Deer Yard Research Articles

Development of Northern White-Cedar (Thuja occidentalis L.) Plantations within and outside Deer Yards

Regional surveys done over the last decades show a clear decline in abundance of Northern white-cedar (Thuja occidentalis L.) throughout its range. A lack of seed trees, difficulties in the establishment of natural regeneration and high browsing pressure caused by increasing deer populations have been identified as plausible causes. Current silvicultural strategies for cedar restoration recommend partial cutting to promote and release natural regeneration, but there is also a need to restore the species in areas where it became absent. Yet, little attention has been given to cedar plantations. This study provides a first characterisation of the effects of competition, silvicultural treatments and deer, moose and hare browsing on planted cedar growth, survival, and stem form. Pure and mixed cedar plantations aged 5–27 years located in Eastern Québec were sampled. Both inside and outside deer yards, planted cedars showed high survival rates and were generally subject to low browsing pressure, but 45% were forked. Cedars showed high growth rates and strong reaction to stand opening. Results suggest that at reduced competition levels, a 9-year browser exclusion could be sufficient to establish safe-from-browsing cedar stands of >3 m in height.

A Framework to Predict the Impacts of Shale Gas Infrastructures on the Forest Fragmentation of an Agroforest Region

We propose a framework to facilitate the evaluation of the impacts of shale gas infrastructures (well pads, roads, and pipelines) on land cover features, especially with regards to forest fragmentation. We used a geographic information system and realistic development scenarios largely inspired by the PA (United States) experience, but adapted to a region of QC (Canada) with an already fragmented forest cover and a high gas potential. The scenario with the greatest impact results from development limited by regulatory constraints only, with no access to private roads for connecting well pads to the public road network. The scenario with the lowest impact additionally integrates ecological constraints (deer yards, maple woodlots, and wetlands). Overall the differences between these two scenarios are relatively minor, with <1% of the forest cover lost in each case. However, large areas of core forests would be lost in both scenarios and the number of forest patches would increase by 13-21% due to fragmentation. The pipeline network would have a much greater footprint on the land cover than access roads. Using data acquired since the beginning of the shale gas industry, we show that it is possible, within a reasonable time frame, to produce a robust assessment of the impacts of shale gas extraction. The framework we propose could easily be applied to other contexts or jurisdictions.

Comparing habitat quality within and between environments using giving up densities: an example based on the winter habitat of white-tailed deer Odocoileus virginianus

We previously developed a model, based on the precepts of optimal patch use, to compare habitat quality both within and between environments. Here we illustrate the use of this model in a study estimating quality of winter habitats (deer yards) of white-tailed deer Odocoileus virginianus near the northern limit of their range by following their foraging behaviour. We compare giving up densities (GUDs), the amount of food remaining in a patch when a forager ceases foraging there, with and without the presence of supplemental food in order to draw inferences about the relative quality either of habitats within an environment or of distinct environments. We use our model to evaluate the impact of alterations to the winter habitat of deer at two distinct sites that differed in their level of predation risk and food availability. The first site, the Mont Rigaud deer yard, was surrounded by farm land and gradually-expanding suburbs. Predators were rare and food was available in winter either in farm fields or around private homes but deer browsing in the past had left little food in the forest. At the second site, the Calumet deer yard, deer experienced a higher predation risk and did not have access to supplemental food from farm fields or private homes. However, past browsing by deer had not drastically reduced food in the forest. We offered food to deer in four habitats per site (forest, forest edge, clearing, clearing edge) with four to six replicates per site and measured the GUDs after 24 h. Analysis of these data, interpreted according to our model, suggests that deer are more sensitive to metabolic costs at Mont Rigaud and food availability at Calumet; predation risk does not alter deer behaviour between the two sites. Within habitats, deer at Mont Rigaud reacted to clearings as though they imposed higher metabolic costs than the forest. They also reacted to an interaction in which missed food costs influenced GUD only when metabolic costs were not too high. Thus our model appears to provide a convenient tool for comparing habitat quality both within and between environments.

