Wednesday, January 23, 2013

Shorebird activity

A few days ago, Laura Jacobs alerted me to an American Oystercatcher that she had just seen at Reeds Beach. This might not seem too great a revelation, given that New Jersey seems to be hosting a crazy set of European birds (Northern Lapwings, Pink-footed Goose, Barnacle Goose), as well as an as-yet-inexplicable arrival of Crested Caracaras, and yet it is certainly intriguing. I quickly recalled that I had indeed seen an American Oystercatcher there myself a couple of weeks ago and hadn't thought any more of it, but Laura's email came just shortly after a longer communication from Tony Leukering, which also brought news of shorebirds on the bayshore.

During the winter, shorebird distribution is largely influenced by the availability of food (as you may well imagine) and the availability of food is more often than not influenced by weather. Most North American shorebirds head well south for the winter, with many wintering around the shores of the Caribbean, while others head way down into South America - even as far as Tierra del Fuego in the very south of Argentina and Chile. In milder winters, however, shorebirds will often stay further north, and this has certainly been the case this year, with Sam Galick reporting some 80 Western Sandpipers and Stone Harbor Point for example and, just yesterday, I counted some 40 Greater Yellowlegs in the tidal creek at Beaver Dam, South Dennis. During milder winters, so-called benthic invertebrates - those creatures that live in that strange world somewhere between solid mud and water - remain nearer the surface and survive the winter in greater numbers, thus providing more food for wintering shorebirds.

But mild weather doesn't seem to fully answer what is happening this year; Tony Leukering's sightings along the bayshore in Villas have revealed numbers of birds that one might expect on the Atlantic coast, at Stone Harbor Point or Two-mile Beach for example, but certainly seem surprising along the bayshore, where sediment - and thus feeding opportunities - are different to those on the coastal side of the Cape May peninsula. Tony's recent note reported 136 Black-bellied Plovers, eight Ruddy Turnstones, 12 Red Knot, six Sanderling, two Western Sandpipers and 250 Dunlin at Miami Beach, an impressive haul for the bayshore.

It will be interesting to see how these numbers might change with a run of colder weather now settling in and we can only speculate at present as to why these birds are favoring the bayshore, but it is not beyond the realms of possibility that sediment shifts caused by Hurricane Sandy may have altered the bayshore ecology and it will be interesting to see if this continues into May and the all important horseshoe crab spawning season.

Sightings Update
Sightings over the past few days have continued to be focused largely on the interesting array of wintering birds at Cape May Point State Park, most of which continue to be reported periodically, including the Townsend's Warbler and the White-eyed Vireo. A Yellow-breasted Chat appears to be wintering at Higbee Beach and the male Western Tanager continues at Cape May Court House (though I am up to seven visits and still no sighting of this bird yet!!!). Other long stayers include the King Eider, which wandered up to Higbee Beach and back to St Mary's and the Western Grebe in Cape May Harbor off Delaware Avenue. An adult Black-headed Gull is currently wandering anywhere along the bayshore between the Cape May ferry terminal and Norbury's Landing, Del Haven, a Vesper Sparrow was reported by Don Freiday from the Cape May NWR at Green Creek on 21st and a flock of eight or nine Red Crossbills, reported as type 10, was at Cape May Point on 20th.

The bizarre Crested Caracara saga continues with a bird seen briefly on 20th, on Dias Creek Road in Cape May Court House, by people looking for the Western Tanager...

Further afield, a Cackling Goose was along River Road, just north of the Cohansey River in Cumberland County on 20th and a Short-billed Dowitcher was photographed with Marbled Godwits and Western Willets at the Brigantine Island shorebird roost, just north of Atlantic City on 21st. Golden Eagle and Eurasian Wigeon were reported on 19th from Corbin City impoundments, but note that currently it is only possible to walk in to this location, due to damage from Hurricane Sandy.