Gaspésie woodland caribou (Rangifer tarandus caribou) recovery plan 2002 to 2012: chapter 4

Background

 

Background

Common name: Woodland Caribou (Atlantic-Gaspésie population)

Scientific Name: Rangifer tarandus caribou

COSEWIC Status: Endangered

Reason for Designation: A small isolated population of less than 200 adult animals confined to the Gaspésie region. The population is at risk from predation and habitat loss.

Canadian Occurrence: Québec

COSEWIC Status History: Atlantic-Gaspésie population designated Threatened in April 1984. Status re-examined and designated Endangered in May 2000. Status re-examined and confirmed in May 2002. Last assessment based on an update status report.

 

Overall distribution

The distribution of the woodland caribou has declined over the past century (Bergerud 1974). In eastern North America, caribou used to inhabit the Maritime provinces and parts of New England. Now the Gaspésie population is the only caribou population to be found south of the St. Lawrence River (Banfield 1961; Boileau 1996, Courtois et al. 2001). North American caribou live in a number of different types of habitats, and their behaviour varies accordingly, which has led to the definition of ecotypes, three of which are found in Quebec: tundra, mountain and boreal (Courtois et al. 2002). The Gaspésie Woodland Caribou population belongs to the mountain ecotype (Courtois et al. 2002).

The situation of this relict population, believed to be genetically distinct, (Roed et al. 1991; Courtois et al. 2002), is precarious, and the species was recently designated as endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC 2000). Provincially, Quebec designated the Gaspésie Woodland Caribou population and its habitat as vulnerable in September 2001 (E-12.01; R.S.Q., c. E-12.01, s.10, r.0.2.3) .

 

Range of the Gaspésie Woodland Caribou population

The Gaspésie Woodland Caribou population lives both in an 802 km2 area within the Gaspésie provincial park, and in a 290 kmarea outside the park boundaries (Appendix 1). Radio-telemetry data gathered in the park between 1998 and 2001 shows, once again, that the caribou use three distinct sectors: Mont Albert, Mont Logan, and the various mountains of the McGerrigle range, with little movement from one area to the other (Rivard 1978; Ouellet et al. 1996; Fournier et al. 2001; Mosnier et al. 2002), although a few females had been observed moving between Mont Albert and the McGerrigle Mountains, and, more recently, some caribou had moved from Mont Albert to the Vallières-de–Saint-Réal area. (Rivard 1978); Fournier et al. 2001). Given that there is hardly any movement between these three main sectors, the Gaspésie Woodland Caribou meet the definition of a metapopulation as set forth in Wells and Richmond (1995): a set of spatially disjunct populations with some genetic or demographic connectedness.

A few years ago, in order to manage activities in areas inhabited by caribou, pursuant to the Regulation respecting wildlife habitats and the Act respecting the conservation and development of wildlife (R.S.Q., c. C-61.1 ),  a 657.2 km area was designated as a legal caribou habitat. In addition to the Gaspésie provincial park, this area also includes parts of the Réserve faunique des Chic-Chocs, notably Petit Mont Sainte-Anne and Mont Vallières-de-Saint-Réal. However, the actual distribution of the Gaspésie Woodland Caribou extends beyond the limits of its legal habitat (Fournier and Turcotte 2002), particularly in the Mont Logan sector (Table 1).

Recent radio-tracking data has revealed that the caribou move to areas adjacent to the park to find food in the summer and winter, and for calving (Fournier and Turcotte 2002). In order to balance forestry activities with the preservation of the caribou habitat, a forest management plan targeting areas adjacent to Gaspésie provincial park has been implemented.

 

Table 1. Caribou radio-telemetry locations outside the park by sector (November 1998 to March 2001)
Sector Percentage of radio-telemetry locations Number of radio-telemetry locations
Mont Logan 54.6 155
Mont Vallières-de-Saint-Réal 38.0 108
Petit Mont Sainte-Anne 1.4 4
Ruisseau Isabelle 0.4 1
Other 5.6 16
Total 100.0 284 1

Out of a total of 1,622 radio-telemetry locations for the entire area.

Biology

Feeding habits

Until quite recently, little was known about the feeding habits of the Gaspésie Woodland Caribou population. Initial observations suggested a fall diet made up primarily of ground lichen, as well as grasses, sedges and mosses (Moisan 1956). Rivard (1978) noted the importance of arboreal lichen, which made up 70% of the caribou’s winter diet. The first quantitative data regarding the main components of the Gaspésie Woodland Caribou population’s diet appeared in Ouellet et al. (1993) [unpublished data].

