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Arnhem, Netherlands

Van Balen S.B.,Basilornis Consults | Eaton J.A.,17 Keats Avenue | Rheindt F.E.,Harvard University
Bird Conservation International | Year: 2013

Summary The Short-tailed Green Magpie Cissa thalassina, a member of an Asian lineage of uniquely coloured corvids, is represented by two subspecies, thalassina and jefferyi, that occur on the islands of Java and Borneo, respectively. The distinct Javan nominate form is poorly described in the literature and next to nothing is published on its biology and occurrence in the wild. We here document the biology and distribution of this taxon based on hitherto unpublished historical data and on our own fieldwork. We also analyse vocal data of jefferyi, thalassina and two other Cissa species and show that jefferyi and thalassina are well-differentiated, and that thalassina is bioacoustically more similar to another Cissa species from the Asian mainland. We also demonstrate important and significant biometric differences between jefferyi and thalassina that may reflect divergent adaptations to the environment, as well as plumage differences that may serve signalling functions. Finally, the application of a novel species delimitation test to our data suggests that jefferyi and thalassina deserve to be classified as biological species because their phenotypic divergence exceeds that found in many sympatric species. The revised taxonomic status of Javan thalassina invites a reconsideration of its threat status. Based on its restricted range, extreme rarity and threats by bird trapping and habitat destruction, we consider the Javan Green Magpie as globally Critically Endangered. Copyright © BirdLife International 2011. Source


Beaudrot L.,University of California at Davis | Struebig M.J.,University of Kent | Struebig M.J.,Queen Mary, University of London | Meijaard E.,People and Nature Consulting International | And 4 more authors.
Oecologia | Year: 2013

Assessing the importance of deterministic processes in structuring ecological communities is a central focus of community ecology. Typically, community ecologists study a single taxonomic group, which precludes detection of potentially important biotic interactions between distantly related species, and inherently assumes competition is strongest between closely related species. We examined distribution patterns of vertebrate species across the island of Borneo in Southeast Asia to assess the extent to which inter-specific competition may have shaped ecological communities on the island and whether the intensity of inter-specific competition in present-day communities varies as a function of evolutionary relatedness. We investigated the relative extent of competition within and between species of primates, birds, bats and squirrels using species presence-absence and attribute data compiled for 21 forested sites across Borneo. We calculated for each species pair the checkerboard unit value (CU), a statistic that is often interpreted as indicating the importance of interspecific competition. The percentage of species pairs with significant CUs was lowest in within-taxon comparisons. Moreover, for invertebrate-eating species the percentage of significantly checkerboarded species pairs was highest in comparisons between primates and other taxa, particularly birds and squirrels. Our results are consistent with the interpretation that competitive interactions between distantly related species may have shaped the distribution of species and thus the composition of Bornean vertebrate communities. This research highlights the importance of taking into account the broad mammalian and avian communities in which species occur for understanding the factors that structure biodiversity. © 2013 Springer-Verlag Berlin Heidelberg. Source


Beaudrot L.,University of California at Davis | Struebig M.J.,University of Kent | Struebig M.J.,Queen Mary, University of London | Meijaard E.,People and Nature Consulting International | And 5 more authors.
American Journal of Primatology | Year: 2013

For several decades, primatologists have been interested in understanding how sympatric primate species are able to coexist. Most of our understanding of primate community ecology derives from the assumption that these animals interact predominantly with other primates. In this study, we investigate to what extent multiple community assembly hypotheses consistent with this assumption are supported when tested with communities of primates in isolation versus with communities of primates, birds, bats, and squirrels together. We focus on vertebrate communities on the island of Borneo, where we examine the determinants of presence or absence of species, and how these communities are structured. We test for checkerboard distributions, guild proportionality, and Fox's assembly rule for favored states, and predict that statistical signals reflecting interactions between ecologically similar species will be stronger when nonprimate taxa are included in analyses. We found strong support for checkerboard distributions in several communities, particularly when taxonomic groups were combined, and after controlling for habitat effects. We found evidence of guild proportionality in some communities, but did not find significant support for Fox's assembly rule in any of the communities examined. These results demonstrate the presence of vertebrate community structure that is ecologically determined rather than randomly generated, which is a finding consistent with the interpretation that interactions within and between these taxonomic groups may have shaped species composition in these communities. This research highlights the importance of considering the broader vertebrate communities with which primates co-occur, and so we urge primatologists to explicitly consider nonprimate taxa in the study of primate ecology. © 2012 Wiley Periodicals, Inc. Source


Collar N.J.,BirdLife International | Van Balen S.,Basilornis Consults
Forktail | Year: 2013

The Rufous-fronted Laughingthrush Garrulax rufifrons, endemic to Java, has been recorded from a total of 15 montane sites, 14 in West Java (nominotypical rufifrons) and one in Central Java (subspecies slamatensis). It occupies montane forest generally in the range 1,000-2,000 m, although this may vary with site, and occurs in monospecific parties of birds but also in bird waves, and has or had an association with Javan Green Magpie Cissa thalassina. Breeding appears to be extended through the year, but lack of records in January-February and July-August may reflect real breaks in the cycle. A lack of recent records from bird markets and a recent hike in prices of captive birds supports other concerns that the Javan bird trade may have affected the species, which in the past 20 years appears only to have been observed at Gunung Gede-Pangrango. Surveys of known sites and of several montane forest reserves are needed before a heavy investment in captive breeding is made. Source


Susanto H.,Balai Taman Nasional Karimunjawa | Taufiqurrahman I.,Yayasan Kutilang Indonesia | Van Balen S.B.,Basilornis Consults
Stilt | Year: 2014

Wader surveys were carried out between December 2007 and December 2013 covering eight areas in Karimunjawa National Park, Central Java, Indonesia. As a result, 23 wader species were recorded, with 10 new records for the park. Terusan on Kemujan Island is an intertidal area of approximately 10 hectares and had the highest number of species recorded. In Terusan, there were 17 species recorded with nine species not recorded elsewhere on the park. Oriental Pratincole (Glareola maldivarum), Whimbrel (Numenius phaeopus), Grey-tailed Tattler (Heteroscelus brevipes) and Common Sandpiper (Actitis hypoleucos) were the most common and widespread waders in Karimunjawa National Park. A compilation of all wader species listed for Karimunjawa NP, including historical records, is presented. © 2014, Stilt. All rights reserved. Source

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