Jean Ferron

How Do Woodchucks (Marmota monax) Cope with Harsh Winter Conditions

Woodchucks ( Marmota monax ) are a solitary species that, unlike other species of marmots, hibernate singly. The object of this study was to analyze how this species copes with harsh winter conditions in the field, in the northern part of its range. Woodchucks in the population studied have a pattern of hibernation similar to that of alpine marmots ( Marmota marmota ), they face comparable burrow temperatures, and their range of body temperatures is similar. However, woodchucks lose more weight than alpine marmots, both on a daily basis and throughout the period of hibernation. Woodchucks are less specialized than montane species of marmots, but their hibernacula provide better insulation than those employed by species residing in mountainous habitats.

Age-Dependent Response of Migrant and Resident Aegolius Owl Species to Small Rodent Population Fluctuations in the Eastern Canadian Boreal Forest

ABSTRACT We investigated the relationship between late summer abundance of small rodents and fall migrant abundance of two nocturnal avian predators, the Boreal Owl (Aegolius funereus) and the Northern Saw-whet Owl (A. acadicus), during their fall movement/migration. In the eastern Canadian boreal forest, Boreal Owls are considered resident (with irruptive movements to the south thought to occur during periods of low prey availability), and Northern Saw-whet Owls migratory. Data on late summer abundance of small rodents collected between 1995 and 2004 were used to develop an index of prey availability. Data on the number and age of irrupting/migrating owls were collected between 1996–2004 (mid-September to late October) using audiolures and mist nets. Our study revealed strong evidence of (1) a negative relationship between the abundance of small rodents and movement of Boreal Owls and (2) a positive relationship between the abundance of small rodents and the number of migrating juveniles and second year Northern Saw-whet Owls. In the latter case, it suggests that prey availability can strongly influence breeding success of this species, which is at the northern limit of its breeding range.

Use of Residual Forest by Snowshoe Hare in a Clear-cut Boreal Landscape

Abstract The short-term negative impacts on Lepus americanus (Snowshoe Hare) of logging activities in boreal forest are widely recognized, and conservation efforts are being taken now in designing residual forest stands to maintain use of logged landscapes by hares. This study evaluated the effectiveness of three types of residual stands in maintaining hares during the high phase of hare density cycle in Picea mariana (Black Spruce) forest of eastern Canada. Residual forest stands sampled were upland strips (60 m wide, 250–950 m long, mesic conditions), riparian strips (100 m wide, 250–950 m long, along a permanent stream), and residual blocks (200–300 m wide, 20–50 ha). Control stands were undisturbed forest. All stands were considered mature (56–97 years old). Pellet and browse surveys were conducted during spring 1998 and 1999. Hare abundance indices were significantly lower (1999), or tended to be lower (1998), in strips than in blocks, although habitat composition and structure of the treatments did not differ from control stands. Pellet presence was positively related to vertical cover. In 1998, foraging activity (browsing) was significantly higher in control and block landscapes than in strip landscapes; browsing was positively related to availability of ericaceous and deciduous twigs. In 1998, twenty Snowshoe Hares were radio-tracked in residual stands to monitor their summer home ranges, fidelity to capture sites and to type of residual stand, use of clear-cuts and uncut forest, and daily movements. There was a clear trend towards lower fidelity to strips than to blocks, and summer home ranges and daily movements (>330 m) tended to be larger in strips compared to those in blocks. Our study suggests that up to 5 years after logging, residual forest blocks appeared to be more suitable habitat in summer for Snowshoe Hare than were 60-m-wide strips.

Group foraging in snowshoe hares (Lepus americanus): Aggregation or social group?

We investigated the behavioural mechanisms involved in group formation at a feeding site in a captive snowshoe hare population. The analysis showed that grouping resulted most often from a feeding attraction which led individuals to use the feeding site independently of each other. However social attraction and especially social repulsion among hares were also involved in group size dynamics. As group size increased, social repulsion underlined by an autocatalytic process led the hares to collectively leave the feeding site. Consequently, the social interactions rates and distance covered per hare increased non-linearly with hare number present at the feeding site. The results suggest that hare behaviour underlined by these mechanisms may influence the risks of starvation and predation. From these results, further field studies are suggested to test in the framework of a multi-factor hypothesis how hare behaviour, food supply and predation may interact simultaneously in population regulation.

