MONITORING MAMMALS AT MULTIPLE SCALES: CASE STUDIES FROM CARNIVORE COMMUNITIES

Carnivores are distributed widely and threatened by habitat loss, poaching, climate change, and disease. They are considered integral to ecosystem function through their direct and indirect interactions with species at different trophic levels. Given the importance of carnivores, it is of high conservation priority to understand the processes driving carnivore assemblages in different systems. It is thus essential to determine the abiotic and biotic drivers of carnivore community composition at different spatial scales and address the following questions: (i) What factors influence carnivore community composition and diversity? (ii) How do the factors influencing carnivore communities vary across spatial and temporal scales? (iii) At local scales, what are the roles of within- and between- guild interactions in structuring carnivore communities? I use carnivore distribution data from protected areas across the global tropics to understand how multiple biodiversity metrics track one another at the regional scale. At the landscape scale, I apply carnivore community data from India to understand how spatiotemporal interactions at the local scale influence carnivore distribution patterns at larger scales. Lastly, at the local scale, I implement a field study of carnivore community occupancy at Kasanka National Park in Zambia using camera traps to understand spatiotemporal patterns of distribution. I employ these studies to delineate the importance of scale in developing a theoretical and applied understanding of community ecology, monitoring mammals at the community level, and conserving carnivore communities. This research shows that carnivore conservation and biodiversity monitoring at the community level is both context-specific and scale dependent

The Antsy Social Network: Determinants of Nest Structure and Arrangement in Asian Weaver Ants.

Asian weaver ants (Oecophylla smaragdina) are arboreal ants that are known to form mutualistic complexes with their host trees. They are eusocial ants that build elaborate nests in the canopy in tropical areas. A colony comprises of multiple nests, usually on multiple trees, and the boundaries of the colony may be difficult to identify. However, they provide the ideal model for studying group living in invertebrates since there are a definite number of nests for a given substrate, the tree. Here, we briefly examine the structure of the nests and the processes involved in the construction and maintenance of these nests. We have described the spatial arrangement of weaver ant nests on trees in two distinct tropical clusters, a few hundred kilometres apart in India. Measurements were made for 13 trees with a total of 71 nests in the two field sites. We have considered a host of biotic and abiotic factors that may be crucial in determining the location of the nesting site by Asian weaver ants. Our results indicate that tree characteristics and architecture followed by leaf features help determine nest location in Asian weaver ants. While environmental factors may not be as influential to nest arrangement, they seem to be important determinants of nest structure. The parameters that may be considered in establishing the nests could be crucial in picking the evolutionary drivers for colonial living in social organisms

Correction: The Antsy Social Network: Determinants of Nest Structure and Arrangement in Asian Weaver Ants

<p>Correction: The Antsy Social Network: Determinants of Nest Structure and Arrangement in Asian Weaver Ants</p

A selection of original variables with their corresponding coefficient values based on PCA analyses of nest arrangement in Asian weaver ants.

<p>A selection of original variables with their corresponding coefficient values based on PCA analyses of nest arrangement in Asian weaver ants.</p

The VarImpPlot is a dotchart of variable importance as measured by a Random Forest.

<p>Here, the predictors are sorted in their increasing order of importance. TempOut: temperature outside the nest, CanopyRadius: canopy radius, Position: position on the tree, DisTrunk: distance of the nest from the trunk, TrunkHt: trunk height until location of first branching, NestSize: number of leaves used in construction of the nest, WindInt: wind intensity, TreeHt: total height of the tree, LeafLength: length of the leaf at the longest points, LeafBreadth: breadth of the leaf at the widest points, Luminosity: luminosity or ambient light, WindDir: direction of wind.</p

<i>Oecophylla smaragdina</i> constructing their nest on a lime tree.

<p><i>Oecophylla smaragdina</i> constructing their nest on a lime tree.</p

Scree plot showing the principal components that explain the most variation.

<p>Here, the first five components explain about 90% of the variation. The first two components account for 48% and 18% of the variation respectively, leading to a cumulative of 66%.</p

Weaver Ant Nest Data

<p>This dataset comprises of data associated with nests of the Asian weaver ant (<em>Oecophylla smaragdina</em>). It has details on the spatial location of weaver ant nests on different trees (in two different urban areas in India), along with information of nest characteristics, tree characteristics, and environmental variables.</p

A boxplot of nest sizes in number of leaves for each of the 13 trees studied.

<p>A majority of the nests observed involved having less than 150 leaves used in their construction. However, some nests were made up of more than 150 leaves, having up to a maximum of 300 leaves.</p

Biplot showing the principal componenents with the factors that contribute to explaining the most variation.

<p>Biplot showing the principal componenents with the factors that contribute to explaining the most variation.</p