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Progressive anthropogenic disturbance can alter ecosystem organization potentially causing shifts from one stable state to another. This potential for ecosystem shifts must be considered when establishing targets and objectives for conservation. We ask whether a predator-prey system response to incremental anthropogenic disturbance might shift along a disturbance gradient and, if it does, whether any disturbance thresholds are evident for this system. Development of linear corridors in forested areas increases wolf predation effectiveness, while high density of development provides a safe-haven for their prey. If wolves limit moose population growth, then wolves and moose should respond inversely to land cover disturbance. Using general linear model analysis, we test how the rate of change in moose ( Alces alces) density and wolf ( Canis lupus) harvest density are influenced by the rate of change in land cover and proportion of land cover disturbed within a 300,000 km2 area in the boreal forest of Alberta, Canada. Using logistic regression, we test how the direction of change in moose density is influenced by measures of land cover change. In response to incremental land cover disturbance, moose declines occurred where <43% of land cover was disturbed; in such landscapes, there were high rates of increase in linear disturbance and wolf density increased. By contrast, moose increases occurred where >43% of land cover was disturbed and wolf density declined. Wolves and moose appeared to respond inversely to incremental disturbance with the balance between moose decline and wolf increase shifting at about 43% of land cover disturbed. Conservation decisions require quantification of disturbance rates and their relationships to predator-prey systems because ecosystem responses to anthropogenic disturbance shift across disturbance gradients. [ABSTRACT FROM AUTHOR]

Presents information on a study that used fallow deer, Dama dama, to test whether female estrus coincides with the availability of preferred males. Methods; Results; Discussion.

Presents a study which examined whether male Kirk's dikdik, Madoqua kirki, forgo monogamous pair bonds when unpaired females are available. Simulated availability of females through scents; Male and female territoriality; Comparison of paired and unpaired males; Lack of plasticity of dikdiks.

Anthropogenic landscape disturbances, including industrial development, can have significant impacts on wildlife populations. In Canada, federal, territorial, and provincial laws require major industrial development projects to submit detailed environmental impact assessments (EIA) reports as part of the project application process. These assessments are meant to establish baseline habitat conditions and predict which landscape components will be altered by the project and to what degree. Based on these changes, indirect predictions for wildlife impacts are made using a variety of models, which can vary in validation adequacy and often rely heavily on expert opinion. In the oil sands region of Canada, wildlife species and habitat types used to make predictions are not comprehensive nor standardized between EIAs, despite a high degree of landscape similarity between projects. We extracted habitat model parameters, projected impacts, and anticipated mitigation effectiveness from 30 project EIAs. Despite all these projects occurring in the same natural region, we found very little agreement in the species used to assess wildlife impacts as well as the parameters used to model impacts on those species. Relative to unvalidated habitat models, we found that models receiving independent validation required half the habitat amount for proponents to conclude that the project will have an adverse effect. Our analyses have exposed many areas where policy could improve the efficiency of the EIA process as well as the scientific rigour underlying regulatory decisions. [ABSTRACT FROM AUTHOR]

In Canada, the National Energy Board (NEB) regulates inter-provincial oil and gas pipelines and maintains historical records that contain data on oil and gas pipeline accidents; these data include information about operators, the accidents' cause, and the resulting consequences. New inter-provincial pipelines are being built in Canada to transport fuels, but no comprehensive statistical analysis of the risk to environmental receptors exists. This study assesses the quality and quantity of NEB pipeline failure data available in Canada with a focus on environmental consequences and investigates differences between Canada and a more thoroughly studied jurisdiction, the United States, in tracking accident data. The discrepancies in agencies' jurisdiction and regulated mileage are analyzed, along with reporting criteria and initial recording year. The level of detail provided by the two agencies is compared, identifying deficiencies in data collection. The Pipeline and Hazardous Materials Safety Administration (PHMSA) regulates 76% of pipelines in the United States, whereas the NEB only monitors 9% of pipelines in Canada. PHMSA provides four databases that include accidents from the 1980s for most pipelines and from 2011 for liquefied natural gas facilities; the NEB database includes accident data starting from 2008, which derive primarily from transmission pipelines. Information about environmental consequences is quite detailed in the US database, which reports 21 descriptive fields, whereas in Canada only two NEB database fields describe environmental outcomes. Moreover, dissimilarities in accident reporting criteria prevent the combination of data from the two agencies. Consequently, the NEB database does not allow for statistically robust and system wide analysis of the environmental consequences of pipeline failures in Canada. Furthermore, to calculate failure rates (annual number of accidents per kilometre of pipeline) for regulated pipelines, annual total mileage estimates are required. Mileage per year is provided by PHMSA for gas gathering, transmission, and distribution pipelines starting from 1984, and for hazardous liquid pipelines from 2004; the NEB provides annual mileage from 2010, a shorter period of record. The Canadian federal agencies are encouraged to improve accuracy and consistency in recording past accidents and in collecting pipeline data, with the goal of preventing and minimizing future pipeline failures. [ABSTRACT FROM AUTHOR]

Despite a low probability of achieving copulations, yearling male (1.5-year-old) fallow deer Dama dama display behavioural changes during rut, interacting with both females and older males. Juvenile interactions in polygynous ungulates may affect further reproductive success through both motor training for future interactions and/or competition for current resources that affect growth. To test this hypothesis, we intensively studied the behaviour of 12 yearling males in two captive populations during a rutting season. Interactions with females were interpreted as motor training aimed at learning to recognize oestrous females, because yearling males rarely interacted with their mother and because interactions essentially consisted of olfactory investigations focused on oestrous females. Because agonistic interactions with older males never involved physical contact and were mainly initiated by the most dominant buck in each population, we concluded that these interactions resulted from the presence of the yearlings close to oestrous females defended by rutting males. Heavier yearlings tended to be dominant over lighter ones and tended to interact more frequently with other animals, suggesting that early growth may influence the ontogeny of social behaviours. [ABSTRACT FROM AUTHOR]

The argument that an optimal age at first reproduction evolves wherethe benefits of reproduction outweigh the costs implies that where conditions change, age at first reproduction should also change. We studied six captive populations of fallow deer (Dama dama) that differed in the age structure of males, male density, and sex ratio. We examined responses of males to changes in competition by simulating the presence of additional males by providing visual, olfactory, and auditory stimuli. Our results suggest that dominance rank was the most important factor in determining the level of reproductive behaviors exhibited. The participation in reproduction increased with dominance status, and this association held for males that are usually socially immature (3--5 years old). Hence, age apart from dominance was relatively unimportant in affecting the reproductive behavior. Male density was positively correlated with the time spent walking and standing. The female-to-male ratio was positively related to male-female interactions, but negatively related to male-male interactions. In response to the simulations, males older than 3 years increased the rate of reproductive behaviors, but younger males did not change or decreased the rate. We conclude that only males up to 3 years of age refrained from reproduction under competition by mature males. However, past 3 years of age, investment in reproduction is a function of dominance rather than a function of age. This implies that 4- and 5-year-old malesdo not seem to defer reproduction until socially mature but that their participation is a correlate of the achievable dominance rank. [ABSTRACT FROM AUTHOR]