Habitat preference of Canada lynx through a cycle in snowshoe hare abundance

2003 ◽  
Vol 81 (10) ◽  
pp. 1736-1745 ◽  
Author(s):  
Garth Mowat ◽  
Brian Slough

We assessed habitat preference of a lynx (Lynx canadensis) population through 8 years of a snowshoe hare (Lepus americanus) cycle. Seventy-four percent of our southern Yukon study area was approximately 30-year-old regenerating forest resulting from a large wildfire. The study area was not trapped and lynx density was very high compared with other populations in North America. Contrary to our prediction, there was no discernable shift in habitat preference through the hare cycle; however, our habitat types were coarsely mapped and our radiolocations relatively inaccurate. Lynx may have altered their habitat preferences at finer scales (for patches <2 ha). Lynx showed strong preference for regenerating habitats over mature white spruce (Picea glauca) and alpine–subalpine. Lodgepole pine (Pinus contorta) dominated regenerating stands were preferred over spruce–willow (Salix spp.) stands of equal age. Riparian willow stands were also preferred over mature spruce forest and alpine. Lynx used riparian willow stands more in winter, but we detected no other shifts in habitat preference between snow-free and winter periods. We did not detect any difference in habitat preference between sexes. Independent juveniles made greater use of mature forest and perhaps riparian willow than adults, but no other difference in preference between the two age groups was noted. Lynx preference for regenerating habitat over mature forest suggests that burns will benefit lynx, especially if the regenerating community is pine dominated. Logging will only likely provide similar benefits if a dense pine understory results, which is unlikely in intensively managed stands. The suppression of forest fires in recent decades may have contributed to the decline of lynx numbers in the south of their range.

1994 ◽  
Vol 72 (8) ◽  
pp. 1444-1451 ◽  
Author(s):  
Dennis L. Murray ◽  
Stan Boutin ◽  
Mark O'Donoghue

We examined the relationship between winter habitat selection among lynx (Lynx canadensis) and coyotes (Canis latrans) and relative snowshoe hare (Lepus americanus) abundance by tracking in snow during three winters. Hare numbers were higher in dense spruce (Picea glauca) than in other habitats in 1987–1988, and both predator species selected that habitat in that year. In 1988–1989, hare distribution was similar among habitats, and both predators used spruce habitats relative to their availability. In 1989–1990, hare numbers were also similar among habitats, and lynx used spruce habitats according to availability, whereas coyotes selected dense spruce. Hares were the main prey of both species, and the distribution of hares chased and killed by lynx was similar to that predicted by habitat use. Lynx hunting success was also similar among habitats. In comparison, coyotes chased and killed more hares than expected and had higher hunting success in dense spruce. Snow was shallower and harder in all spruce habitats used by coyotes than in those travelled by lynx. This suggests that coyotes were more selective of snow conditions than lynx, probably as a result of their high foot-load (ratio of body mass to foot area) relative to that of hares. Coyotes scavenged more often than lynx, but neither species seemed to select habitats on the basis of carcass availability. We concluded that high hare densities influenced selection of dense spruce by both species in 1987–1988, and that coyotes may also have chosen habitats on the basis of hunting success and snow conditions.


1990 ◽  
Vol 68 (5) ◽  
pp. 845-851 ◽  
Author(s):  
Gary M. Koehler

Lynx (Lynx canadensis) and snowshoe hare (Lepus americanus) population characteristics and use of habitats were studied during 1985–1987 in north central Washington. Lynx used areas above 1463 m elevation that were dominated by lodgepole pine (Pinus contorta) and Engelmann spruce – subalpine fir (Picea engelmannii – Abies lasiocarpa) cover types. Snowshoe hares were the most common prey of lynx, with remains of snowshoe hare occurring in 23 of 29 scats. Counts of tracks and pellets showed snowshoe hares to be most abundant in 20-year-old lodgepole pine stands. Fire suppression and natural fire frequencies in the past 5 decades has limited the amount of these early successional forests, which are important as habitat for snowshoe hares. Marginal habitat conditions for snowshoe hares probably resulted in a scarcity of prey in the study area and may explain the relatively large home ranges of lynx (69 ± 28 km2 for five males and 39 ± 2 km2 for two females), low density of adults (2.3 lynx/100 km2), and high kitten mortality rates (88% for eight kittens in three litters). Demographic characteristics of lynx in the study area may be representative of lynx populations along the southern periphery of their range where habitat conditions are marginal for lynx and snowshoe hares.