An innovative use of white-tailed deer (Odocoileus virginianus) foraging behaviour in impact studies

We developed an innovative method for estimating human impacts on animal species by measuring changes in feeding behaviour. We illustrate our approach with a study of the effect of vegetation control in a power-line right-of-way (ROW) passing through essential winter habitat of white-tailed deer ( Odocoileus virginianus (Zimmermann, 1780)) at the northern limit of their range. We used giving-up densitiy (GUD; i.e., the amount of food left behind when an animal stops foraging in a patch) to evaluate, in one deer yard, if the loss of forest shelter caused by the power-line installation had a greater effect on deer than the gain of food regenerated in the cleared area. We used GUDs to compare deer estimate of habitat quality in the ROW and in the forest. Our results suggest that the ROW had a negative impact on deer. GUDs were lower in the forest compared with the ROW. Either increased metabolic costs or increased predation risk in the ROW, apparently the latter, lead deer to abandon more food in the ROW than elsewhere. Higher GUDs were strongly correlated with greater snow depth in the ROW. Deer preferred habitats at the edge of the ROW where food and cover were both available.

Browse occurrence, biomass, and use by white-tailed deer in a northern New Brunswick deer yard

Winter browse abundance influences population growth of white-tailed deer (Odocoileus virginianus) in northeastern North America, where they regularly experience harsh winter conditions. We surveyed browse biomass and abundance among vegetation types and determined the extent of browse species selection and avoidance in a northeastern deer yard. Deer browsed 19 species but only red and striped maples (Acer rubrum L. and Acer pensylvanicum L.) were consistently selected. Regenerating, mature mixedwood, and mature spruce–fir stands were most likely to have high amounts of browse cover. Mature mixedwood stands had greater total browse biomass than submature hardwood and mature cedar stands. It is possible that our observed selection and avoidance of browse species reflects changes in availability as snow depth increased in middle to late winter. Thus, browse availability and use should be interpreted with respect to known patterns of deer habitat use during varying degrees of winter severity. We recommend that mixedwood stands be recognized as important part of winter habitat for deer. We underscore their importance for wintering deer, because they allow them to access shelter and browse simultaneously.

Erratum: Browse occurrence, biomass, and use by white-tailed deer in a northern New Brunswick deer yard

Winter browse abundance influences population growth of white-tailed deer (Odocoileus virginianus) in northeastern North America, where they regularly experience harsh winter conditions. We surveye...

A comparison of biochemical and meat quality variables in red deer ( Cervus elaphus) following either slaughter at pasture or killing at a deer slaughter plant

To investigate effects of pre-slaughter handling on blood and muscle biochemistry and venison quality, paddock-shot ( n=8) and commercially slaughtered red deer ( n=8) were compared. The deer were kept in two larger groups. One stag per group per day was head-shot, exsanguinated, electrically stimulated then transported 150 m to a deer slaughter premises (DSP) for processing. Prior to each slaughter day one of the groups was mustered into a deer yards and six (including two experimental) deer were selected for commercial handling and processing (including electrical stimulation) at the same DSP. Blood samples taken during exsanguination showed higher levels of cortisol, progesterone, glucose, lactate, albumin, creatine kinase, lactate dehydrogenase, aspartate aminotransferase and packed cell volume in the DSP-killed deer compared with the paddock-shot deer ( P<0.05). Interpretation of these values indicated that pre-slaughter handling created moderate stress and high levels of muscular exertion or damage, possibly related to antagonism during lairage. However muscle glycogen, pH and meat quality measurements showed only minor, muscle-specific differences between treatments.

Alimentation d'urgence de cerfs de Virginie lors d'hivers rigoureux: Rabattage de tiges non commerciales versus distribution de moulée

In northeastern regions of North America, deer sometimes face hard winters, which may kill more than 40 percent of the population. Management of their winter habitat is not enough to avoid extensive losses from starvation. Emergency feeding programs have therefore been developed to reduce population fluctuations, which make it difficult to manage the species. During the winters of 1996 and 1997, we simulated two emergency feeding programs for deer in two deer yards located in Bas Saint-Laurent, Quebec. One of the programs was linked to the cutting of stems of non-commercial species, and the other to the distribution of a specially adapted animal feed. In accordance to the regional intervention strategy, we supplied additional feed to satisfy about 50 percent of the deers' feed requirements. In this study, we have compared the costs of the two programs during four and eight week periods. In comparison to stem cuttings, feed distribution reduces by two to three times the expenses related to the program, while facilitating spatial distribution of the food. In conditions encountered in northeastern North America, feed distribution is definitely the most economically effective method of establishing an emergency feeding program for deer. Key words: costs, branch cutting, browsing, feed, emergency feeding, winter, deer yard, deer, Odocoileus virginianus

