LISTEN TO THE AUDIO VERSION
By Carla Allen
Atlantic Puffin on Green Island, Yarmouth County. Alix d’Entremont Photo
Bird bioacoustic data to be used for conservation of species-at-risk, biodiversity and more in southwest NS project
YARMOUTH, N.S. —
After receiving a tip from the owner of Mark’s Island, south of Yarmouth, regarding strange noises at night and what looked to be bats flying about, volunteers visited the site on June 26 and left an AudioMoth.
Kathleen MacAulay, Bertin D’Eon and Alix d’Entremont, who is also a Nova Scotia Bird Society (NSBS) boardmember, are participants in the Listening Together Project in southwest Nova Scotia.
The tiny recording devices they left on Mark’s Island, as well as nearby Spectacle Island, were set to record four 10-minute sessions at night and one 10-minute period at 6 a.m.
D’Entremont says he chose those two islands specifically since he thought there might be Leach’s Storm-Petrels breeding. The tiny seabirds breed underground in burrows and only go to and from them at night.
On July 19, he and MacAulay retrieved the devices and were ecstatic to have found vocalizations of Leach’s Storm-Petrels from both islands, instead of bats.
“We knew they bred on nearby Outer Bald Island but breeding evidence from two new sites in the Tusket Islands is exciting,” says d’Entremont.
To fully confirm breeding, they’ll have to search for burrows on the island. That’s something he hopes to do next spring/summer.
Although COVID-19 regulations delayed the Listening Together project this year, there are three monitoring initiatives in progress, involving 17 volunteers.
An AudioMoth deployed and ready to record birdsong.
The project is one of several initiatives in southwest Nova Scotia funded by the federal government’s Canada Nature Fund. The protection and recovery of species-at-risk through innovative ecosystem-based projects is one of the significant components of the fund.
Southwest Nova Scotia is one of 11 “Priority Places” in Canada identified in the federal program.
The four-year project is aimed at enhancing biodiversity through the use of bioacoustics.
John Kearney, also a NSBS boardmember and lead partner in the Listening Together project, says recent technological advances make it economically feasible to record species of risk over a wide geographical area on a 24-hour basis.
“At the same time, scientists are developing methods through artificial intelligence to process large quantities of acoustic data,” he says.
“Our project aims to empower environmental organizations and Mi’kmaq communities in the use of bioacoustics for the conservation of species at risk and biodiversity.”
There are three parts to the project including the monitoring initiative that involves breeding bird surveys on offshore islands. Knowledge of breeding birds on coastal islands is limited.
Researchers hope to determine if these islands play a critical role as refugia as temperatures increase due to climate change.
D’Entremont says that likely one of the most noticeable trends on the Tusket Islands is the increase in the number of Atlantic Puffins.
“The cause of this change is probably not a warming climate, but a bounce back to historical numbers,” he says.
Predation by non-native species and humans are thought to have been the cause for the decline in the past.
D’Entremont adds that recent estimates of Atlantic Puffins on the Mud Islands range from 300-400 individuals compared to maximum counts of 25 in the mid-1990s. This increase could be an expansion from the colonies in Maine.
Changes in bird populations resulting from the infestation of the Hemlock Woolly Adelgid will be tracked. Infestations have resulted in significant levels of tree death, even destroying whole forests in the Eastern United States.
Breeding bird surveys in hemlock stands is also being monitored. Changes in bird populations resulting from the infestation of the Hemlock Woolly Adelgid will be tracked.
The third initiative is mapping the migratory stop-over and staging areas of the threatened Canada Warbler on coastal peninsulas, headlands, and islands. Previous acoustic studies show a concentrated movement of Canada Warblers between Brier Island and Yarmouth in August.
“We wish to learn the full extent of this movement and take appropriate actions to protect the migratory habitat of this species at risk, says Kearney.
D’Entremont has placed audiomoths on Green Island (near Gannet Rock) and John’s Island (near Harris/Big Tusket Islands) and will also be placing one at Pubnico Point to monitor Canada Warblers.
Acoustic studies show a concentrated movement of Canada Warblers between Brier Island and Yarmouth in August.
The Canada Warbler breeds most abundantly in moist forests but can be found in more varied habitat during migration.
As Green Island has no forests at all, d’Entremont placed the device on a light tower facing away from the fog horn. The one on John’s Island is in an open area facing a low area (which can be wet) and a deciduous ridge.
“Hopefully the wet area and deciduous trees will be a good foraging area for the warbler and the clearing will allow the microphone to pick up sounds from a distance,” he says.