Canada Lynx (Lynx canadensis) Classification

Connectivity is determined by the degree to which inhospitable habitat matrices are permeable to gene flow. Successful gene flow requires that dispersing individuals travel to new populations, survive there, and finally, reproduce. Consequently, examinations of connectivity must consider both the permeability of the landscape and individual survival patterns, as surviving individuals are the only ones that have the potential to reproduce.

We investigated functional connectivity of Canada lynx (Lynx canadensis) populations in the northwestern boreal forest using an unprecedented dataset of 207,957 relocations from 142 individual lynx. As a specialist predator of snowshoe hare (Lepus americanus), lynx populations follow a 10‐ to 12‐year population cycle, which lags a few years behind the population cycles of hares. We used integrated step selection analyses to quantify habitat selection, and Bayesian counting process implementation of wrapped Cauchy survival models to evaluate mortality risk during dispersal. We compared movement patterns and survival across behavioral states and population phases, following a population decline.

Our results showed few complete physical barriers to dispersal in the study region, with many lynx dispersing greater than 3000 km. Step‐selection analysis of lynx movement revealed a higher tolerance for poor quality habitats in dispersing lynx as compared to resident lynx, primarily in selection for rugged terrain and closer proximity to roads. These differences resulted in a higher estimate of landscape permeability for dispersing lynx compared to residents. When survival patterns were considered, there were increasingly stark differences between resident and dispersing lynx during population declines. Dispersing lynx faced markedly lower survival rates than resident lynx.

Overall, this paints a picture of a more connected landscape during population highs, which becomes increasingly fragmented during population lows. Canada lynx populations appeared to have few impermeable barriers across the landscape, but they face periods of low functional connectivity driven by lower survival during population declines. This emphasizes the significance of maintaining high‐quality refugia habitats from which population rebounds can occur following cyclic lows.

Arnold, Derek & Breed, G.A. & Laufenberg, Jared & Berg, Nathan & Bertram, Mark & Scotton, Bradley & Kielland, Knut. (2025). Cyclic functional connectivity of Canada lynx (Lynx canadensis) populations across North American boreal landscapes. Journal of Animal Ecology. 10.1111/1365-2656.70080.

Variation in coat colour within mammal species is of enduring interest, likely because of its potential to be either adaptive or maladaptive. Coat colour in the genus Lynx tends to be stable, with little variation within species compared to that of other felids.

Canada lynx (Lynx canadensis) have coats that typically are silver grayish in winter and reddish brown in summer with dark spots, and black hairs on the tips of their tails and ears. A rare pallid colourmorph is occasionally observed, suggestive of partial albinism.

Here, I report the first record of a melanistic Canada lynx. The individual was photographed during summer in the Yukon (Canada). It had a black coat containing whitish gray guard hairs throughout, as well as whitish gray hairs in the facial ruff and the rostrum and dorsal regions. There are only a small number of records of coat colour polymorphisms in the genus Lynx. The adaptive significance of melanism in lynx is unknown, but the loss of camouflage when hunting during winter is likely maladaptive.

Jung, Thomas. (2023). Paint it black: first record of melanism in Canada lynx (Lynx canadensis). Mammalia. 87. 10.1515/mammalia-2022-0025.

Context: Methods for estimating density of meso-carnivores in northern ecosystems are labour intensive and expensive to implement if mark-recapture and radio collaring are used. One alternative is to count tracks in the snow along transects as an index of density, but this method has been criticised as imprecise and lacking validation.

Aims: We aimed to examine the utility of track counts along snowmobile trails in the snow for measuring changes in populations of Canada lynx and coyotes in the boreal forest of north-western Canada.

Methods: We compared winter track counts of Canada lynx at three study sites and of coyotes at one site with concurrent estimates of density based on locations of radio-collared animals and estimates of numbers of uncollared animals from three 7-9-year studies in the Yukon and Northwest Territories, during a period of cyclical population fluctuations.

Key results: Snow track counts were positively correlated (r2=0.83) with density of Canada lynx, estimated by live trapping and radio collaring in the three survey areas. Coyotes also showed a clear relationship (r2=0.80) between known density and snow track counts, but track counts were strongly affected by season, with much higher counts in the early winter when snow was shallower. This indicates the need to control for season or snow depth when using track counts as indices of coyote abundance. We recommend sample sizes of at least 10 track counts per winter along a 25-km transect to maximise precision.

Conclusions: Snow track counts are a relatively simple, inexpensive method of concurrently tracking abundance of multiple species of meso-carnivores. These data indicate that track counts may be reliably used to monitor trends in numbers, but we suggest site-specific validation of the regressions reported here between tracks and animal abundance are required to translate these indices into estimates of density.

Implications: Track counts have the potential to be an affordable alternative to more intensive methods of monitoring trends in abundance of medium-sized mammals, for purposes such as management of harvest or to measure the success of programs to increase or reduce population abundance.