Use of mixedwood stands by wintering white-tailed deer in southern New Brunswick

On the northern edge of their range, white-tailed deer (Odocoileus virginianus) congregate during winter to cope with severe climate conditions. We documented the winter habitat use of deer in southern New Brunswick, where winters are of moderate severity, and tested predictions concerning the influence of food and cover availability on habitat use by deer under different snow depth regimes. Sixty-three radio-collared deer were monitored during the winters of 1995 to 1997. Within wintering areas, deer showed a preference for mixedwoods. Mixedwood stands provided only moderate amounts of food and cover relative to some other cover types, but were the only type to provide both simultaneously. Current habitat management guidelines in parts of northeastern North America consider critical habitat for wintering deer to be softwood-dominated stands. These guidelines may not provide adequate habitat in this region, since deer appear to use mixedwood stands under some conditions. Key words: deer, deer wintering area, deer yard, habitat, habitat management, mixedwood, Odocoileus, winter, yard

Conservation implications of browsing by Odocoileus virginianus in remnant upland Thuja occidentalis forests

Regeneration success of canopy dominants is linked to multiple factors, including the ability of their seedlings to survive browsing and to utilize available resources in the understory. In remnant upland northern white cedar Thuja occidentalis L. forests, effects of browsing on recruitment of cedar seedlings were evaluated at 7 sites, including known deer yards, located on a portion of the Lake Superior Highlands in northeastern Minnesota. Experimental plantings and vegetation surveys were conducted inside and outside large deer exclosures constructed between 1937 and 1997. Objectives were to determine severity and intensity of browsing by Odocoileus virginianus Zimmerman, the ability of seedlings to survive browsing in environments beneath T. occidentalis and adjacent paper birch ( Betula papyrifera) Marshall canopies, and potential long-term sapling recruitment under different browsing scenarios. From 1994 to 1997, 76% of unexclosed planted T. occidentalis seedlings had been browsed at least once, compared with 0% of exclosed seedlings. Increased browsing intensity and decreased light availability increased T. occidentalis mortality rates. Simulation models and vegetation surveys demonstrated that the best recruitment rates occurred for seedlings planted under Betula canopy and subjected to low browsing severity, but no recruitment occurred under high browsing pressure under either canopy type. The current level of browsing in these forests has the potential to alter the future composition of canopy tree species through sustained prevention of T. occidentalis recruitment.

Spatial dynamics of a migratory wolf population in winter, south-central Ontario (1990-1995)

We examined the spatial distribution and movements of migratory wolves (Canis lupus lycaon) to a deer yard located adjacent to Algonquin Provincial Park, Ontario, during 5 winters from 1990 to 1995. Wolves from eastern and central Algonquin Provincial Park followed the annual migration of deer to yards located 13 km outside of the Park boundary. Spatial distributions were determined through mapping of telemetry locations and nearest neighbour analysis. We defined three spacing systems: consistent/high fidelity, clustered/moderate fidelity, and transitional/low fidelity. We found inconsistencies among packs in their adherence to these systems. Data indicate that areas of use changed quickly and tolerance levels among wolves in the deer yard were very high; alien wolves were recorded 163 times in close spatial and (or) temporal proximity. The social behaviour exhibited by this migratory population of wolves has never been recorded in a forested wolf-deer ecosystem. Factors that may contribute to this behavioural plasticity include food abundance, a high degree of genetic relatedness among wolf packs, and high rates of human-caused mortality.

Fence Line Pacing in Farmed Red Deer Hinds at Calving

AbstractThe frequency, intensity and location of fence line pacing were observed daily, in four groups of six farmed red deer hinds, over a 3-week period at calving. The groups were confined in neighbouring paddocks (5000m2 in area; two containing a wooden shelter) adjacent to deer yards containing an observation hide. At 1100h, a person entered each paddock to weigh, sex and tag newborn calves.Pacing (moving parallel to and within 0.5m of a fence line) was mainly at walking speed, and its frequency differed according to the time relative to parturition. It was recorded in 13.6 (± 1.09) per cent of observations during the period 2-4 to days before calving, increased to 27.6 (± 1.9)per cent on the day before birth and then declined to 4.6 (± 0.39) per cent for the period of 0-3 days after calving. Pacing relative to total movement was greater before (65.7%) than after (43.5%) parturition (SED 3.7%; P &lt; 0.001), indicating that it was not just a consequence of greater activity before birth. The hinds were observed to be grouped together rather than distributed randomly, but when some of the hinds were pacing, groups were spread out over more quarters of the paddock than when none were pacing (P &lt; 0.001). However, there was no definite suggestion of avoidance of other deer. Within each group, most pacing occurred along certain fence lines, but no general pattern was observed. Regardless of whether hinds had given birth or not, there were graded increases in pacing depending on the degree of human presence (not present&lt;within deer yards &lt;visible&lt;in paddock; P &lt; 0.05); and deer favoured areas distant from human presence (P &lt; 0.01). The findings in relation to fence line pacing and location support suggestions that human interference at calving should be minimized, but did not indicate which environmental features were responsible for this motivational drive.

