Disturbance From Roads Negatively Affects Andean Condor Habitat Use

Animal Behaviour, 2017

Animals may divert time and energy in similar ways in the presence of predators, humans or landscape infrastructures. Roads have facilitated the economic and social development of human populations. Nevertheless their presence and human use cause environmental changes, such as clearing, which increase perception of predation risk. Among the responses to this are changes in animal behaviours. In the present study, we sought to assess whether roads in an Argentine reserve affect perception of predation risk by guanacos, Lama guanicoe, through behaviour changes. We analysed the effects of two types of roads (unpaved track and paved route) and their surrounding environment (e.g. vegetation structure) on group size variation and on three behaviours: vigilance, foraging and movement. We also used the group structure of guanacos, such as the number of calves, to explain these behaviours. Roads in the protected area had no impact on the size of guanaco groups. However, individuals in larger groups were less vigilant and foraged more closely to roads, indicating that closeness to roads is less risky for these animals. Although guanacos' time spent moving was not affected by roads, nearness to the unpaved track and high plant cover showed the highest proportions of animals moving in the area, and individuals moved more when in small groups and in areas with medium-height vegetation. The number of individuals displaying vigilance or foraging behaviours was not affected by any of the explanatory variables. Based on these findings, we conclude that guanacos perceive the roadside environment as safer, possibly because open areas adjacent to roads facilitate detection of predators. Knowing the effects of roads on wildlife in protected areas is necessary to find ways to reach a balance between the economic development of a region and conservation of its biodiversity.

Bird Conservation International, 2014

Journal of Raptor Research, 2009

IBIS, 2018

The analysis of factors that determine the distribution of top-scavengers at large scales can provide clues to understanding important ecological processes and may be useful in establishing conservation and management strategies. Here, we conducted a large-scale survey to study the distribution of the threatened Andean Condor Vultur gryphus in relation to environmental factors in southern Patagonia. This area has undergone the settlement of livestock and the introduction of exotic wildlife, although to a lesser extent than in the condor's distribution in northern Patagonia. The aim of this study was to determine the relevance of different factors such as the availability of food resources, the availability of suitable nesting and roosting places and the presence of humans on large-scale condor distribution. Our results show that the presence of meadows was the primary factor shaping Andean Condor distribution, despite the fact that this habitat occupies only 4% of the Patagonian landscapes. However, this habitat has a high probability of herbivores presence, thus condors seem to optimize their searching. The availability of nesting and roosting cliffs also contributed to explaining the observed distributions. Our results suggest that condor distribution in southern Patagonia is a compromise between the spatial locations of two low-frequency habitats, meadows and cliffs. A successful condor conservation strategy in southern Patagonia should include the protection of these habitats and the regulation of farming expansion, including the recovery of meadows.

Biological Conservation, 2020

Mobile species face an array of human threats across political boundaries, and their protection relies on identifying and prioritizing areas for conservation. Large avian scavengers are one of the widest ranging and most threatened species globally, and efforts to preserve them have come to the forefront of wildlife management. Vultures require access to functionally distinct habitats for roosting, foraging and flying, yet behavior-specific habitat modelling has been overlooked in management planning. Herein, we developed a spatial prioritization model for the threatened Andean condor (Vultur gryphus) that integrates activity-specific habitat selection across heterogeneous landscapes. We tracked 35 individuals in two regions of Argentina and Chile differing in topography and vegetation composition, and analyzed how landscape covariates influence where condors roost, forage and fly, while accounting for individual differences. We found that individuals responded differently to environmental covariates during each behavior, and identified regional differences for some covariates dependent on behavioral state. We also found important individual differences in habitat selection between birds inhabiting each region. We combined these results into an ensemble spatial prioritization model, and found that most areas of high priority for Andean condor conservation are not under protection. The strategic implementation of conservation measures in these priority areas could have important implications for the recovery of this species. Our study illustrates the value of integrating behavioral-and individual-specific habitat analyses into spatial conservation planning, and points to opportunities for effective management of threatened vultures. connectivity (Nandintsetseg et al., 2019), and developing temporally and spatially dynamic management actions (Reynolds et al., 2017). The success of these conservation efforts relies on identifying critical areas for the focal species (Runge et al., 2014). In particular, identifying the functional value of habitats can lead to improved conservation of mobile and migratory species (Sawyer and Kauffman, 2011). Yet, the importance of recognizing and integrating habitats with different functional value into landscape-level management planning remains overlooked (Frans et al., 2018). While conservation efforts take place at the population level, individuals can exhibit markedly different habitat-selection patterns