The caribou’s diet is different in the summer than in the winter. In the summer, caribou eat mainly lichens and herbaceous plants, whereas in the winter, their diet consists primarily of ground and arboreal lichens. Arboreal lichens play an important role in the caribou’s diet, because they are an essential source of food when it becomes difficult to access ground lichen in the winter months in alpine regions (Serveheen and Lyon 1989). An analysis of the Gaspésie Woodland Caribou’s winter diet revealed large amounts of bark and needles, suggesting that the proportion of arboreal lichen in the caribou’s diet is greater than what was previously believed (Ouellet et al. 1993, unpublished).

Rutting and mating

In the fall mating season, the caribou gather in the alpine areas on the summits of the Albert, Logan, McGerrigle and Vallières-de-Saint-Réal mountains (Moisan 1957; Bergerud 1973; Rivard 1978, Fournier et al. 2001). They form groups, known as “rutting companies” (Bergerud 1973) but, contrary to reports in Banfield (1977), there are no harems of females per se within the Gaspésie Woodland Caribou population, since females are free to switch groups and mate with males in other groups. There is, however, a clear hierarchy among males within a given group (Bergerud 1973). The mating season is characterized by sparring battles between male caribou. The males are polygamous. Females are polyestrous (Banfield 1977). Mating usually takes place around the middle of October (Bergerud 1973).

Disrupting or displacing individuals in their traditional rutting site could adversely affect optimal mating. According to Moisan (1956), the use of the open areas in Gaspésie provincial park is important, because these areas enable a better recognition among individuals and improve the chances of successful reproduction.

Calving

The gestation period is seven to eight months. Calves are born between mid-May and mid-June (Bergerud 1973). Generally, only one calf is born per cow; twins are very rare (Banfield 1977). Newborn calves start to graze when they are about two weeks old. Nursing is very important during the first month, and often continues until winter. Calves are able to stand within an hour of their birth, and can run several kilometres within 90 minutes (Banfield 1977).

Home range

According to the work of Ouellet (1996), the average home-range area of females in the Gaspésie population is estimated to be 145 km²; with 50% of their activities taking place within an area of 14 km². In contrast, recent radio-telemetry data (1998 to 2001) has shown that the average size of the home range of caribou in the Mont Logan, Mont Albert and McGerrigle Mountains sectors is approximately 60 ± 0.6 km(Mosnier et al. 2002). When sectors are examined separately, the home range of caribou in the McGerrigle Mountains sector is larger, and is a result of movement between two peaks. Similar movements were not observed in the Mont Albert and Mont Logan sectors.

Migration and movements

The annual migration of large herds of barren-ground caribou is well documented. A distance of several hundred kilometres may separate their calving grounds and the area where they spend the winter. Seasonal migration is also common among caribou living in wooded areas. However, initial observations of caribou in the Gaspésie herd indicate that these migrations are quite limited. Moisan (1956) mentions “elevational migration,” i.e., the caribou’s tendency to move to certain elevations at specific times of the year. On the other hand, Ouellet et al. (1996) concluded that the elevational movements of the Gaspésie herd were not as clear as those observed in herds in western Canada.

In early fall, during the rutting and mating season, the caribou move to areas of alpine tundra (Moisan 1956; Bergerud 1973; Rivard 1978). Open spaces allow for improved recognition among individuals and more successful reproduction (Moisan 1956; Bergerud 1973). The caribou remain at these higher elevations at the beginning of the winter until snow conditions force them to descend to the subalpine forest level to find food (Moisan 1956).

When the weather conditions improve in early spring, the caribou become more mobile. As snow melt exposes new vegetation, the caribou return to the summits to feed.

Genetics

In order to assess the impact of geographical isolation on genetic drift, 226 muscle and blood samples were taken from the Gaspésie mountain population, as well as from five forest populations and one tundra population. Eight microsatellite DNA (msDNA) loci were examined. The number of alleles per locus varied among populations. The lowest average values were seen in the mountain population and two isolated forest populations in southern Quebec. The genetic distance was greatest among populations that were furthest apart geographically, particularly between the Gaspésie population and the tundra population. Genetic drift is prevalent in isolated populations, but does not appear to be problematic at this time. To conserve genetic diversity, appropriate measures should be taken to maintain genetic exchanges among populations of the same ecotype, and to increase local populations (Courtois et al. 2002). In the case of the Gaspésie population, the number of individuals should be increased (J.P. Ouellet, pers. comm.), [1] and habitat corridors connecting the three main sectors should be maintained to facilitate occasional interchanges of caribou (Mosnier et al. 2002).

