Isolation and characterization of microsatellite markers from the great hornbill, Buceros bicornis

Thirteen polymorphic microsatellite markers were isolated and characterized from the great hornbill, Buceros bicornis. In analyses of 20 individuals, the numbers of alleles per locus varied from two to 11. The expected and observed heterozygosities ranged from 0.22 to 0.88 and from 0.20 to 1.00, respectively. The mean polymorphic information content was 0.62. Among these, three loci deviated from the Hardy-Weinberg equilibrium. However, no significant genotypic disequilibrium was detected between any pair of loci. These microsatellite markers are useful for the population genetic study of the great hornbill.     

Diet of the Silvery-cheeked Hornbill Bycanistes brevis during the breeding season in the East Usambara Mountains,Tanzania

The breeding season diet and nesting characteristics of the Silvery-cheeked Hornbill Bycanistes brevis are poorly known. To further understand these aspects of the breeding biology of this hornbill species, 14 nests were studied in and around Amani Nature Reserve located in the East Usambara Mountains, Tanzania. Nesting tree species were identified and the diet composition of nesting hornbills was evaluated between July and November 2001. The ejecta from each nest were collected, inventoried, identified (as completely as possible) and enumerated. Food items were categorised as plant, vertebrate or invertebrate. Plants, represented largely by fruits, were the dominant food type (n = 861), followed by invertebrates (n = 306; mainly millipedes and beetles), and vertebrates (n = 15; mainly smaller birds and chameleons). A comparison of results from the current study to other nesting observations made approximately seven decades earlier in the same area suggest that (1) the invasive tree species Maesopsis eminii, which was the most common food type consumed (n = 4 539 seeds), has become a favoured new food source in the breeding season, and (2) the breeding season appears to have shifted to an earlier period, potentially due to the fruiting phenology and abundance of Maesopsis eminii.     

广西冠斑犀鸟的种群数量及分布状况

冠斑犀鸟(Anthracoceros albirostris albirostris)属于国家Ⅱ级重点保护野生动物,并且是亚洲热带地区重要的种子传播者.冠斑犀鸟在20世纪70年代以前曾广布广西西南部中越边境地区,但其分布范围持续萎缩,2000年以后只残存于3个孤立的分布点,而西大明山林区一直是冠斑犀鸟的主要分布点.为了解此物种在广西的最新分布状况,我们于2009年在广西西大明山自然保护区首次进行了冠斑犀鸟的同步调查,同时调查了当地犀鸟可利用的植物资源.结果显示至少有50只冠斑犀鸟在当地栖息,是广西目前最大的种群,但数量明显呈下降趋势.本文记录了124种犀鸟可潜在利用的植物,探讨了广西犀鸟面临的威胁,并呼吁国家有关部门和科学界加强对中国犀鸟保育研究的关注.     

笼养冠斑犀鸟繁殖生态的初步观察

2002~2004年通过对笼养冠斑犀鸟的繁殖生态进行观察,结果表明:冠斑犀鸟的发情期为3月中旬至4月初,求偶的追求者为雌鸟,雌鸟占据选巢营巢主导地位,从入巢到破巢的整个营巢期雌鸟始终把自己封闭在巢洞内,雄鸟担负了运送巢料和食物的所有任务直到雌鸟出巢,出巢后幼鸟在未具有觅食能力前,绝大部分的哺育任务仍由雄鸟承担。冠斑犀鸟的繁殖封巢期为89.0±12.99天,首次营巢的时间较长达15天左右,从第二年起营巢时间缩短为3天,孵化期为25.25±3.86天,育雏期为45.75±2.87天,繁殖成功率为100%。繁殖期除了人工投料外,冠斑犀鸟仍可从生态园中获得多种食物,以满足幼鸟的生长需要。     

Captive breeding and reintroduction of the oriental pied hornbill (Anthracoceros albirostris) in Khao Kheow Open Zoo,Thailand

