When livestock are killed by predators, circumstantial evidence is often the only information available to determine which predator species made the kill. Evidence can consist of rake marks, scat, hair, attack points, tracks, sightings, and canine punctures. Canine punctures in particular can be informative because they offer the most direct evidence of attack, particularly if they are linked to tissue hemorrhaging. When investigating canine punctures, a common technique to identify the predator species is to measure the canine cusp spread for maxillary and mandibular tips as measured from the maxillary to maxillary tip or mandibular to mandibular tip. The assumption is that different predator species will have different and distinct canine spread. Surprisingly, little has been published on canine spread and comparing different carnivore species, leaving wildlife managers unable to reliably use this technique for predator identification. During 2008, we started a project to assess the width of canine spread in carnivores. The majority of information gathered to date shows a narrow range of measurements for coyotes and broad variation in feral/free ranging dogs that can overlap coyote measurements. The information provided on scientifically measured canine spread will assist the wildlife damage manager in determining the actual predatory species, especially when used with additional evidence gathered on site.

Recovery of the endangered Mount Graham red squirrel (MGRS) will likely be long and challenging. Its limited habitat, isolation to Pinaleño Mountain range, and demographic characteristics restrict its ability to rebound quickly from threats that impact both the squirrel and its habitat. Currently, threats to the MGRS include habitat degradation and loss through high-severity wildfire, fire suppression activities, insect outbreaks, climate change, and human development, and predation, as well as competition with Abert’s squirrels. The most recent wildfire in 2017 impacted over 48,000 acres of already reduced habitat. A critical first step is to protect and manage the remaining population of the MGRS and its habitat. Management includes but is not limited to maintaining and improving the spruce-fir and mixed conifer biomes, while balancing the need to reduce risk of catastrophic wildfire with the needs of the squirrel. The U.S. Department of Agriculture, Animal and Plant Health Inspection Service Wildlife Services is conducting an Abert’s Squirrel Removal Project at the request of the Arizona Game and Fish Department and the U.S. Fish and Wildlife Service (USFWS), in collaboration with a team of Mount Graham red squirrel experts and managers, to reduce the number of Abert’s squirrels in historical MGRS habitat throughout the Pinaleño Mountains to assist in meeting the needs of the USFWS’ 2011 MGRS draft recovery plan. Abert’s squirrel removals are conducted monthly to minimize competition with MGRS.