Clearing Width and Movements of Understory Rainforest Birds1

We assessed the capacity of three species of disturbance‐sensitive understory birds to traverse a highway (50–75 m width) and large farm clearing (250 m width), by radio‐tracking translocated individuals in central Amazonia, Brazil. Most individuals translocated across the highway (eight of nine birds) or moved within continuous forest (five of seven birds) returned to their home ranges, whereas none of five birds moved across the large clearing returned. Our results suggest that large clearings (>250 m width) can significantly reduce the movements of some understory rainforest birds.     

BREEDING OF THE INDIAN WHITEBACKED VULTURE AT JODHPUR

Vulture populations have declined globally as well as regionally within Africa. Little is known about the status of the African White-backed Vulture Gyps africanus in Kenya, but ongoing studies indicate that its population has declined over the last two decades. A total of 32 African White-backed Vulture nests were monitored in the Masai Mara National Reserve over a five-year period between 2003 and 2007. Mean nesting success was 59%, which is comparable to that of populations from southern Africa. Nearest neighbour distances were significantly closer in wooded habitats (‘trees and shrubs savanna’) than in more open grassland habitats (‘open low shrubs’). Based on nearest neighbour distances, the estimated total breeding population within the Masai Mara National Reserve is 1 106 pairs, a figure that may be an overestimate and requires ground-truthing. Collecting baseline data on numbers of breeding pairs and regular nest monitoring are essential in order to assess the impact of various threats to vultures in Kenya, which include growing threats (elephant-mediated habitat disturbance and fire) as well as emerging threats (such as poisoning with the carbamate-based pesticide Furadan?).     

西双版纳热带雨林片断小气候边缘效应的初步研究

本文以林缘为中心,研究了西双版纳地区３个热带干性季节性雨林片断和１个同样植被类型的连续森林林内至林外样带上小气候要素水平梯度分布。结果表明,热带雨林片断林缘对温度、相对湿度和光照的影响范围北向林缘伸至林内１５ｍ、南向林缘伸至林内２５ｍ。林外小气候水平梯度大于林内,这种梯度变异尤以林缘附近（－１０～１０ｍ范围）最大。热带雨林片断后,林内与林外之间的小气候环境差异和对林外气候变化的缓冲作用都明显减弱。本文还给出了温度和湿度随水平距离变化的线性关系,并探讨了小气候边缘效应对群落结构、物种分布的影响。     

Birth Patterns in Wild and Captive Lion-Tailed Macaques (Macaca silenus)

During a 5-yr study of lion-tailed macaques in their natural habitat, we found that: 1) most births occurred from January to April (70%) and from September to December (19%), showing a bimodal pattern with a major and a minor birth peak; 2) the period of peaks remained the same over 5 yr; and 3) a similar pattern of birth peaks occurred both in groups in large forest complexes that had overlapping home ranges with other groups and in single groups that were isolated in forest fragments in the same region but with similar ecological conditions. The results suggest more of a birth seasonality than mere breeding synchronization in the wild lion-tailed macaques. We also analyzed data on births in captivity in European Zoos for 10 yr. We observed no seasonality or peaks in births, and the pattern was the same over the years. Data on rainfall suggest that resource availability in the wild habitat may not be uniform throughout the year; hence, ecological factors may play an important role in determination of birth patterns in the natural habitats of lion-tailed macaques.     

Is the keystone role of figs maintained across a gradient of increasing human disturbance?

Fig trees provide important resources to tropical animals, but is their keystone role affected by human disturbance? In Sri Lanka, we found that more bird species were found in close association with fruiting figs in urban areas, suggesting their role is accentuated there, and justifying their planting.     

破碎化次生林斑块面积及栖息地质量对繁殖鸟类群落结构的影响

于1998～2000年夏季。运用GPS定位系统确定了12块面积范围为6．5～112．8hm。的彼此隔离的森林斑块。比较了斑块面积和栖息地质量对繁殖鸟类群落结构的影响。结果表明：不同面积斑块中繁殖鸟类的群落结构有所差异。各斑块所容纳的繁殖鸟类的物种数从4种到26种不等。鸟类物种数随着斑块面积的增大而增多。不同鸟类对斑块面积的反应并不相同,耐边缘种偏爱面积较小的斑块。而非边缘种偏爱在大面积的斑块中繁殖。斑块栖息地质量也是影响鸟类群落结构的重要因素,质量好的斑块包容的鸟类物种较多。鸟类物种丰富度与斑块质量的相关性(R2=0．67)小于与斑块面积的相关性(R2=0．88)。各斑块中的鸟类群落结构在不同年份间比较相似。栖息地破碎化不但缩小了栖息地面积。同时也不同程度地降低了栖息地的质量。从而消极地影响着鸟类群落结构的稳定性和鸟类的物种多样性。     

