Body temperature variation of free-ranging and captive southern brown bandicoots Isoodon obesulus (Marsupialia: Peramelidae)

To investigate patterns of thermoregulation in free-ranging and captive southern brown bandicoots Isoodon obesulus, we measured abdominal body temperature (T_b) of five free-ranging bandicoots over 42 days using implanted data loggers and T_b of three captive bandicoots over 3 months using implanted temperature-sensitive radio transmitters. Bandicoots in the wild had a mean T_b of 36.5±1.0 °C (range 33.4–39.8 °C) and showed a pronounced nychthemeral pattern with two distinct temperature phases. T_b increased at 13:30±2.6 h each day and remained high for 10.65±2.07 h, suggesting a crepuscular and early evening activity pattern. Daily T_b variation of I. obesulus would save considerable energy by reducing daytime thermoregulatory costs in the wild. Captive bandicoots had a similar mean body temperature (36.9±0.2°C) and range (33.0–39.9°C) as free-ranging bandicoots. However, the nychthemeral T_b pattern of captive bandicoots was different from free-ranging bandicoots, with a less pronounced daily cycle and the nocturnal rise in T_b occurring mainly at sunset and the daily decline occurring mainly at dawn.     

Scaling of swim speed and stroke frequency in geometrically similar penguins: they swim optimally to minimize cost of transport

It has been predicted that geometrically similar animals would swim at the same speed with stroke frequency scaling with mass^−1/3. In the present study, morphological and behavioural data obtained from free-ranging penguins (seven species) were compared. Morphological measurements support the geometrical similarity. However, cruising speeds of 1.8–2.3 m s⁻¹ were significantly related to mass^0.08 and stroke frequencies were proportional to mass^−0.29. These scaling relationships do not agree with the previous predictions for geometrically similar animals. We propose a theoretical model, considering metabolic cost, work against mechanical forces (drag and buoyancy), pitch angle and dive depth. This new model predicts that: (i) the optimal swim speed, which minimizes the energy cost of transport, is proportional to (basal metabolic rate/drag)^1/3 independent of buoyancy, pitch angle and dive depth; (ii) the optimal speed is related to mass^0.05; and (iii) stroke frequency is proportional to mass^−0.28. The observed scaling relationships of penguins support these predictions, which suggest that breath-hold divers swam optimally to minimize the cost of transport, including mechanical and metabolic energy during dive.     

Test of the ecological-constraints model on ursine colobus monkeys (Colobus vellerosus) in Ghana

For group-living mammals, the ecological-constraints model predicts that within-group feeding competition will increase as group size increases, necessitating more daily travel to find food and thereby constraining group size. It provides a useful tool for detecting scramble competition any time it is difficult to determine whether or not food is limiting. We tested the ecological-constraints model on highly folivorous ursine colobus monkeys (Colobus vellerosus) at the Boabeng-Fiema Monkey Sanctuary in Ghana. Three differently sized groups were followed for 13 months and two others were followed for 6 months each in 2004-2005 using focal-animal sampling and ranging scans; ecological plots and phenology surveys were used to determine home-range quality and food availability. There was relatively little difference in home-range quality, monthly food availability, diet, adult female ingestion rates, and rate of travel within food patches between the groups. However, home-range size, day-range length, and percent of time spent feeding all increased with group size. We performed a single large test of the ecological-constraints model by combining several separate Spearman correlations, each testing different predictions under the model, using Fisher's log-likelihood method. It showed that the ecological-constraints model was supported in this study; scramble competition in this population is manifesting in increased ranging and time spent feeding. How costly this increased energy expenditure is for individuals in larger groups remains to be determined.     

近地面激光雷达点云密度对森林冠层结构参数提取准确性的影响

基于激光雷达技术获取冠层结构为森林生态学研究增加了新的维度。搭载于多旋翼无人机的近地面激光雷达相比于固定翼有人机的机载激光雷达，能够更加灵活高效地获取森林群落样地高密度点云。但在实际操作中，往往出现局部低密度点云数据，影响了冠层结构参数提取的准确性。使用4块森林动态样地的近地面激光雷达点云数据；利用航带分解方法分析各样地低密度样方成因；采用点云抽稀模拟算法计算并拟合偏差曲线，对比不同样地、参数和取样尺度间的点云密度对冠层结构参数提取准确性的影响；根据偏差曲线计算各条件下保证参数提取准确性的最低点云密度。结果发现：1)低密度区域主要受地形或(和)近地面遥感设计规划的影响。地形复杂的测区(西双版纳和古田山样地),遥感规划难度大，整体难以获取高密度点云(在30点/m²左右),容易在沟谷和高海拔处出现低密度样方。平坦测区(长白山两块样地)虽可获取高密度点云(均超过150点/m²),但欠佳的遥感规划设计导致长白山1测区北部出现1hm²低密度区域。2)冠层参数提取准确性随点云密度减少而迅速降低，呈负指数幂函数关系。这一变化趋势在不同...     

