Ivory-billed
woodpecker |
Robert
Leverett |
Apr
03, 2006 06:08 PDT |
Ed and Don,
Great discussion thread on loss of genetic
diversity. Please, keep
the thread going. Your debate brings to mind a related subject -
the
complex nature of species perpetuation and how human activity
supports
or interferes with it. I'm reminded of the probable rediscovery
of the
ivory bill in Arkansas.
Perhaps the ivory bill, as few other species,
shines light on the
importance of nature being allowed to do what nature does to
produce
habitat necessary for the survival of species. On the March 24th
field
trip, one of the Fish and Wildlife people gave us a briefing at
Dagmar
WMA on habitat restoration efforts. He noted that when the
endangered
species act kicked in for the ivory-billed, his agency was
prohibited
from active management. Basically, I understood active
management to
mean the implementing of various cutting plans to induce the
growth of
one species or another, or some mix. The intentions of the
managing
agencies are clearly good. The briefers demonstrated expertise
in many
ways, but looking at the hulking forms of 1000+ year old
cypresses, I
was reminded of what they can't do and that is produce an
abundance of
huge cypress and large tupelos in a short time period from
simply
managing the areas thick with young trees. Releasing the young
trees
certainly speeds growth, but it takes a long time to produce the
environment that the ivory bill exploits as evidenced by where
it was
found. In one way or another, the big trees are apparently
necessary for
the ivory bill's survival. For one thing, the cover that the big
trees
provide is of an entirely different level than what is provided
by
smaller, younger trees. When the bird is bigger than the tree,
the
tree's roll as cover is compromised as is the tree's roll as a
food
source. The ivory bill needs large larvae - lots of large larvae
and
from recently dead trees, as opposed to the long dead ones. That
was a
surprising revelation for me. A few standing snags don't provide
the
ivory bill with its required feeding habitat. To get a mix of
older dead
and newly killed trees of sufficient size for an ivory bill to
have both
cover and food, a very large area is needed. I hope the Arkansas
area of
the Cache and White Rivers is large enough to sustain a
population of
ivory bills, as opposed to being the last shrinking vestige of
what was
the ivory-billed woodpecker's required habitat.
I'll close by saying that I was impressed with
the competence and
dedication of the Fish and Wildlife departments - both state and
federal.
Bob
|
Re:
Transitioning to the ivory-billed woodpecker |
wad-@comcast.net |
Apr
03, 2006 06:45 PDT |
Bob,
ENTS
Do you think the DDT had anything to do with the Ivory billed
woodpecker's decline? Maybe the birds decline was for a group of
reasons. DDT could have affected the insect population it
depended on too? With Dursban and other nasty insecticides
recently off the market, I can only guess that the bird food
level in the web of life will increase.
I can't say for sure, but the raptor population in Se Pa is on
the rise. A Bald Eagle has been spotted in Se Pa, which is a
first for a long time. Local Red tailed hawk and Coopers Hawk
populations seem to be on the rise too. I also saw my first
Great Horned Owl this winter, three to be exact. I am guessing
that the songbird populations will suffer if this is factual.
Scott
|
Re:
Transitioning to the ivory-billed woodpecker |
Kirk
Johnson |
Apr
03, 2006 07:22 PDT |
Interesting
tidbit. I was talking to an ornithologist last week at the Roger
Tory Peterson Institute in Jamestown, NY. He is a colleague of
the
researchers who "rediscovered" the ivory billed
woodpecker, as well the
skeptics who believe they are mistaken and that it was a rush to
judgement
and a rush to publish.
He told me interviews with old-timers who remember the ivory
billed have
revealed that people deliberately killed them quite often.
Apparently they
were considered very noisy and annoying by many, so they were
killed for
that reason, but they also tasted good. After killing the
"annoying"
noisemaker, a person would take it home and cook it up. So there
was double
motivation to kill them.
Kirk Johnson
|
|