Advancing North: White-nosed coatis Nasua narica Range Expansion in Arizona

Over the past century, the white-nosed coati (WNC; Nasua narica) has expanded its northernmost range from the United States-Mexico border into northern Arizona. WNC are medium-sized, opportunistic omnivores that often occur in large groups ("bands") and forage on insects, fruits, and small vertebrates. We compiled data from iNaturalist, published literature, Arizona Game and Fish records, museum collections, personal communications, and our own camera trap photography to chronicle this range expansion. Historical records documented WNC populations in mountainous areas along the US-Mexican border but rarely north of Tucson, AZ. The popularity of using wildlife cameras in both research and recreation, paired with the advancement of citizen science projects like iNaturalist have generated a vast amount of new data on species distributions. With this new body of information we report the range of WNC now occurs over 400 km farther north, extending north of Flagstaff, Arizona. Recent records include occurrence in ponderosa pine forest that sustain sometimes heavy winter snow - an environment vastly different from the species normal range. The northward expansion of this meso-carnivore invites many questions about drivers of range expansion, including climate change, mesopredator release, or simple opportunism. More research into the behavior and ecology of WNC in the northern extent of their range is needed to guide understanding and potential future management of this species, its impacts, and prediction of other such range expansions.