Population dynamics

Population density

The population density of the Gaspésie Woodland Caribou population is high (0.14 individuals/km²). Although, caribou population density in northern Quebec is greater than one individual/km² (Crête and Huot 1993), and sometimes exceeds 10/km²

when the animals gather at calving grounds (Crête et al. 1989); caribou are scarce in the

Recent trend data (Desrosiers and Faubert 2007) shows a dramatic decline in the caribou population in recent years (Figure 1)

.

Figure 1.  Estimated population of the Gaspésie Woodland Caribou population based on aerial survey data, with a visibility correction factor of 70% and a 95% confidence interval.

Figure 1.  Estimated population of the Gaspésie Woodland Caribou population based on aerial survey data, with a visibility correction factor of 70% and a 95% confidence interval.

Sex ratio

The sex ratio fluctuated between approximately 0.45 bulls per cow in the 1950s to about 1.20 bulls per cows in 1984, 1985 and 1986. However, it is difficult to track sex ratio changes between 1973 and 1983 because identification criteria used in aerial surveys do not permit the calculation of this type of data (Messier et al. 1987). Until 1992, the sex ratio hovered slightly above 1 bull per cow (1.14 to 1.07) (Desrosiers 1993); the current rate is also about 1:1 (Fournier and Faubert 2001).

Adult survival rate

Radio-telemetry data gathered from 1998 to 2002 places the adult survival rate at approximately 85% (Fournier and Faubert 2001). This is contrary to the results of a study conducted by Crête and Desrosiers (1993), in which the adult survival rate was estimated to be over 90%, based on radio-telemetry data from 1987 to 1992.

 

Description of the habitat used

A description of the habitat used by the caribou was created from radio-telemetry locations. The Gaspésie Woodland Caribou live in mountainous areas made up of mature coniferous stands at lower elevations and alpine tundra on the summits. Using these telemetry locations, an analysis was made of caribou habitat use in different sectors (Monts Logan, Albert and McGerrigle) and in different habitat types (dry and wet alpine tundra, hardwood stands, immature stands less than 70 years old, and mature fir and spruce stands). In comparison with other habitats, tundra was used proportionally more than it was available by sector. Hardwood forests were under-used in the Mont Albert and McGerrigle Mountains sectors, but were used on Mont Logan according to their availability. In all three sectors there were few localities in immature forest. Mature fir stands were used to the degree available on Mont Logan, and were under-used on Mont Albert and in the McGerrigle Mountains sector. Mature spruce stands were under-used on Mont Logan and Mont Albert, and were used according to availability in the McGerrigle Mountains sector (Mosnier et al. 2002). 

Although the forest of Gaspésie provincial park has experienced a number of minor natural disturbances, the last major forest fire in the park was in 1965, at which time 22 km² of forest in the Mont Richardson region was destroyed. The eastern spruce budworm (Choristoneura fumiferana) does not seem to have had a major impact on the park’s forest stands (Dansereau 1999). According to calculations in Boileau (1993), only 3% of the study area, which included the entire McGerrigle Mountains sector, had been affected by the spruce budworm, and the majority of the forest stands in question were outside the park. Cold temperatures in the region limited the insect’s devastating effects to such an extent that water bombing was not even required (L. Dorais, pers. comm.) [2].

Seasonal habitat use by the Gaspésie Woodland Caribou population has already been studied. Recent telemetric data from 1998 to 2001 has shown that alpine tundra habitats are used in all seasons, while fir stands are the most widely used forest habitat (Mosnier et al. 2002). Preliminary findings from telemetric data gathered between 1987 and 1992 also reveal that Gaspésie Woodland Caribou make extensive use of alpine tundra and fir stands (Ouellet et al. 1996). Contrary to the findings of previous studies, this study demonstrated that there was little seasonal variation in habitat use, particularly among females (Table 2).

These authors suggested that habitat use by females, who now tend to spend more time on the alpine tundra, may have changed in response to the arrival of a new predator, the coyote. This new strategy offers calves better protection from predators, since caribou seem to have a greater chance of protecting their calves in open areas rather than on wooded land (Crête et al. 1989, 1990). It is also possible that extensive use of radio-telemetry has provided researchers with a more complete portrait of habitat use than in previous years.

