This project will gather data on the disease and parasites carried by moose, deer, and elk to determine the risk of transmission to caribou.

Land managers need to know the threats faced by caribou in order to conserve declining populations. Landscape disturbance is creating greater overlap between caribou ranges and other ungulates such as moose, deer, and elk. This could potentially increase the risks of transmitting diseases and parasites to caribou, reducing survival and reproduction.

To help collect ungulate samples, the Caribou Program is providing sample kits to hunters in west-central Alberta. These samples will be tested for pathogens to determine their presence, abundance, and location to identify potential sources of disease outbreaks in caribou.

Caribou Health 

Health contributes to the survival and reproductive success of individuals in free ranging ungulate populations. Certain pathogens kill ungulates directly, while others have more subtle chronic effects such as compromised immunity, and reduced body condition. In turn, these effects can contribute to population declines through increased predation risk, reduced pregnancy rates, low calf survival and juvenile recruitment, or by diminishing the ability of affected animals to cope with natural or anthropogenic stressors including severe weather and industrial development.

The relative importance of health as a driver of ungulate population performance will likely increase with climate change and increased overlap of different ungulate species. Within small or fragmented populations of ungulates, there is also an increased risk of compromised health, disease transmission, and catastrophic disease outbreaks. For caribou, disease transmission from sympatric ungulate species such as moose, deer, and elk may also lead to disease-mediated apparent competition and as the range and density of other ungulate species expand within early seral landscapes—the result of anthropogenic activities across caribou ranges—the risk of disease transmission to caribou may increase.

Since 2013, the British Columbia Boreal Caribou Health Program has identified pathogens and parasites including winter tick, Erysipelothrix rhusiopathiae, and Neospora caninum in live captured and dead radio collared caribou that may be shared with other ungulates. The same pathogens have been recorded in a small sample of unexplained (non-predator related) caribou mortalities assessed by the fRI Research Caribou Program from 2013–2015.

Pathogens

Winter tick (Dermacentor albipictus), is an ectoparasite typically associated with moose. In moose populations, winter tick has been linked to poor body condition, reduced reproduction, and even significant die-offs of up to 30% of the population.

E. rhusiopathiae is a multi-host bacterial pathogen recently found to be associated with large-scale mortality events in muskoxen in the Canadian Arctic Archipelago.

Neospora caninum is a protozoan parasite that can infect a wide-range of hosts and has been found to be a major cause of abortions in cattle.

These emerging pathogens may represent a distinct threat to the health status and sustainability of caribou in Alberta. However, without baseline data on these and other potential pathogens in ungulates within caribou ranges, it is impossible to determine the sources of exposure in caribou and the potential effects that these pathogens and parasites may have on caribou populations. 

Previous Research

To date there has been little focus on the health status of caribou in Alberta. As caribou are listed as a protected species at the provincial and federal level, and given that caribou are not hunted in Alberta, the full range of biological samples required to develop herd health baselines are not readily available. However, the more abundant ungulates (moose, deer and elk) that are hunted within caribou range provide an opportunity to proactively monitor the diversity and prevalence of pathogens shared with caribou. 

Study Area

The main study area is the Grande Cache area within the Narraway, Redrock-Prairie Creek and Little Smoky caribou ranges. However, samples collected by hunters in the surrounding region are still of value to this project. The surrounding region includes: Hinton, Edson, Grande Prairie, Valleyview, Fox Creek and Whitecourt. 

Objectives

The overall purpose of this project is to establish a health baseline for ungulates that occur within caribou ranges in west-central Alberta. This baseline information can be used to identify ungulate populations that may be at risk from cross species disease transmission and establish health baselines in ungulate species that may be used to track future changes under alternate scenarios (i.e. climate change, and habitat fragmentation) and to identify areas where caribou could be affected by pathogen-mediated apparent competition (disease transmission).

The project has the following objectives:

1. Identify pathogens from blood and hair samples collected from ungulates (moose, deer, and elk) harvested in caribou ranges.
2. Establish partnerships and a monitoring framework to continue health monitoring of ungulates into the future.
3. Investigate the spatio-temporal prevalence of pathogens in relation to landscape conditions (anthropogenic and natural disturbance), protected areas, and ungulate species distribution to assess the risk of disease transmission from moose, deer, and elk to sympatric caribou populations.

This project addresses important knowledge gaps identified by PTAC: boreal woodland caribou calving habitat selection and wildlife (including predator) use of anthropogenic features associated with oil and gas developments.

Our results will provide a greater understanding of how different landscape features such as seismic lines and well sites influence both predators and caribou. In addition, we will produce spatial data products that can be used to identify caribou calving habitat with the highest likelihood of calf survival.

Ultimately this project will help minimize industrial impacts to caribou populations in an efficient and cost-effective manner by prioritizing restoration areas and identifying areas of high conservation value.

