, poaching and illegal trade for consumption and pet businesses that involve raptors remain problematic in Asia. Some more recent threats also should not be overlooked. Falconry activity in Southeast Asia seems to be a new trend that has been promoted via social media, although tracing the sources of supply and demand of such activities is difficult. Some of the more localized issues posing threats to raptors include feeding of unnatural food to coastal raptors as part of tourism attractions, intentional and accidental trapping of birds by farmers and fishermen, and limestone quarrying. Thanks to the efforts of many local raptor researchers and volunteers, there have been increasing numbers of ecological studies on Asian raptors over the last two decades, which is encouraging for raptor conservation. However, there is still a dearth of studies on many forest-dependent species, island endemics, and habitat specialists with small geographic ranges and/or long generation times. Many of these species are extinction-prone, found in habitats that are difficult to access, elusive, and scarcely distributed. Given the long-term effects of global climate change and rising sea level, there is an urgent need for longterm and/or more in-depth studies to fill knowledge