Posted by: badbirdz2 | April 18, 2007 @ 5:33 am

Timing is everything

It’s that time of the year again- when neotropical migrants have to decide between migrating in poor conditions, or risking being late on the breeding grounds. Last night was definitely evidence of such a decision, as winds were primarily out of the north at most altitudes, with a slight southwesterly component only at the surface. This has caused the radar images to be a bit “messy”; as you can see from the velocity images whereby most movement is from NW –> SE yet there is still a migration signal from S –> N. Birds are seen crossing the Straits from Cuba, as well as leaving the Miami, Tampa, and Melbourne radars just after sunset. Birds are fighting a headwind, so they’re not likely to continue “overshooting” as they make landfall. The movement is not huge, but it’s possible that the effects will be evident at local migrant traps across the state, especially along the east coast where birds seem to be concentrated due to the winds. Please come back and post your reports!

Frames are every 1/2 hour for reflectivity and velocity, and 1 hour for the regional composite
Base Reflectivity image from Key WestBase Velocity image from Key West Base Reflectivity image from MiamiBase Velocity image from Miami Regional Base Reflectivity for the Southeast

Advertisements

Responses

  1. “Messy migration” = “messy banding” in Cape Florida today. Our sample of birds today was eclectic and continues to be birds coming from/through Caribbean and mainland South America with smattering of trans-Gulf migrants. The thrushes, tanagers and grosbeaks are showing up in A.D. Barnes Park, ~ 12 miles farther inland. The birds’ conditions were all over the place — from great breast muscle and fat to a couple of hard luck cases. With supposed wind shift to west tonight, tomorrow’s banding should be good experiment in ground truth — at least for extreme SE Florida.

  2. what did you get? stronger fliers? I’m thinking that possibly only the stronger fliers would have chanced it last night.

  3. Ovenbird, Black-throated Blue, Worm-eating, Common Yellowthroat, Gray Catbird, Western Palm, Black-and-white (poor condition), Prairie, American Redstart and Red-eyed Vireo (these were also poor condition). Seen but not banded: Bobolink, Blackpoll (1 banded yesterday) and Cape May. Compared with recent birds, birds today were generally 1-2 notches down on breast muscle and ~3 notches down on fat. Painted Buntings were the exception and were butterballs.

  4. AD Barnes was a good place to be today. I’m thinking some new birds landed over night from down south and others from further west looking for food. There was one tree with lots of fruit and thats where the birds were.

    Lot of variety for recent weeks.

    Compiled list from various observers
    Warblers

    Yellow
    Northern Parula
    Prairie
    BT Blue
    Yellow-throated
    Red Start
    Black-poll
    Swainson’s
    Prothonotary
    Wormeating
    Palm
    Magnolia
    Cape May
    Louisiana Waterthrush
    Northern Waterthrush
    Ovenbird

    Thrush

    Veery
    Gray-cheeked
    Swainson’s (possible)

    Others

    Yellow-billed Cuckoo
    Cedar Waxwing
    Rose-breasted Grosbeak
    Summer Tanager
    Scarlet Tanager
    Blue Grosbeak
    Indigo Bunting

    and a Sora! A first for the park…


Categories

%d bloggers like this: