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Re: Southern Lapwing chase - 6/22 (item #2)

From:

Phil Davis

Reply-To:

Phil Davis

Date:

Fri, 23 Jun 2006 14:22:57 -0400

MD Osprey ... FYI ...

>From: Paul Pisano <>
>To: 
>Date: Fri, 23 Jun 2006 11:17:38 -0400 (EDT)
>
>Hi Phil,
>
>You've probably already seen this, but this was just posted on
>FL Birds.  (snip).
>
>Paul
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>Subject: Lapwing stuff
>From: tom curtis
>Date: Fri, 23 Jun 2006 11:07:35 -0400
>
>
>I have been researching the possibility that Southern Lapwings might
>naturally reach North America.  Now that someone else has seen the St.
>Marks bird, and since there appears to be one reported in Maryland, I
>thought I would present my results.  In the interest of saving space I did
>not include references, but can provide an annotated copy to anyone who
>might be interested.
>
>Several factors suggest that this species may reach North America on
>occasion:
>
>1.  Southern Lapwing has undergone a significant range expansion and now is
>an established breeder in the Lesser Antilles in the Caribbean and as far
>north as Costa Rica in Central America.
>
>2.  Competition with cattle egrets may be driving lapwings into new areas,
>possibly contributing to the range expansion.
>
>3.  Conversion of South American forest to agricultural purposes has
>resulted in significant increases in Lapwing population sizes, and
>increased population size has been tied to vagrancy.  Consistent with this
>observation, out-of-range Southern Lapwings have been noted along the north
>Pacific coast of South America, and in Belize and Mexico in Central
>America.  In fact, it appears that the Belize bird may derive from a
>southern (lampronotus) population, further establishing precedent for
>long-range (several hundred miles) vagrancy in this species.
>
>4.  The 2005 hurricane season was one of the most intense on record and
>there is precedent for birds being move long-distance via hurricanes. In
>this vein, it should be noted that in the last fifty years there have been
>only 7 named storms that passed through the southern Caribbean earlier than
>August 1.  Of these, two occurred in 1960 (7/10) and 1961 (7/20), and three
>occurred between 2003 (7/7) and 2005 (7/4, 7/10).  These storms represent
>the four earliest dates for named storms in that area.  The only November
>and December storms in that area occurred in 2003 (12/4) and 2005
>(11/11).  Interestingly, both "clusters" coincide reasonably well with
>periods when Lapwings were seen in North America.
>
>5.  Although not migratory, seasonal variations in local lapwing abundance
>suggest intra-range expansion/contraction cycles or nomadic following of
>resources, increasing the probability for vagrancy.
>
>6.  All but one North American sighting of Southern Lapwing has occurred
>during late spring/early summer (28 April, 21 May, 1 June, 2 June, 17 June,
>25 June, 23 July) and all except the MD bird have occurred in Florida.  One
>more recent spring report (mid-February - 21 April, 2003) detailed two
>individuals that showed clear indications suggesting previous
>captivity.  There appears to be only one fall report (1959).  If these were
>all truly escapes, one would expect either a more even geographic and
>temporal distributions or a concentration during the peak of hurricane
>season when birds might get accidentally released.
>
>Establishing the true nature of such sightings is critical.  For example,
>Stevenson & Anderson (1992) stated that several previous sightings of this
>species in Florida were unlikely to be of true vagrants, and it appears
>that this assertion was the basis for excluding Southern Lapwing from the
>Migratory Bird Treaty Act.  Care must be taken in applying consistent
>critieria when establishing vagrancy status for out-of-range birds.  In
>this case, previous reports of Southern Lapwings were ascribed
>to escapees since the species typically does not engage in long-distance
>movements.  However, the same criterion may argue against a given
>individual being an escapee unless captive sources are close enough that
>long-distance movements are not required for the bird to reach the area
>where a sighting occurs.
>
>My two cents, let the flaying begin.
>
>Have fun,
>
>Tom Curtis
>tcurtis AT psy.fsu.edu

==================================
Phil Davis      Davidsonville, Maryland     USA
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