Impact of flowering on bird community dynamics in some central Victorian eucalypt forests

Many species of Eucalyptus in Australia provide copious amounts of nectar during their reproductive seasons. The nectar is used by many animal species but especially by birds, insects and some bats, which act as pollinators. One of the major features of eucalypt flowering in southern Australia is the patchy, asynchronous flowering of different species, which appears to drive mass nomadism of nectarivorous birds among regions and among habitats. Here we explore whether flowering asynchrony or climate is primarily responsible for the influxes and effluxes of vast numbers of nectarivorous birds in central Victoria, Australia. By using a structured sampling program, we show that winter flowering by red ironbark Eucalyptus tricarpa is the most likely agent controlling avian-nectarivore dynamics rather than climatic differences among regions. Densities and species richness of nectarivores, and numbers of nectarivory events, are all closely related to measures of flowering intensity. However, nonnectarivores, such as insectivores and granivores, show no relationships with either habitat or region. We discuss how dependence on a patchily distributed but highly rewarding resource such as nectar influences population densities and community structure in birds.     

西双版纳勐养旱季季风常绿阔叶林的林下鸟类群落组成和特点

2008年10月—2009年3月,用网捕法对西双版纳勐养季风常绿阔叶林林下鸟类群落进行了研究。共张网15 840网·h,捕到林下鸟类90种1 423只,隶属28科7目。优势种为银胸丝冠鸟(Serilophus lunatus)、褐脸雀鹛(Alcippe poioicephala)、白喉冠鹎(Alophoixus pallidus)、金眶鹟莺(Seicercus burkii)、白尾蓝地鸲(Cinclidium leucurum)、黑胸鸫(Turdus dissimilis)、棕头幽鹛(Pellorneum ruficeps)、棕胸雅鹛(Trichastoma tickelli)等8种。留鸟为林下鸟类主要成分,其捕获数量,占总数量的89.3%。平均网捕率9.0只/(100网·h),月份变化极显著(x²_{5, 282}=, P=0.000);2008年12月平均网捕率最高,为（12.5±1.3）只/(100网·h);2009年2月最低,为（5.2±0.6）只/(100网·h)。林下鸟类群落呈现多物种而低密度特征。画眉科鸟类优势地位不明显。国家二级保护鸟类银胸丝冠鸟是本地区捕获数量最多的鸟,其栖息地需重点保护。     

A comparison of bird communities of two fragmented and two continuous southeast Asian rainforests

A large proportion of forest-dependent bird species have disappearedfrom Singapore, probably due to heavy forest loss that started in the 1800s. Thebird fauna seems to have relaxed (attained a lower and relatively stablediversity following habitat destruction) in Singapore. Using mist-netting, Icompared understory bird communities of two lowland rainforest fragments inSingapore (Nee Soon and MacRitchie) with two continuous forests in Sarawak(Malaysia) (Matang Wildlife Sanctuary and Gunung Gading National Park). Icompared community characteristics (e.g. rarity [<2 individuals/1000mist-netting hours]), population characteristics (e.g. sex ratio) and individualquality (e.g. prevalence of ectoparasites) among avifaunas of the forests. Onaverage, more bird species and individuals were caught in continuous foreststhan in fragments. There were more rare species in Gading. The proportion ofadults and the sex ratios did not differ among the forests. Ectoparasiteprevalence and intensity also did not differ among the forests. Proportionallymore individuals contained fault bars in MacRitchie. My study shows that aviancommunities in rainforest fragments are depauperate but show few signs ofenvironmental stress. Thus there may be long-term resilience in some forest birdspecies. However, it is essential to protect large tracts of tropical lowlandrainforest to preserve rare forest-dependent avifauna.     

Altitudinal and latitudinal distribution of east Malagasy forest bird communities

Aim To describe variation in forest bird communities with altitude and latitude. Location Eastern Madagascar. Methods Extraction of data from forest bird inventories conducted in eastern Madagascar. Results There is a strong decline in species richness with altitude, above about 1300 m. Below this altitude, species richness is about constant or declines slightly. Seventy-eight percent of species occurring regularly in forest are absent from at least one of low, mid-altitude or high altitude forest. Of eighty-seven species occurring regularly in forest, only four or possibly five have latitudinally limited distributions, over a latitudinal range of over 1200 km. Three or possibly four are limited to the northern two-thirds, and one appears to be at least much more common in the southern half. Main conclusions Eastern Malagasy rain forest birds show previously unanalysed variation in altitudinal distribution. There is much less latitudinal variation. Species currently considered threatened are concentrated in the lowland and high-altitude zones. This may be at least partly due to lack of survey effort giving the impression that these species are rare, but lowland forests at least are under great human pressure. Bird conservation initiatives would probably have most effect if targeted at lowland east Malagasy rain forest.     

