Frank L. Miller

Traditional behaviour and fidelity to caribou calving grounds by barren-ground caribou

Evidence for the fidelity of female barren-ground caribou (Rangifer tarandus spp.) of each herd to specific calving grounds is convincing. Involvement of learned behaviour in the annual return of those cows to the same calving grounds implies such actions are a form of «traditional» behaviour. Even wide variations in population size have not yet knowingly led to marked changes in size or location of calving grounds or prolonged abandonment of established ones. Rarely is the adoption of new calving grounds reported and emigration to another herds calving ground or interchange between calving grounds has not yet been unequivocally documented. The calving experience of individual caribou and environmental pressures may modify the cows use patterns of her calving grounds. The current definition of herds based on traditional calving grounds may require modification, if increasing caribou numbers result in changes in traditions. However, current data do not contradict either the fidelity to traditional calving grounds or the concept of herd identity based on that fidelity.

Distribution Patterns of Black-Tailed Deer (Odocoileus Hemionus Columbianus) in Relation to Environment

During 1964, 1410 hours of observation yielded 6746 sightings of black-tailed deer (Odocoileus hemionus columbianus) within the Cedar Creek study enclosure on the Tillamook Burn, Oregon. Deer activity was influenced by age, sex, reproductive phase, extremes or sharp changes in temperature, minimum relative humidity, and precipitation. Deer sought cover by midmorning from mid-May to November when weekly extreme temperatures exceeded 60°F. Their activity was sharply reduced by heavy summer rainfall, but was not influenced by winter rains. Monthly and annual home ranges were related to age and sex, and varied with changes in the reproductive cycle and forage availability. Annual home ranges varied from one-eighth to one-half square mile.

Dental anomalies in caribou, Rangifer tarandus.

The dentitions of 43 of 1226 caribou (Rangifer tarandus) skulls examined had anomalies. Of the 43, 13 had supernumerary teeth, 25 had missing teeth, and five had extreme variations in root development and abnormal dentary patterns. These anomalies appear to be genetically produced and further study from the standpoint of evolutionary origin might be fruitful. sented. The 1176 caribou were taken from the Kaminuriak population, which calves and summers in the District of Keewatin, Northwest Territories, and winters for the most part in northwestern Manitoba and northeastern Saskatchewan. The 50 caribou were from a herd that is resident in north-central Baffin Island. Anomalies in the dentitions of Cervidae are generally uncommon. They are regularly reported in Odocoileus, a genus in which maxillary canines, in particular, appear with some frequency. Canines in the maxillae are normal in the genus Rangifer, the accepted dental formula for which is 0/3, 1/1, 3/3, 3/3 = 34 (Banfield, 1961:26). The associated maxillae, mandibles, and anomalous teeth were examined for evidence of the possible origin of anomalies from trauma. The incisiform teeth were extracted. The absence of normal sockets or the presence of extra sockets was determined, as was the possible migration of incisiform teeth due to the absence of one or more teeth from the incisiform row. The classification of the present or absent tooth was based on the form, size, and position of existing teeth.

Sea-ice crossings by caribou in the south-central Canadian Arctic Archipelago and their ecological importance

The islands of the Canadian Arctic Archipelago lie immediately north of mainland North America in the Arctic Ocean. They are surrounded by ice for most of each year. Caribou (Rangifer tarandus) cross the sea ice in seasonal migrations among the islands and between the mainland and Arctic Islands. We compiled observations of 1272 discrete caribou crossings on the sea ice of northeastern Franklin Strait, Bellot Strait, Peel Sound and Baring Channel in the south-central Canadian Arctic Archipelago during four May—June search periods from 1977 to 1980. We clustered the 850 caribou trails found on the sea ice of northeastern Franklin Strait and on outer Peel Sound as 73 sea-ice crossing sites. We investigated whether caribou at the origin of a sea-ice crossing site could see land on the opposite side at the potential terminus. We measured the straight-line distance from where the caribou first came onto the ice (origin) to the first possible landfall (potential terminus). Potential termini were geodetically visible to caribou from elevated terrain near 96% of the origins of the 73 sea-ice crossing sites and still visible at sea-level at the origins on 68%. Caribou are able to take advantage of seasonal use of all of the islands and the peninsula by making sea-ice crossings, thereby helping to increase the magnitudes and durations of population highs and reduce their lows. Knowledge of these alternative pat¬terns of use made possible by sea-ice crossings is necessary to fully understand the population dynamics of these caribou and the importance of possible future changes in ice cover.