 

Table 2. Caribou habitat use (females and calves) in Gaspésie provincial park
Stand Relative
Importance
(%)
Use (%)
Females
Fall
Use (%)
Females
Winter
  Use (%)
Calves
Summer
Use (%)
Calves
Winter
Spruce stands 4 9 <1   2 3
Fir stands 49 21 38   35 33
Other coniferous stands 1 0 0   2 3
Birch stands 8 2 7   2 4
Other hardwood stands 4 2 1   0 <1
Regeneration 13 0 4   2 4
Dry alpine tundra 20 65 50   57 54

(Source: Ouellet et al. 1996)

Features of the summer habitat

Caribou do not seem to use specific habitats during the summer, since food is available just about everywhere (Rivard 1978). High temperatures on the summits lead the caribou to seek cooler locations, such as ravines or patches of lingering snow (Rivard 1978; Fuller and Keith 1981). Dumont (1993) regularly observed caribou in July on patches of snow on Mont Jacques-Cartier.

Caribou also leave the summits to feed on new vegetation growing in transition forests and subalpine stands. Caribou have been observed near lakes and marshes where mosses, lichens and shrubs can be found. However, the caribou regularly return to the alpine plateaus to escape harassment from insects (Bergerud 1973; Trépanier 1984).

Features of the winter habitat

A number of studies have shown that the optimal winter habitat in the boreal forest is one in which the topography is varied, thus producing different snow conditions throughout the winter, which ensures greater accessibility to food during this difficult season.

Arboreal lichen, found primarily in mature fir stands, are an important part of the Gaspésie Woodland Caribou population’s diet. They constitute an essential food source when ground lichens become hard to access in alpine regions (Rominger and Oldemeyer 1989; Mosnier et al. 2002). Caribou also make extensive use of the summits (Mosnier et al. 2002). This has been observed in Gaspésie provincial park and the Selkirk Mountains.

In mature fir stands, the caribou select fir stands characterized by dense snow conditions and trees that are wider in diameter bearing the greatest biomass of lichen (Mosnier et al. 2002).

Calving

From end of May to mid-June, females travel to various calving sites (Bergerud 1973; Rivard 1978). Unlike northern caribou herds, the Gaspésie herd does not have a specific calving location within the park or in the surrounding areas, nor a shared calving area.

The patchiness of snow melt is similar one year to the next in this rugged mountanaous terrain. This patchiness makes these areas favourable to predators. When there are fewer areas free of snow, it is more difficult for females to disperse at calving, and for calves to move freely after they are born. Consequently, in addition to impeding movements, deep snow may also affect calf survival.

 

Known or potential limiting factors

Predation

As is true for many large mammals, the survival of caribou populations depends primarily on calf survival. A number of studies have shown that extensive predation on calves can lead to a sharp decline in populations with low reproductive rates (Seip 1992; Stuart-Smith et al. 1996; Rettie and Messier 1998). Caribou calves are particularly vulnerable to predation during the first four to six weeks of their lives (Rettie and Messier 1998).

Studies conducted in western North America on caribou (Seip 1992; Boertje et al. 1996) and other cervids, including moose (Alces alces) (Stewart et al. 1985), have shown that, in situations where the calf survival rate was very low, removing a large number of predators resulted in a rapid and significant rise in the calf survival rate. Even though they do not occupy the same habitats as caribou, the presence of other cervids, such as moose and white-tailed deer (Odocoileus virginianus), tends to lead to an increase in the number of predators (Schwartz and Franzmann 1989; Bergerud et al. 1985) and, consequently, greater caribou predation (Bergerud and Ballard 1988).

Coyote and black bear

A large proportion of caribou calf mortality can be blamed on coyotes in those regions where coyotes are found. In north-eastern Alberta, Canada Lynx (Lynx canadensis) and coyote are responsible for 44% of calf mortality from predation (Stuart-Smith et al. 1996). In Gaspésie provincial park, coyote and black bear predation accounted for 75% of calf mortality in some years (Crête and Desrosiers 1993). Predation is therefore a major cause of the low recruitment rates seen in 1987, 1988 and 1989 (4, 7 and 13 calves/100 females) and in 1999, when the recruitment rate was 31 calves/100 females (Crête and Desrosiers 1993; Crête et al. 1990; Desrosiers and Faubert 1999) [Figure 2].  Data is only available for the Mont Albert and McGerrigle Mountains sectors; there is no data for the Mont Logan sector, since caribou were only first observed in this region in the past few years. It should also be noted that calves may remain vulnerable to predation until the age of six months (Crête and Desrosiers 1993).

