Bioacoustics Almanac — July Listening Together Project
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This month’s bioacoustics Almanac will feature species at risk occurring in Nova Scotia.
The Eastern Wood-Pewee is listed as “special concern” by the Canadian Species at Risk Act (SARA) and “vulnerable” by the Nova Scotia Endangered Species Act (NSESA). It nests primarily in deciduous forests, and it is very likely that you have heard its plaintive call, “pee-ah-wee.” It is much harder to see than to hear as it nests and forages in the forest canopy. The species is declining due to a loss of habitat in breeding, migratory, and wintering areas of North, Central, and South America, respectively. It has also been affected by the use of insecticides which diminishes its food supply, and by heavy browsing by White-tailed Deer which reduces understory habitat (Painting Louis Agassiz Fuertes, Sound: Xeno-Canto, Martin St-Michel).
The Common Nighthawk is listed as “threatened” by SARA and “threatened” by the NSESA. It is a bird familiar to many who spend summer evenings outdoors where one can hear its “peent” call and booming courtship dives in both the country and the city. With its bat-like flight, it is also seen in flocks as it begins to migrate south in early August. The Common Nighthawk has declined in Canada by 50% in recent years, due to unknown factors, but probably related to the decline in insects from pesticide use or habitat loss (Painting: Louis Agassiz Fuertes; Sound: Xeno-Canto, Thomas Ryder Payne).
The Piping Plover is listed as “endangered” by SARA and “endangered” by the NSESA. It nests on sandy beaches on the coast of Nova Scotia. As the same beaches are popular recreational areas for people during the summer, careful management is required to keep people and their pets separated from this critical habitat for the Piping Plover (Painting: Louis Agassiz Fuertes; Sound: Birdzilla).
The Red Knot is listed as “endangered” by SARA and “endangered” by the NSESA. This cosmopolitan species is experiencing its sharpest declines in Eastern North America. Nesting in the most northerly latitudes of the planet and wintering in some of the most southerly, the subspecies of Red Knot that migrates through Nova Scotia in the autumn, depends heavily on the eggs of horseshoe crabs during the spring migration in Delaware Bay. Horseshoe crabs are heavily harvested since their blue blood is used to test the safety of vaccines. The decreasing availability of horseshoe crab eggs is believed to be responsible for the steep decline of Red Knots in Eastern North America (Painting: John Gould; Sound: Xeno-Canto, Stanislas Wroza).