Don E. Russell

Estimating fat content of caribou from body condition scores

Body condition scores provide a subjective measure of body fatness. We scored the condition of 64 barren-ground caribou (Rangifer tarandus granti) and 10 reindeer (R. t. tarandus) that were later killed and analyzed for chemical composition. A body reserve index (product of body condition score and body mass) was superior to either body mass or body condition score as a predictor of fatness for older calves and adults. The probability of pregnancy for adult female caribou was significantly related to both body condition score (n = 107, P = 0.017) and body reserve index (n = 103, P < 0.001).

Detection of early pregnancy in Caribou : Evidence for embryonic mortality

To investigate relations between body condition and fecundity, we determined pregnancy status of arctic caribou (Rangifer tarandus granti) from presence or absence of pregnancy-specific protein B (PSPB) and progesterone concentration in blood sera or plasma. We drew peripheral blood samples from female caribou 3-5 (n = 142) and 20-23 (n = 44) weeks after the breeding season. We then weighed and estimated the fat content of each caribou, and we radiocollared 115 of 184 individuals. We verified parturition status for 96 of these radiocollared females in June. In addition, we determined presence of PSPB for captive caribou in autumn and early winter. Progesterone concentration was superior to PSPB as a predictor of pregnancy during early gestation, and a threshold value of 1.5 ng/mL was used to separate pregnant from nonpregnant females in autumn and winter. Pregnancy status was strongly related to body condition in both autumn and winter, and fatter or heavier caribou were more likely to be pregnant. Use of both PSPB and progesterone concentration allowed detection of early embryonic mortality among lactating caribou that were in poor condition.

Modeling sustainability of Arctic communities: an interdisciplinary collaboration of researchers and local knowledge holders.

How will climate change affect the sustainability of Arctic villages over the next 40 years? This question motivated a collaboration of 23 researchers and four Arctic communities (Old Crow, Yukon Territory, Canada; Aklavik, Northwest Territories, Canada; Fort McPherson, Northwest Territories, Canada; and Arctic Village, Alaska, USA) in or near the range of the Porcupine Caribou Herd. We drew on existing research and local knowledge to examine potential effects of climate change, petroleum development, tourism, and government spending cutbacks on the sustainability of four Arctic villages. We used data across eight disciplines to develop an Arctic Community Synthesis Model and a Web-based, interactive Possible Futures Model. Results suggested that climate warming will increase vegetation biomass within the herd’s summer range. However, despite forage increasing, the herd was projected as likely to decline with a warming climate because of increased insect harassment in the summer and potentially greater winter snow depths. There was a strong negative correlation between hypothetical, development-induced displacement of cows and calves from utilized calving grounds and calf survival during June. The results suggested that climate warming coupled with petroleum development would cause a decline in caribou harvest by local communities. Because the Synthesis Model inherits uncertainties associated with each component model, sensitivity analysis is required. Scientists and stakeholders agreed that (1) although simulation models are incomplete abstractions of the real world, they helped bring scientific and community knowledge together, and (2) relationships established across disciplines and between scientists and communities were a valuable outcome of the study. Additional project materials, including the Web-based Possible Futures Model, are available at http://www.taiga.net/sustain.

Rain on Snow: Little Understood Killer in the North

In October 2003, a severe rain-on-snow (ROS) event killed approximately 20,000 musk-oxen (Figure 1) on Banks Island, which is the westernmost of the Canadian Arctic islands (approximately 380 kilometers by 290 kilometers in size). The event reduced the isolated herd by 25% and significantly affected the people dependent on the herds well-being. Because of the sparsity of weather stations in the Arctic and the lack of routinely deployed weather equipment that was capable of accurately sensing the ROS event, its detection largely was based on reports from hunters who were in the affected areas at the time. Such events can significantly alter a frozen ecosystem—with changes that often persist for the remainder of a winter—by creating ice layers at the surface of, within, or below the snowpack. The water and ice layers are known to facilitate the growth of toxic fungi, significantly warm the soil surface under thick snowpack, and deter large grazing mammals. Although ROS events of the magnitude that was experienced in Banks Island in 2003 likely have reverberations throughout the entire Arctic and subarctic ecosystem, little is presently known about them and their impacts. As understanding of ROS events expands, many ROS-related aspects of the Arctic ecology and hydrology are likely to be discovered. They may include topics such as the fate of small mammals under the snowpack at the iced soil surface, the difficulty of ptarmigans to burrow into the iced snow, the limited infiltration of spring snowmelt into the iced over soil, and the changing drifting patterns of ice-crusted snowpack.

