Camera traps are valuable sampling tools commonly used to inventory and monitor wildlife communities but are challenged to reliably sample small animals. We introduce a novel active camera trap system enabling the reliable and efficient use of wildlife cameras for sampling small animals, particularly reptiles, amphibians, small mammals and large invertebrates. It surpasses the detection ability of commonly used passive infrared (PIR) cameras for this application and eliminates problems such as high rates of false triggers and high variability in detection rates among cameras and study locations. Our system, which employs a HALT trigger, is capable of coupling to digital PIR cameras and is designed for detecting small animals traversing small tunnels, narrow trails, small clearings and along walls or drift fencing.

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Amphibian populations have been declining at higher rates than bird and mammal populations. Agriculture, urbanization, including roads, and resource extraction continue to put pressure on all species. Roads in particular, are major sources of mortality. The Santa Cruz long-toed salamander (Ambystoma macrodactylum croceum), one of the most critically endangered species in the US, is one amphibian that is declining as a result of anthropogenic impacts, especially habitat loss and fragmentation due to urban development. Migration across roads puts these salamanders at risk from road-related death. This thesis quantified the rate of road mortality to these salamanders and other common amphibians during two A. m. croceum breeding-migration seasons in 2011-13 in a portion of the subspecies' range. Vehicular traffic was a major source of mortality to the salamander. Through traffic doubled the overall vehicle load on roads where the A. m. croceum migrated to and from breeding ponds. The Pacific chorus frog was also killed on the roads. This common species can be used as an indicator of road mortality risk for rarer amphibians. This study indicated that measures to reduce road mortality to the Santa Cruz long-toed salamander could include restricting vehicular traffic on roads adjacent to salamander ponds by limiting traffic to residential use only during breeding migrations, installing structures to protect A. m. croceum while crossing roads, and potentially assisting animals crossing roads at nighttime during the breeding migrations. v ACKNOWLEDGMENTS I would like to thank my committee members for the time they have spent working directly with me on this thesis. I am amazed at their commitment, energy, and passion to helping all students. Special thanks to Dr. Lynn Trulio for her ability to see what I could not, for coaching me forward when I had stumbled, and for being available when I was in need. Her heart is large and her love for animals true. Special thanks to Dr. Rachel O'Malley for her technical excellence and push for greater knowledge. Special thanks to Dr. Nina D'Amore for her expertise on amphibians and for guiding me toward experts in the field.