Response by wolves to prey variation in central Ontario

The influence of variation in prey availability in a wolf–moose–deer–beaver predator–prey community was studied from 1987 to 1992 in Algonquin Park, Ontario, Canada. Density, food habits, and movements of 57 radio-collared gray wolves (Canis lupus) were compared among three regions of varying moose (Alces alces) and white-tailed deer (Odocoileus virginianus) spatial and temporal abundance. Relative moose and deer availability was determined annually from 16 track surveys (5 km each), 150 pellet surveys (300 × 2 m), stratified aerial surveys (2 or 3 each winter), and prey carcass data. One region contained high moose abundance and virtually no deer year-round. The second region had high moose levels with moderate levels of deer, and a third region varied in deer winter abundance annually. Wolf use of deer was high, based on the proportion of deer in winter scats (9.3–32.1% frequency of occurrence; 4.3–22.5% total biomass) and the number of deer predation cases (50 carcasses) that occurred in all three regions, even in areas where deer were considered to be very rare. Wolf use of deer was positively correlated with increases in winter deer abundance (r2 = 0.66). Wolf density correlated with deer numbers (r2 = 0.74). In winter, deer in the third region migrated to a deer yard 15 km from Algonquin Park. A remaining overwintering deer density of less than 0.02/km2appears to have prompted a movement of wolves to the deer yard. Of the 41 moose consumed by wolves in winter, most (71%) were scavenged animals that had died with infestations of winter tick (Dermacentor albipictus). Beaver (Castor canadensis) apparently acted as important buffer prey species when deer numbers were low. The Algonquin wolf's reliance on smaller prey items appears to be a function of the fluctuating prey base, which promotes alternative hunting strategies, and the small size of the Algonquin wolf, which makes it an inefficient predator of moose. Even though moose were relatively constant in availability, and a major food item, the wolf population was responding primarily to the availability of deer.

Biodiversity implications of changes in the quantity of dead organic matter in managed forests

Dead organic matter is an important structural and functional element in natural forests, but its quantity, quality, and spatial distribution are greatly modified by intensive harvesting and management through forestry. From the perspective of conflicts with biodiversity, the most important changes are associated with reductions in the abundance of snags, cavity trees, and coarse-woody debris, all of which are well known as critical habitat elements for a wide range of indigenous species. Changes in the depth and quality of the forest floor of managed stands are also important for some species and guilds of wildlife. Resolution of this conflict between forestry and biodiversity will require the design and implementation of management systems that accommodate the critical habitat qualities associated with dead organic matter, particularly with large-dimension deadwood and cavities. This goal may be most effectively achieved by an integrated strategy that involves (i) basing forest-management planning on shifting-mosaic habitat models of stand harvesting and replacement, designed to ensure a continuous availability of sufficient areas of stands old enough to sustain habitat features associated with dead organic matter, along with (ii) the provision of protected areas of mature and older growth forest, associated with riparian buffers, deer yards, and nonharvested ecological reserves and other kinds of protected areas. The protected areas are necessary to accommodate those elements of biodiversity that cannot tolerate the conditions of managed stands.Key words: biodiversity, managed forests, plantations, old-growth forests, coarse-woody debris, cavity trees, snags.