Bird diversity and abundance in forest fragments and Eucalyptus plantations around an Atlantic forest reserve, Brazil

Little of Brazil's remaining Atlantic forest is protected, so it is important to assess how well the region's wildlife can persist in areas/habitats outside reserves. We studied bird diversity and abundance during 546 point counts in the Sooretama/Linhares reserve, 200 point counts in 31 forest fragments (10–150 h), and 50 point counts in <30-year-old Eucalyptus plantations, within 7 km of the reserve. Only eight bird species were recorded in Eucalyptus, and this impoverishment, as compared to some Eucalyptus plantations elsewhere in Brazil may be a result of intensive clearance of understory vegetation. Species diversity in forest fragments was significantly lower than in the reserve. Twelve, mostly non-forest or edge species, were significantly commoner in the fragments, but nineteen species were frequent in the reserve but rare or absent in forest fragments. These included two Pyrrhura parakeets, a Brotogeris parakeet, a trogon Trogon, a jacamar Galbula, woodpeckers Piculus and Campephilus, Myrmotherula antwrens, and Hemithraupus and Tachyphonus tanagers. Bird species richness at points in forest fragments did not decline with fragment size, distance from the reserve, or forest quality. However, forest in fragments was more heavily degraded than forest within the reserve and poor forest quality may be the cause of declines in some species. Whilst protection of forest within reserves is a priority, management of forest fragments may aid conservation of some threatened species.     

Specificity for a CCR5 Inhibitor Is Conferred by a Single Amino Acid Residue: ROLE OF ILE198

The chemokine receptors CCR5 and CCR2b share 89% amino acid homology. CCR5 is a co-receptor for HIV and CCR5 antagonists have been investigated as inhibitors of HIV infection. We describe the use of two CCR5 antagonists, Schering-C (SCH-C), which is specific for CCR5, and TAK-779, a dual inhibitor of CCR5 and CCR2b, to probe the CCR5 inhibitor binding site using CCR5/CCR2b chimeric receptors. Compound inhibition in the different chimeras was assessed by inhibition of chemokine-induced calcium flux. SCH-C inhibited RANTES (regulated on activation, normal T cell expressed and secreted) (CCL5)-mediated calcium flux on CCR5 with an IC₅₀ of 22.8 nm but was inactive against monocyte chemoattractant protein-1 (CCL2)-mediated calcium flux on CCR2b. However, SCH-C inhibited CCL2-induced calcium flux against a CCR5/CCR2b chimera consisting of transmembrane domains IV–VI of CCR5 with an IC₅₀ of 55 nm. A sequence comparison of CCR5 and CCR2b identified a divergent amino acid sequence located at the junction of transmembrane domain V and second extracellular loop. Transfer of the CCR5 sequence KNFQTLKIV into CCR2b conferred SCH-C inhibition (IC₅₀ of 122 nm) into the predominantly CCR2b chimera. Furthermore, a single substitution, R206I, conferred partial but significant inhibition (IC₅₀ of 1023 nm) by SCH-C. These results show that a limited amino acid sequence is responsible for SCH-C specificity to CCR5, and we propose a model showing the interaction with CCR5 Ile¹⁹⁸.     

Potential Effects of Ateline Extinction and Forest Fragmentation on Plant Diversity and Composition in the Western Orinoco Basin,Colombia

Cattle and agricultural farming in the western Orinoco Basin began in 1555, and since then fragmentation of continuous forest has occurred. We evaluated the effects of the disturbances and the absence of large primates on plant community composition, diversity, and regeneration patterns. Atelines (Lagothrix and Ateles) inhabited the lowlands close to the Andean mountains, but no longer live in fragmented habitats. Their absence may have negative effects on plant populations because atelines play important roles as seed dispersers in neotropical forests, especially for large-seeded plants, which are rarely swallowed by other seed dispersers. We compared 2 1-ha vegetation plots in forest fragments north of the La Macarena Mountains with 7 plots in continuous forest in Tinigua National Park. Both sites share the same climatic conditions and have similar geological origins. There is floristic affinity between forests with similar ecological characteristics; the fragmented forests are also less diverse than the continuous forests. As predicted, the forest fragments have fewer individuals with large seeds. The results suggest that forest fragmentation and local ateline extinctions affect plant communities, reducing diversity and affecting large-seeded plants.