Photo from the Field: Failed
by Ben Wurst / Habitat Program Manager
In the coming weeks CWF staff, NJDEP Biologists, and a handful of dedicated volunteers will descend onto the coastal saltmarshes of New Jersey to conduct a census of nesting ospreys. The last census was conducted in 2017 when 668 nesting pairs was recorded. They will survey remote areas of back bays by boat. Nests are surveyed in a variety of methods, with ladders being the traditional method, which allow for closer inspection of nests and banding of young for future tracking. Other nests are surveyed from a distance using optics or cameras with telephoto lenses, a mirror, smartphone or GoPro on an extension pole and a sUAS (when operated by a FAA licensed unmanned pilot). The goal is to recorded the total number of nesting pairs throughout the State.
Nests are surveyed to determine the overall size of the population and their outcome. Nests that contain plastic marine debris are cleaned. Notes on nest condition are taken, for repairs in the non-breeding season. Lastly, fish are left at nests when banding young to offset disturbance.
We have already conducted a few early season nest surveys on Barnegat Bay and the Mullica River and have documented reduced production and/or empty nests. The empty or failed nests seems to be the result of the week long nor’easter which hit the area during the second week of May. The strong NE winds made foraging very difficult for coastal nesting ospreys and caused females to abandon incubation to attempt to forage for themselves (since their mates were unable to catch prey) and avoid starvation. This left eggs vulnerable to predation from avian predators like gulls and crows.
We witnessed this behavior at our Barnegat Light Osprey Cam, where the female would leave the nest and eggs for up to 45 minutes at a time. This happened several times, for a variable length of time, over several days after the nor’easter. After young hatch, food stress will lead to brood reduction. This too has been observed at some nests that have or had young and now don’t.
Even though it may end up being one of least productive years since the early 2000s, ospreys have done quite well with above average productivity. Ospreys are an important bioindicator for the health of our coastal environment and our surveys are crucial to documenting this. We can’t thank all of our volunteers who survey osprey nests to help us keep track of the state population! If you live near an osprey nest, then you can report nesting activity online, using Osprey Watch, which is a global osprey watching community.
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We have been busy up here in the northwest quadrant of NJ checking nests since March!! I don’t want to “count chicks before they hatch”, but many more ARE hatched compared to last year, so we are hoping for good numbers of fledglings! Happily, our weird metal tower nests on hill and mountain ridges by rivers and lakes don’t seem to have been affected by the nor’easter as have your shoreline, salt marsh platforms! Stay tuned….
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