On this visit to the reserve, I will live-trap animals using Sherman traps baited with birdseed and oats in accordance with standard protocols. Traps will be set out multiple subsequent nights until the target number of individuals is captured; a maximum of fifteen individuals will be collected to have sample size sufficient for gene expression analyses. Traps will be set out in the evening and checked before sunrise in the morning to reduce risk of exposure in traps. Peromyscus individuals will be live-trapped and euthanized with an overdose of isoflurane and secondarily via cervical dislocation. Testes, seminal vesicle, prostate, epididymis, preputial glands, liver and kidney will be harvested and preserved in RNAlater and ethanol. Peromyscus is common in California with a large population size, so these collections should have no negative impact on local populations. I will live capture animals using Sherman traps, with a target of 15 individuals per species of interest (Peromyscus maniculatus and Peromyscus californicus) at Hastings, prepare museum-quality specimens, and collect 6 tissues per specimen, including liver, testes, seminal vesicle, epididmymis, prostate, and preputial glands. Non-target animals will be released upon capture.

Approved