Where the wild things are: Seasonal variation in caribou distribution in relation to climate change

In this study, we develop a method to analyse the relationships between seasonal caribou distribution and climate, to estimate how climatic conditions affect interactions between humans and caribou, and ultimately to predict patterns of distribution relative to climate change. Satellite locations for the Porcupine (Rangifer tarandus granti) and Bathurst (R. t. groenlandicus) caribou herds were analysed for eight ecologically-defined seasons. For each season, two levels of a key environmental factor influencing caribou distribution were identified, as well as the best climate data available to indicate the factors annual state. Satellite locations were grouped according to the relevant combination of season and environmental factor. Caribou distributions were compared for opposing environmental factors; this comparison was undertaken relative to hunting access for the Porcupine Herd and relative to exposure to mining activity for the Bathurst Herd. Expected climate trends suggest an overall increase in access to Porcupine caribou for Aklavik (NWT) hunters during the winter and rut seasons, for Venetie (Alaska) hunters during midsummer and fall migration and for Arctic Village (Alaska) during midsummer. Arctic Village may experience reduced availability with early snowfalls in the fall, but we expect there to be little directional shift in the spring migration patterns. For the Bathurst Herd, we expect that fewer caribou would be exposed to the mines during the winter, while more caribou would be exposed to the combined Ekati and Diavik mining zone in the early summer and to the Lupin-Jericho mining zone during the fall migration. If changes in climate cause an increased presence of caribou in the mining sites, monitoring and mitigation measures may need to be intensified.

Need and opportunity for a North American caribou knowledge cooperative

The importance of migratory caribou (Rangifer tarandus) to northerners, the increasing pressure to extract non-living resources, and predicted global climate change have led researchers, managers and resource users alike to focus on how to improve our knowledge of this unique northern ungulate. Unprecedented threats to caribou sustainability, along with the increasingly acknowledged value of indigenous hunters’contribution to caribou research, pose the additional challenge to innovate research methods that accommodate differing cultural perspectives and facilitate communication among groups. This paper surveys the state of scientific knowledge of the eleven major northern mainland herds of North America. We recommend an approach to improve our working knowledge of barren-ground caribou in order to assess better future impacts. The transfer of knowledge gained from years of research and indigenous experience on many aspects of caribou ecology should be evaluated and, where applicable, transferred to herds with more modest databases. The establishment of a North American Caribou Monitoring and Assessment System, based on a synthesis of local knowledge and research-based science, is recommended as a tool for improved communication and collective learning.

Standardized monitoring of Rangifer health during International Polar Year.

Monitoring of individual animal health indices in wildlife populations can be a powerful tool for evaluation of population health, detecting changes, and informing management decisions. Standardized monitoring allows robust comparisons within and across populations, and over time and vast geographic regions. As an International Polar Year Initiative, the CircumArctic Rangifer Monitoring and Assessment network established field protocols for standardized monitoring of caribou and reindeer (Rangifer tarandus) health, which included body condition, contaminants, and pathogen exposure and abundance. To facilitate use of the protocols, training sessions were held, additional resources were developed, and language was translated where needed. From March 2007 to September 2010, at least 1206 animals from 16 circumpolar herds were sampled in the field using the protocols. Four main levels of sampling were done and ranged from basic to comprehensive sampling. Possible sources of sampling error were noted by network members early in the process and protocols were modified or supplemented with additional visual resources to improve clarity when needed. This is the first time that such broad and comprehensive circumpolar sampling of migratory caribou and wild reindeer, using standardized protocols covering both body condition and parasite disease status, has been done.

Are warbles and bots related to reproductive status in West Greenland caribou

In March-April 2008-09, using CARMA protocols, 81 cows and 16 calves were collected in West Greenland from two caribou populations; Akia-Maniitsoq (AM) and Kangerlussuaq-Sisimiut (KS). In both populations, warble larvae numbers were highest in calves and higher in non-pregnant than pregnant cows. Nose bots showed no relationship with pregnancy or lactation; KS calves had higher nose bot loads than cows, a pattern not observed in AM. Pregnant cows had more rump fat than non-pregnant cows. KS cows lacking rump fat entirely had the highest warble burdens. We observed lactating pregnant cows with moderate larval burdens. Projected energy cost of the heaviest observed combined larvae burdens was equivalent to 2-5 days basal metabolic rate (BMR) for a cow, and 7-12 days BMR for a calf. Foregone fattening in adult cows with average burdens was 0.2 to 0.5 kg, but almost doubled with the heaviest infestations to 0.4 and 0.8 kg. Average burdens in calves resulted in forgone fattening of about 0.5 kg, with peak costs equivalent to 0.7 and 1.1 kg fat for AM and KS calves respectively. Although modest, these projected energy costs of hosting larvae for cows support the negative relationship between rump fat and larvae burden. For calves, hosting high burdens of warble larvae could affect winter survival, specifically those weaned normally in October or in early winter. Harmful effects of oestrid larvae burdens may remain subtle but clearly cumulative in relation to seasonal forage availability and incidence of other parasites.

Carma's merra-based caribou range climate database.

1 Yukon College, Box 10038, Whitehorse, YT, Y1A 7A1, Canada (Corresponding author: don.russell@ec.gc.ca). 2 Department of Earth Sciences, Simon Fraser University, Burnaby BC, V5A 1S6, Canada. 3 Department of Statistics, Simon Fraser University, Burnaby BC, V5A 1S6, Canada. 4 368 Roland Road, Salt Spring Island, BC. V8K 1V1, Canada. 5 Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA. 6 Aurora Wildlife Research, 1918 Shannon Point Road, Nelson B. C., V1L 6K1, Canada.

Pregnancy rate as an indicator of nutritional status in Rangifer. implications of lactational infertility

Monitofing pregnancy rates to detect changes in nutrition is best accomplished by sampling lactating females because they will be more responsive to changes in nutrienr availability: nutrition influences pregnancy fate of lactating caribou both through autumn body condition and lactational infertility.