The Tree X Violet-green Swallow hybrid combination appears to be new, but
the two are relatively close relatives (and the V-G is a long way from home).
However, Barn X (American) Cliff, Cave, and House Martin (Delichon) hybrids
occur relatively frequently. Offspring are usually intermediate between their
parents. There is little evidence as to their fertility, but introgression
seems to be minor.

Paul DeBenedictis
SUNY Health Science center at Syracuse

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[reply to query about unusual "mooing" vocalization of Green Heron...SR]

Date: Tue, 14 Jun 1994 14:51:03 -0500
From: cgdrw at UXA.ECN.BGU.EDU
Subject: Re: green heron seen

Tom, thanks for getting back to me. I have seen the heron give the
low moo call. I have seen it give the call on several occasions. I
have seen the call given while the heron stood on low branches of
trees surrounding my study sites. The heron lifts its' head and
emits the call. The call is usually given when I approach the marsh
or soon thereafter. I presume the call is to its' mate as an
alert/alarm call warning of an intruder. The herons usually fly some
distance away. I have also seen the call given while in the
water/cattail and then the bird flies off to a safe distance. My
best estimate of the call is a warning or alert call. These herons
are probably breeding and are in distinct pairs. I have also seen
the higher pitched call given although usually while in flight. By
the way, you may already know this, but other herons, like the
Black-crowned Night Heron, also give deep guttural sounds. These are
also described as frogs on occassion. Perhaps you might try to
....

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Date: Mon, 13 Jun 1994 16:29:38 -0500
From: cgdrw at UXA.ECN.BGU.EDU
Subject: Re: Green Heron call

Sorry to respond to this question so late, but I have been working on
my master's thesis in east-central Illinois. I spend most of my time
in marshes and see Green Herons frequently. I have heard the low
mooing call come from these herons on almost a daily basis. Some
people have confused them with frogs(bullfrogs) or other amphibians.
I have also heard them give a high pitched shrill, often in flight.
Doug Wood
cgdrw at eiu.edu
Eastern Illinois U.

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