Thursday, April 19, 2007

Insects

Megan and I went to the Sun Lakes area of central Washington last weekend and explored around a bit.

While wandering among the rocks and brush I came upon this scene.



I'm curious what kind of ants and beetle these are. I also wonder if the ants killed the beetle or found it already dead. In the full size version of the image hairs are visible on the hind end of the ant (the metasoma?)

Sunday, April 01, 2007

Outing

Megan and I went to a park near Monroe yesterday. It ended up being quite nice. We explored around, the sun came out for a while. We saw wood ducks, chickadees having territorial disputes, and a beaver swimming around. We also saw the tracks of around 10 different mammal species.

While we took a break in the sun by the river we discussed some of the things I think are my weak points that would be likely to come up in the tracking evaluation I will take in May. One of those weaknesses is bird tracks. There are just so many birds that I can't even identify by sight or sound, let alone by tracks. There is the advantage though that the more common a bird is the more likely it will be on the evaluation and I at least know the names and general sizes of most common birds in the area.

While discussing birds the difference between crow and magpie tracks came up. They are both corvids of similar size so I figured the tracks would be quite similar, but that there would probably be a discernible difference for the practiced eye (much as coyote and dog tracks are usually not too difficult to distinguish once you know what to look for). Megan thought perhaps they could be distinguished "kind of like Tom Brown can tell which way a person is looking from their tracks". To which I off handedly responded, "Oh, that's fairly easy." Whoops. Megan wanted me to demonstrate. Now, I have some knowledge about determining head movement from tracks, but I have not practiced it much, and not at all on human tracks. With that caveat, it seemed like a good experiment. While I had my eyes closed, Megan walked 10 steps or so and in the middle looked to the side. The first trial I mainly looked at individual tracks and tried to decide based mainly on what direction her toes had been pointing. I ended up being wrong. I suspect that is a useful bit of information, but not necessarily sufficient on its own and I think there were minor landscape features that affected it which lead to me being tricked. The second trial was on a longer, flatter stretch of sand and these time I tried to take a broader perspective. Mainly I noticed that her feet would alternate side to side, slightly out of line as expected, but then there was a series of three steps that were in a straight line on the left side of her trail. There were also some smaller details that seemed like supporting evidence, but that I was much less comfortable with. Anyway, I explained my reasoning to her and this time I was right. A 50% success rate isn't very high, but it was getting late, we were tired and hungry and she was satisfied with my explanation so we did not hold any more trials (though I think it would be fun to do again some other time).