An Assessment of the Effectiveness of High Definition Cameras as Remote Monitoring Tools for Dolphin Ecology Studies.

Research involving marine mammals often requires costly field programs. This paper assessed whether the benefits of using cameras outweighs the implications of having personnel performing marine mammal detection in the field. The efficacy of video and still cameras to detect Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the Fremantle Harbour (Western Australia) was evaluated, with consideration on how environmental conditions affect detectability. The cameras were set on a tower in the Fremantle Port channel and videos were perused at 1.75 times the normal speed. Images from the cameras were used to estimate position of dolphins at the water’s surface. Dolphin detections ranged from 5.6 m to 463.3 m for the video camera, and from 10.8 m to 347.8 m for the still camera. Detection range showed to be satisfactory when compared to distances at which dolphins would be detected by field observers. The relative effect of environmental conditions on detectability was considered by fitting a Generalised Estimation Equations (GEEs) model with Beaufort, level of glare and their interactions as predictors and a temporal auto-correlation structure. The best fit model indicated level of glare had an effect, with more intense periods of glare corresponding to lower occurrences of observed dolphins. However this effect was not large (-0.264) and the parameter estimate was associated with a large standard error (0.113).The limited field of view was the main restraint in that cameras can be only applied to detections of animals observed rather than counts of individuals. However, the use of cameras was effective for long term monitoring of occurrence of dolphins, outweighing the costs and reducing the health and safety risks to field personal. This study showed that cameras could be effectively implemented onshore for research such as studying changes in habitat use in response to development and construction activities

Domestic dogs in Atlantic forest preserves of south-eastern Brazil: a camera-trapping study on patterns of entrance and site occupancy rates

Presence of exotic species in forest remnants is a major concern for the conservation of wild species, not only on islands, where potential impact is higher. Although the problem is widespread and increasing, there are few studies on Neotropical forests. Here we quantify the occurrence of domestic dogs (Canis lupus familiaris) in an Atlantic forest reserve in south-eastern Brazil (Santa Lúcia Biological Station - SLBS). Throughout two years of monitoring with camera traps (2,142 camera-days), 25 records of 16 individual dogs were obtained in the interior of SLBS, making dogs the fourth most frequently recorded species of mammals in general and the first-ranking among Carnivora, ahead of the ocelot and puma, the top two terrestrial predators present in SLBS. Dogs entered the forest year round, in almost half of the sampled months (48%), and predominantly during daytime (89%). They were detected in various trails inside the reserve, but mostly in areas nearest to the reserve's border (<200 m from the edge). Record rates of domestic dogs did not correlate significantly with climate variables, with frequency of mammal records and richness in general, or with any particular mammal species (Spearman rank correlation, p > 0.05 in all cases), suggesting an erratic, non-seasonal pattern of entrance in the reserve. Data indicate that domestic dogs can be abundant and frequent visitors to little disturbed Atlantic forest reserves even when these are located in regions of low density of human population. The potential impact to native fauna is discussed

Jaguar (Panthera onca Linnaeus, 1758) roadkill in Brazilian Atlantic Forest and implications for species conservation

AbstractWe report the roadkill of a jaguar in one of the longest highways in Brazil (BR-101), in the stretch where this road crosses one of the most important Atlantic Forest remnants in the country: the Linhares-Sooretama block. The jaguar population present in this area represents the very last in entire Espírito Santo state. There is an approved project to the lines duplication of the entire BR-101 Highway and the company responsible by the work has already started the first activities in the state. However, there is no environmental impact assessment already done neither planning for the implementation of measures to avoid or reduce the roadkill risk in the region. Thus, to minimize the impacts associated with the BR-101, we do not recommend its lines duplication along the 15 km stretch traversing the Linhares-Sooretama block. In addition, alternatively, we suggest the deviation of the current route of the BR-101 Highway or the construction of overpasses to fauna in the most critical points, interspersing these overpasses with electronic speed monitoring devices and warning and educational plates

Jaguar (Panthera onca Linnaeus, 1758) roadkill in Brazilian Atlantic Forest and implications for species conservation

AbstractWe report the roadkill of a jaguar in one of the longest highways in Brazil (BR-101), in the stretch where this road crosses one of the most important Atlantic Forest remnants in the country: the Linhares-Sooretama block. The jaguar population present in this area represents the very last in entire Espírito Santo state. There is an approved project to the lines duplication of the entire BR-101 Highway and the company responsible by the work has already started the first activities in the state. However, there is no environmental impact assessment already done neither planning for the implementation of measures to avoid or reduce the roadkill risk in the region. Thus, to minimize the impacts associated with the BR-101, we do not recommend its lines duplication along the 15 km stretch traversing the Linhares-Sooretama block. In addition, alternatively, we suggest the deviation of the current route of the BR-101 Highway or the construction of overpasses to fauna in the most critical points, interspersing these overpasses with electronic speed monitoring devices and warning and educational plates

Domestic dogs in a fragmented landscape in the Brazilian Atlantic Forest: abundance, habitat use and caring by owners

This study aimed at estimating the population size and attitudes of residents towards caring for domestic dogs, through questionnaire surveys, as well as the frequency of these animals in different habitats (anthropic and forest patch), using scent stations. The study was conducted in a severely fragmented area of the Brazilian Atlantic Forest. A large number of unrestricted dogs was recorded, averaging 6.2 ind/km². These dogs have owners and are regularly fed. Dog records decreased from the anthropogenic matrix to the forest patch edge, which suggests that dogs act as an edge effect on forest patches. Encounters between domestic dog and wild animals can still be frequent in severely fragmented landscapes, mainly at the forest edges. However the fact that most dogs have an owner and are more frequent in the anthropic habitat suggests that their putative effects are less severe than expected for a carnivore of such abundance, but the reinforcement of responsible ownership is needed to further ameliorate such effects