AN EVER CHANGING PICTURE

Thus far, the focus of the blog so far was a bit of art and some biology, while I was analyzing the results of my research. This summer I am thoroughly examining the behavior of the various food resources of Western pond turtles. Specifically, I am looking at where they live and their life histories. Hence, I can display them using interesting and artistic images and tell interesting stories about their anatomy, physiology, and life histories – something I will continue to do.

However, I now work along side the sound of chain saws, brush cutters, and wood chipper as I set traps yesterday changes the focus of my posts. Specifically, I am going to add the impact of human activity in urban waterways to the list of topics.

SOME CONCLUSIONS ABOUT THE DIET AND FEEDING ECOLOGY OF WESTERN POND TURTLES LIVING IN SANTA ROSA CREEK

Last week’s survey of the diet of Western pond turtles living in Santa Rosa Creek yielded two turtles that I have not captured before. Both were very animated females unlike many of there species that I have caught this summer. For example, when I set them down on the patio to wash them off, they bolted for nearby bushes to hide. This is something I have not experienced in four years of working with this species. Upon flushing their stomachs, I discovered that both of these turtles are feeding on mosquito fish (Gambusia affinis) as well as insect larvae and adults. The turtle in the above picture had two fish in her stomach and was very active.

CRAYFISH CLAW

CRAYFISH APPENDAGE

After four years of research on the diet and feeding ecology of Western pond turtles (Emys marmorata) living in urban ecosystems, it is clear they are predators. Unlike those turtles examined in a previous study done in wildlands, they do not eat any vegetation. Their main food resource is aquatic insect larvae and adults, crayfish, and small fish living in the bankside and emergent vegetation. Because they are opportunistic predators, they also eat terrestrial and aerial adult insects that fall in the water (i.e., Odonata, Lepidoptera, Orthoptera, and Coleoptera).

LEPIDOPTERA or BUTTERLY

MOSQUITO FISH

ORTHOPTERA OR GRASSHOPPER BEAK AND LEGS

FISH BONES