Background

Woodland caribou populations are declining throughout western Canada. Anthropogenic landscape changes are thought to contribute to caribou declines via habitat loss and degradation, and by creating favourable habitat for sympatric ungulates and predators that increase predation pressure on caribou. Mortality of caribou neonates is particularly important because population growth is inherently limited by the ability of caribou to produce only a single calf per reproductive cycle, and some studies report that up to 50% of calves die in the 6-week period post-calving. Management actions aimed at improving calf survival therefore offer a significant opportunity to contribute to caribou recovery efforts.

Predation is the main cause of mortality for newborn caribou during the calving season. Caribou calves are vulnerable to a wide guild of predators including wolves, grizzly bears, black bears, cougars, and lynx. Historically, caribou have adapted to this predation pressure and decreased the chance of encountering predators by using low productivity and high visibility habitat during the calving season, including black spruce bogs in the boreal forest and alpine areas in mountainous regions.

However, recent anthropogenic landscape changes could limit the ability of caribou to avoid predators during the calving season by decreasing the amount of suitable calving habitat and thus forcing caribou to calve in suboptimal habitat with higher predation risk and improving habitat suitability for predators via apparent competition (i.e., increased numbers of alternate prey driving an increase in predator numbers), thus increasing overall predation risk on the landscape. To date, there has been little research on how multiple industrial features (e.g. cutblocks, roads, seismic lines, pipelines, well sites) interact with multiple predators on the landscape (i.e., wolves, bears, etc.) impact caribou calf survival.

By evaluating calf survival as a function of exposure to both anthropogenic features and predation risk from multiple predators, land management actions can aim to mitigate the most important sources of calf mortality. Ultimately, the project results can be used to prioritize areas for restoration that negatively affect calf survival or that increase predation risk, and to improve caribou population growth in a cost-effective manner.

Objectives

1. Use GPS collar data and resource selection functions for caribou to model the distribution of calving habitat within the Little Smoky boreal caribou herd range and the A la Peche, Redrock-Prairie Creek, and Narraway mountain caribou herd ranges in relation to landcover, terrain, and anthropogenic disturbance.
2. Use GPS collar data for wolves, grizzly bears, existing habitat selection models developed for cougars, and camera trap data for wolves, grizzly bears, black bears, cougars, and lynx to develop spatial data layers depicting predation risk on the landscape for the Little Smoky boreal caribou herd and the A la Peche, Redrock-Prairie Creek, and Narraway mountain caribou herds.
3. Conduct a survival analysis to determine the relative influence of exposure to anthropogenic disturbance and predation risk on calf survival. This analysis will be designed to evaluate multiple spatial and temporal scales of exposure to disturbance and predation risk as well as compounding environmental factors, such as winter severity, to determine the impacts on calf survival.

Methods

Stage 1: Identify the distribution of caribou calving habitat

We will use a statistical method developed specifically for caribou that utilizes sudden changes in movement rates among GPS-collared female caribou to identify calving events and subsequent calf survival (Nobert et al. 2016, Demars et al. 2013). To identify calving sites, we will apply this movement-based method to long-term (1998 – 2017) GPS collar datasets, provided by fRI Research and the Government of Alberta, within the Narraway (n = 85), Redrock-Prairie Creek (n = 124), A la Peche (n = 26) and Little Smoky (n = 43) herds. We will construct resource selection function models of caribou calving habitat by comparing the landscape attributes (e.g., elevation, slope, canopy cover, industrial features etc.) at calving sites to the surrounding available landscape. We will apply the calving habitat model within a GIS to map the spatial distribution of the relative probability of a female caribou giving birth to a calf within the four herd ranges. The products of this analysis will help to identify caribou calving habitat and the types of anthropogenic features caribou avoid during the calving season. In addition, the movement-based method will also determine calf survival within the first four weeks after a calf is born, and this information will be used in stage 3 to evaluate the impacts of anthropogenic features and predation risk on calf survival.

Stage 2: Mapping predation risk from multiple predators

We will use GPS collar data from 46 wolves (GOA, University of Alberta) and 300 grizzly bears (fRI Research Grizzly Bear Program) to build a series of spatially explicit RSF models that are proportional to the risk of a caribou encountering a predator. For species where GPS collar data is unavailable (i.e., black bear, cougar, and lynx), we will use RSF models developed by other researchers in neighbouring regions and occupancy data from 50 camera traps deployed annually (2013-2017) by fRI Research along with 120 camera traps deployed by InnoTech Alberta (2006-2010) within the study area. Knopff et al. (2014) developed cougar RSFs in the neighbouring Rocky Mountain House Region, and Keim et al. (2011) created Lynx RSFs in the Athabasca Region. We will use GIS to translate these statistical RSF models into spatial data layers depicting the amount and distribution of predator habitat within caribou calving areas. The spatial risk layers will be provided as a project deliverable and will also be a key component of subsequent survival analysis of this project.