In the Gaspésie, the black bear opportunistically preys on young caribou in the park (Boileau 1993). In recent years, a considerable number of black bears have been seen on the bare summits in recent years (Desrosiers and Faubert 2001).

In an effort to increase the number of calves, control measures were implemented between 1990 and 1996 in the Mont Albert and McGerrigle Mountains sectors, with positive results. The control measures led to a rise in the number of calves. These results corroborate various studies on other cervids, including moose (Stewart et al. 1985; Seip 1992; Boertje et al. 1996). In Alaska, long-term control of the wolf, the caribou’s main predator, resulted in significant growth in the size of the caribou population (Boertje et al. 1996). Nevertheless, these studies also showed that, for controls to be truly effective, they need to take place over a period of several years.

Figure 2.  Percentage of calves observed during fall aerial surveys of the Gaspésie Woodland Caribou population between 1981 and 2006. (Source: Desrosiers and Faubert 2004, 2007).

Figure 2.  Percentage of calves observed during fall aerial surveys of the Gaspésie Woodland Caribou population between 1981 and 2006. (Source: Desrosiers and Faubert 2004, 2007).

CanadaLynx

Canada Lynx may be harmful to caribou populations if there is a drop in the number of Snowshoe Hare (Lepus americanus), their primary prey. However, no cases of predation by lynx on the Gaspésie Woodland Caribou population have been reported (N. Fournier, FAPAQ, pers. comm.). [3] Consequently, in the short term, Canada Lynx do not pose a threat to the survival of the population.

There appears to be a relatively large lynx population, with little fluctuation in relation to the Quebec average (Courtois et al. 1996).

Golden Eagle

Despite the fact that there have been many reports of Golden Eagle (Aquila chrysaetos) predation in Yukon and Alaska (Roseneau and Curatolo 1976), this predator is only a marginal threat to the caribou population in Gaspésie provincial park. Only one case of predation has been reported in the region (Crête and Desrosiers 1993). The Golden Eagle only attacks newborn calves, and observation has shown that the mother is usually able to protect her calf (Dumont 1993).

Measures taken:

The following caribou predator control measures, aimed at reducing predation, have been taken:

Action Year
ÿ Resumption of predator control in the Mont Albert and McGerrigle Mountains sectors. 2001
ÿCoyote trapping by Société de la faune et des parcs du Québec personnel (Pilon 1997). 1990-1996
ÿ Creation of Golden Eagle feeding sites in an open area close to the hilltop alpine tundra in Gaspésie provincial park (Boileau 1996). In the spring, the site was supplied with the carcasses of white-tailed deer and moose that had been killed in highway accidents. Golden Eagle used the site ever since it was set up in 1990. The site was maintained until 1994. 1990-1994
ÿ Introduction of black bear hunting in regions adjacent to Gaspésie provincial park (Réserve faunique des Chic-Chocs). 1992
ÿ Training and information on trapping canids for trappers operating in the region adjacent to Gaspésie provincial park. 1991
ÿExtension of the official coyote trapping season. 1991
ÿTrapping of black bears on summits by Société de la faune et des parcs du Québec personnel. 1990-1991

Availability of arboreal lichen

Forestry activities may have an effect on the availability of arboreal lichen, which constitutes the caribou’s principal food source during the winter months. Arboreal lichen is found in mature fir stands located on summits both within Gaspésie provincial park and in surrounding areas (Bergerud 1983; Rivard 1978; Ouellet et al. 1996; Champagne et al. 1999; Fournier and Turcotte 2002).

