Who let the dogs out? Occurrence, population size and daily activity of domestic dogs in an urban Atlantic Forest reserve

Domestic dogs (Canis lupus familiaris) are one of the most common exotic species in protected areas, and their impact is an important conservation concern. This study evaluated the occurrence of domestic dogs in one of the world's largest urban forests, the Tijuca National Park (TNP; 3953 ha), the most visited Park in Brazil. From April to September 2016, 42 camera-trap stations, spaced 0.5 km among them, were set in TNP, covering an area of 1050 ha. Population size and density of dogs were estimated, and the spatial distribution of dogs evaluated in relation to the distance to the Park's boundaries and to paved roads. Dogs’ circadian activity pattern and its overlap with those of the five most recorded native mammal species were also studied. The estimated population size of dogs was 29 ± 4.86 (mean ± SE) individuals, and the estimated density was between 0.74 ind./km2 and 1.37 ind./km2. Domestic dogs were widely distributed in the Park, and the number of independent dog records was not related to proximity to paved roads or the boundaries of the Park. The domestic dog was mainly diurnal in TNP, overlapping its activity mostly with the red humped agouti Dasyprocta leporina and the coati Nasua nasua. The absence of pups indicates that dogs come from surrounding areas rather than being a feral population within TNP. Therefore, managing strategies must consider the engagement of local people.