Birding After Dark: Eastern Whip-poor-will Monitoring in Manitoba

With IBA events on hiatus due to COVID-19 in early summer 2021, our IBA team turned to monitoring that could be done individually. One of the focal species we were looking at was the Eastern Whip-poor-will. It is not often seen, but rather heard, with the whip-POOR-will call heard for up to three hours at a time! This species is the soundscape to rural Manitoba for many people. It is also a Species at Risk – designated as Threatened by both the federal and provincial governments.

Eastern Whip-poor-will. Photo from allaboutbirds.org.

Most bird monitoring happens in the early morning hours but for some species, like the Eastern Whip-poor-will, moonlit nights are the best times to monitor! Interestingly, none of the different types of popular bird surveys in Manitoba capture Eastern Whip-poor-wills all that well, according to the COSEWIC species report for the Whip-poor-will. The Breeding Bird Survey happens at the right time of year, but is a morning survey when the birds at not that active. The Nocturnal Owl Survey happens at the right time of day (night) but at the wrong time of year.

So, with a grant from the Habitat Stewardship Program, we set out to determine how many Whip-poor-wills call our IBAs home. Most IBA activities happen during the early morning hours, so conducting surveys at night was a new experience for myself and our summer students.

Surveys were conducted at the North, East and West Shoal Lakes IBA and Delta Marsh IBA. We surveyed between June 15th and July 15th, which is the period around the full moon during the breeding season. The full moon provides enough light for Eastern Whip-poor-wills to extend their nightly foraging. Surveys started 30 minutes before sunset and went for two hours. Due to a lack of historic data, surveys this year were exploratory, with stops in areas of Eastern Whip-poor-will habitat, rather than specific locations decided upon a head of time. Each stop included 6 minutes of passive listening targeting nightjars (Eastern Whip-poor-wills and Common Nighthawks).

Eastern Whip-poor-will habitat can include deciduous, conifer or mixed woods forests with little to no understory and near to open areas. Open areas are used for foraging for insects, while forested areas are used to roost during the day and for nesting.

Eastern Whip-poor-will recording from xeno-canto.org.

Delta Marsh IBA

Surveys were run on the east side of Delta Marsh IBA on June 21st and June 22th. We started up near St Ambroise 30 minutes before sunset and worked our way south and west over the next two nights. We were unsure what to expect during these surveys but were pleased to hear Whip-poor-wills at 9 stops over the two nights, for a total of four individuals heard during our surveys. We were keeping track of distance and direction of the calls during our surveys to reduce the chance of double-counting individuals as the sound of a Whip-poor-will can travel far. Two individuals were heard along mile road 81N and the other two were heard along mile road 77N. We also head two Common Nighthawks the first night, one near to the town of St Ambroise and the other near to the intersection of HWY 430 and HWY 411.

Birding at dusk and into the night was an interesting experience. Of course, at dusk there was a cacophony of bird sounds each evening. Near dusk at Delta Marsh we heard Killdeer, Hermit Thrush, Eastern Meadowlarks, Grey Catbirds, Baltimore Orioles, Yellow Warblers and more. Once night hit it was considerably quieter, however we did get an excellent view of a Great Horned Owl both flying overhead and later perching in a tree.

Locations of stops where Eastern Whip-poor-will were heard on June 21-22, 2021 at Delta Marsh IBA. Some points are of repeat birds. A total of four individuals were heard over the two days.

North, East and West Shoal Lakes IBA

Surveys were conducted at the Shoal Lakes IBA on June 28th and June 29th. We started on the west side of the lakes and made our way eastward. Manitoba IBA staff had a total of seven stops where Eastern Whip-poor-will were heard calling, which accounted for a total of nine individuals. A further two more birds were originally heard but taking into account the distance and direction of the song, were determined to be repeat individuals. There were no Common Nighthawks heard on the surveys at Shoal Lakes.

The general pattern of bird diversity during the survey at the Shoal Lakes was similar to Delta Marsh. Bird activity was high leading up to sundown with species like Killdeer, Yellow Warblers, Red-eyed Vireos, Clay-coloured Sparrows and Grey Catbirds singing and calling.

Locations of stops where Eastern Whip-poor-will were heard on June 21-22, 2021 at Delta Marsh IBA. Some points are of repeat birds. A total of four individuals were heard over the two days.

“Birding After Dark”

Overall, we found “birding after dark” to be an interesting new way to experience the birds and their habitat. It will be interesting to see what we are able to find next year as we plan to run the surveys again. If you are interested in joining us next summer send an email to iba@naturemanitoba.ca.