
Purple martins on Denman Island
Posted onDecember 9, 2024byDenman Island Purple Martin Preservation Project & WPC|Eastern Loggerhead Shrike, Loggerhead Shrike, News and Events, Western Purple Martin
Top: Purple martins and their nest boxes. Photo: C. Rea
The Denman Island community is excited and grateful to strike a new partnership with WPC to preserve the western purple martin. It should be noted that this partnership is not a first for WPC! The first conservation breeding program of the Taylor’s Checkerspot butterfly in Canada was established by WPC in 2012, with operational support from 2013 to 2016. A breeding facility was created by Peter Karsten on his Denman Island property, an instrumental step toward a successful program execution. With the help of volunteers, approximately 3,000 post-diapause larvae were bred and released to augment the dwindling population on Denman Island. After this success, WPC moved the program to the Vancouver Zoo in May of 2016, and it is ongoing to this day.
Work crew at the Community Dock. Photo: C. Rea
In early spring of 2012, Peter Karsten recognized a similar conservation need related to the purple martin population decline. He built and placed six nest boxes at the Denman Community Dock to attract purple martins to start a nesting colony. This approach had been supported by avian biologists, citing the decline in standing dead trees which have been historically used by these birds prior to competition from starlings and house sparrows. The purple martins occupied the nest boxes that same year, encouraging volunteers to continue with this effort. Additional boxes were mounted in 2014 and 2015 to accommodate the growing colony, a sign that the program had potential for success.
Over the years, the task to maintain and replace the nest boxes grew and in 2024 a group of 20 volunteers formed the Denman Island Purple Martin Preservation Project. The group’s mission is to “sustain a viable breeding colony of Western Purple Martins on Denman Island B.C. for its preservation into the future”. The task force sprang into action in the fall of 2023 to replace the aging 22 nest boxes with an additional five to spare. Peter milled about 250 feet of western red cedar boards on his Swedish sawmill, and even fabricated metal elevator mounts to raise and lower nest boxes on poles bolted to the railing of the gangway at the dock. Eager volunteers teamed up to construct the new boxes and mounted 22 of them before the purple martins returned from their wintering grounds in Brazil in late April. A handful of long white pine needles and fine twigs were added to give the nests starting material. Purple martins use this as a foundation for their nest and will add a few green leaves to complete.
The purple martins returned in 2024 and took to the refurbished homes with enthusiasm, occupying nearly all of the nest boxes. Local volunteers monitored the nests and estimated that approximately 50-70 purple martin chicks were raised to fledge, heading back to Brazil in late August.
Over the next few months, the Denman Island Team will clean the nest boxes and plan for community education and outreach efforts moving forward. Short term goals include outreach to the elementary school to educate students on the biology of purple martins and their relationship to Denman Island. Inciting excitement about these birds, which many students see flying about the ferry terminal(s) between April and August, could lead to implementing an annual celebration of their return each spring. A longer-term plan includes developing (at Denman West) and replacing (at Buckley Bay) an informational kiosk to educate the public about the biology of these important birds. Ultimately developing an ‘army’ of citizen scientists would do a great service to continued support for this project. WPC is excited to be part of this amazing initiative and to play a significant role in helping the community of Denman Island and beyond to ensure continued support for this important species.
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