Status of endangered and threatened caribou on Canada's arctic islands

Caribou (Rangifer tarandus) on the Canadian Arctic Islands occur as several populations which are nationally classified as either endangered or threatened. On the western High Arctic (Queen Elizabeth) Islands, Peary caribou (R. t. pearyi) declined to an estimated 1100 caribou in 1997. This is the lowest recorded abundance since the first aerial survey in 1961 when a high of ca. 24 363 caribou was estimated on those islands. Peary caribou abundance on the eastern Queen Elizabeth Islands is almost unknown. On the southern Arctic Islands, three caribou populations declined by 95-98% between 1973 and 1994 but our information is unclear about the numerical trends for the two other populations. Diagnosis of factors driving the declines is complicated by incomplete information but also because the agents driving the declines vary among the Arctics different climatic regions. The available evidence indicates that severe winters caused Peary caribou die-offs on the western Queen Elizabeth Islands. On Banks Island, harvesting together with unfavourable snow/ice conditions in some years accelerated the decline. On northwestern Victoria Island, harvesting apparently explains the decline. The role of wolf predation is unknown on Banks and notthwest Victoria islands, although wolf sightings increased during the catibou declines. Reasons for the virtual disappearance of arctic-island caribou on Prince of Wales and Somerset islands are uncertain. Recovery actions have started with Inuit and Inuvialuit reducing their harvesting but it is too soon to evaluate the effect of those changes. Recovery of Peary caribou on the western Queen Elizabeth Islands is uncertain if the current trends toward warmer temperatures and higher snowfall persist.

Conservation of erupting ungulate populations on islands – a comment

A generalised model for herbivores experiencing abundant forage over time is that their numbers erupt and then decline. This model has been applied to fluctuations in caribou (Rangifer tarandus) populations especially those on islands. Since this generalised model for erupting herbivores was first proposed, two assumptions have slipped in (1) that an erupting population will crash; and (2) that the crash will be density-dependent. The problem with the assumptions is that, without testing, they can lead to inappropriate management such as culls. The first assumption arises from uncritical use of earlier accounts and the second assumption from not discriminating between the effects of environmental variation from the effects of the high herbivore numbers on forage availability (density-dependence). Often typical densitydependent effects such as lowered initial reproduction, reduced early survival of calves, and subsequent calf, yearling and juvenile survival are used to justify the contention that there are too many herbivores. But such reasoning is flawed unless cause/effect relationships are established and the role of environmental variation is evaluated. We argue that it is overly simplistic to believe that every population’s subsequent performance and fate will follow a singular pattern with only one paramount factor driving and ultimately dictating an inevitable outcome. The relative importance of unpredictable abiotic factors in influencing and causing variation in the response of ungulate populations should be investigated, no matter whether those factors are sporadic or periodic.

The current status and future of Peary Caribou Rangifer tarandus pearyi on the Arctic Islands of Canada

Abstract The Peary caribou Rangifer tarandus pearyi is an unique subspecies confined almost entirely to the Canadian Arctic Archipelago. The decline of the population by 89% on the western Queen Elizabeth Islands between 1961 and 1974 has continued until at least 1977. The decline was principally caused by climatic changes but Peary caribou are potentially under additional pressure from hunting and disturbances associated with increasing industrial activities. We believe there are only 10–15,000 Peary caribou in Canada, and the subspieces was classified as ‘Threatened’ in 1979. The population dynamics of Peary caribou are unique among North American ungulates because weather, especially winter weather, dominates not only the reproductive rate but also recruitment and adult survival. The inter-island movements are a significant adaptation not only to sparse ranges and snow conditions, but also to recolonisation of islands that periodically, through a series of severe winters, lose their caribou.

An enigmatic group of arctic island caribou and the potential implications for conservation of biodiversity

We investigated the status of caribou classified as Rangifer tarandus pearyi by DNA analyses, with an emphasis on those large-bodied caribou identified as ultra pearyi that were collected in summer 1958 on Prince of Wales Island, south-central Canadian Arctic Archipelago. Our comparative assessment reveals that the ultra pearyi from Prince of Wales Island belong to a group of pearyi and are not hybrids of pearyi x groenlandicus, as we found for the caribou occurring on nearby Banks Island and northwest Victoria Island. The ultra pearyi from Prince of Wales Island cluster with high arctic pearyi and are separated genetically from the caribou populations that we sampled on the low Canadian Arctic Islands and the Canadian mainland. Our findings reveal biodiversity below the level of subspecies or regional designations. These results support the position that to retain the biodiversity present among caribou populations on the Canadian Arctic Islands, conservation efforts should be targeted at the smaller scale level of the geographic population, rather than on a wider regional or subspecific range-wide basis.

