By Michelle Jackson, Conservation Biologist

A Rocha’s Conservation Science team has been studying swallows at Brooksdale and throughout the Little Campbell Watershed since 2014. This year, thanks to a partnership with Amanda Edworthy, a post-doctoral fellow at Washington State University (and former A Rocha intern!), we’ve expanded the scope of our monitoring to include DNA analysis of swallow poop.

Why study their poop, one might ask? Swallows are a group of migratory birds that have been drastically declining over the past 20 years. They are also great at controlling insect populations, but one reason for their decline is lower insect abundance due to pesticide use, along with loss of farmland and open field habitat.

So we’d like to know what the swallows are eating, and whether the insect composition of their diet varies across space and time. Dr. Edworthy’s team is collecting poop samples from birds on organic vegetable farms across the western US to analyze diet and pathogen prevalence, with the hope of placing value on birds as a form of natural pest control. They use DNA analysis to determine what the birds are eating and which pathogens are present in their bodies. By contributing samples from Brooksdale’s swallows, we can help contribute to this larger dataset while benefiting from the DNA analysis techniques for our own program.

So how does one go about collecting poop from birds that are constantly on the move? For Brooksdale’s Cliff Swallow colony, consisting of 45 nests adhered to the face of a barn, it’s quite easy. For the analysis to work, the samples need to be collected fresh and placed immediately into ethanol. Because the Cliff Swallow nests are concentrated along one wall of the barn, we spread out long pieces of cardboard below the nests and simply wait. Every few minutes there will be a mass return of several adults to the nests, mouths and bellies full of insects ready to feed to hungry chicks. Amidst the noise of chicks begging for food, a characteristic “splat!” indicates a sample ready for collection. The poop can then be scraped off the cardboard into a tube of ethanol, which is labeled and placed into a container of liquid nitrogen. The liquid nitrogen is necessary to keep samples at the required temperature of -80° C or below.

Swallow Poop with Liquid Nitrogen

Along with the Cliff Swallow colony, Brooksdale also hosts several Barn Swallow nests in our pasture barn. We hope to collect samples from Barn Swallows as well, to compliment our on-going nest monitoring program.

Barn Swallow populations have declined by 76% in Canada over the past 40 years and are federally listed as threatened (by COSEWIC). Eventually, we would like to compare the diets of Brooksdale’s Barn Swallows to those from different sites across the watershed and over time, both within a season and across years. For now we are focusing on fine-tuning our methods for collecting samples and gathering as much as we can from swallows at Brooksdale. We are grateful for the partnership made possible by our former intern and hope that this project will contribute toward swallow conservation in North America.

Learn more about our Conservation Projects