Subject: [Tweeters] Re:PURPLE MARTINS ARE RETURNING!
Date: Aug 20 14:15:20 2007
From: stan Kostka lynn Schmidt - lynnandstan at earthlink.net


Hi Tweeters,
Regarding Purple Martins double brooding, the topic has been
controversial. Generally, more recent accounts support single
brooding, whereas earlier authors believed the birds to be double
brooded. One very early account written by Audubon even mentioned
third broods, in Louisiana. Charles Brown in his 1997 Birds of
North America species account briefly refers to second broods, and
discusses double-broodedness at length in the 1978 Wilson Bulletin.
In short, double brooding occurs rarely, only in the extreme southern
US, and, to the best of my knowledge, has only been documented with
certainty, with banded birds and daily nest checks, in Texas, where
martins begin arriving early in January. There, first egg dates of
second broods were in June. In contrast, martins here near the
northern extent of their western range generally do not begin
arriving until April, and in my experience of doing years of nest
checks do not lay their first clutch until June. Even if that
schedule were pushed ahead a full month in a hypothetical extreme
case, there simply is not enough time here for a pair to pull off
two successful nests, a process that generally takes about ten
weeks, or longer, figuring a week to build a nest, a week to lay
eggs, more than two weeks to incubate, about four weeks to fledge,
and a week or more for post fledging care by parents. Perceived
double broods here are most likely re-nesting attempts, as martins
sometimes lay replacement clutches if the first fails to hatch or the
young die soon after hatching. Re-nesting attempts can result in
young still in the nest in late August or even into September.

Stan Kostka
lynnandstan at earthlink.net
Arlington WA

Subject: PURPLE MARTINS ARE RETURNING!
From: "Andy Stepniewski" <steppie AT nwinfo.net>
Date: Fri, 17 Aug 2007 13:36:08 -0700
... Some pairs have even completed two broods...