Visitation rate and behavior of urban mesocarnivores differs in the presence of two common anthropogenic food sources

Abstract

Cat food left out for feral and domestic cats and bird seed spilled from backyard bird feeders are two common anthropogenic food sources that may attract non-target animals like urban mesocarnivores but no studies have quantified mesocarnivore visitation at these food sources. We used motion-activated video cameras to monitor mesocarnivore use of spilled bird seed below 25 bird feeders maintained by residents in four neighborhoods in Flagstaff, Arizona, June-September 2012 and 2014. During the first five nights of monitoring only seed that spilled naturally below feeders was available. On each of the subsequent five nights, we placed a bowl of commercially available dry cat food below feeders so that both spilled seed and cat food were present. In both years, after cat food was added, the number of visits by striped skunks (Mephitis mephitis), raccoons (Procyon lotor) and domestic cats (Felis cattus) doubled and the number of times two animals were present simultaneously also increased. Aggressive interactions, in the form of displays or contacts, increased for all species combinations but significantly only between skunks in the presence of cat food. These results demonstrate that both spilled bird seed and cat food may be exploited frequently by urban mesocarnivores and that the type of food can elicit different behavioral responses that could have important implications for human-wildlife conflict and disease transmission.

Urban residents' perceptions of birds in the neighborhood: Biodiversity, cultural ecosystem services, and disservices

“…Prey switching is one mechanism proposed to account for weak correlations between predator densities and predation pressure in urban areas where supplementary foods are abundant , Fischer et al 2012. However, results of evaluations of this mechanism have been mixed and few field experiments have been conducted (Preston and Rotenberry 2006, Borgmann et al 2013, Theimer et al 2015. In one experiment, researchers increased the probability that Wrentits (Chamaea fasciata) would successfully fledge young by providing bird feeders within the territories of their most frequent nest predator, California Scrub-Jays FIGURE 2.…”

“…These supplementary foods, provided through both intentional means such as bird feeders and unintentional means such as poor refuse management, often make patchy resources more continuously available in space and time (Beckmann and Berger 2003, Bozek et al 2007, Robb et al 2008. Relationships between breeding birds and their nest predators in developed landscapes may be especially influenced by supplementary foods because both songbirds and generalist predators readily exploit these resources, and thus congregate in the same areas (Marzluff et al 2001, Robb et al 2008, Theimer et al 2015. However, despite many studies on avian reproduction in urban landscapes, no clear pattern has emerged regarding the effect of urbanization and associated supplementary foods on the relationship between predators and nest survival (Chamberlain et al 2009).…”

“…However, despite many studies on avian reproduction in urban landscapes, no clear pattern has emerged regarding the effect of urbanization and associated supplementary foods on the relationship between predators and nest survival (Chamberlain et al 2009). Current understanding is limited because few field experiments have provided supplementary food directly to predators (Preston and Rotenberry 2006, Borgmann et al 2013, Theimer et al 2015.…”

“…In this final scenario, rates of nest survival may be similar across a wide spectrum of availability of supplementary foods. Experiments in which free-ranging predators are supplemented are relatively rare but have great potential to identify mechanisms by which predators and prey are influenced by supplementary foods (Preston and Rotenberry 2006, Borgmann et al 2013, Theimer et al 2015.…”

Secrets of Success in a Landscape of Fear: Urban Wild Boar Adjust Risk Perception and Tolerate Disturbance

“…The number of mammals living in urban environments increases (Bateman and Fleming, 2012;Magle et al, 2012). Hence, urban environments can support wildlife and provide various food sources: natural food (Stillfried et al, 2017b) or anthropogenic, easily accessible food (Cahill et al, 2012;Theimer et al, 2015;Tryjanowski et al, 2015), both of which can contain a high amount of energy (Ottoni et al, 2009;Maibeche et al, 2015). The urban landscape of fear should be worse than the rural one because the threat increases with human proximity per se, a high traffic volume and additional predators such as domestic dogs and other companion animals (Frid and Dill, 2002;Baker et al, 2005;Hughes and Macdonald, 2013).…”