Friday, July 24, 2009

What were they thinking?

The dedicated counters had 1,200 bats exiting the pier at the Woodard Bay bat colony last night, there were 3,300 last Thursday. The counters are going out to count again tomorrow night, as there was a SW breeze tonight. That can throw off the count--the bats seem to head into the wind more, which could have put some of the exiting bats out over the water, out of sight of the counting. We've used an extra person with a scope to verify this on occasion. With that caveat, plus that this is the time of the summer with the highest variability in the counts, I can report that we've never had a one-week change of this magnitude (-2,100).

Is this an effect from draining Capitol Lake at the most critical feeding period of the summer maternity cycle? We can't say for sure, but it certainly
could be. The vast majority of the pregnant and nursing bats from several large maternity groups travel many miles to each night to Capitol Lake, feeding on minute aquatic insects like midges, mayflies, and the like. These insects spend most of their life aslarvae in the muddy bottom of the lake. Then one fine night they mature, pop to the surface, shed their extra layers, flap their new wings, and rise from the water's surface... into a bat's mouth! They don't do this from a dry mudflat like we have now. So, the normally super-rich lake is now effectively a desert, as far as these thousands of nursing mother bats are concerned. No, they won't have this food source if/when the area is converted to intertidal mudflat.

What are they thinking?

How did 260 acres of fresh water habitat... in downtown Olympia... below the Capitol Campus... whose fate has been under public discussion for the past 6 years... jsut get drained without consultation with anyone who monitors the flora and fauna of the lake?

Consider the readers' comments from the July 16 Olympian article about the draw-down, which at that time was reported to be a few feet lower for a short period of time:

It was reported in the July 16 Olympian article that "
Lakefair officials learned a couple of weeks ago that the lake would be drawn down during Lakefair." Since this was planned at least two weeks in advance, it hardly sounds like an emergency. Doesn't this mean that G.A. approved this proposal in June?

Update, Saturday 25 July 09:
I took the Radar-mobile out for a spin last night, and took some screen images at Capitol Lake to compare with those from 2 years ago. Dramatically fewer bats over the water, and almost none over the mudflats. No, not a surprise. A couple years ago at this time they were all over the lake's 3 chambers, the fewest were where the river channel is (faster water, fewer insects). That is the only place water has been during this draining event. So even the water that was there was the last place the bats would normally feed (as in poorest foraging locations).

1 comment:

  1. On Friday the Woodard Bay bat count was 1,800. That's better, but nothing like the 3,300 of last week...