Prothonotary Warbler at Lord Stirling Park
(Click on the photo for a larger image.)
The Prothonotary Warbler (PROW) at Lord Stirling Park is usually seen carrying nesting material on visits to the nest box. This is viewed from the enclosed blind on the west side of Branta Pond. From personal and other accounts, this PROW has never been heard or seen singing. These are clues to the gender of this individual even without a plumage discussion.
The following excerpt is from Cornell Laboratory of Ornithology’s Birds of North America: “Only female builds nest, although male often places foundation of moss in cavity during territory establishment…Males establish territories shortly after spring arrival, through intense and frequent vocalization and aggression against other males. Territory is centered on ≥1 nest cavities in which males place up to 8 cm of moss.”
Based on that criteria, the PROW in the photographs is a female as it has clearly been seen carrying twigs, grasses and other nesting materials but never moss. For a comparison, this observer watched a male PROW at the Lincoln Park Gravel Pits in May, 2016. It sang continuously only stopping to gather mossy material and placing it in one or two tree cavities. Unfortunately, it apparently never found a mate. This corroborates the Birds of North America statement.
Gulls in Somerset County
New Jersey ornithological history is being made in Somerset County. 145 Lesser Black-backed Gulls were at Opie Road on May 31 (Jeff Ellerbusch). As far as is known, this high a total has never been recorded this late in spring before in New Jersey.
This group is made up of mostly 1st through 3rd cycle gulls and have been present in varying numbers throughout the spring. The gulls wander between the Norz Farm Fields and Opie Road. Lately, they are absent early in the morning bringing up the question: where do they go? The Hunterdon County reservoirs, Round Valey and Spruce Run, are likely answers, possibly Merill Creek in Warren County, but no observations from there are recorded.
40 Ring-billed Gulls were with the Lesser Black-backed Gulls on May 30. Semipalmated Plovers have been observed there recently. Jeff also had an alternate plumaged Black-bellied Plover at Opie Road on May 30. This is a rare bird for Somerset County (and an even rarer species in Morris County).

Black-bellied Plover with Ring-billed and Lesser Black-backed Gulls, Hillsborough Twp., May 30, 2017 (photo by Jeff Ellerbusch)
The Lesser Nighthawk of Lord Stirling Park
The Lesser Nighthawk (LENI) continues to inhabit Lord Stirling Park. Last evening, this observer was present when the LENI lifted off at 20:08 and hunted over Esox Pond before disappearing out of sight. It was a treat to see the LENI in flight rather than the roosting pose, as in the above photo, familiar to the many people who come to view this southwestern vagrant.
The news came through the birding texting services today that The Raptor Trust was planning to capture the LENI and relocate it. The latest word mocosocoBirds knows of is that this plan is shelved for now and that The Raptor Trust will wait and see for a week. Hopefully, The Raptor Trust will let nature take its course and not try to move the LENI once again.
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