Tuesday, May 20, 2008

Tracking a nest

This season I will share with you, the trials and tribulations of a nesting pair of ospreys. This nest is one of many that I survey annually to determine whether or not the state population has had a productive season.

Location: Bass River Township, NJ
Nest name: 146-B2
Year found: 1999
Structure type: 1 post, man-made nesting platform. w/ predator guard
Link here for platform construction plans.

This area along the Atlantic Coast of NJ has been slow in terms of osprey colony growth. It takes time to increase smaller less dense osprey colonies. It is known that when a male osprey returns to breed, he looks for other nesting ospreys. This shows him that this is "suitable" nesting habitat, because ospreys nest near water and their prey, fish. It's simple, when there's more ospreys nesting in a small area, it signifies that the area is suitable to a new bird.
OK, more about 146-B2, since '99 when the nest platform was erected, it has only been active 5 times in nonconsecutive years over 9 years. Since '99 it has only produced 2 young in 2007. Not the best results, but promising. This year, the total colony of ospreys will probably have reduced productivity(# young produced per active nest), due to the unseasonably cool and wet conditions during incubation and hatching. In 2003 we had the same conditions, a damp cool spring, which showed by a reduction in productivity. Today I checked two nests in Sedge Islands WMA at the Southern tip of IBSP. One nest had failed (= no eggs or young produced from an active nesting pair) and the other was still incubating. When the nest fails it could mean a variety of things happened, everything from how experienced the male is at catching prey, prey availability, weather, or predation. This year weather will play a big factor in the # of failed nests.

More to come soon on nest 146-B2 on the Mullica River. I plan on kayaking out to the nest this weekend.


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