Simone Ciuti is currently monitoring elk movements from the US border to the Livingstone Range using recent developments with GPS radiotelemetry. Dispersal behaviour, behavioural response to hunters and other humans are among the topics currently being studied. In particular, topics actually investigated are:
- to understand strategies adopted by bulls to survive during the hunting season. Males that avoid to adopt risky strategies during the hunting season (i.e. by avoiding to use open areas during the day, or by reducing the mobility thus the detectability during the week end) are supposed to have the higher probability to survive than other males.
- to accurately understand how hunting practices and times are able to shape elk spatial behaviour. Elk are supposed to adapt their spatial behaviour on a fine scale (moving among protected areas, private lands and crown lands) as a response to different degree of hunting pressure.
- to understand how dispersal individuals are exploring unknown territories. Dispersal individuals, i.e. those animals permanently emigrating even 150 km far from the birth place, are supposed to explore unknown territories by adopting peculiar (and still unknown) spatial strategies.
Recent developments with GPS radiotelemetry allow us to collect a large amount of detailed information about the elk spatial behaviour. Indeed, we are collecting the exact location (error < 10 m) of each collared elk (over a hundred individuals) every 2 hours. However, to asses the human impact on elk properly, it is important to simultaneously collect both accurate GPS telemetry data and behavioural information. Behavioural modifications affected by disturbance can explain how animals respond to changes in their environment.
Researchers performing behavioural observations of elk in different areas of SW Alberta (Bob creek provincial park and private lands around Pincher Creek).
Empirical studies suggest that a high disturbance rate can modify the behaviour by increasing the time spent in vigilance behaviour (i.e. the behaviour shown by individuals while scanning the landscape to detect potential predators and other sources of disturbance) and significantly reducing daily feed intake, with negative consequences for female reproductive success and population dynamics. Thus, a new research goal of this project is to quantify the effect of human activities (ATV, hiking, camping, hunting, and, more in general, road access including industrial activities) on the behaviour of elk in SW Alberta. Data on vigilance behaviour are currently collected by direct observations of elk herds carried out in different areas of SW Alberta affected by varying degrees of hunting pressure and human disturbance.
Elk herd scanning the landscape to detect potential predators and other sources of disturbance along the border of the Waterton lakes NP.
If human activities are affecting the vigilance behaviour of a herd and its stress levels, we expect to detect specific spatial strategies in such a herd as a response (e.g. increased use of safe habitats), and this is possible by combining for the first time data on vigilance behaviour with elk GPS biotelemetry data. Elk are an important wildlife resource in southern Alberta, and data from this study are designed to help improve the management of this species.
RESEARCH TECHNICIANS
Silvia Simi, B.Sc., M.Sc., research technician.
Human impact on elk behaviour - Behavioural observations of elk herds in different areas of SW Alberta affected by different degrees of hunting pressure and human disturbance.
Determining the number of ungulates missed during surveys is a crucial component of interpreting survey results (Caughley 1974). Not accounting for sightability during aerial surveys can cause substantial errors in the resulting population calculations, including biases in sex and age structure and wide confidence intervals (Caughley 1974, McCorquodale 2001). Slight changes in weather patterns have proven to influence herding behaviour of elk, with potentially important implications for the proportion of elk observed during a survey (Boyce 1989, Allen 2005). Even trend-type surveys, which seek to estimate the trajectory of population change, may suffer when sightability differs within a survey or among surveys (Lancia et al. 1996).
Elk aerial surveys in southwestern Alberta are currently conducted as total trend counts during winter when elk are congregated and when snow cover provides good sightability. While these surveys provide a useful measure of elk relative abundance through time, they are a minimum count and do not allow estimates of the proportion of elk missed.
Current Elk Surveys: Winter range trend counts; no correction for sightability. Bull:Cow ratios likely underestimated. Accurate sex ratios are necessary for management; mature bulls most important. Bull Sightability: May use separate winter ranges, travel in smaller herds, or spend more time in forest. Existing sightability model (Allen 2005) not compatible with non-random survey method.
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Methods
Using previously collected Global Positioning System (GPS) collar location data from both mature bull (3+ antler points) and cow elk during 2008, we examined patterns of spatial overlap between the two sexes during the period when aerial surveys would be conducted (January - March). We developed 95% Minimum Convex Polygon and kernel home ranges in ArcGIS 9.2 for each collared elk and calculated the amount of within- and between-sex overlap. We tested for differences in space-use using one-tailed t-tests, ANOVA and Volume of Intersection calculations in Microsoft Excel and R.
Results
In 2008/09 we compared percent overlap of five mature (3 point+) bull elk and 13 cow elk using their winter GPS locations (January - March). Our initial observations suggested mature bull elk winter home range size was half that of cow elk, on average. Individual bull and cow elk used consistent home range boundaries from January to March, allowing pooling of all GPS collar data from each animal across all three months. When pooled, mature bull elk home ranges overlapped less with cow elk home ranges than cows overlapped with each other (P = 0.017), indicating that bulls utilized different home ranges than cows during the winter. Finally, volume of intersection analyses indicated that bulls and cows showed different patterns of space use within their home ranges (P = 0.040).
