Ecological context is central for understanding the evolution of traits. We explore a unique and poorly studied avian behavior: the use of shed snake skins in nest construction and suggest that the evolution of this behavior is context dependent upon, at least, nest morphology and predator communities. Of the 78 species from 22 families reported to use shed snake skin, all but one are passerines, and this behavior is disproportionately observed in cavity-nesting species. Next, we tested three hypotheses whereby snake skin could award fitness benefits (nest predation, nest microbiotas, and nest ectoparasites) and found support for the predation hypothesis. Snake skin reduced nest predation in cavity, but not cup, nests. These unequal fitness benefits highlight different ecological conditions between nest morphologies and likely explains why, across species, cavity-nesting birds show this behavior more frequently and use snake skin more consistently in nest construction compared to cup-nesting birds.

Humans and non-human primates (NHPs) harbor complex gut microbial communities that affect phenotypes and fitness. The gut microbiotas of wild NHPs reflect their hosts’ phylogenetic histories and are compositionally distinct from those of humans, but in captivity the endogenous gut microbial lineages of NHPs can be lost or replaced by lineages found in humans. Despite its potential contributions to gastrointestinal dysfunction, this humanization of the gut microbiota has not been investigated systematically across captive NHP species. Here we show through comparisons of well-sampled wild and captive populations of apes and monkeys that the fraction of the gut microbiota humanized by captivity varies significantly between NHP species but is remarkably reproducible between captive populations of the same NHP species. Conspecific captive populations displayed significantly greater than expected overlap in the sets of bacterial 16S rRNA gene variants that were differentially abundant between captivity and the wild. This overlap was evident even between captive populations residing on different continents but was never observed between heterospecific captive populations. In addition, we developed an approach incorporating human gut microbiota data to rank NHPs’ gut microbial clades based on the propensity of their lineages to be lost or replaced by lineages found in humans in captivity. Relatively few microbial genera displayed reproducible degrees of humanization in different captive host species, but most microbial genera were reproducibly humanized or retained from the wild in conspecific pairs of captive populations. These results demonstrate that the gut microbiotas of captive NHPs display predictable, host-species specific responses to captivity.

COVID-19 created a host of challenges for science education; in our case, the pandemic halted our in-person elementary school outreach project on bird biology. This project was designed as a year-long program to teach fifth grade students in Ithaca, New York, USA about bird ecology and biodiversity, using outdoor demonstrations and in-person games and activities to engage students in nature. As a central part of this effort, we set up nest boxes on school property and had planned to monitor them with students during bird breeding in the spring. Here, we describe our experiences transitioning this program online: we live streamed nest boxes to students’ virtual classrooms and used them as starting points for virtual lessons on bird breeding and nestling development. We suggest that instituting similar programs at local schools can promote equitable learning opportunities for students across geographical locations and with various living situations. In an era of social distancing and isolation, we propose that nest box live streaming and virtual lessons can support local communities by providing access to the outdoors and unconventional science learning opportunities for all students.