A Comparison of Presettlement and Present-Day Forests in Two Northern Michigan Deer Yards

Deer yards are wintering areas used by white-tailed deer in the northern part of their range. In northern Michigan, deer yards typically consist of extensive stands of cedar- dominated (Thuja occidentalis) or mixed conifer swamps where thick evergreen overstories provide shelter from winter conditions. Forest and wildlife management in and around cedar- dominated swamps of the upper Great Lakes have created a nearly optimal interspersion of early-seral summer range and mature conifer winter range. For a variety of reasons which include favorable habitat changes, deer populations are today larger than those of presettle- ment conditions. We used General Land Office survey records from the 1840s to compare presettlement forest composition with present-day forest composition in two important deer yarding areas in Michigan's Upper Peninsula. Except for tamarack (Larix laricina), woody plant species that are unpalatable to deer or tolerant of browsing have increased. Species that are palatable and intolerant of browsing have decreased. Ages of extant mature cedars indicate establishment during a period of low deer populations in Michigan. Change in forest composition has many causes, but deer populations encouraged by forest and wildlife man- agement may contribute to a changing ecology in northern Michigan's conifer swamp com- munities, and may change the structure of plant communities in areas where deer use is concentrated.

La fréquentation des peuplements riverains par le cerf de Virginie en hiver: sélection de site ou pure coïncidence?

AbstractIn north-east North America, it has been often reported that white-tailed deer (Odocoileus virginianus Zimmermann) preferentially locate their winter yards along streams and lakes. However, it has never been determined if this pattern of habitat use was related to the distribution of coniferous stands associated with more humid, down slope sites along waterways or if deer preferentially use riparian stands in their winter yard. An experimental design to discriminate the effect of stream or lake proximity from other habitat features, was established in the lac des Baies deer yard, near Rimouski (eastern Quebec). Using pellet-group counts as an index of habitat use, the use of mature coniferous stands (3.75 ha balsam fir—northern white-cedar stands) contiguous to water (n = 8) was compared with similar fir—cedar stands (n = 8) located in the same deer yard but away (< 300 m) from streams or lakes. According to this index, riparian stands were used almost twice as much as the non-riparian stands (P =...

Evaluation of an experimental wolf reduction and its impact on deer in Papineau-Labelle Reserve, Quebec

From 1984 to 1986, 56 wolves were removed by aerial shooting from two reduction blocks in Papineau-Labelle Reserve: the mean reduction rate was 71% in RB1 and 40% in RB2, compared with 17 and 9% for two untreated blocks (UB1 and UB2). Corresponding mean wolf densities in the four blocks at the end of winter were 0.6, 1.2, 1.6, and 1.7 wolves/100 km2, respectively. Each year, wolf numbers returned to their former level in the subsequent winter in RB1, mainly through immigration. Three blocks were each associated with a large deer wintering area containing 1400–1700 animals before the wolf reduction. The deer yard in RB1 reached a population of 4200 deer, a 1.32% finite rate of increase per year, compared with annual rates of 1.15–1.18% in UB1 and RB2. The harvest of bucks was not affected by the wolf reduction. The number of fawns per 100 does in the harvest was higher in RB1 than in UB1 in 1985 and 1986. We do not recommend wolf reduction as a management tool in the current context, as deer numbers increased markedly, even where no control was applied, as a consequence of mild winters.

Behavioural and heart rate responses to velvet antler removal in red deer

Heart rate and behaviour during and following velvet antler removal were monitored in yearling red deer stags to determine the extent to which this procedure was perceived by the deer to be aversive. Nine stags normally kept at pasture were habituated over 5 weeks to the following daily handling procedure. Each deer was fitted with a harness containing a heart rate monitor. It was then allowed to run through a fixed course in a deer yard, restrained for 40 s in a mechanical deer crush, and then confined for 3.5 h with the remainder of the group of stags in an indoor pen containing food and water. In Week 6, the deer were subjected to either restraint for 6 minutes (the control treatment) or removal of one velvet antler under local anaesthesia. Each velvet antler was removed on separate occasions, either on Days 1 and 2 (five deer) or Days 3 and 4 (four deer). The control treatment was applied to all deer when velvet antler was not being removed, and on Day 5. Heart rate and behaviour (time taken to enter the treatment area, and number of struggles made during restraint) were measured before and during treatment, and post-treatment activities were recorded at 0, 1 and 3 h (indoors), and at 6 and 9 h (at pasture). Heart rate was higher during the second velvet antler removal treatment than during the first, but lower during the second control treatment than the first (P<0.05). During velvet antler removal, stags struggled more, and after the treatment flicked their ears, shook their heads, and groomed themselves more than control stags (P<0.05). Stags whose velvet antler had been removed spent less time eating than control stags, and spent progressively more time sitting during the 3.5 h of confinement (P<0.05). However, during the paddock observation at 9 h post-treatment, stags which had had their velvet antler removed grazed more than control stags (P<0.05). The increase in heart rate over the two velvet antler removal treatments and the greater amount of struggling during velvet antler removal indicated that it was more aversive than the control treatment. Post-treatment differences in behaviour may have been due to pain following velvet antler removal.