O'Donoghue, M.; Slough, B.G.; Poole, K.; Boutin, S.; Hofer, E.J.; Mowat, G.; Murray, D.; Krebs, C.J.
Snow track counts for density estimation of mammalian predators in the boreal forest
2023 Wildlife Research (50): 425-434

The Canada lynx (Lynx canadensis) and the bobcat (Lynx rufus) are closely related species with overlap at their range peripheries, but the factors that limit each species and the interactions between them are not well understood.

Habitat selection is a hierarchical process, in which selection at higher orders (geographic range, home range) may constrain selection at lower orders (within the home range). Habitat selection at a very fine scale within the home range has been less studied for both lynx and bobcat compared to selection at broader spatiotemporal scales.

To compare this fourth-order habitat selection by the two species in an area of sympatry, we tracked lynx and bobcat during the winters of 2017 and 2018 on the north shore of Lake Huron, Ontario.

We found that both lynx and bobcat selected shallower snow, higher snowshoe hare abundance, and higher amounts of coniferous forest at the fourth order. However, the two species were spatially segregated at the second order, and lynx were found in areas with deeper snow, more snowshoe hare, and more coniferous forest.

Taken together, our findings demonstrate that the lynx and bobcat select different resources at the second order, assorting along an environmental gradient in the study area, and that competition is unlikely to be occurring between the two species at finer scales.

Morin, S.J.; Bowman, J.; Marote, R.R.; Fortin, M.
Fine-scale habitat selection by sympatric Canada lynx and bobcat
2020  Ecology and Evolution (10): 9396-9409

Forest managers are often tasked with balancing opposing objectives, such as altering forest structure and conserving forest-dwelling animals. Consequently, to develop holistic strategies managers require information on how forest manipulations influence species of conservation concern, particularly those that are federally threatened or endangered.

Here, we characterized how differing silvicultural treatments (n=1,293 - forest thinnings; removal of small trees, selection cuts; trees harvested in small patches, and regeneration cuts; clearcuts of nearly all trees) influenced the resource use of a threatened forest carnivore, Canada lynx (Lynx canadensis), over a temporal gradient of 1-67 years after treatment. To do this, we used an extensive GPS dataset on 66 Canada lynx (i.e., 164,593 locations) collected during 2004-2015 within the Northern Rocky Mountains, U.S. We used univariate analyses and hurdle regression models to evaluate the spatio-temporal factors influencing lynx use of treatments.

Our analyses indicated that Canada lynx used treatments, but there was a consistent cost in that lynx use was low up to ~10 years after all silvicultural actions. However, cumulative use (in both winter and summer) by lynx reached 50% at ~20 years after a thinning treatment, whereas it took ~34-40 years after a selection or regeneration cut. This indicated that Canada lynx used thinnings at a faster rate post-treatment than selection or regeneration cuts, and that lynx used selection and regeneration cuts in a similar fashion over time. Further, we discovered that lynx occupancy and intensity of treatment use was influenced by the composition of forest structure in the surrounding neighborhood. In some instances, the existing forest structure surrounding the treatment and the time since treatment interactively influenced lynx use; a pattern characterizing a spatio-temporal functional response in habitat use.

This demonstrated that both the recovery time as well as the spatial context of a particular area are important considerations when implementing different silvicultural treatments for Canada lynx at the landscape scale. For example, if a selection cut was implemented with abundant mature, multi-storied forest (i.e., a preferred habitat by lynx) in the surrounding landscape, lynx would use these treatments less over time than if the neighborhood contained less mature forest. Forest managers can apply our spatio-temporal understandings of how lynx respond to forest silviculture to refine expectations and develop strategies aimed at both forest management and the conservation of Canada lynx.

Holbrook, J.D.; Squires, J.R.; Bollenbacher, B.; Graham, R.; Olson, L.E.; Hanvey, G.; Jackson, S.; Lawrence, R.L.
Spatio-temporal responses of Canada lynx (Lynx canadensis) to silvicultural treatments in the Northern Rockies, U.S
2018 Forest Ecology and Management (422): 114-124

The snowshoe hare (Lepus americanus) is a keystone species in the boreal forest because it affects the demography and population dynamics of many other species in the ecosystem.

Throughout Canada and Alaska, hare abundance fluctuates regularly over periods of 9 to 11 years. Hare population dynamics have a strong impact on specialist hare predators, such as lynx (Lynx canadensis), which fluctuate in response to hare abundance with a 1 - 2 year lag in their own cycle.

The numerous studies conducted since the snowshoe hare - lynx cycle was first described have improved our understanding of the mechanisms behind it. However, there are still unanswered questions on the role of food in the population fluctuations of both hare and lynx.

Majchrzak, Y.
The role of food in the snowshoe hare - Canada lynx cycle
2016  Arctic (69): 450-453