Predation ends the Osprey Cam nest’s season; a look at how the ospreys are faring this summer.
On July 17, at 5:34am, the Henry L. Ferguson Museum Osprey Cam at Middle Farms captured the last remaining osprey fledgling being removed from the nest by a bald eagle. The annual osprey count had been completed just the previous day by Museum board members Jim Baker and Todd McCormack. The incident at the nest—and the results of the count, when considered historically—paint the picture of an evolving dynamic between these two large avian predators. Our nascent bald eagle population appears to be flourishing. Their nest appeared on the southern shore of Middle Farms Pond almost two years ago, but this is the first year they have produced offspring. There are two fledglings in the nest, one of which is already flying.
The nesting bald eagles have had very promising start. This year our summer resident ospreys have not fared as well.
On Fishers Island, 17 osprey fledglings are reaching maturity this summer—a 12-year low. Fishers Island has 37 nesting sites, 28 of which were occupied by breeding pairs this season. Only 12 of those nests had fledglings as of the count. Two fledglings previously recorded at the Bogert nest disappeared one week before the count. An examination of the data after the Osprey Cam predation shows that no fledglings now exist between the Gate House and the Big Club. For that area to be lacking fledglings is a first for this century. However, a single year’s data is not indicative of a trend. Nevertheless, the presence of bald eagles, known for preying on the fledglings of other birds, has been a factor in osprey population declines in other areas of the country.
What we do know is that the relationship between bald eagles and ospreys on our island is evolving. If you are interested, an informative exploration of their interactions is given in this short article by ornithologist Rob Bierregaard.
The causes of the declining osprey fledgling success rates are under study nationally. The HLF Museum’s Wildlife Committee continues to collect data to help understand how these new interactions effect our island ecosystems. You too can help by signing up to monitor a specific osprey nest as part of the Osprey Observation Program or, if you are interested in other ways to help the HLFM Wildlife Committee, please contact Pierce Rafferty (prafferty@fergusonmuseum.org).
By Terry McNamara, H.L. Ferguson Museum Wildlife Committee Chair
The mission of the Henry L. Ferguson Museum is to preserve our shared history and conserve our natural habitats by engaging, educating, and inspiring all Fishers Islanders.