Currently, predation risk layers in the study area are available only for wolves (DeCesare et al. 2013), however caribou mortality investigations conducted by the fRI Research Caribou Program indicate that cougars and grizzly bears are equally important predators of adult caribou. In other caribou ranges where calf mortality has been studied through direct observation, black bears and meso-carnivores (e.g., lynx) are also important predators of calves. Direct observations of calf predation events are difficult due to logistical and ethical constraints. However, by building predation risk models, we will be able to rank the relative risk of mortality from each predator species of interest and identify ‘hotspots’ where predation risk is particularly high. These maps will delineate areas where the relative risk of predation from one or multiple predator species is high for caribou, and therefore could be an area of focused restoration to reduce predation risk for caribou.

Stage 3: Relating anthropogenic disturbance and predation risk to calf survival

In the final stage of the proposed project, we will develop a survival model to test the relative influence of exposure to anthropogenic disturbance and predation risk on calf survival. Calf survival within the first four weeks after birth will be determined using the movement-based method detailed in Step 1 of the project (Nobert et al. 2016, Demars et al. 2013). We will assess the impacts of industrial development and predation risk on calf survival throughout the gestation period as well as during the first four weeks of a calf’s life, to account for a potential time lag between stressors on pregnant female caribou and calf survival. The calf survival models will allow managers to rank the relative impacts of different anthropogenic features and multiple predators on calf survival, and in turn develop management actions to mitigate potential negative impacts of the industrial landscape on caribou populations. This stage of the analysis will provide a strong link between calving habitat, calf survival, and exposure to anthropogenic disturbance and predation risk. The results of this analysis will be prepared for peer-review publication in the context of landscape management to promote caribou recovery.

This 3-year study will evaluate the potential of new forest management practices to benefit both woodland caribou and growth and yield.

Over the course of the project, we will explore stand characteristics of areas woodland caribou use, the likelihood of harvested areas becoming woodland caribou habitat, and how this potentially differs from burned stands.

We will also identify gaps and opportunities in Alberta’s forest policies for regional silviculture treatments with the potential to improve the trajectory of harvested stands to become caribou habitat while still meeting desired fibre volume objectives.

Background

Declines of woodland caribou populations are linked to human-caused landscape changes that convert mature forests to early seral stands, resulting in habitat loss for caribou, abundant forage for primary prey species, and increased predation risk for caribou via apparent competition. Long-term solutions for caribou conservation will require habitat restoration and adaptive management.

Within managed forests, current reforestation strategies as well as future timber harvesting systems and silviculture practices could influence the timeline and effectiveness of re-establishing functional caribou habitat. Differences in forest stand characteristics and habitat attributes between natural disturbances and harvest disturbances may also influence availability of current and future woodland caribou habitat.

Objectives

1. Literature review

We will carry out a literature review to assess and summarize previous research investigating caribou response to fire and harvest disturbances, including research from ranges within Alberta and research from ranges in similar landscapes elsewhere in Canada. We will consider peer-reviewed literature and technical reports. This review will help determine knowledge gaps, to focus research questions on more specific variables of interest, and to refine both field methods and data analysis techniques

2. Stand characteristics of areas with documented use by woodland caribou in Alberta

Using caribou location data and collect field data from harvested areas used by caribou to relate forest stand characteristics within areas of caribou use. We will then develop models specific to herd ranges, providing information for partners in different regions of Alberta with differing ecosite types and local conditions.

3. Comparing similarly aged cutblocks and areas disturbed by fire

We will determine the differences in stand characteristics and vegetation understory between harvested areas and wildfires, and how these differ with the age of the disturbance and across different ecosites and caribou ranges. We will use this to create models specific to ranges, providing useful information for partners in different regions of Alberta with differing ecosite types and local conditions that could be used to inform future harvesting within caribou ranges and to determine when and where harvested areas are most similar to wildfires.

4. Assessment of historical cutblocks for their ability to produce future woodland caribou habitat

We will assess:

1. How understory and stand characteristics within historical cutblocks differ across natural subregions and ecosites (and as a function of harvest systems, age since disturbance, etc);
2. Characteristics of cutblocks in areas used by caribou (building on results from analyses of forest stand characteristics);
3. Characteristics of cutblocks used by predators (black bears, grizzly bears, wolves, and cougars) and alternate prey (deer, moose, and elk);
4. Whether/which historical cutblocks within caribou ranges contain understory and stand characteristics favourable to caribou and unfavourable to predators and alternate prey;
5. Fibre volumes and stand structure of cutblocks used by caribou (based on data from FMA holders and our field data, i.e. tree heights and DBH measurements).

5. Integrate the results into an interactive GIS tool

This GIS tool will allow land managers to:

1. Identify areas that are on a trajectory towards producing future woodland caribou habitat;
2. Assess how different silviculture practices may change the trajectory of historical and current cutblocks towards producing future woodland caribou habitat;
3. Assess how silviculture practices identified in ii) may impact fibre volumes now and into the future.

6. Review of Alberta’s forest policies

We will create a summary of current and potential silviculture treatments by region, FMA, ecosite and their value towards current and future caribou habitat.

We will also deliver a map of current and potential silviculture treatments by region, FMA, ecosite and their value towards current and future caribou habitat that could be used for spatial planning by forestry.