In order to limit the impact of these activities, forestry guidelines should take the following into consideration:


Measures taken for caribou habitat protection

A-   Forestry management plan

A forestry management plan for the areas surrounding Gaspésie provincial park was developed jointly by the Ministère des ressources naturelles and the Société de la faune et des parcs du Québec. The goal of the plan was to reconcile caribou protection with the economic benefits of timber harvesting (Champagne et al. 1999). The plan covered the period from 1999 to 2004 and targeted 29,000 hectares of land previously allocated to the forestry industry. An improved plan and renewed agreement apply from 2006 to 2011. The plan’s main objectives were to ensure:

B-   Comparisons of forestry operationmethods

Since forest harvesting eliminates a part of the lichen biomass in relation to the extent of the cutting, various studies have been conducted to assess the key variables favouring maximum conservation of arboreal lichens:

-      During selective cutting by chain saw in the Réserve faunique de Matane region, arboreal lichen loss was in the 37 to 55% range; however, when mechanical thinning methods that preserve the largest trees were used, arboreal lichen loss was limited to 32% (Arseneau et al. 2000).

- Removing 25% of the basal area of a mature fir stand did not have a significant impact on the amount of arboreal lichen on residual stands. Lichen loss was limited to that on felled trees.

- A study dealing with the effect of forestry operations on maximum caribou habitat protection (Déry and Bélanger 2000) suggests that it is necessary to maintain an irregular structure in order to ensure the ongoing preservation of trees bearing arboreal lichens.

Among other things, these forestry methods seem to coincide with the natural dynamics of fir stands in Gaspésie provincial park. Thinning or partial cutting ensures the preservation of both the caribou habitat and the original structure. This can be explained by the presence of dominant softwood regeneration already firmly established in the park’s fir stands. In fact, partial cutting not only reduces the time between cutting rotations but also makes the habitat more rapidly accessible by caribou than does HARP.

Effects of disturbances

Forestry operations

Caribou tend to avoid certain areas (Murphy and Curatolo 1987) when their migration routes are affected by forestry activities. They also spend less time foraging and resting, and more time monitoring their environment, walking and running. This likely leads to increased energy expenditure (Murphy and Curatolo 1987; Dyer et al. 2001). Females and calves seemed to be particularly affected by these disturbances and reacted by moving greater distances than males (Murphy and Curatolo 1987; Chubbs et al. 1993). A Newfoundland study on the effect of clear-cutting on the caribou’s summer habitat showed that females who had been using open burn sites and hardwood habitats (and mature stands) before logging, would abandon these areas and move to undisturbed mature stands (Chubbs et al. 1993). However, caribou are able to partially adapt to habitat disturbances, depending on the severity (Bergerud 1974). Avoidance of human activity and roads by caribou appears to be greater in forested areas than in open areas (Racey et al. 1991).

Human Activities

The impact of human activities is the subject of much controversy, and the effects of these activities seem to vary depending on the population being studied. Bergerud (1974) found that various activities, and the resulting noise, seemed to have little impact on caribou in Newfoundland. The Selkirk caribou herd in southern British Columbia seems to have grown accustomed to the highway that runs through the area where they live. On the other hand, certain populations seem to be sensitive to disturbances, as is shown by studies assessing the impact of the construction of highways and railways in Norway, and the installation of the Alaska pipeline. In addition, the results of recent studies, indicate that tundra caribou herds did not avoid oil fields, and that the oil fields have not had an effect on the population’s growth rate (Pollard et al. 1996; Cronin et al. 1998a, 1998b). In contrast, Dyer et al. (2001) found that woodland caribou avoided human-made industrial infrastructure (oil wells and mining exploration roads and seismic lines), particularly when they were being used extensively. Avoidance levels attained distances of up to 1,000 metres for oil wells, and 250 metres for mining exploration roads and seismic lines, which meant that approximately 22 to 48% of the study area was relatively inhospitable to the caribou. Avoidance was more pronounced in late winter and during the calving season, probably because there was an increase in traffic during these periods.

Interpretation activities

The findings of a study on the impact of hikers on the Gaspésie population indicate that the behaviour of caribou is affected by the presence of hikers: the caribou spend less time foraging and resting, and more time monitoring their environment, walking and running (Dumont 1993). Living on the alpine tundra is an effective way for caribou to avoid their main predators (Crête et al. 1989; Seip 1989; Ouellet et al. 1991); however, the presence of hikers in this region, which prompted the caribou to leave the alpine tundra and seek refuge in the subalpine forest (observed in 64.2% of cases), increased the risk of black bear and coyote predation (Crête et al. 1990; Dumont 1993). In light of this situation, Gaspésie provincial park managers introduced a number of measures aimed at better controlling access to the alpine tundra and the activities of hikers who visit the summits (Crête et al. 1990). Tourist activities on Mont Logan, home to a large group of caribous, are growing in popularity, and will eventually have to be controlled as well.

