The relationship between weather and caribou productivity for the La-Poile Caribou Herd, Newfoundland

To describe the relationship between weather and caribou (Rangifer tarandus) productivity, we compared weather variables (snow on ground, winter temperature and measures of growing season) with measures of productivity (calves seen by hunters, calves and yearlings in the harvest and percent calves and yearlings and pregnancy rate for caribou classified during fall and spring surveys) for the LaPoile Caribou Herd in southwestern Newfoundland. Hunter statistics reliably estimated changes in population demography. Percent calves seen by hunters was correlated with calves/100 females classified in fall. Weather may have influenced productivity for the LaPoile Caribou Herd in Newfoundland. Colder winter temperatures were associated with fewer calves the next fall and pregnancy rates and yearlings/100 females in the spring were negatively correlated with snow on ground the previous winter. These relationships appear to be density related

Phenotypic Variation in Skull Size and Shape Between Newfoundland and Mainland Populations of North American Black Bears, Ursus americanus

It is well recognized that differences in environmental selection pressures among populations can generate phenotypic divergence in a suite of morphological characteristics and associated life history traits. Previous analysis of mitochondrial DNA and body size have suggested that Black Bears (Ursus americanus) inhabiting the island of Newfoundland represent a different subspecies or ecotype from mainland populations. Assuming that body size covaries positively with skull size, we predicted that skull size would be greater for bears on the island than the mainland, and the distribution of size-related shape components in multivariate space should show a distinct separation between Newfoundland and mainland populations. Measurements of 1080 specimens from Newfoundland, Alberta, New York, and Quebec did not provide unequivocal support for our prediction that skull size in Newfoundland bears would be larger than bears from the mainland populations. After removing ontogenetic effects of skull size, between-population variation in skull shape was greater in females than males, and the analysis significantly separated Newfoundland bears from mainland populations. Explanations for this pattern are numerous, but currently remain hypothetical. Limited covariation between skull size and body size suggests that genetic traits regulating the size of Black Bear skulls are more heritable (i.e., less influenced by environmental selection pressures) than characteristics affecting body size. We hypothesize that if gape size does not limit prey size in solitary terrestrial carnivores, large degrees of among-population variation in body size should be coupled with little covariation in skull size. In general, sexual dimorphism in skull size and shape was marginal for the phenotypic characters measured in our study. We believe that sexual dimorphism in skull size in Black Bears is primarily driven by intrasexual selection in males for increased gape size display, while similarity in skull shape between sexes is associated with the constraints of a temporally-selective, but similar diet

Morphological change in Newfoundland caribou: Effects of abundance and climate

The demographic and environmental influences on large mammal morphology are central questions in ecology. We investigated the effects of population abundance and climate on body size and number of male antler points for the La Poile and Middle Ridge caribou (Rangifer tarandus, L. 1758) herds, Newfoundland, Canada. Across 40 years and 20-fold changes in abundance, adult males and females exhibited diminished stature as indicated by jawbone size (diastema and total mandible length) and the number of antler points at the time of harvest. Associations between jawbone size and population abundance at birth were consistently negative for both herds, both sexes, and all age classes. Large-scale climate patterns, as measured by the North Atlantic Oscillation in the winter prior to birth, were also negatively associated with jawbone size. Declines in male antler size, as measured by the number of antler points, were not well predicted by either abundance or climate, suggesting other factors (e.g., current, rather than latent, foraging conditions) may be involved. We conclude that these morphological changes indicate competition for food resources

MOOSE HABITAT USE THROUGHOUT GROS MORNE NATIONAL PARK

Previous research indicated high variability in availability and habitat use by female moose in the lowlands of Gros Morne National Park (GMNP), Newfoundland and Labrador, an area dominated by bogs and forest. Here, we extend the earlier analysis with an additional 7 female moose (Alces alces americana) occupying the Park highlands, a region dominated by heath and shrub vegetation with forest limited to sheltered valleys, typical of interior and highland parts of the province. Resource selection function (RSF) models with differences in habitat use between moose resident in the 2 regions and 2 moose that migrated from the lowlands in winter to the highlands in summer were rejected. In summer, more use of closed-canopy forest types occurred on the lowlands, while more use of non-forest habitat types occurred on the highlands. As before, we found that selection of disturbed forest is a winter phenomenon on the lowlands of GMNP; the same series of habitat types associated with disturbance were avoided in summer. Summer migration by about 20% of GMNP moose to the highlands suggests that foraging opportunities are better during that season than in winter, a motivation for migration perhaps augmented by an overabundance of moose on the lowlands and unfavourable temperatures in disturbed areas that might otherwise serve as lowland foraging areas. An observation of more clustered relocations of moose on the highlands than on the lowlands of GMNP is consistent with our conclusion that moose use habitats within the highlands and lowlands of Newfoundland and Labrador very differently. We recommend 2 approaches to moose management for these different landscapes, both within GMNP and elsewhere in Newfoundland and Labrador

