Wednesday, May 14, 2008

Bug trap

After my first night of data collection I learned a few things: 1. It takes 30 minutes to set up the equipment but only 10 to take it down. 2. One of my recorders is not working, which I found out only after the fact. 3. Looks like there might only be Mexican Freetails in the city. Of course it's way too soon to tell. 4. There are very few flying insects in the city. 5. Some people are interested in what I'm doing, but most people in the city are careful not to look too closely. Kind of sad, but it bodes well for the safety of my equipment. I added a photo to my last entry so you can see the finished detector rig. And on this entry you can see my sticky trap for flying insects. It's a water bottle painted camo, with a coat hanger stuck inside. Double-sided tape holds an 8.5 x 11 inch transparency sheet to the outside. I spray it with tanglefoot and then hang it near the bat detector to get a sense of relative insect activity in the night. In the morning I wrap a second transparency sheet around the sticky first one and pull them both off. I've got to run now but will write more after I upload the second night's data and have a look at it.

Monday, May 12, 2008

Have a plan in case of goats

Today was my first full day in the field for my project. I've got three sets of equipment, complete with camo-painted waterproof casings and human-proof cages pictured above hanging from a tree. I made up a random schedule of my 19 parks, and this afternoon set off around 6:30pm. My first two stops, at the Interior Green Belt and Golden Gate Heights, went fairly uneventfully. I was able to lug the cages to the previously selected random location and secure them to a tree. I also set out traps for flying insects, which I'll also tell you more about later. I'll be curious to see if I get any Light Brown Apple Moths which are causing quite a controversy here in the bay area. When I got to my last location, Glen Canyon, I got my surprise. Goats! I knew they periodically deploy a herd of goats in the park to keep the plants grazed and reduce fire danger. My first clue was a sign pasted over the park entrance warning neighbors to keep their dogs on leash. Then I saw goat droppings on the ground. Then I saw electric fencing up and goats happily munching plants exactly around my carefully selected random location. OK: I'm not going to record bats here tonight! Even if the goats hadn't been in the exact spot I needed I probably wouldn't have left my equipment there. Too much of a chance that they'd disrupt bat activity (or otherwise make it not average for the park.) Also, I would worry that the electric fence might generate ultrasonic interference. So, I'll have to wait a few days and try that park later. With some quick thinking I decided to try for another park nearby, at Twin Peaks. This spot was easy to get to in the dwindling light. As I was setting up the equipment, a local resident got curious and came to see what I was doing. Hopefully I rattled off enough bat trivia to convince him I was not a terrorist or a spy. I really do need to come up with some kind of label on my equipment in case someone actually does notice it. So tomorrow I'm up early and will go collect the detectors and the insect traps and see what I got. Woo-hoo! Science in progress!