Niche separation in flycatcher-like species in the lowland rainforests of Malaysia

Nor S, Mansor MS. Distribution of Six Urban Bird Species in Urban Agglomeration of Central Region of Peninsular Malaysia Using Ebird Database

Developing countries are undergoing rapid urbanisation to fulfil the high demands of incremental population growth, construction, and development. Excessive development has negative impacts on biodiversity by altering or destroying habitats. However, each bird species may respond differently to habitat alteration. Therefore, this study was conducted to determine the distribution of urban bird species in metropolitan cities and nearby areas in Peninsular Malaysia. The main objective of this study was to determine the distribution patterns of six aesthetically valuable urban bird species (Black-naped Oriole [Oriolus chinensis], Yellow-vented Bulbul [Pycnonotus goiavier], White-throated Kingfisher [Halcyon smyrnensis], Pink-necked Green-Pigeon [Treron vernans], Coppersmith Barbet [Psilopogon haemacephalus] and Common Iora [Aegithina tiphia]) in Greater Kuala Lumpur (the Klang Valley region) using observations from a citizen science (eBird) database. We mapped species abundance throughout the focal area using ArcGIS and analysed the data using Minitab. Three urban bird species dominated, with the highest number of observations recorded: Yellow-vented Bulbul (46.59%), Pink-necked Green-Pigeon (19.25%), and Black-naped Oriole (13.00%). While, the Coppersmith Barbet had the lowest recorded observations (2.76%). Species abundance differed significantly across the study region (F=5.12,p<0.05), with the studied species’ occurrence increasing as green spaces increased. Such dynamic mapping is crucial for better understanding the mechanisms of the persistence of urban biodiversity. We suggest creating more green areas and planting roadside trees to provide green corridors within cities to help sustain urban biodiversity.

Nor S. The Breeding Ecology of the Painted Stork Mycteria leucocephala in Central Peninsular Malaysia

The Painted Stork (Mycteria leucocephala) populations in Putrajaya and Shah Alam, Peninsular Malaysia, have increased by almost 10%–13% every year. If this trend continues, it is believed that habitat overlap may occur between this species and the Milky Stork (Mycteria cinerea), which is currently threatened with extinction. Habitat overlap could lead them to compete for food and other necessary resources, and consequently, one species would outcompete another. However, little is known about the breeding ecology of the Painted Stork in Peninsular Malaysia. Therefore, this study aimed to evaluate the breeding ecology of the Painted Stork and examine its nesting characteristics and their effects on breeding success. Direct observations were made of colonies in the Upper Bisa Putrajaya Wetland (UBPW) and Tasik Shah Alam (TSA) during the breeding season from March to September 2016 and 2017. The peak of the breeding season was in June, and no differences were found in nesting colony parameters between study sites, including the nest diameter and nest building period, except for nest height. The average height above the ground level of TSA nests was higher than in UBPW. Human activities near the nesting site in Shah Alam may have led to the birds constructing nests higher to prevent disturbance and predation. Nest diameter and nest building period were influenced by the number of nestlings raised by parents. These findings provide new information that may be used in management programs to control Painted Stork populations and can be useful for conserving threatened species, particularly the Milky Stork.

Shifts in foraging behaviour of heterospecific flocking birds in a lowland Malaysian rainforest

Mixed-species flocks (MSFs) serve important roles in bird communities, especially in tropical forests. Although structure of mixed-species bird flocks and its benefits has been intensively studied globally, the foraging plasticity of a species when joining MSFs has rarely been evaluated. The present study examines foraging strategies of the Rufous-crowned Babbler (Malacopteron magnum), Chestnut-winged Babbler (Cyanoderma erythropterum) and Black-naped Monarch (Hypothymis azurea) when participating in MSFs in the Krau Wildlife Reserve, central Peninsular Malaysia. These species exhibit active foraging shifts in utilisation of vertical strata, foraging substrate, attack manoeuvres and foliage density, when foraging in MSFs, compared to when foraging outside MSFs. While the Rufous-crowned Babbler and Chestnut-winged Babbler commonly used gleaning and stretching (to completely extend the legs or neck to reach the food items) manoeuvres when foraging outside MSFs, respectively, they adopted probing manoeuvre and frequently used higher strata upon joining MSFs. The Chestnut-winged Babbler tended to forage on the underside of leaves and the Black-naped Monarch frequently utilised branches when joining MSFs, while they exclusively used aerial leaf litter and live green leaves, respectively, when foraging with conspecifics. The monarch also adopted the hovering manoeuvre and frequently foraged within denser foliage cover when joining MSFs. This study demonstrated that flock members exhibits foraging plasticity either through an expansion or active shift in foraging niches when participating in MSFs, thus suggesting the occurrence of possible foraging improvement and/or reductions in predation risk.

Niche shift in three foraging insectivorous birds in lowland Malaysian forest patches

With the rapid growth of agricultural areas globally, forest birds increasingly encounter fragmented landscapes in which forest patches are surrounded by an agricultural plantation matrix, yet how birds respond behaviourally to this fragmentation is poorly understood. Information on microhabitat requirements of birds is scarce, but nevertheless essential to predicting adaptation of bird species to the patchy landscapes. We investigated foraging patterns of three tropical insectivorous birds, Green Iora Aegithina viridissima, Pin-striped Tit-Babbler Macronus gularis and Chestnut-winged Babbler Cyanoderma erythropterum, to determine whether they vary in foraging methods in different forest patches. Our study area encompassed old-logged lowland forest; one continuous forest and three forest patches. Observations were performed for 15 days every month for a period of 13 months. Information on foraging height, substrate, attack manoeuvres, and foliage density was collected independently for each foraging bird individual. All three species used different foraging substrates and attack manoeuvres in different habitat types. The Green Iora frequently used lower strata when foraging in forest patches as opposed to continuous forest, while the Pin-striped Tit-Babbler tended to forage in more dense vegetation in patches. Only Chestnut-winged Babbler displayed complete foraging plasticity across all study parameters. Different habitat features (e.g., edges, microclimates) between continuous forest and forest patches significantly influenced the foraging strategies of the study species. These changes in foraging strategies suggest that some Malaysian forest birds (e.g. generalist species) can respond behaviourally to fragmentation and habitat loss. Although continuous forest has critically important characteristics that need to be conserved, remnant forest patches are also important as ecological movement corridors and foraging grounds for birds.