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Bryant - It is interesting that you note the westerly winds caused by the subtropical storm off NE Florida last week produced a large fallout in south FL - several people mentioned it was one of the largest they have seen in a long time.  Normally these birds keep flying further north under good conditions, but fighting this west wind caused them to drop down to the first landfall.  This appears to be consistent with what we observed last year, that west winds are needed to produce a fallout along the east coast of FL.  In periods of easterly winds, it appears that the transatlantic migrants use the winds to make their flights, and are even pushed across the state to the west coast.   Ken Tracey has had some huge counts (of primarily Caribbean migrants) at the Green Key funnel the last few days, influenced by a strong east wind, whereas on the east coast, in Volusia County, there has been little to no activity.  During the subtropical storm last week, causing very strong NE
 winds north of the center, there was a large shorebird fallout, but relatively few passerines.

Trying to predict fallouts on the east coast seems to require:
1. Good weather in the islands, with South or East winds to promote the flight, and 
2. Strong West or NW winds hitting the birds upon their arrival in the state.

Additional comments would be appreciated.

Bob Wallace
Alachua FL

----- Original Message ----
From: Bryant Roberts <[log in to unmask]>
To: [log in to unmask]
Sent: Tuesday, May 15, 2007 11:41:10 PM
Subject: Re: [FLBIRDS] Smoke & Its Effect On Migrants

We never got the heavy smoke and haze down here that you got in North
Central Florida, the worst visibility I witnessed was about one mile.  The
smoke probably wasn't a problem in south America and the Caribbean and
didn't effect the numbers of migrants departing from there.  The main
controlling factors for spring migrant numbers on the southeast coast are
wind direction and heavy rain.  The rain will force down migrants that
would normally overfly the area and westerly winds will cause migrants that
find themselves out over the ocean to attempt to fly towards the coast and
land.  On the west coast easterly winds have a similar effect.

The only unusual thing I noticed while birding near the coast during the
smoky westerlies was that while there was the usual peak in arrivals late
in the morning birds appeared to be coming in off the ocean through the
late afternoon.  This makes me wonder if the limited visibility caused some
disorientation while the migrants were over the ocean, perhaps causing
losses there.  It would be interesting to know if there were reports during
this period of unusual numbers of birds landing on ships in the Atlantic
off the southeastern US.

I really haven't studied migratory behavior as much as I should have but I
believe important factors influencing the departure of migrants include the
physical condition of the bird, wind direction, and the birds ability to
see stars after sunset.  Smoky conditions in Florida could have made it
difficult for birds to see the stars and delayed departure.


Bryant Roberts
Davie, Fl


> [Original Message]
> From: [log in to unmask] <[log in to unmask]>
> To: <[log in to unmask]>
> Date: 5/15/2007 9:47:12 PM
> Subject: Re: [FLBIRDS] Smoke & Its Effect On Migrants
>
> I can accept that this report is flawed--it's not from a reliable 
> birding source, but I thought it was of interest.  I have been 
> wondering, especially when the smoke gets heavy here, how the birds 
> react.  Don't have any sources that I know of that say they hunker 
> down, or fly from it, or become dioriented or impaired.  So I was 
> interested to hear this report.  I can live with a misidentified 
> species--but wonder if the general phenomenon is true.
>
> Dotty
>

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