This article discusses two related issues of the captive breeding and reintroduction of the Oriental pied hornbill (Anthracoceros albirostris) in order to increase its population in the natural habitats. Oriental pied hornbills were bred in Khao Kheow Open Zoo. Three pairs were separated and kept in breeding cages. Females occupied artificial nests between February and April 2005–2007. Eggs were laid and incubated between February and March each year from 2005 to 2007. Nestlings hatched in late March and left the nest in late April 2005–2007. Each breeding pair was fed with approximately 400 g of food each day. All three pairs reproduced resulting in mature offspring of seven in 2005, six in 2006, and five in 2007. Four of sixteen 3‐year‐old birds were randomly selected and equipped with a GPS receiver on their backs. Activities of the birds attached and unattached with GPS were not significantly different. The first two birds (one female, one male with GPS) were reintroduced on August 5, 2006, and another nine birds (four birds with GPS) were reintroduced on December 26, 2006. The average home range of these reintroduced birds was 0.13 km². Their foods consisted of wild plants and animals in the home range. The first reintroduced pair was able to breed naturally by laying and hatching eggs in an artificial nest. Two juveniles left the nest in April 2008. These results indicate that both captive breeding and reintroduction are potentially important ways to increase the population of the Oriental pied hornbill in natural habitats. Zoo Biol 31:683‐693, 2012. © 2011 Wiley Periodicals, Inc.     

Forest cover,hunting pressure,and fruit availability influence seed dispersal in a forest‐savanna mosaic in the Congo Basin

Forest fragmentation, reduced forest cover, and hunting pressure are the main threats affecting animal‐mediated seed dispersal. However, their combined effects on seed dispersal rates have been simultaneously investigated only rarely, and never in Africa. We aimed to disentangle the effects of forest cover, hunting pressure, frugivore abundance, and fruit availability at the local and landscape scales on the seed dispersal rates of Staudtia kamerunensis (Myristicaceae). To estimate the percentages of seed dispersal failure (undispersed seeds), we quantitated fruit remains below fruiting trees distributed across five contrasting sites in a semi‐natural forest‐savanna mosaic in the Democratic Republic of Congo. We used statistical analyses accounting for spatial autocorrelation and found that forest cover in the surrounding landscape, hunting level, the associated abundance of dispersers, and fruit availability all had significant effects on the percentage of seed dispersal failure. The combination of high fruit availability and reduced abundance of seed dispersers could accelerate seed disperser satiation, causing the seed dispersal system to be saturated. Our study highlights how two major factors associated with anthropogenic activities, forest cover and hunting, affect seed dispersal by animals. These findings could have far‐reaching implications for our understanding of tree‐frugivore interactions and the conservation of tropical communities.     

Evidence for acoustic niche partitioning depends on the temporal scale in two sympatric Bornean hornbill species

Understanding niche partitioning of closely related sympatric species is a fundamental goal in ecology. Acoustic communication space can be considered a resource, and the acoustic niche hypothesis posits that competition between species may lead to partitioning of communication space. Here, we compare the calling behavior of two sympatric Bornean hornbill species—the rhinoceros hornbill (Buceros rhinoceros) and the helmeted hornbill (Rhinoplax vigil)—to test for evidence of acoustic niche partitioning. Both hornbill species emit calls heard over many kilometers and have similar habitat preferences which is predicted to result in interspecific competition. We collected acoustic data on sympatric populations of both hornbill species using 10 autonomous recording units in Danum Valley Conservation Area, Sabah, Malaysia. We found that there was substantial spectral overlap between the calls of the two species, indicating the potential for competition for acoustic space. To test for evidence of acoustic niche partitioning, we investigated spatial and temporal patterns of calling in each species. Both hornbills were strictly diurnal and called throughout the day, and we were equally likely to detect both species at each of our recorders. We did not find evidence of temporal acoustic avoidance at a relatively coarse timescale when we divided our dataset into 1 h bins, but we did find evidence of temporal acoustic avoidance at a finer timescale when we used null models to compare the observed duration of overlapping calls to the expected amount of overlap due to chance.