RADIO TRANSMITTERS
I was able to easily find the two turtles with radio transmitters on them and get close enough to hear them "plop" into the water as I approached. It is nice to know I have not lost my "transmitter touch". When you see them do it on television in a nature film it looks easy, but it's not. The radio waves easily reflect off of objects and there are spurious signals from other generating devices that make tracking challenging. This is particularly true in urban areas and it can be vexing.
BIKE SURVEY
Yes, we rode twenty-one miles while doing the survey today. Actually in this setting a bicycle is a distinct advantage because it is possible repeatedly survey both sides of the waterway more than once. Actually I have a method for doing this. The first time I ride along and get a general impression of the waterway and mark significant waypoints with my GPS as I move along. At the end of the pass I take field notes and discuss them with my co-worker Kate. Then I make a second pass through the area stopping from time to time to take photographs and revisit the waypoints I recorded on my GPS unit. In addition, I will add new waypoints and make notes about it in my field journal. As I did the first time, I stop at the end, evaluate the notes, and form some conclusions. On the third pass I test my conclusions and take more notes. Since each loop is four miles long, a bicycle is the ideal tool.
The bike survey yield was both positive and negative. The positive result is I found a drainage that in the past seemed unpromising but now it is likely to have western pond turtles in it. The negative results indicate that most of Santa Rosa Creek has poor western pond turtle habitat. Specifically I found that areas that once had deep pools, basking spots, and were somewhat secluded no longer exist. The water is barely knee deep near possible basking and foraging sites, making them unsafe. Specifically,most of the sites are easily accessible and human activity has a negative effects on important western pond turtle activities of daily living. For example, wading by humans or dogs playing in the water nearby a basking site prevent them from basking long enough to digest food they eat. In addition, equipment vandalism is very high in these settings and I lose traps. Two weeks ago two hoop traps went missing and replacing them on the budget I have is not possible. I started the project with thirty traps and now I have ten left after two summers of work. Hence being exposed to human activity has a negative affect on my research efforts as well.
Tomorrow I will survey the entire reach on foot to take a closer look.
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| At this location there was once a six foot deep pool with basking logs nearby and Himalayan blackberry bushes prevented access. Because of modifications to the channel downstream water no longer pools here and vegetation removal makes it easy to access the site from both sides of the waterway. Hence, it is no longer suitable western pond turtle habitat. |
