Assessing the accuracy of small satellite transmitters on free‐living flying‐foxes

Satellite telemetry using ARGOS platform transmitter terminals (PTTs) is widely used to track the movements of animals, but little is known of the accuracy of these systems when used on active terrestrial mammals. An accurate estimate of the error, and therefore the limitations of the data, is critical when assessing the level of confidence in results. ARGOS provides published 68th percentile error estimates for the three most accurate location classes (LCs), but studies have shown that the errors can be far greater when the devices are attached to free‐living animals. Here we use data from a study looking at the habitat use of the spectacled flying‐fox in the wet tropics of Queensland to calculate these errors for all LCs in free‐living terrestrial mammals, and use these results to assess what level of confidence we would have in habitat use assignment in the study area. The results showed that our calculated 68th percentile errors were larger than the published ARGOS errors for all LCs, and that for all classes the error frequency had a very long tail. Habitat use results showed that the size of the error compared with the scale of the habitat the study was conducted in makes it unlikely that our data can be used to assess habitat use with great confidence. Overall, our results show that while satellite telemetry results are useful for assessing large scale movements of animals, in complex landscapes they may not be accurate enough to be used for finer scale analysis including habitat use assessment.     

温度对赤拟谷盗爬行和起飞活动的影响

在不同温度下研究了赤拟谷盗Tribolium castaneum(Herbst)在固体物面、设定粮面、温度均匀的粮(小麦)柱和具有温度梯度粮柱内爬行扩散速度、起飞温度等.主要结果为:赤拟谷盗在17℃开始有爬行为,25℃开始有飞行行为,在15～25℃时水平爬行速度和15 ～ 20℃时竖直运动速度与温度呈显著正相关,在无障...     

谁是腊梅的主要传粉者:昆虫行为与传粉作用

访花昆虫不同的访花与飞行行为导致其访花频率小同,进而对植物传粉产生不同的影响.意大利蜜蜂(Apis mellifera ligustica)、苍蝇和食蚜蝇是腊梅(Chimonanthus praecox)最常见的访花类群(或种类),但是它们的访花行为却有很大不同.意大利蜜蜂主要以快速飞行为主,偶见爬行,苍蝇访花时主要以快速飞行、爬行和跳跃为主,而食蚜蝇以长时间单花访问和悬空飞行以及间歇性休息为主.根据访花类群(或种类)在一朵花上的访花时间和花间飞行时间进行推算,每只意大利蜜蜂、苍蝇和食蚜蝇每分钟分别可以访问4.57、2.65和0.53朵花.结合每种(类)昆虫的访花数量推算出意大利蜜蜂、苍蝇和食蚜蝇每分钟分别可以访问498.19、1,089.74和99.78朵花.传粉效力(相同条件下单位时间内相同数目访花者能够授粉的花朵数)实验结果证明苍蝇和意大利蜜蜂分别是93％、100％(n=30),而食蚜蝇只有13％(n=30).苍蝇和意大利蜜蜂可携带大量花粉且具有很高的传粉效力,因此,访花速度的快慢是二者访花能力强弱的主要限制因素.由此,我们认为苍蝇可能是腊梅最主要的传粉者,意大利蜜蜂次之(数量偏少),食蚜蝇再次(访花与飞行行为的影响以及访花效力较低是限制其访花能力的主要因素).     

10—14世纪四柱亭榭之结构探析

通过对金元亭榭、《营造法式》以及相关宋画三者进行对照比较，总结出10—14世纪四柱亭榭之结构做法，内容包括举折、出檐、出际、安槫四项。具体提出以下5点结论：1）举屋在四分举一至二分举一之间；2）椽径份值介于9~10份；3）大型亭榭之出檐，可参考《法式》规定，小型亭榭之出檐，需据檐步架尺寸进行折算；4）歇山亭榭之出际可据步架尺寸之0.8~1确定；5）安槫方式可归作三类：“斗栱悬挑型”、“过渡型”和“趴梁抬承型”，每一类又可进一步细分为两种做法，在此基础上，对不同做法之历史演变进行了客观梳理。研究结果可为中古亭榭建筑结构补阙，又可补充完善《法式》内容。     

Effects of Logging Pattern and Intensity on Squirrel Demography

ABSTRACT We examined the effect of harvesting intensity and pattern on red squirrels (Tamiasciurus hudsonicus), northern flying squirrels (Glaucomys sabrinus), and yellow-pine chipmunks (Tamias amoenus) in mature inland Douglas-fir (Pseudotsuga menziesii glauca) forests in south-central British Columbia, Canada. We sampled squirrels 1 year before harvesting through 4 years after harvesting and estimated population parameters using open-population models. Relative to unharvested stands, each of the 3 species showed a strong response to tree removal. From 2 years to 4 years after logging, red squirrel density was 40% (SE = 7.1) lower in stands with 50% basal-area tree removal. From 1 year and up to 4 years after logging, northern flying squirrel density averaged 60% (SE = 5.2) lower in harvested treatments regardless of intensity or pattern of logging. In contrast, density of yellow-pine chipmunks increased markedly with increased logging intensity. Beginning 3 years after logging, yellow-pine chipmunk density was 734% (SE = 269) greater in stands with 50% basal-area tree removal. In the short term, harvesting intensity was a more important determinant of squirrel density than harvesting pattern. Retaining >10 m² per ha of live residual stand structure in mature inland Douglas-fir forests maintained habitat for forest-dependent species such as red squirrels and northern flying squirrels, albeit at lower densities.     

Pteropus lylei primarily forages in residential areas in Kandal,Cambodia

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The pollination system of the widely distributed mammal‐pollinated Mucuna macrocarpa (Fabaceae) in the tropics

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Contributions of bats to the local economy through durian pollination in Sulawesi,Indonesia

Durian is economically important for local livelihoods in Indonesia. Our study investigated the identity of pollinators of semi‐wild durian and subsequently estimated the economic contribution of these pollination services. We conducted pollination exclusion experiments and deployed camera traps at durian trees from October 2017 to January 2018 in an area where the local economy depends on durian production in West Sulawesi, Indonesia. Durian flowers in the experiment that were accessible to bats had significantly higher fruit set compared with flowers that were completely closed to animal visitors or those that could only be visited by insects, suggesting that bats were the primary durian pollinator. The small, highly nectarivorous cave nectar bat (Eonycteris spelaea) visited more inflorescences (n = 25) and had visits of much longer duration ( = 116.87 sec/visit) than the two species of flying foxes: Pteropus alecto (n = 7 inflorescences visited,  = 11.07 sec/visit) and Acerodon celebensis (n = 6 inflorescences visited,  = 11.60 sec/visit). Visits by large and small bats were influential in differentiating successful durian fruit production from unsuccessful. Using a bioeconomic approach, we conservatively estimate that bat pollination services are valued at ~$ 117/ha/fruiting season. By demonstrating an ecological link between bats and the local economy, this research provides an urgent message for Southeast Asian governments regarding the need to promote bat conservation in order to increase the production of durian grown under semi‐wild conditions. Abstract in Indonesia is available with online material.