Population Ecology, 2011

The conservation of wildlife populations living adjacent to roads is gaining international recognition as a worldwide concern. Populations living in road-impacted environments are influenced by spatial parameters including the amount and arrangement of suitable habitat. Similarly, heterogeneity in threatening processes can act at a variety of spatial scales and be crucial in affecting population persistence. Common wombats (Vombatus ursinus) are considered both widespread and abundant throughout their eastern Australian continental distribution. They nevertheless face many threats, primarily human induced. As well as impacts from disease and predation by introduced species, high roadside fatality rates on many rural roads are frequently reported. We parameterized a model for common wombat population viability analysis within a 750-km 2 area of the northwestern corner of Kosciuszko National Park in New South Wales, Australia, and tested its sensitivity to changes in the values of basic parameters. We then assessed the relative efficiency of various mitigation measures by examining the combined impact from roads, disease and predation on wombat subpopulation persistence in the area. We constructed a stage-structured and spatially explicit model incorporating estimates of survival and fecundity parameters for each of the identified subpopulations using RAMAS GIS. Estimates of current threatening processes suggest mitigating road-kill is the most effective management solution. Results highlight the importance of recognizing the interplay between various threats and how their combination has the capacity to drive local depletion events.

The Wilson Journal of Ornithology, 2013

Ecological …, 2005

Roads and traffic affect animal populations detrimentally in four ways: they decrease habitat amount and quality, enhance mortality due to collisions with vehicles, prevent access to resources on the other side of the road, and subdivide animal populations into smaller and more vulnerable fractions. Roads will affect persistence of animal populations differently depending on (1) road avoidance behavior of the animals (i.e., noise avoidance, road surface avoidance, and car avoidance); (2) population sensitivity to the four road effects; (3) road size; and (4) traffic volume. We have created a model based on these population and road characteristics to study the questions: (1) what types of road avoidance behaviors make populations more vulnerable to roads?;

Diversity

Roads can affect animals as well as their habits at different levels. Avoidance behavior is a common response of animals to this type of perturbation, preventing access to areas rich in resources. The effects of roads on ungulates have not been studied in South America extensively, especially in arid environments. We have studied the space use by ungulates in relation to roads, using a dung heap count and camera traps. The aim was to evaluate whether paved road and unpaved road may have an effect on the spatial use of a low density population of guanacos (Lama guanicoe) in Ischigualasto Provincial Park, Argentina. We observed an increase in dung heap abundance in unpaved road as respect to paved road, this difference was larger for both. Besides, we recorded less individuals in paved road zones than in unpaved road zones. This showed that roads, especially paved roads, negatively affect the space used by guanacos. Our results are relevant to the management and conservation of animal...

Oikos, 2015

Ecologists are increasingly documenting individual variation in resource selection across populations in response to temporal or spatial environmental context. These behavioral patterns are assumed to be adaptive although previous studies have not linked them directly to survival and reproductive data to verify the assumed relationship between behavior and fitness. Recent work documented that higher density of secondary roads within home ranges of free‐ranging canids (wolves, coyotes and hybrids) increased mortality risk in the hybrid zone adjacent to Algonquin Park in Ontario, Canada. Here, we examine individual behavioral responses of canids to spatially varying levels of human‐disturbance and determine whether these responses to secondary roads resulted in differential mortality risk for canids across the hybrid zone. Specifically, we investigated resource selection within home ranges with GPS telemetry to determine whether canids selected roads more at night than during the day ...