Disturbance at the Fill
MKeigley at bothell.washington.edu
Tue Mar 5 16:14:30 PST 2002
Hi Stuart (and all - want you all to see info about the restoration
Thanks for this information. You've made some good points here that I
didn't mention. I'm going to print your message, and mine, and give it to
the UBNA manager. I think it's good for him to consider the original
intention of the "natural area" and the current state of it's use.
Regarding the mowing, I agree it is a disturbance--but a disturbance with a
greater purpose. The main goal at UBNA is to eradicate the blackberry so
that native grasses and other native plants can establish. If they let the
blackberry go, the fill would quickly return to an entire blackberry patch.
Many non-native species (and some natives-few) do thrive in the blackberry,
but many more native species take advantage of the native plants and open
areas that are trying to re-establish. One example is the thistle that the
goldfinches feed on. I don't think Northern Harriers would hunt here unless
we had the open, grassy areas. And, there are no ground nesting sites in
the grass when a site is entirely blackberry.
Our resident restoration ecologist is in charge of this and I think he's the
best person we could possibly have for the job. He coordinates with the
UBNA manager to make sure mowing takes place outside of nesting season and
is done only in gradual pieces. I still think it's better to have a site
undergoing ecological restoration rather than having yet another badly
invaded expanse of non-native plants. We have plenty of blackberry in
Seattle, but not many lakefront restoration efforts.
About the "unofficial trails," those paths will get wider and more prominent
with continued use. This only makes them look like inviting and acceptable
secondary paths to take off the main path. I think some of the trails were
originally wildlife trails used to travel from the water to other areas of
the site. People have made them into larger trails. I encourage people to
stop using them or the situation will only deteriorate. UBNA is relatively
small, so wildlife doesn't really have anywhere to go - other than to leave
- to avoid our intrusions.
I know it's tempting. Remember the big picture here - natural area - a
haven - a small patch of habitat on Lake Washington.
From: Stuart MacKay [mailto:stuart at blarg.net]
Sent: Tuesday, March 05, 2002 3:31 PM
To: tweeters at u.washington.edu
Subject: Disturbance at the Fill
I read with interest Melissa Keigley's posting about disturbance at the
First I should point out that I regularly go "off-trail" to bird watch -
usually I follow the unofficial trails. While some disturbance to birds
undoubtedly results I would like to point out some additional sources of
disturbance - not just to assuage my guilt:
1. Dogs - on and off leash. I do not have the figures but anecdotal
evidence suggests that the numbers of wildfowl found on the ponds are a
fraction of what they were before dogs were encouraged into the area.
Keeping dogs leashed and on the path does not change anything - the path
runs close to all of the ponds (except the tree-lined one, north of
Waikiakum Lane). I have frequently seen birds fly from the central pond
when sighting a dog being walked along the path.
2. Joggers, particularly late evening and at night. There are a
surprising number of people walking around the Fill at night. a lot of
wildfowl used to congregate on the ponds but are often disturbed by
people running around the area.
3. The large number of people using the area. Since the paths are
regularly maintained the numbers of people using the Fill for recreation
(non-birding) has increased enormously. This results in increased
disturbance by default.
4. Predators - not just the dreaded 'c' - word. Crows and rats are
probably the most significant causes of nest failure in songbirds. As an
example there are usually 2-3 pairs of Kildeer nesting in the area and
to the best of my knowledge the number of chicks fledging in the past 5
years or so can be counted on one hand with a few fingers left over.
5. Mowing of the blackberry. This occurs regularly that vegetation fails
to develop so large areas of the Fill are left looking like lawns. I'm
not sure what the solution to this is but leaving the blackberry alone
is one. The policy of blackberry removal has resulted in numbers of
sparrows and warblers being reduced considerably though again the
evidence is anecdotal rather than scientific.
I am not sure where birders would come on this list in terms of amount
of disturbance caused.
On the last point I should state that I used to be an avid advocate of
removing all non-natives so that the area was returned to something
close to the grassy meadow that was so successful in attracting
shorebirds in the 1970's and 1980's before trees, blackberry and
loosestrife took hold. With the current state of the Fill I will be more
careful in what I wish for in future.
Stuart MacKay, Seattle, WA
stuart at blarg.net
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