Habitat quality and population density drive occupancy dynamics of snowshoe hare in variegated landscapes

Temporal variability in primary productivity can change habitat quality for consumer species by affecting the energy levels available as food resources. However, it remains unclear how habitat-quality fluctuations may determine the dynamics of spatially structured populations, where the effects of habitat size, quality and isolation have been customarily assessed assuming static habitats. We present the first empirical evaluation on the effects of stochastic fluctuations in primary productivity—a major outcome of ecosystem functions—on the metapopulation dynamics of a primary consumer. A unique 13-year dataset from an herbivore rodent was used to test the hypothesis that inter-annual variations in primary productivity determine spatiotemporal habitat occupancy patterns and colonization and extinction processes. Inter-annual variability in productivity and in the growing season phenology significantly influenced habitat colonization patterns and occupancy dynamics. These effects lead to changes in connectivity to other potentially occupied habitat patches, which then feed back into occupancy dynamics. According to the results, the dynamics of primary productivity accounted for more than 50% of the variation in occupancy probability, depending on patch size and landscape configuration. Evidence connecting primary productivity dynamics and spatiotemporal population processes has broad implications for metapopulation persistence in fluctuating and changing environments.

Download Full-text

Effects of selection cuts on winter habitat use of snowshoe hare (Lepus americanus) in northern temperate forests

Canadian Journal of Forest Research ◽

10.1139/cjfr-2018-0014 ◽

2018 ◽

Vol 48 (9) ◽

pp. 1049-1057

Author(s):

Véronique Simard ◽

Louis Imbeau ◽

Hugo Asselin

Keyword(s):

Habitat Quality ◽

Temperate Forests ◽

Lepus Americanus ◽

Snowshoe Hare ◽

Gap Formation ◽

Winter Habitat ◽

Selection Cutting ◽

Key Species ◽

Northern Temperate Forests ◽

Positive Effect

Selection cutting is used in northern temperate forests where regeneration dynamics are driven by gap formation. By creating openings in the canopy, selection cutting modifies shrub cover, an important criterion in winter habitat selection by snowshoe hare (Lepus americanus Erxleben, 1777), a key species in North American forests. The objective of this study was to determine the effects of selection cuts on snowshoe hare habitat and to evaluate the restoration of habitat quality over time. Occurrence indices for snowshoe hare (fecal pellets and tracks) were modelled according to habitat quality parameters for 22 hardwood stands that were subjected to selection cutting between 1993 and 2007 and 30 untreated stands (15 hardwood and 15 mixedwood) in Abitibi-Témiscamingue, Quebec. Model selection based on the Akaike second-order information criterion (AICc) identified lateral cover as the only habitat structure parameter having a positive effect on snowshoe hare abundance in the study sites. Indicators of snowshoe hare presence were highest in untreated mixedwood stands but more abundant in selection cuts than in untreated hardwood stands. The use of selection cuts by snowshoe hare increased with time since logging was performed. We conclude that selection cutting exerted a positive effect on the use of hardwood stands by snowshoe hare.

Download Full-text

Proximate causes of losses in a snowshoe hare population

Canadian Journal of Zoology ◽

10.1139/z86-090 ◽

1986 ◽

Vol 64 (3) ◽

pp. 606-610 ◽

Cited By ~ 36

Author(s):

Stan Boutin ◽

C. J. Krebs ◽

A. R. E. Sinclair ◽

J. N. M. Smith

Keyword(s):

Population Density ◽

Population Increase ◽

Snowshoe Hare ◽

Snowshoe Hares ◽

Causes Of Mortality ◽

Proximate Causes ◽

Hare Population ◽

Kluane Lake ◽

Predation Rates

We used radiotelemetry to monitor proximate causes of mortality of snowshoe hares during a population increase, peak, and decline at Kluane Lake, Yukon. Predation and starvation rates increased 1.6- and 9-fold, respectively, in the winter of peak population density. Predation accounted for 58% of the losses during the winter of peak densities while losses were equally divided between predation and starvation in the winter following the peak. Starvation and predation rates were lower on a food-supplemented grid than on control grids in the peak winter. In the following spring and winter, starvation rates remained low on the food grid while predation rates increased to equal those on control areas. We conclude that both starvation and predation were the proximate causes of mortality during the hare decline at Kluane Lake.

Download Full-text

Estimation of snowshoe hare population density from turd transects

Canadian Journal of Zoology ◽

10.1139/z87-087 ◽

1987 ◽

Vol 65 (3) ◽

pp. 565-567 ◽

Cited By ~ 60

Author(s):

Charles J. Krebs ◽

B. Scott Gilbert ◽

S. Boutin ◽

R. Boonstra

Keyword(s):

Population Density ◽

Fecal Pellet ◽

Accurate Method ◽

Yukon Territory ◽

Lepus Americanus ◽

Snowshoe Hare ◽

Model Average ◽

Pellet Counts ◽

Hare Population ◽

Kluane Lake

We counted the number of snowshoe hare (Lepus americanus) fecal pellets on 50 quadrats of 0.155 m2 on each of six areas near Kluane Lake, Yukon Territory, once a year from 1977 to 1983. On four of these areas we livetrapped hares once a month and estimated population density from the Jolly–Seber model. Average hare density for the year was linearly related to fecal pellet counts (r = 0.94) over the range 0–10 hares/ha. Mean turd counts also are related to the variance of these counts by Taylor's power law with exponent 1.30, indicating a clumped pattern in turd deposition. Fecal pellet counts provide a quick and accurate method for snowshoe hare censuses on an extensive scale.

Download Full-text

Urban-rural gradients of ecosystem services and the linkages with socioeconomics

Landscape Online ◽

10.3097/lo.201539 ◽

2015 ◽

Vol 39 ◽

pp. 1-31 ◽

Cited By ~ 14

Author(s):

Yin Hou ◽

Felix Müller ◽

Bo Li ◽

Franziska Kroll

Keyword(s):

Ecosystem Services ◽

Population Density ◽

Habitat Quality ◽

Unemployment Rate ◽

Rural Areas ◽

Road Density ◽

Urban Fabric ◽

Housing Area ◽

Urban Rural

The principle of urban-rural gradients can reveal the spatial variations of ecosystem services and socioeconomic dimensions. The interrelations between ecosystem services and socioeconomics have scarcely been considered in the context of urban-rural areas. We investigated the spatial gradients and the mutual linkages of several ecosystem services and socioeconomic variables in the urban-rural areas of Leipzig, Germany, and Kunming, China. The results showed some regularities in the spatial patterns of ecosystem services and socioeconomic dimensions in both study areas. Habitat quality and f-evapotranspiration of Leipzig and habitat quality of Kunming demonstrated apparent increasing trends along all gradient patterns. However, the other ecosystem services presented divergent spatial variabilities in different gradient patterns. Road density, urban fabric and population density showed identical declining trends in both case study areas. Differently, household size, housing area as well as unemployment rate in Leipzig presented inconsistent spatial dynamics with considerable fluctuations. With regard to the gradient interrelations, road density, urban fabric and population density were strongly correlated with most ecosystem services in both case study areas. In contrast, the gradients of household size, housing area and unemployment rate of Leipzig showed inconsistent correlations with the ecosystem services gradients. Our study provides evidence to the argument that typical patterns of ecosystem service gradients do not exist in different urban-rural areas.

Download Full-text