A modeling algorithm for exploring the architecture and construction of bird nests

Zebra finches have style: Nest morphology is repeatable and associated with experience

We investigated whether birds build nests in repeatable styles and, if so, whether styles were associated with past nest-building experience. Laboratory, captive bred zebra finches in an Experimental group were given nest-building experience, whereas, birds in a Control group were not. Each pair (n = 20) then built four nests that underwent image analyses for nest size, geometric shape and entrance orientation. Birds built nests in repeatable styles, with lower morphometric variation among nests built by the same pair and higher morphometric variation among nests built by different pairs. Morphology was not associated with construction time, body weight, nor age of birds. We found lower morphometric variation among nests built by the Experimental group, which also used less material to build nests compared to the Control group. Prior experience may therefore have been advantageous, as learning to reduce material usage while achieving a similar product (nest) may have lowered building costs.

Bird Functional Diversity in Agroecosystems and Secondary Forests of the Tropical Andes

Agricultural systems have increased in extension and intensity worldwide, altering vertebrate functional diversity, ecosystem functioning, and ecosystemic services. However, the effects of open monoculture crops on bird functional diversity remain little explored, particularly in highly biodiverse regions such as the tropical Andes. We aim to assess the functional diversity differences of bird guilds between monoculture crops (coffee, cocoa, and citrus) and secondary forests. We use four functional diversity indices (Rao Q, Functional Richness, Functional Evenness, and Functional Divergence) related to relevant morphological, life history, and behavioral traits. We find significant differences in functional diversity between agroecosystem and forest habitats. Particularly, bird functional diversity is quite homogeneous among crop types. Functional traits related to locomotion (body weight, wing-chord length, and tail length), nest type (closed), and foraging strata (canopy and understory) are dominant at the agroecosystems. The bird assemblages found at the agroecosystems are more homogeneous in terms of functional diversity than those found at the secondary forests, as a result of crop structure and management. We recommend promoting more diverse agroecosystems to enhance bird functional diversity and reduce their effects on biodiversity.