We continued to test for yearly differences by examining winter 2009 and 2010 GPS collar data. We compared the percent overlap of four mature bull elk and three cow elk during winter 2009 and compared the overlap of two mature bull elk and eight cow elk in 2010. During 2009 and 2010, the overlap between bull and cow elk home ranges did not differ from that of cow home range overlap with each other 2009 (P = 0.477), 2010 (P = 0.328). Volume of intersection analysis also failed to show that bulls and cows were using space differently within home ranges 2009 (P = 0.681), 2010 (P=0.482).
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Conclusions
Bull and cow elk in southwestern Alberta exhibited different patterns of space use during the winter of 2008. The analysis for both 2009 and 2010 winter data did not result in the same pattern as observed in 2008. We continue to struggle with maintaining an adequate sample size throughout winter months and therefore these may not represent patterns for the population. Due to the timing of animal collar drop-offs, animal harvest and re-collaring of elk, we end up with few elk with complete data for all three winter months and these are limited to one elk herd in the Castle-Carbondale area.
The potential to which mature bulls will separate from cow elk herds during the winter season could be a factor of individual herds (some herds have fewer options to access preferred winter range) or individual years (intraspecific competition, predatory pressure, winter severity). We will continue overlap analysis to test for yearly differences to help better understand winter range use of mature bulls during the winter aerial survey season.
All collared elk captured up to 2010 were analyzed at 28 variable genetic markers. These genetic markers allow us to accurately measure relatedness between individuals and to infer gene flow/past movement between herds. Preliminary analysis has revealed that all individuals/herds belong to a single genetic unit, suggesting that ongoing gene flow between herds is being maintained. However, there is evidence that more northerly herds are somewhat separated from southerly herds. This may be caused by geographic isolation but could also be caused by landscape barriers in between, possibly natural or human influenced (such as Highway 3) features, perhaps both.
Ongoing analyses are examining the roles of individual landscape features and behaviour on determining gene flow and genetic structure of elk in Southwest Alberta. This will be achieved by combining genetic data with spatial data from GPS collars and habitat data. The results of this will ultimately help us disentangle the effects of a multitude of factors involved in determining genetic structure in an important game species in Alberta.
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My study will identify elk herds in SW Alberta which consist of migratory phenotypes of elk and the characteristics of the elk migration route. Connectivity between season ranges is expected to be important to maintaining migration. The loss of connectivity for wildlife across landscapes worldwide has led researchers to investigate the effects of habitat fragmentation and human disturbance to migrations of animals traversing tens to hundreds of kilometers. Migration events are expected to be an ecological necessity for the existence of migrating populations and meta-populations, often essential to population genetics and allowing for increased access to resources for far-ranging species. Elk migration is an adaptive behavioral strategy that evolved to avoid constraints on resource availability in temperate regions. Movement to seasonal mountain ranges allows elk to follow elevation gradients tracking optimal patches of nutrient rich vegetation for an extended time period, enhancing fitness and reproduction. In turn, elk contribute to ecosystems function by their grazing pressure on plants and influence on soil dynamics.
In my study area blocking or reducing connectivity of migratory movement routes could result in elk spending more time on wintering grounds located on private lands than traditional ranges on provincial forest reserves. This in turn could cause changes in distribution or increased elk and land owner conflicts from crop depredation and result in ecological losses due to over grazing, affect calving or potentially reduce fitness of elk. Elk undertaking migration may also be less vulnerable to predators.
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Migration routes are not well known for the Castle-Carbondale herd. Using Global Positioning Systems (GPS) collars, elk were tracked for a two year period over a 4 year study acquiring relocation points every 2 hours. We use an investigative framework applying the Brownian bridge movement model to delineate the population migration network for a subpopulation of partially migratory elk. Our analyses will use migration GPS data to identify elk stopover areas which are expected to be important to elk for increasing body condition, resting and the movement corridors between these habitat patches during migration. With this ecological knowledge of migration, managers will have fundamental data for conservation of migrating elk herds in SW Alberta.
See the article published on Alberta Outdoorsmen Magazine about this study
Mathieu Pruvot is looking at 5 livestock production limiting diseases that are known to be present and important in Alberta (Bovine viral diarrhea, Infectious bovine rhinotracheitis, Neosporosis, Johne's disease and liver flukes). These pathogens are representative of different transmission routes in order to figure out what type of pathogen may be transmitted between cows and elk.
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Mathieu is currently finishing his fieldwork in soutwestern Alberta. In complement of the samples collected during the elk captures, he collected elk droppings from different elk herds exposed or unexposed to cattle (in agreement with landowners when necessary). By comparing these different herds, he will assess the effect of elk interactions with cattle. Similarly, he also sampled cows in 2 groups of 15 ranches that are exposed or unexposed to elk. Questionnaire and interview also collected the necessary information to interprete the results.
The samples will be processed at the laboratory of the Faculty of Veterinary Medicine-University of Calgary, and the results will then be analysed to assess the effect of cattle-elk comingling on the circulation of these pathogens.
Further analysis and modelling techniques will be used to test the hypothesis that only certain types of transmission route can occur at the interface between cattle and elk.
