Hi Tweets,

On Orcas Island in a small fresh water pond near Deer Harbor Saturday
afternoon we made another observation of a Hooded Merganser eating a
Rough Skinned Newt (Taricha granulosa). We posted this behavior on
Tweeters for the first time in the Spring of 2003.

The Merganser was a juvenile accompanied by an adult female. The
behavior of the Merganser was similar to other observations of this
feeding behavior. The Merganser manipulated the Newt with its beak,
methodically rolling and passing the Newt between the mandibles and
then rapidly swishing the newt in the water. It did this for several
minutes before swallowing the newt. Both Mergansers were observed
about an hour later resting among the cattails with no apparent ill
effects.

The toxicity of this newt is well documented. Several years ago an
Oregon college student died, when on a dare, he swallowed a rough-
skinned newt. The tetrodotoxin or TTX is a dangerous neurotoxin to
mammals and is similar to that found in puffer fish and the blue-
ringed octopus. The toxin in one newt has been estimated to be
sufficient to kill several humans.
See: http://www.calacademy.org/calwild/sum98/eye.htm

Once again this behavior raises several questions from the previous
post:

1. Are rough skinned newts a common dietary regime of the HOME?
Apparently they are since we have observed this feeding behavior of
Hoodies on several occasions.
2. Do other diving ducks feed on rough-skinned newts?
3. Was the rolling in a serrated beak and washing of the newt a
behavior of the HOME to remove the toxin from the newts surficial
poison glands?
4. Are HOME and other birds immune to tetrodotoxin? Some reptiles
have been observed eating Rough Skinned Newts. (Garter Snakes)
6. Is there a geographic difference in Newt toxicity?
5. How do they do that?

Don and Sandi McVay
Queen Anne & Deer Harbor
dmcvay at cmc.net