Snakes, raccoons, and Great Horned Owls are everywhere!
From: Ken Kostka, Edinboro, PA
Date: 9/16/99
Time: 5:47:53 PM
Comments
Every spring, the PMCA receives dozens of calls from distraught landlords wanting
to know why their martins didn’t return. Many mistakenly believe the popular
myths that when this happens it means the colony must have been killed in a
big storm during migration, or that they were shot while wintering in Brazil.
We explain that neither scenario is likely since martins do not migrate or overwinter
as a colony, and their roosts sites are protected in Brazil. We tell them that
martins usually abandon a breeding site because they experience “total reproductive
failure” – that is, they fail to fledge any young, and that one of the most
common reasons for “total reproductive failure” is owl, raccoon, or snake predation.
(Almost inevitably, these landlords didn’t do nest checks or have predator guards
on their housing.) Now what I 
hear next, although predictable, never ceases to amaze me. It’s usually something
like "Well we don’t have any of those around here." !!!!!
hmmm... I usually explain that these predators are active at night, and that
they’re unlikely to be detected because of their nocturnal nature. (I assume
most people aren’t out prowling around in their backyards in the middle of the
night.) I think many people are reluctant to admit the possibility of nocturnal
predation since they are understandably uncomfortable with the thought of their
martins having been eaten! Also, many people don’t believe that snakes and raccoons
can climb metal poles quite easily. I have found myself installing climbing
predator guards at certain colony sites after having given up trying to convince
the landlords just how risky it is to not have a predator guard. In any case,
spread the word -- snakes, raccoons, and Great-Horned owls are EVERYWHERE at
night, even in suburbia, so make sure your housing has predator guards! For
more information on martin predators, go to
http://purplemartin.org/forumarchives/interest.htm
Ken Kostka, Purple Martin Conservation Association