Author(s):  
Mateo López Victoria ◽  
Matthias Jurczyk ◽  
Volkmar Wolters

The Colombian leaf-toed gecko (Phyllodactylus transversalis) is the least known reptile species of Malpelo Island (Eastern Tropical Pacific). In the 37 years since its original description, no single study strictly dedicated to this species has been conducted. With the goal of providing information on the ecology and population size of this gecko, data collected during two visits to the island are presented. Behavior and reproduction were studied by following individuals during the night and by searching for hidden individuals and eggs during the day. Population’s density and habitat preferences were estimated by classifying the island’s surfaces into four types and counting geckos inside those habitats within band transects. General morphological measurements of geckos were performed as reference points for future comparisons. Phyllodactylus transversalis lays its eggs in narrow crevices of rocks, apparently communally. Reproduction seems to take place during most of the year, probably associated with the peak breeding season of seabirds. Although conspecifics shared shelters during the day, densities during the night suggest no apparent habitat preference for foraging. Population size of this species was estimated at approximately 114000 individuals.


2010 ◽  
Vol 86 (1) ◽  
pp. 118-129 ◽  
Author(s):  
M J Waterhouse ◽  
E. C. Wallich ◽  
N. M. Daintith ◽  
H. M. Armleder

Mature lodgepole pine (Pinus contorta) forests were harvested using group selection (GS) (0.02-ha openings) and irregular group shelterwood (IGS) (0.05-ha openings) systems to maintain arboreal and terrestrial lichens in the winter range of northern woodland caribou (Rangifer tarandus caribou). Ten years after planting, lodgepole pine showed excellent survival, but were smaller in the partial cut openings compared to the clearcuts. Pine grew less in the Sub-Boreal Pine–Spruce biogeoclimatic subzone (SBPSxc) than in the Montane Spruce subzone (MSxv), and trees were smaller in the GS versus IGS treatment within the MSxv subzone. Interior spruce (Picea glauca × engelmannii) grew best in the MSxv and partial cut treatments, but was significantly affected by summer frost in the clearcuts. In an operational-scale Adaptive Management trial, openings were enlarged to 0.15 ha, and both pine and spruce showed excellent survival, minimal frost damage, and 10-year size similar to clearcut conditions. This study suggests that lodgepole pine and interior spruce can be successfully regenerated in partial cut openings with acceptable growth in gaps of 0.15 ha. Key words: caribou, group selection, interior spruce, irregular group shelterwood, light level, lodgepole pine, Montane Spruce zone, partial harvest, soil moisture, soil temperature, Sub-Boreal Pine Spruce zone, summer frost


1991 ◽  
Vol 6 (3) ◽  
pp. 64-67 ◽  
Author(s):  
Thomas P. Sullivan ◽  
Wayne L. Martin

Abstract The incidence of meadow vole (Microtus pennsylvanicus) and brown lemming (Lemmus sibiricus) feeding damage to young plantations of lodgepole pine (Pinus contorta var. latifolia) and interior spruce (Picea glauca × Picea engelmannii) was studied in west-central British Columbia. Fifty-eight plantations were surveyed for seedling survival and stocking, and an additional 21 older plantations of lodgepole pine were surveyed for tree damage. Average survival of pine (47.7%) was significantly lower than that of spruce (56.0%). Because of mortality from vole feeding, 24 of the 58 plantations were not satisfactorily restocked. Planted trees were attacked significantly more than natural regeneration. Severely attacked plantations occurred in the spruce-subalpine fir (Abies lasiocarpa) forest type at elevations > 800 m on N to NE aspects. Susceptible plantations generally had mechanical or no site preparation with complex post-harvest debris and limited vegetation cover. West. J. Appl. For. 6(3):64-67.


1985 ◽  
Vol 63 (12) ◽  
pp. 2817-2824 ◽  
Author(s):  
Richard M. P. Ward ◽  
Charles J. Krebs

The behavioural responses of lynx (Lynx canadensis) to declines in snowshoe hare (Lepus americanus) abundance were examined in the southwestern Yukon. Between April 1982 and June 1984, 11 lynx were radio tagged and monitored in and near the Kluane Game Sanctuary. Lynx home range size increased from 13.2 to 39.2 km2 concurrent with a decline in snowshoe hare abundance from 14.7 to 0.2 hares/ha. Below about 0.5 hares/ha, several lynx abandoned their home ranges and became nomadic, although they remained within the general study area. Lynx concentrated their foraging efforts in areas of relatively high snowshoe hare abundance and abandoned these areas after hares declined. Straight-line daily travel distance remained constant at 2.2−2.7 km/day above 1.0 hare/ha. Below 1.0 hares/ha, straight-line daily travel distances increased rapidly, reaching 5.5 km/day at 0.2 hares/ha. Three of seven radio-tagged lynx dispersed 250 km or more from the study area during the 1982 period of rapid hare decline. No similar long-distance emigrations were recorded after hare densities stabilized at less than 1.0 hares/ha. Trapping mortality was responsible for the loss of seven of nine radio-tagged lynx that travelled outside the game sanctuary. One lynx probably starved during the winter or spring of 1984. The high rate of trapping mortality outside the game sanctuary suggests that refugia in wilderness areas are important in maintaining lynx populations during periods of low recruitment.


