Road induced edge effects on a forest bird community in tropical Asia

Background: Edge effects cause changes in bird community richness, abundance, and/or distribution within a landscape, but the avian guilds most influenced can vary among regions. Although Southeast Asia has the highest rates of deforestation and projected species loss, and is currently undergoing an explosive growth in road infrastructure, there have been few studies of the effects of forest edges on avian communities in this region.Methods: We examined avian community structure in a dry evergreen forest in northeastern Thailand adjacent to a five-lane highway. We evaluated the richness and abundance of birds in 11 guilds at 24 survey points on three parallel transects perpendicular to the edge. At each point, 10-min surveys were conducted during February-August 2014 and March-August 2015. Vegetation measurements were conducted at 16 of the bird survey points and ambient noise was measured at all 24 survey points.Results: We found a strongly negative response to the forest edge for bark-gleaning, sallying, terrestrial, and understory insectivores and a weakly negative response for arboreal frugivore-insectivores, foliage gleaning insectivores, and raptors. Densities of trees and the percentage canopy cover were higher in the interior, and the ambient noise was lower. In contrast, arboreal nectarivore-insectivores responded positively to the forest edge, where there was a higher vegetation cover in the ground layer, a lower tree density, and a higher level of ambient noise.Conclusion: Planners should avoid road development in forests of high conservation value to reduce impacts on biodiversity. Where avoidance is impossible, a number of potential mitigation methods are available, but more detailed assessments of these are needed before they are applied in this region.

Roost selection of the endangered Spotted Greenshank(Tringa guttifer) in critical habitat in the Inner Gulf of Thailand

Background: Roost-site quality can significantly affect the individual fitness of shorebirds, but roost sites remain poorly described for many threatened species on the East Asian–Australasian Flyway. We studied roost-site selection of the globally endangered Spotted Greenshank (Tringa guttifer) in the Inner Gulf of Thailand, an area which supports approximately 24% of their global wintering population, during two non-breeding seasons (October 2014–May 2015 and December 2015–February 2016). Methods: We measured nine variables associated with roost site characteristics including water depth, indicators of disturbance/predation risk, and associations with other shorebird species. We predicted that roost ponds with shallow water in proximity to foraging sites would receive higher usage than those further away. Results: A total of 94 sites were measured of which 46 were used for roosts with 23 used repeatedly. All used sites were human-modified ponds, of which 44 were used for salt farming and two used for aquaculture. Roosts were on average 1.10 ± 0.78 (SE) km from foraging sites and 5.8 ± 2.4 cm deep. The most supported model indicated that roost sites were negatively associated with distance to foraging sites and positively associated with the presence of Grey Plover (Pluvialis squatarola) and water depth. Conclusions: Traditional saltpans and other artificial wetlands near (< 1 km) mudflats serve as the primary high-tide roost habitat in the Inner Gulf of Thailand for this Spotted Greenshank population and perhaps seven other globally threatened or near-threatened species. Critically, all observed roost sites are on private land with no formal protection and thus will require creative public–private partnerships to manage sustainably.

Spatial distribution of display sites of Grey Peacock-pheasant in relation to micro-habitat and predators during the breeding season

Background: The destruction and fragmentation of forest in Southeast Asia is accelerating biodiversity loss, resulting in a range of management and conservation actions. For some species, a detailed understanding of microhabitat selection is critical for this, especially in the breeding season.Methods: To understand the factors that explain how specific habitats are used by the Grey Peacock-pheasant(Polyplectron bicalcaratum) in the breeding season, we used camera trapping and microhabitat sampling to assess the microhabitat selection of males. We also looked at their interaction with predators in an area of 1200 m May 2013.× 1200 m at the Huai Kha Khaeng Wildlife Sanctuary, Thailand, between January andResults: We show that display scrapes are situated on flatter open areas with small saplings and some vines, typified by low horizontal understory density. We hypothesise that this allows a trade-off between courtship display and the avoidance of predators. Our study showed that the position of Grey Peacock-pheasant display scrapes regularly overlapped with predators within the same microhabitat. We hypothesise that the species' behavioural responses to temporal variation in predation risk allows them to avoid most predators.Conclusions: Particular microhabitats are required for Grey Peacock-pheasant display. They avoid predators at these places by being active when predators are not.