Paying attention to Barn SwallowsSeptember 3rd, 2019
By Meghan Cooling, Conservation Technician
It has been a banner year for the Barn Swallow colony in Stanley Park this year. The colony has fledged a record number of 142 chicks so far (Figure 1), and the season’s not over yet!
This gregarious swallow species has been nesting in the Vancouver Police Horse Barns and Vancouver Parks Board Equipment Shed since before 2001, and has been monitored annually by the Stanley Park Ecology Society (SPES) beginning in 2014, using the Barn Swallow Conservation Project protocol (2014). Barn Swallows are unique among swallows in nesting almost exclusively on human structures. Only 1% of Canadian nest records for Barn Swallows are from natural sites, such as cliffs and caves (RISC 1998, pg. 4). The colony in Stanley Park has over 80 nests, about half of which were used this year. This makes our colony one of the largest in B.C., which provides SPES with a unique opportunity to monitor the population dynamics of a provincially blue-listed species (considered of “special concern”). Using this monitoring data, SPES aims to understand how numbers are changing over the years, if nests are being built at new sites within the Park, and to use what we learn to apply best management practices when needed, including informing the best timing for Park operations and other disturbances (Worcester and Titaro 2012). This passive monitoring survey consists of observing all of the nests within the colony with binoculars, and noting:
- The timing and length of arrival
- The type of activity such as nest building, incubating, feeding hatchlings
- The number of hatchlings/fledglings and the number of deaths
- The number of nests that are used for two broods
- The last sighting before migration
Figure 1. Top: Three Barn Swallow hatchlings in their distinctive mud cup nest. Nests are made out of mud, feathers, grass, and in the case of these swallows, horse hair! These swallows are close to fledging (leaving the nest for good) (Photo: Frank Lin, 2019). Bottom: Barn Swallow fledglings being fed by their parents. Fledglings leave the nest 15-27 days after hatching, but continue to be fed by their parents for about a week after leaving. The fledglings in this photo are perched by Lost Lagoon (Photo: Frank Lin, 2019).
So far this season, Julie Emerson (dedicated volunteer) and Meghan Cooling (SPES Conservation Technician) have conducted 22 Barn Swallow surveys, with several more still to happen before these migrants head back down to spend the winter in Central and South America in mid-September. Figure 2 and Table 2 summarize the data collected during the SPES monitoring surveys since 2014.
Barn Swallows are insectivores, which means they eat insects. These little birds provide free pest control for the Vancouver Mounted Police, whose barns are completely free of flies (personal communication with VPD officer Joanne Hardman). A pair feed their chicks over 400 meals, each consisting of multiple insects, A DAY (Canadian Wildlife Federation, 2015). That’s approximately 43, 000 insects to fed one nest of chicks.
If you detect a barn swallow nest, you can report it to email@example.com or call 604-989-1007. If you find an injured barn swallow, you can call Wildlife Rescue Association at 604-526-7275. Barn Swallows are protected under the Migratory Birds Convention Act, 1994 (Environment Canada, 2004), which means it is illegal to intentionally damage or destroy their nests, eggs, or young.
Figure 2. Barn swallow productivity for 2014 – 2019. Please note that during 2014, 2015, and 2016, monitoring was not conducted over the entire season, so numbers for these years may be underestimates.
Barn Swallow Conservation Project, 2014. Barn Swallow Nest Monitoring Methods. Retrieved from https://bcswallowconservationproject.files.wordpress.com/2014/05/baswnestmonitoringmethods.pdf. Accessed August 15 2019.
Canadian Wildlife Federation. 2015. Hinterland Whos Who: Barn Swallows. Retrieved from http://www.hww.ca/en/wildlife/birds/barn-swallow.html. Accessed August 15 2019.
Environment Canada, 2004. Migratory Birds Conservation. Retrieved from https://laws-lois.justice.gc.ca/eng/acts/m-7.01/FullText.html, Accessed August 15 2019.
Resources Inventory Standards Committee (RISC) (1998). Inventory Methods for Swifts and Swallows. Standards for Components of British Columbia’s Biodiversity No. 16. Version 2.0. Ministry of Environment, Lands and Parks, Resources Inventory Branch, Victoria, BC.
Worcester R., Titaro B., 2012. Best Management Practices for Species of Significance in Stanley Park. Stanley Park Ecology Society, 177 pages.