Himalayan <Emphasis Type="Italic">Semnopithecus entellus</Emphasis> at Langtang National Park,Nepal: Diet,Activity Patterns,and Resources

Though researchers have studied lowland gray langurs extensively, there is little information about the Himalayan populations. We provide foraging data from a field study of Himalayan langurs in Langtang National Park, Nepal at 3000–4000 m elevation. Phenological records show marked seasonality in resource abundance, with extremely low availability in winter, increasing abundance in spring and monsoon, and a reduction in fall. Activity budgets indicated greater time devoted to feeding as total vegetation abundance decreased. Diet included leaf buds, ripe fruit, and evergreen mature leaves in winter; deciduous young leaves in spring; and deciduous mature leaves in the monsoon and fall. Supplemental resources, such as underground storage organs, bark, and herbaceous vegetation, were also seasonally important. Among plant part classes included in the phenological sample, abundance and consumption correlate positively for all primary food resources except evergreen mature leaves and unripe fruit. Daily path lengths varied by season and, when controlled for overall vegetation abundance, positively relate to the consumption of soft underground storage organs, fruits, and deciduous mature leaves. The results contradict the common generalization of leaves as ubiquitous or nonpatchy resources.     

Movement patterns of forest elephants (Loxodonta cyclotis Matschie, 1900) in the Odzala-Kokoua National Park,Republic of Congo

African forest elephants (Loxodonta cyclotis Matschie, 1900) are ecological engineers that play a fundamental role in vegetation dynamics. The species is of immediate conservation concern, yet it is relatively understudied. To narrow this knowledge gap, we studied the drivers of daily movement patterns (linear displacements) of forest elephants—characterised by a set of geographical, meteorological and anthropogenic variables—in the Odzala-Kokoua National Park, Republic of Congo. Explicitly, we used conditional random forest to model and disentangle the main environmental factors governing the displacements of six forest elephants, fitted with GPS collars and tracked over 16 months. Results indicated that females moved further distances than males, while the presence of roads or human settlements disrupted elephant behaviour resulting in faster displacements. Forest elephants moved faster along watercourses and through forest with understory dominated by Marantaceae forests and bais, but moved slower in savannahs. Finally, flood-prone areas—described by elevation and accumulated precipitation—and higher temperatures prevented longer displacements. We expect these results to improve the knowledge on the species movements through different habitats, which would benefit its conservation management.     

Seroprevalence of Trypanosoma cruzi and Leishmania mexicana in Free‐Ranging Howler Monkeys in Southeastern Mexico

Natural infection of wild mammals by protozoa parasites is quite common in nature. For Neotropical Primates different infections of parasites that are etiological agent of disease in human have been identified. In particular, infections by Trypanosoma cruzi and Leishmania sp., have been reported for some New World primate species, but there are no reports of infection with these parasites in any primate species in Mexico. A serological study was conducted on two howler monkey species (Alouatta pigra and A. palliata) from the Mexican states of Campeche and Tabasco. A total of 55 serum samples (20 samples from A. pigra, 20 samples from A. palliata, and 15 samples from semifree ranging A. palliata of Los Tuxtlas, Veracruz as negative controls) were analyzed for the detection of immunoglobulin G antibodies against T. cruzi and Leishmania mexicana through enzyme linked immunosorbent assay test, indirect immunofluorescence assay and Western blot. The overall prevalence of antibodies in howler monkeys was 17.5% for T. cruzi and 30% for L. mexicana. Our results also indicate that A. pigra is more susceptible to develop leishmaniasis than A. palliata. Finally, the finding of positive serology in these primates should be given serious consideration for public health, given the potential role of these primate species as wild reservoirs for these diseases and the increasing contact of monkeys with human populations due to habitat loss and fragmentation. Am. J. Primatol. 75:161‐169, 2013. © 2012 Wiley Periodicals, Inc.     

Ecological consequences of a group fission event in the Tana River mangabey (Cercocebus galeritus)

A group of Tana River mangabeys Cercocebus galeritus studied in 2000–2001 fissioned into two daughter groups in 2004, the first reported case of fission in Cercocebus. Data were collected on each daughter group in 2005–2006 to investigate how the groups divided the parent group's range, the quality of habitat used by each group, and if fruit abundance was correlated with the spatial relationships between the groups. Six days of ranging data were collected each month and input into ArcView GIS 3.3 to measure home ranges and core areas. Phenological data were collected from nine important food species. Habitat quality was measured by counting all reproductive‐sized individuals of those nine food species in the ranges. The daughter groups shared the parent group's home range and core area, although the larger group used more of those areas than the smaller group. The two groups got equal quality home ranges and core areas as measured by per capita food trees, but the larger group had access to a larger and richer exclusive area. Proximity of the groups to each other was not correlated with fruit abundance. This study contributes to the small body of literature that addresses ecological consequences of primate group fission.     

Forest structure predicts species richness and functional diversity in Amazonian mixed-species bird flocks

Secondary forest has the potential to act as an important habitat for biodiversity and restoring ecological benefits. Functional diversity, which includes morphological and behavioral traits that mediate species interactions with the surrounding environment, relates to the resilience of ecosystems. To assess the relationship between habitat structural differences in primary and secondary forest and the resultant differences in functional diversity of avian species, we followed 11 mixed-species flocks at the Biological Dynamics of Forest Fragments Project, near Manaus, Brazil. We used remote sensing LiDAR to assess which three-dimensional forest structural features are most closely associated with variation in species richness and functional diversity in secondary and primary tropical forest flocks. The species richness of flocks in primary forest increased in areas with higher elevation and higher leaf area density in the understory and subcanopy but was not correlated with habitat structure in secondary forest. Functional diversity increased at lower elevations and with a denser subcanopy in both primary forest and secondary forest but only increased with greater understory leaf area density in primary forest. Together, these results indicate that a dense subcanopy and understory can be important for mixed-species flocks and that flock richness and functional diversity can be predicted by vegetation structure.