Subject: various threads long i guess
Date: Jul 17 21:56:01 1996
From: William H. Lawrence - whl at localaccess.com


>To: tweeters at u.washingtone.edu
>From: whl at localaccess.com (William H. Lawrence)
>Subject: various threads long i guess
>
>there have been several past threads i wanted to respond to but lacked time
when they were hot. this information maybe still be of interest.
>
> swimming mammals thread--these observations are based on several
yrs of field work in upper mich on a beaver study.
>
> swimming Beaver produce a head wake without much following
turbulence
>produced by their tail. head and body are continuous above the surface even
with kites.
>rear feet provide the swimming force. the tail is used for diving
frequently with a warning slap if disturbed.
>
> Swimming Muskrats produce in addtion to their smaller head
wake a following turbulence generated by the skulling action from their
laterally compressed tail. very visible on flat water. their tail is always
actively skulling when moving on the surface of a pond.
>
>muskrats in active beaver ponds will construct a separate nest chamber in
the side of occupied lodges. their nest chamber is not visible from outside
the lodge and is entered thru a submerged tunnel or opening. beaver seem to
tolerate this joint occupancy. beaver will swim at the muskrat but no chase
seems to follow. i'm sure that during the winter the "rats" use the beavers
stored food pile.
>
> Nutria appear to have a bigger head held higher above the
water surface than beaver when swimming. back is out of the water. the tail
of this species is round and tapering like a brown rat. also they are can be
quite vocal when with kites.
>
> River Otter seem to wiggle thru the water head held high
looking around.their back and even their thick tapered tail shows. they
porpoise with both short and long intervals. they seem to play alot. they
have approached my canoe literally standing upright treading water with
their fore paws and upper 1/2 of their body out of the water. walking as it
were to the canoe and looking inside the canoe. kits were playing around the
bow. re the people attacks by otter-- perhaps kites were about and the
attacks were protective behavior.
>
>voles (microtus sp ) swim like brown puff balls floating high. they can be
encountered in flooded meadows & open water in marshs. shrews swim too. mink
are like small 16"+/- otters in and out of water as they work the water edge.
>
>regarding ectoparasites of birds---miriam rothchild (english) wrote a book
titled-"fleas, flukes, and cuckoos during the '60's. in this book the life
cycles of several blood sucking ectoparasites of swallows are described.
there are mites, fleas, and bugs as in "bedbug type". it is feast or famine
with these swallow ectos. the etcos wait the return of the nesters and tank
up to reproduce for the next batch of young. outstanding book thats out of
print at least in this country however a reference librarian can no doubt
find one on inter lib loan. there is a paper back book currently in print
titled "the beauty of the beastly " by natalie angier. this author,a leading
science writer (pulitzer prize) for the new york times reportes on the
impact of bloodsucking parasites on tail length and symmetry of male barn
swallows and the subsequence adverse affect of a shorter and asymmetric tail
on breeding success. read about it in chapter 1. there are comments re the
purple martin as well.
>
>rothchild has a new book titled "butterflies cooing like doves" i'm sure
this will be equally interesting natural history as her book noted above.
>
>enough for now however my next two comments will deal with scrub jays in
lewis co and an unlikely crow story of a young crow (with down showing)
sunning next to and equally young,wild cottontail. on the ground to be sure.
i'll be off line for 10 days viewing the arctic ocean from a village in the
mackenzie river delta. paddled the river in the '70's but ran out of time to
reach the arctic ocean. on the river 1 month mack did it all in 14 days!!
>
>whl
>the jhl message sent by mistake sorry about that