Report of an Albino Red Squirrel from Sainte-Luce, Quebec, Canada

Abstract We report the observation of an albino male Tamiasciurus hudsonicus (Red Squirrel) from Sainte-Luce in eastern Quebec, Canada. While occurrences of entirely albino individuals have been sporadically reported in the wild in other sciurid species, true albinism is rare in T. hudsonicus. That albino sciurids can survive in the wild may be related to their relatively minor visual deficits compared to other albino mammals, which experience a greater loss of vision. The lack of pigmentation, however, may be a major disadvantage in the wild for the Red Squirrel, which is a diurnal and arboreal prey species. In conjunction with the recessive nature of albinism, it is not surprising that albino individuals are rarely reported for this species.

Cover changes, during the 1954-1990 period, in the alpine vegetation used by the Gaspesie Provincial Park caribou herd

The Gaspesie provincial park (P.Q., Canada) caribou herd, classified as threatened, is the only remaining native caribou population on the continent, east of the St. Lawrence River. The alpine belt of the range, such as the Mt. Albert plateau (the largest alpine area of the park, 16 km 2), is heavily used by caribou in summer and in the fall. In 1954 and in 1963, the alpine vegetation cover of Mt . Albert was surveyed by Moisan (1974; Changements dans la vegetation de Palpage du Mont Albert, M.T.C.P. Report no. 3. p. 292-297). We repeated this study in 1990 to monitor vegetation changes of Mt. Albert over the last three decades and their management implications for the caribou herd. Most of the vegetation categories decreased significantly relative to the previous two surveys suggesting a reduction in total vegetation cover on the plateau. Mean vegetation cover was 62% and 53% respectively for 1954 and 1990. However, lichen cover increased from 8.6% in 1963 to 14.6% in 1990. Interpretation of changes in the alpine vegetation cover of Mt . Albert during the last 37 years should be viewed in light of the following potential forcing factors: caribou grazing, climatic changes, and plant succession dynamics. From 1954 to 1963, the alpine vegetation showed a decrease in lichen cover and a slight increase in other plant categories. This trend was attributed to caribou grazing by Moisan (1974). It is likely that utilization of the plateau by caribou decreased in the 1963-1990 period relative to the previous one as the caribou population has declined. Significant increase in lichen during the 1963-1990 period would thus support the caribou grazing hypothesis. However, the link between the observed pattern of cover change and caribou razing on Mt. Albert is questionable: 1) Reduction in grazing pressure, as suggested by an increase in lichen cover, should not be correlated with a decrease in total vegetation cover. 2) Despite a probable decrease in grazing pressure in the last four decades, grazing pressure is still relatively high as — 60 caribou are observed each fall on the plateau. 3) The low lichen cover on the plateau suggests that caribou might not selectively feed on lichens. Consequently, we suggest that other factors might have also influenced the observed cover changes. Casual observations indicate that tree line is regressing in the study area suggesting an increase in climate harshness. Such climatic stress could partially explain the overall decrease in plant cover, setting favourable conditions to pioneer species, such as the lichens, by reducing competition. Recent investigations suggest that the alpine belt of the range is a key component for the survival of that threatened population. However, its importance to caribou feeding ecology remains to be shown. It is possible that the role of the plateau as escape habitat from predators might be more crucial to caribou survival than its use as a feeding ground. _ _ . 1 T ^T „ 8 8 Rangifer, Special Issue No. 7: 159 Printed from manuscript after editorial review. 159 Rangifer, Special Issue No. 7, 1991

Développement physique post-natal chez le grand polatouche (Glaucomys sabrinus)

The objective of this paper is to study the postnatal physical development of the Northern flying squirrel (Glaucomys sabrinus) from birth to the age of 55 days, when it is weaned and its socialization period ends. The effect of growth on weight and on several linear measurements is presented with the corresponding instantaneous growth rates. The timing of different events marking the physical development is also reported. Comparison of our results with those on other sciurid species suggests that arboreal species have a slower physical development than terrestrial species, at least with regard to body weight. Our previous observations on behavioural ontogeny concurs with this hypothesis.