Thursday, May 01, 2014

Warbler count = 10


Warbling Vireo - courtesy of National Geographic Magazine

Joe Decostanzo reports on his AMNH walk this fine May morning:
It was slightly misty with a low overcast for the start of my Amer. Mus. Nat. Hist. bird walk in Central Park this morning at 7 am, but it was not raining. More importantly there were birds! Highlights below:

Eastern Kingbird – 1, the Point Blue-headed Vireo – several
Warbling Vireo – 1 singing east of the Maintenance Meadow
House Wren – singing northeast of Upper Lobe
Wood Thrush – west side of Azalea Pond
Yellow Warbler – singing on the Point
Yellow-rumped Warbler – all over
Black-throated Green Warbler – 2, east of the north end of the Upper Lobe
Prairie Warbler – Hernshead and Bank Rock Bridge, also one singing west of Azalea Pond
Palm Warbler – scattered individuals
Black-and-white Warbler – scattered individuals
American Redstart – male on the Point
Ovenbird – 2, singing near Azalea Pond
Northern Waterthrush – singing by Upper Lobe and the Oven
Common Yellowthroat – singing at Hernshead
Rose-breasted Grosbeak – 3, south of the weather station
Orchard Oriole – 1 calling south of Tupelo Meadow 

I did not see but heard reports of Great Crested Flycatcher, Blue-winged Warbler (singing, old Pin oak area to Azalea pond), Northern Parula (east of Upper Lobe), Magnolia Warbler (the Point), Worm-eating Warbler (northwest of Azalea), Scarlet Tanager, indigo Bunting.



Wednesday, April 30, 2014

Q & A with John Blakeman


Pale Male, Octavia [his mate] and one of their 2 chicks in the nest on Monday 4-28-14
photo courtesy of PaleMale.com


 Reader  Katy Salter Goodell sent in a question about Red-tailed Hawks that I forwarded to Ohio hawk expert John Blakeman. Here is the question and his reply:
         
                      Q:        
I have a question about the sibling pecking among red-tailed hawk hatchlings that lasts for ten days to two weeks. It sure looks--at first--like aggression, since the hatchlings peck at each other rather than at twigs, unhatched egg, etc.  BUT it doesn’t seem correlated with conflict over food or establishment of dominance. And then it disappears.
Is there any scholarly research on this pecking?  Any interesting comparisons with other species?
(I know that sibling pecking has been studied in grebes, where it definitely is associated with access to food, and would be defined as aggression. But red-tails don’t fit that model) 
Katy Salter Goodell

             John Blakeman replies :


Although these behaviors of young Red-tailed Hawk eyasses can be labeled "sibling pecking," they are not. Hawks do not, and cannot "peck," that is, that they cannot thrust their bills into food or other objects.
Hawks, even as young hatched eyasses, can only bite. Their curved-over bills aren't made for pecking. They can only bite, not peck. The muscles controlling biting motions in the jaw are extremely week. The little hawks can barely open their bills, and their ability to grip down tightly when biting is very limited.
Hence, there is never any injury when Red-tail eyasses so typically spend lengthy periods "biting" each other. Mostly, they are just pushing their bills against each other, and also learning how to truly bite and grip --- without injury to the sibling. All of this hones head and neck motion controls. Essential.
These behaviors and neuromuscular reflexes are exactly the same as used when plucking tidbits of food from the mother's food-garnished bill during feeding. At this young age, the neurological pathways and circuits of the tiny hawk are very limited. Every behavior is a "going through the motions" reflex. Rather indistinct and repetitive.
But in the second week, behaviors become more varied, deliberate, and controlled, as the brain begins to mature.
--John Blakeman

Monday, April 28, 2014

Yellow-throated Warbler!

Yellow-throated Warbler - Central Park 4-23-07
photo by LLOYD SPITALNIK http://www.lloydspitalnikphotos.com 


Gerard Savaresse writes [via ebirdsNYC]:

Today at 2:19 p.m. Yellow-Throated Warbler seen on the West side of the drive in a patch of Elm trees just South of former(?) Tavern on the Green. The bird was actively feeding there around 12:30--possibly the same individual seen by others on the Mall this morning. 

Other birds of note included a Northern Parula singing in the North End, along the East slope of Great Hill (near the swimming pool); Prairie Warbler at the Point/Oven/Riviera area. Also a hooded warbler singing near here, but I couldn't find it. 

Gerard









Sunday, April 27, 2014

7 warbler species today!

Ruby-crowned Kinglet -- photo - 4/24/07 by LLOYD SPITALNIK http://www.Lloydspitalnikphotos.com
Date: April 27, 2014
The NYC Audubon Bird Song class had a  very nice day in Central Park. We recorded 33 species  including:
7 warbler species (Pine, Palm, B&W, BT Green (2 singing nicely), N. Waterthrush (singing), Prairie (2 singing), Yel-rumps)
Also seen were many Ruby-crowned Kinglets (some in display), Br. Thrashers (4), BG Gnatcatchers (6), Swamp Sparrow and a good number of Hermit Thrushes
Good Birding,
Joe Giunta