To evaluate whether the abundance of coyotes Canis latrans was influenced by the availability of anthropogenic foods in a humanized landscape, we compared three neighboring areas (hereafter referred to as NA, CA, and SA) under contrasting human pressures within the Santa Monica Mountains of California, USA. We quantified the use of anthropogenic foods by coyotes and assessed local densities within these three regions. Overall, 761 coyote feces were analyzed; identified food items were categorized into 11 food types (7 native and 4 anthropogenic). Though small mammals (lagomorphs and rodents) were the main prey of coyotes in all areas and seasons, log‐linear modeling of multiway contingency tables indicates that consumption of anthropogenic foods by coyotes varied significantly throughout study areas. Thus, in the most humanized area (CA; 24% of this region is residential habitat), anthropogenic foods (trash, livestock, domestic fruit) comprised seasonally between 14 and 25% of total items in coyote diets, whereas in the least humanized area (NA; 2% residential) anthropogenic foods only comprised seasonally between 0 and 3% of items. Coyote density, estimated by foot‐hold trapping surveys and by genotyping feces, was also highly variable between areas. The heavily human‐impacted CA area had the highest coyote density (2.4–3.0 ind. km−2), whereas coyote density was significantly lower (0.3–0.4 ind. km−2) in the least humanized area (NA). In the third region (SA; 10% residential), with an intermediate level of human pressure, both importance of anthropogenic foods in coyote diet (4–6%) and coyote density (1.6–2.0 ind. km−2) were intermediate compared to the other regions. Our data suggest that subsidization by anthropogenic foods augments coyote densities and alters their diets in the Santa Monica Mountains, California. We include data from literature to show that anthropogenic foods are used by omnivorous mammals throughout the world. Surprisingly, however, the potential effects of allochthonous inputs on such species are not well‐understood. Thus, further research on this phenomenon in humanized landscapes is needed.

X. 2004. Geographical variation in the potential of mice to constrain an ant-seed dispersal mutualism. Á/ Oikos 105: 181 Á/191.Pre-and post-dispersal Helleborus foetidus (Ranunculaceae) seed predation by mice Apodemus sylvaticus as well as post-dispersal seed removal by ants was studied, during two years, in six plant populations within three geographical regions (Caurel, Cazorla and Mágina) of the Iberian Peninsula. An observational approach revealed strong interregional differences in seed predation by mice during the pre-dispersal phase, with high and similar rates of predation in Cazorla and Mágina and much lower rates in Caurel. There were also significant inter-annual variations on pre-dispersal seed predation by mice, while the existing habitat-related differences (of lower magnitude) were not consistent across regions. Field experiments based on seed-offering exclosures, showed that, despite some interregional variation, post-dispersal seed removal by ants was consistently high through all spatial and temporal scales considered, with most seeds being removed within 48 h. Conversely, post-dispersal seed predation by mice was highly variable among regions, being very high in Cazorla and minimal or absent in Caurel and Mágina. Interestingly, in Cazorla, in presence of mice, the number of seeds removed was rather independent of the presence/absence of ants, while under mice exclusion, it was determined by the presence/absence of ants. Conversely, in Caurel, the number of seeds removed by each remover agent (ants or mice) was independent of the presence/absence of the other agent. Thus, though uniquely in Cazorla, mice limited the number of seeds available to ants and, therefore, in this region could potentially have interfered on the development of seed traits that enable ants to efficiently harvest them. Our results support the notion that geographical variation over the Iberian Peninsula of mice seed predation may have promoted a mosaic of well-matching and mismatching situations between H. foetidus diaspore traits and the characteristics of ant communities, which is consistent with some recent theories on the geographical structure of interactions.

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