2005 ◽  
Vol 81 (4) ◽  
pp. 575-581 ◽  
Author(s):  
Oscar Garcia

Growth and yield predictions for managed even-aged stands in British Columbia are based on TASS, an individual-tree distance-dependent growth model driven by an unusually detailed description of crown development. Because of its complexity, most applications utilize previously generated stand-level yield tables rather than running TASS directly. I have developed a differential equation approximation to the stand-level dynamics predicted by TASS that mimics the aggregate behaviour with sufficient accuracy for many practical purposes. Versions of this model, called TADAM, exist for planted coastal Douglas-fir, lodgepole pine, and white spruce. TADAM can efficiently project stand development starting from any initial conditions, and subject to any combination of thinnings. Its relative simplicity makes it suitable for embedding into landscape-level planning models and other decision support systems. It has been implemented as a C function library, as an interactive simulator running on a PDA, and as an Excel spreadsheet add-in. An example of thinning and planting density optimization is briefly described. Key words: growth and yield, stand dynamics, thinning, optimization, Pinus contorta, Picea glauca


2006 ◽  
Vol 36 (7) ◽  
pp. 1684-1694 ◽  
Author(s):  
André Gagné ◽  
Jean-Luc Jany ◽  
Jean Bousquet ◽  
Damase P Khasa

Seedlings from three conifer species (Pinus contorta Doug. ex Loud. var. latifolia Englem., Picea glauca (Moench) Voss, and Picea mariana (Mill.) BSP) were planted on two clear-cut sites in Alberta, Canada, after inoculation in the nursery with strains of six different ectomycorrhizal species (Hebeloma longicaudum, Laccaria bicolor,Paxillus involutus,Pisolithus tinctorius,Rhizopogon vinicolor, and Suillus tomentosus). Five and 6 years after planting, morphological characterization and molecular typing techniques (internal transcribed spacer – restriction fragment length polymorphism (ITS-RFLP) and simple sequence repeat (SSR) markers) were used to identify the ectomycorrhizal fungal communities and to assess the occurrence of the inoculated ectomycorrhizal fungi on host roots. Ectomy corrhi zae recovered from the roots of the planted trees on each of the two sites showed little diversity, with a total of 16 and 19 ITS-RFLP patterns corresponding to 11 and 13 ectomycorrhizal taxa, respectively. The most abundant ectomycorrhizal fungi found on colonized roots were ascomycetes and the widespread basidiomycete Amphinema byssoides. Amongst the six introduced fungal strains, only L. bicolor UAMH 8232 was detected on one site after 5 and 6 years, as determined using six SSR markers. Although not detected after 5 years, some of the introduced strains might have had a positive effect on the early growth of the trees before their replacement by competing species, because significant differences in plot volume index were detected between inoculation and control treatments.


1970 ◽  
Vol 48 (10) ◽  
pp. 1703-1726 ◽  
Author(s):  
Paul W. Stringer ◽  
George H. La Roi

Twenty stands of uniform, mature, undisturbed Pseudotsuga menziesii var. glauca forest were selected in Banff and Jasper National Parks, using a combination of airphoto and ground surveys. Quantitative sampling methods were used to describe their floristic composition, vegetation structure, and physical habitats.Scattered trees of Pinus contorta, Picea glauca, and Populus tremuloides occurred in the Pseudotsuga forests. The poorly developed shrub strata contained Shepherdia canadensis, Rosa acicularis, Spiraea lucida, Juniperus communis. Major herb, dwarf shrub, bryophyte, and lichen species were Elymus innovatus, Calamagrostis rubescens, Fragaria virginiana, Astragalus decumbens, Aster conspicuus; Arctostaphylos uva-ursi, Linnaea borealis; Hylocomium splendens, Abietinella abietina, Tortula ruralis; Peltigera canina. A cyclical pattern of vegetation change is related to the death, replacement, and maturation of Pseudotsuga trees.Relations between vegetation and physical habitat were analyzed by simple correlation and multiple regression. Available potassium in soil, stand age, and slope exposure were most influential in regression equations for tree stratum development. Understory strata were primarily correlated with tree stratum development.A two-dimensional stand ordination based on the vegetational similarity of subordinate vascular strata showed a pronounced separation of Banff and Jasper Pseudotsuga forests, and prompted recognition of two new climax associations (sensu Daubenmire): Pseudotsuga / Elymus innovatus in Jasper; Pseudotsuga / Calamagrostis rubescens – Elymus innovatus in Banff. Habitat differences between the two associations include macroclimate, parent materials, and soil moisture.


Sign in / Sign up

Export Citation Format

Share Document