I have read (and been told) that the berries don't have the irritating oil
that the rest of the plant has.  The source below seems to imply otherwise,
but I believe that it simply means to say that the birds don't become
sensitive to the oils contained in the rest of the plant.  This is also true
of some humans; I am one of them. Na-na-na-na.  

Dayle Ann

From the Pennsylvania State University website (link below):

<<Poison ivy is a very widespread and productive plant. It flowers in May
and June and produces dense clusters of white berries that ripen between
August and November and often persist through the winter. Over sixty species
of birds have been documented to eat the berries of poison ivy! These birds,
apparently, do not become sensitized to the volatile oils and do not
experience allergic reactions to the plant. As mentioned in the "Winter
Bird" section of this web site, poison ivy berries are an important natural
food source for the over-wintering birds on the Nature Trail.

A secondary consequence of birds' eating the poison ivy berries is the
passage of the poison ivy seeds through the birds' digestive systems. The
seeds, then, are energetically dispersed throughout the active range of the

>  -----Original Message-----
>  From: Vermont Birds [mailto:[log in to unmask]] On Behalf 
>  Of Charlotte Bill
>  Sent: Sunday, January 20, 2008 1:56 PM
>  To: [log in to unmask]
>  Subject: [VTBIRD] Ruby-crowned Kinglet & Hermit Thrush
>  Am back today after a trip to Arizona, where I had the 
>  opportunity to bird 
>  at a magical place called Montezuma Well -
> .... 
>  One hundred fifty feet away and separated from the kinglet's 
>  feeding area by   
>  a huge wall of rock, the hermit thrush was foraging in the 
>  shade on the 
>  ground near the swallet (the interior outlet of the well). 
>  To my amazement, 
>  I watched it eat five or six poison ivy berries! I expect 
>  many birders on 
>  this list already know that some bird species eat poison ivy 
>  berries, but it
>  was an astounding bit of new learning for me. I'm curious about the 
>  physiology that allows the poison-ivy-feeding species to do 
>  that. Any 
>  comments?
>  Thanks!
>  Charlotte Bill
>  Enosburgh, Vermont