The Flight of the Bank Swallow, November 16

0

by Cheryl Morris-Putman for MVFN

On Thursday, November 16, 2017 at 7:30 pm. the Mississippi Valley Field Naturalists (MVFN) will offer the third presentation of the season, reflective of the theme “When Things Go Bump In The Night”.

The event will take place in the Social Hall of Almonte United Church, 106 Elgin St., Almonte Ontario.

Our speaker for the evening will be Dr. Greg Mitchell, a research scientist with the Wildlife Research Division of Environment and Climate Change Canada and an adjunct professor at Carleton University. He has entitled his presentation “Where Do Bank Swallows Go When The Sun Sets”? We will explore with Dr. Mitchell conservation strategies that may help to reverse the declining numbers of yet another aerial insectivore.

How many of us have watched with wonder the aerial acrobatics of swallows as they dip and skim over the glassy surface of a lake, or swoop and follow the contours of a farm field? The swallow, one of the most graceful and attractive of songbirds, was often featured in Native American folklore and considered to be closely related to the magical Thunderbird because it will fly before a thunderstorm arrives. In Greek mythology, the swallow was associated with the goddess Aphrodite, and in Rome, where it was the symbol of Venus, this elusive little bird was considered a creature who carried the souls of deceased children. To northern Europeans, the fork-tailed swallow was a symbol of springtime and love, and therefore was sacred to the May Queen. For the people of ancient China, the swallow was a bird of daring and came to signify upcoming success and fidelity. There are countless stories written by medieval scholars featuring this enchanting bird and describing its mystical powers.

On the evening of November 16, guided by Dr. Mitchell, we will enter the world of the bank swallow (Riparia riparia), a bird that is found on every continent except Antarctica and Australia. This small songbird is a threatened species in Ontario, meaning that it is not yet endangered, but is likely to become endangered if steps are not taken to address factors that threaten its survival. The bank swallow is the smallest of the swallow family in the western hemisphere, averaging 12 centimetres in length and weighing between 10 to 18 grams. It displays a grey-brown head, mantle, rump and wing coverts, contrasting with darker brown feathers and white underparts separated by a well-defined, brown upper breast band that distinguishes it from other swallows. The bank swallow can be recognized in flight from other swallows by its almost constant buzzing, chattering vocalizations and its quick and erratic wing beats.

Bank swallows are aerial insectivores, feeding singly, in pairs, or in flocks. They will also eat land and water-based insects or spiders when there are many available. They nest in burrows in natural and man-made settings where there are vertical exposures of silt and sand deposits. Many nests are found on the banks of rivers and lakes, but they can also be found in sand and gravel pits when the banks remain suitable. With the approach of winter, they migrate to areas primarily in South America. In Ontario, bank swallows most commonly breed in the southern part of the province, the largest colonies located along the shores of Lakes Erie and Ontario, and along the Saugeen River. There are sparse numbers in the northern parts of the province. Bank swallows roost at night during migratory and post-breeding periods in large wetlands or shrub thickets in or near water. During the breeding and migratory seasons, they can be found foraging in a variety of open terrestrial and aquatic habitats including wetlands, open water, riparian areas, open grasslands and shrubland, and agricultural areas.

Dr. Mitchell will describe the use of automated telemetry technology in a study geared to monitoring the cryptic and broad-scale movements of bank swallows from their breeding colony 30 kilometres west of the wetlands on the north shore of Lake Erie to a major wetland complex around Long Point Ontario. These movements occurred during the early evening hours. Follow-up research sought to determine whether the birds were willing to make this same journey from colonies located up to a distance of 80 km. from the Long Point Wetland Complex. In Dr. Mitchell’s words “We also investigated the timing of these movements in relation to sunset and sunrise, the potential function of these movements with respect to temperature and precipitation, and the energetic and opportunity costs of making such large movements during the breeding period. The potential importance of breeding season wetland roosting habitat will be discussed in the context of historic rates of wetland loss in Ontario.”

Please join us for an interesting and informative evening. Doors will open at 7 pm. Refreshments will be available throughout the evening. A discussion will follow the presentation. There is a non-member fee of $5 and no charge for youth under 18. For further information, please contact MVFN’s Program Chair, Gretta Bradley at glbradley@icloud.com.