Temporal Changes in Winter Diet Selection by White-Tailed Deer in a Northern Deer Yard

We followed short-term changes in the winter foraging behavior of yarded northern white-tailed deer (Odocoileus virginianus) over 3 winters to evaluate the hypothesis that deer forage nonselectively. We used a sequential-clipping, browse-monitoring technique to measure browse use and availability at biweekly (1983-84) or weekly (1984-85, 1985-86) intervals. From initial diets composed of 1-4 browse species, deer expanded their diets to include up to 16 out of 19 species by the end of each winter. Rate and magnitude of diet expansion were influenced by the degree of browsing pressure in the study area. We found partial preferences in diet choice, but important diet items were used in nonrandom runs once adopted into the diet. Proportional representation of all browse species in the diet varied on a short-term basis. Three dominant species, red-osier dogwood (Cornus stolonifera), pussy willow (Salix discolor), and white ash (Fraxinus americana), exhibited gradual compensatory shifts in proportional use over each winter, which reflected early season preferential selection of red-osier dogwood. During the third winter, browsing was nonrandom and selective, and temporal changes in patterns of browse use occurred. Forage ratios and relativized electivity indices of the 3 dominant species also changed gradually, indicating sequential shifts in preference for redosier dogwood, pussy willow, and white ash, respectively. Overall, deer foraging in the winter yard was dynamic, with high diet selectivity at the beginning of the yarding season and gradual diet generalization as browse was depleted in the yard. J, WILDL. MANAGE. 55(3):361-376 In winter, white-tailed deer in north-temperate regions congregate in deer yards, which provide shelter during periods of deep snow and inclement weather (Telfer 1967, Rongstad and Tester 1969, Marchinton and Hirth 1984). However, deer yards only represent a small proportion of the total annual range, resulting in high population densities in areas of limited food availability. Yarded deer meet their energy and nutrient requirements from 2 main sources: catabolization of limited body fat and protein reserves (DelGiudice et al. 1988) and ingestion of woody browse (Mautz 1978). Prolonged confinement of deer to winter yards causes the gradual depletion of the browse supply, often resulting in high deer mortality by starvation late in the yarding season. The consumption of browse in winter slows the rate of tissue catabolization, a process that is critical to survival in northern regions (Mautz 1978). Efficient use of limited browse resources during periods of thermal stress is evolutionarily advantageous; presumably, the selective pressures of overwintering have contributed to the evolution of a particular foraging strategy in deer which is adapted to food-limited situations such as those in a northern deer yard. Several authors have discussed foraging behavio of large ungulates in food-limited environments from a theoretical standpoint. Westoby (1974) and Belovsky (1978) proposed that herbivore diet specialization should occur when food resources are abundant, and diet generalizati n should occur at low food levels. Using data from Wetzel et al. (1975), Nudds (1980) suggested that a shift in foraging strategy from specialist to generalist occurs as winter food resour es are depleted. Though criticized on methodological grounds by Jenkins (1982), Nudds (1980) posed a pertinent question about possible changes in foraging strategy adopted by deer in the face of ever-diminishing winter food resources. To date, most winter field studies of deer foragi g have examined total use of foodstuffs within a given habitat over the entire yarding season. Standard browse inventory techniques involve establishing transects or sample plots at a few critical times in the year (Gysel and Lyon 1980), usually fall and spring, to assess winter browse use. LaGory et al. (1985) employed seasonal totals of browse use to plot relative browse use over an entire winter as a function of estimated relative browse availability at the beginning of the winter. They found significant positiv linear regressions between use and

Effets de coupes de dimensions restreintes sur l'abondance des populations d'oiseaux nicheurs en milieu boréal

The objective of this study was to evaluate the effects of small clearcuts on breeding bird communities found in adjacent forest stands. The study was conducted in a deer yard of the Duchenier Wildlife Preserve located in the boreal balsam fir-yellow birch ecological domain of eastern Quebec. The balsam fir-northern white cedar stands of the deer yard had been treated by strip cutting 2 years before the study. Total abundance of nesting passerines in stands adjacent to 60-m-wide strip cuttings was greater (P = 0.10) than in similar control unlogged stands. The establishment of shrub strata within the strip probably provided an additional food source for shrub- and ground-feeding species without significantly affecting canopy-feeding species.