Measures taken in the park to reduce human disturbances

The following measures have been introduced in order to reduce disruptions to the Gaspésie Woodland Caribou population:

-        Access to Mont Jacques-Cartier is prohibited prior to June 24 and after the end of September, in order to avoid disturbances during the calving and mating seasons. Furthermore, visitors are only allowed on the mountain between 10 am and 3 pm, and access to the summits of Mont Albert and Mont Richardson is forbidden during mating season (after September 30).

-        Visitors are informed about the impact of their presence on the caribou and its habitat by means of interpretation panels and brochures.

Poaching and incidental take

Even though it is obvious that not all cases are reported, poaching does not appear to be a serious problem within Gaspésie provincial park and in the surrounding areas. Over a 15-year period (from 1971 to 1986), only five cases of poaching and two of incidental take were reported (Dupuy and Desrosiers 1986). A hunting accident near Saint-Marcellin was also reported in 1996, and there was one poaching incident in the fall of 2000 (N. Fournier, FAPAQ, pers. comm.). Owing to a lack of detailed information, it is difficult to determine the exact impact of poaching and incidental take. Nevertheless, we must not dismiss acts such as these, which are unacceptable within a context of biodiversity preservation.

Diseases

Meningeal worm

The meningeal worm (Parelaphostrongylus tenuis) is a parasite that inhabits the nervous system of white-tailed deer. The parasite causes little damage in its principal host, the white-tailed deer, but can be fatal for moose and caribou (Claveau and Fillion 1984). This parasite was responsible for the disappearance of caribou reintroduced into an environment with white-tailed deer in Nova Scotia in 1968-1969 (Dauphiné 1975), as well as on a Wisconsin reserve (Trainer 1973).

Despite the fact that this parasite has been found in Gaspésie deer (Claveau and Fillion 1984), the risk of transmission to other wild cervids seems to be minimal. There have been no reports of infection of caribou and moose in Gaspésie provincial park (Crête and Desrosiers 1993; Crête et al. 1994). This may be attributed to the fact that the various cervids in the park have specific distribution ranges and separate habitats (Dumont and Crête 1995). The risk of an outbreak has been further reduced by the decline in the number of deer during the 1990s. Nevertheless, the situation should be monitored for signs of infection, and the presence of deer in Gaspésie provincial park should not be encouraged.

Chronic Wasting Disease (CWD)

Chronic Wasting Disease (CWD) is a disease that affects the nervous system of cervids. It belongs to the transmissible spongiform encephalopathy family. In Colorado and Wyoming, between 6 and 15% of deer and 1% of wild elk (Cervus elaphus) are believed to be infected (Lachapelle 2000). In Canada, the only reported cases were detected primarily on farms in Saskatchewan, where herds were contaminated by imported animals carrying the disease. These herds were subsequently destroyed. No cases of the disease in wild animals have been reported by either the Canadian Food Inspection Agency (CFIA) or the Veterinary Services Branch of Manitoba Agriculture and Food (Whiting 1999), and these agencies consider the transmission risk to be virtually non-existent. The only remaining transmission risk for caribou in the Gaspésie park would be from red deer (Cervus elaphus) farms or from imported animals that are infected. Since the disease is spread by the mother, or through contact with placenta material during calving, the risk of infection in the park is minimal, given the different habitats used by the cervids in question (Dumont and Crête 1995).

Avalanches

Studies from British Columbia (Simpson 1987) have shown that, in certain high-risk areas, avalanches are responsible for a considerable number of mortalities. The characteristics of Gaspésie provincial park--summits exceeding 1,000 metres in altitude, surrounded by steep-sloped valleys that can receive four to five metres of snow annually--seems to be favourable to the development of avalanches (Boucher 2000).

A study of winter skiing areas, both within the park and in the surrounding region, identified the following avalanche sectors: the Vallée du diable on Mont Albert, Mont Hog's Back, Petit Mont Sainte-Anne, Madeleine mines, Mont de la Passe, Mont Xalibu and Mont Vallières-de-Saint-Réal. A few years ago, winter activities were prohibited in the Mont Vallières-de-Saint-Réal sector in an effort to prevent caribou mortality.

Although caribou in the park are sometimes victims of avalanches, there are no precise statistics on this cause of mortality (N. Fournier, FAPAQ, pers. comm.). At the current time, only a few cases have been reported.