Single-island home range use by four female Peary caribou, Bathurst Island, Canadian High Arctic, 1993-94

Spatial and temporal use of seasonal, and collectively, annual ranges by four female Peary caribou (Rangifer taran-dus pearyi) was investigated using satellite telemetry. Knowledge of how caribou use space allows a better understanding of their demands on those ranges and enhances evaluation of associated environmental stressors. The study took place during an environmentally favorable caribou-year with high reproduction and calf survival and low (none detected) 1+ yr-old mortality, 1 August 1993 to 31 July 1994, Bathurst Island, south-central Queen Elizabeth Islands, Canadian High Arctic. All four females exhibited a pattern of single-island seasonal, and collectively, annual range use. Estimates of the maximum area encompassed by each individual during the course of the annual-cycle varied from 1735 to 2844 km2 (mean±SE = 2284±250 km2). Although, there was 46% spatial overlap among individual ranges, temporal isolation resulted in the four individuals maintaining seasonal ranges distinctly separate from each other. This collective area encompassed 4970 km2 and equaled about 31% and 18% of Bathurst Island and the Bathurst Island complex, respectively. Individual wintering areas formed a relatively small portion of each individuals annual range (mean±SE=71±17 km2): 24 km2, 158 days of occupation, <1% of the annual area; 70 km2, 187 days, 4%; 95 km2, 200 days, 4%; and 94 km2, 172 days, 6%. Seasonal movements were greatest during pre-rut and pre-calving.

St. Matthew Island reindeer crash revisited: Their demise was not nigh—but then, why did they die?

Twenty-nine yearling reindeer (Rangifer tarandus) were released on St. Matthew Island in the Bering Sea Wildlife Refuge in 1944: 24 females and five males. They were reported to have increased to 1350 reindeer by summer 1957 and to 6000 by summer 1963. The 6000 reindeer on St. Matthew Island in summer 1963 were then reduced by 99% to 42 by summer 1966. The evidence suggests that after growing at a high average annual rate of lamda = 1.32 for 19 years, the entire die-off occurred in winter 1963—64, making it the largest single-year crash ever recorded in any R. tarandus population. Although a supposedly meaningful decline in successful reproduction and early survival of calves was originally reported for the population between 1957 and 1963, our reevaluation indicates this is an error resulting from the wrong sample being used in the between-year comparison. The quantitative data indicate no meaningful change occurred, and the calf:cow ratio was about 60 calves:100 cows in both 1957 and 1963. Calf production and survival were high up to the crash, and in the die-off population the age distribution (72%, 1—3 years old) and the sex ratio (69 males:100 females) reflected a still fast-growing R. tarandus population. All of these parameters do not support the hypothesis that the limited abundance of the absolute food supply was at a lethal level between 1957 and 1963 or in winter 1963—64. We now know from other studies that a high density of R. tarandus is not a prerequisite for a major single-year winter die-off. Existing population dynamics data do not support lack of lichens as a major causative factor in this single-year crash. If a decline had been caused by the limitation of the absolute food supply, it would have followed a multi-year pattern—it would not have been a single-year event. There was no evidence of a sudden, massive, island-wide loss of the absolute food supply, or that its nutritional value was inadequate for sustaining the reindeer. Mean weights of reindeer by sex and age class declined between 1957 and 1963, but only to levels similar to those of mainland reindeer. The reindeer population on St. Matthew Island undoubtedly was or soon would have been seriously influenced by heavy use of the lichens and the future did not bode well for continued population growth. Although the food supply through interaction with climatic factors was proposed as the dominant population-regulating mechanism, a general acceptance that only density-dependent food-limitation was necessary to cause the crash remains strong in some quarters. We challenge this; we believe that the winter weather was the all-important factor that led to the premature, extreme, and exceptionally rapid, near total single-year loss of 99% of the reindeer on St. Matthew Island in winter 1963—64.