Desmoglein-2 is Important for Islet Function and β-Cell Survival

Type 1 diabetes is a complex disease characterized by the lack of endogenous insulin secreted from the pancreatic β-cells. Although β-cell targeted autoimmune processes and β-cell dysfunction are known to occur in type 1 diabetes, a complete understanding of the cell-to-cell interactions that support pancreatic function is still lacking. To characterize the pancreatic endocrine compartment, we studied pancreata from healthy adult donors and investigated a single cell surface adhesion molecule, desmoglein-2 (DSG2). Genetically-modified mice lacking Dsg2 were examined for islet cell mass, insulin production, responses to glucose, susceptibility to a streptozotocin-induced mouse model of hyperglycaemia, and ability to cure diabetes in a syngeneic transplantation model. Herein, we have identified DSG2 as a previously unrecognized adhesion molecule that supports β-cells. Furthermore, we reveal that DSG2 is within the top 10 percent of all genes expressed by human pancreatic islets and is expressed by the insulin-producing β-cells but not the somatostatin-producing δ-cells. In a Dsg2 loss-of-function mice (Dsg

The relationship between weather and caribou productivity for the La-Poile Caribou Herd, Newfoundland

To describe the relationship between weather and caribou (Rangifer tarandus) productivity, we compared weather variables (snow on ground, winter temperature and measures of growing season) with measures of productivity (calves seen by hunters, calves and yearlings in the harvest and percent calves and yearlings and pregnancy rate for caribou classified during fall and spring surveys) for the LaPoile Caribou Herd in southwestern Newfoundland. Hunter statistics reliably estimated changes in population demography. Percent calves seen by hunters was correlated with calves/100 females classified in fall. Weather may have influenced productivity for the LaPoile Caribou Herd in Newfoundland. Colder winter temperatures were associated with fewer calves the next fall and pregnancy rates and yearlings/100 females in the spring were negatively correlated with snow on ground the previous winter. These relationships appear to be density related

POTENTIAL MISUSE OF BLACK BEAR LICENCES TO HARVEST MOOSE IN NEWFOUNDLAND: A REVIEW

Wildlife management policy is often strongly influenced by public perception. In Newfoundland, the inappropriate use of black bear licence to harvest moose has been rumoured since the introduction of the current management systems for both species in 1973, pressuring managers to alter harvest programs. The opportunity for misuse potentially exists for 4 groups of moose hunters: those successful in procuring both a moose licence and a bear licence for different management units (MU’s), enabling hunters to harvest moose in a more preferred area than that for which they are licenced; Those unsuccessful in procuring a moose licence who purchase a bear licence to hunt moose anyway; those with a bear licence but no connection to the moose/caribou licencing system; and those convicted of big game hunting violations who purchase a bear licence to hunt moose illegally. This paper attempts to assess objectively the amount of abuse that could be occurring and evaluates reasonable management responses to these problems. A dramatic increase in bear licence sales following the introduction of a more restrictive moose management system in 1973, as well as a drop in bear licence sales after the establishment of non-overlapping moose and bear hunting seasons in 3 MU’s implied misuse. From 1989 to 1994, 223,705 moose hunters were allotted licences, 5,918 (2.6%) purchased a black bear licence and 3,517 (1.6%) selected for a bear MU different than their moose MU. Similarly, of the 141,943 hunters who applied but did not receive a moose licence, 7,280 (5.1%) purchased a black bear licence. The licence sales do however mean that most bear licence holders were associated with the moose hunt application process; of 18,348 black bear hunters, 32.3% (5,918) also held a moose licence, and 39.7% (7,280) were unsuccessful in procuring a moose licence. Eighteen percent of bear hunters did not participate in the moose hunt process at all. Individuals convicted of big game offences were permitted to purchase bear licences, and while they were considered at high risk for further illegal activity only 5.2% (25/482) purchased a bear licence