Snow conditions

A study conducted in Alaska (Denali National Park) showed that the body mass of newborn calves declined with increasing snowfall levels (Adams et al. 1995). This study, as well as studies by Boertje et al. (1996), also found a distinct correlation between the survival rate and the birth mass of calves. Furthermore, calf mortality was higher in years when spring came late and there were still large banks of snow on the summits. This can be explained, in part, by the fact there were fewer areas clear of snow that allow caribou to move to calving grounds, and to wander after the birth of their calves. Stuart-Smith et al. (1997) identified an inverse relationship between caribou movements and snow accumulations in Alberta. In addition to limiting calf survival and mobility, snow depth results in increased energy expenditures and reduces the quality and variety of forage (Boertje 1985).

 

Situation in Quebec

Current status of the population

The Gaspésie Woodland Caribou population is geographically and genetically isolated from other Quebec caribou populations (Courtois et al. 2002). It has been estimated that there were at least 750 caribou in the population at the beginning of the 1950s; however, by the end of the 1980s, the size of the herd had declined to only 200 individuals. Judging by the number of caribou spotted during aerial surveys over the past 10 years, the situation does not seem to have improved in recent years. There are currently only about 140 caribou in the population. Historically, the most probable causes are hunting, and habitat loss linked to logging, mining and forest fires (Moisan 1957). More recently, a newly arrived predator, the coyote, kills a significant number of calves, in addition to those killed by black bears (Fournier and Faubert 2001), and is the primary cause of current decline in the Gaspésie Woodland Caribou population (Crête and Desrosiers 1993).

Measures taken to preserve the Gaspésie population

A number of measures have been taken to protect the Gaspésie Woodland Caribou population (Moisan 1957). The sale of venison was prohibited in 1929, and hunting was banned for five years (Moisan 1956). Hunting was allowed again in 1934, but in 1937 Gaspésie provincial park was created, and hunting was prohibited in the park. Hunting was finally banned in the entire Gaspésie region in 1949. The park’s boundaries were reviewed in 1981. Since 1977, logging and mining operations have not been permitted within the park’s boundaries. A recovery plan was implemented between 1990 and 1995 (Gaspésie Caribou Recovery Team 1994). Finally, a forest management plan was drawn up in 1999 (Champagne et al. 1999). The next version is currently being drafted. The implementation of measures set forth in the current Recovery Plan (2002-2012) should lead to an increase in the size of the caribou population. A monitoring committee will be set up to oversee the implementation of these measures. Other measures, such as caribou farming, may be considered if recruitment remains too low to ensure the recovery of the caribou population.

 

Recovery potential

The current situation of the Gaspésie Woodland Caribou population is particularly alarming and worrying. Since this herd is the only vestige of the woodland caribou populations that used to live south of the St. Lawrence River, appropriate action must be taken as swiftly as possible to conserve this population. The situation of the Gaspésie population is critical at the present time because of extensive predation on calves by coyotes and black bears. For this reason, predator control operations were implemented between 1990 and 1996, and again in 2001, following a significant drop in the number of calves. These controls will be systematically applied over a three-year period, until the number of individuals in the population reaches 150. The methods used will then be re-assessed in order to ensure the maximum efficiency of ongoing operations in terms of sites, periods, extent, etc. Since calf protection is essential to the recovery of the population, control operations must be maintained on a long-term basis. Without these direct interventions, it would be quite difficult to ensure the population’s recovery, and the Gaspésie population could disappear completely over the course of time. It is also just as important to protect the caribou’s habitat and, in this respect, various measures, such as protecting areas adjacent to Gaspésie provincial park through improvements to the forest management plan, controlling tourist and recreational development and limiting disturbances, are essential.

 

Recovery Team’s advice

Predation appears to be the major limiting factor affecting the Gaspésie Woodland Caribou population. In light of the fact that predator control measures taken in the early 1990s produced very satisfactory results, the Recovery Team is convinced that it will indeed be possible to increase the size of the Gaspésie Woodland Caribou population. In addition, a number of legal and administrative measures (legal status, forest management, limits to disturbances) have been taken over the years, and have received the approval of a vast majority of the various players involved, as well as the public at large.

However, given the caribou’s low reproduction levels, the Team acknowledges that the recovery will take a considerable length of time.

 

 

[1]Université du Québec à Rimouski

[2]Ministère des Ressources naturelles et de la Faune (MRNF)

[3]Société de la faune et des parcs du Québec

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