I am writing this post from the perspective of wolf biology but the contents might refer to other large carnivore (and even large herbivore, mesopredators, omnivore etc.) species, as well.
I have observed a tendency in the Latvian media to publish articles on wolf depredation of livestock or increased sightings of wolves following periods of intense logging that has raised concern, e.g., in environmental NGOs and that has also been portrayed in the media.
Those are incidents of livestock losses but also claims by public that ‘the wolf population is growing out of control’ (unsubstantiated by scientists).
It suggests to me that the wolf population is not growing but rather there are other factors influencing sighting and conflict rates.
I believe that high rates of logging are followed by displacement of wildlife species from their former home ranges or readjustments of those ranges that force the species to disperse or to roam or to expand their ranges (in order to satisfy food demands) or to change the utilization of their ranges in a manner that brings them closer to places which they did not use to frequent before.
Thus, people might perceive an increase in, e.g., wolf numbers because wolves are spotted more often or because wolves supposedly ‘settle in new places’.
Instead these might be wolves that have been displaced and/or forced to alter their range or the use of their range in response to major habitat loss in their home area.
Such perceptions are very dangerous because public might call for predator control in a population that has not increased but that has been forced to alter its distribution and its rates of interaction (including conflict) with humans.
Without scientific input, lethal management could thus be executed with respect to a population that is not overabundant and that might even be endangered due to habitat loss and fragmentation.
Large predators have, accordingly, large home ranges.
In this case, change in use patterns might be the case rather than displacement because clearings can be incorporated into large predators’ territories that can exceed 200 – 300 km2.
However, for example, large herbivores have relatively small home ranges and loss of cover can cause their migration out of an area which, consequently, becomes unsuitable for predators (lack of prey) who follow their food resources.
There might be a lag effect because clearings can be used by ungulates while stands that have outgrown the browsing level (ca. 2 m) are no longer as viable and much depends on the understorey species composition in secondary growth forests.
Large predators might also considerably change their use of range if other significant resources, e.g., den sites have been threatened (through disturbance or loss).
Other species (such as mesopredators) might become displaced entirely because their ranges are smaller and they might not be able to incorporate vast logged areas.
They could be forced out of their former homes while other forest segments could still be habitable and occupied by conspecifics.
Such individuals would end up dispersing out of the forest and closer to human settlements where conflict and sightings might, once again, occur at increased rates.
The relation between habitat loss (due to logging and other factors) as well as large predator habitat use patterns have been implied and studied.
However, I have not really encountered any studies aimed specifically at determining whether certain scales of logging operations (that can be spatial as well as temporal because noise disturbance and constant human or vehicle presence might be as influential as loss of physical structures) are statistically correlated with sighting and conflict rates of a species that is affected by these operations.
For example, it might be useful to study whether wolf (or other large predator) sightings and wolf-livestock conflict rates increase after a specific threshold of logging in the area has been reached and surpassed.
Lag effect should be considered, as well, if wolves follow ungulates or if wolves are displaced from their traditional summer denning sites while the logging has occurred in the previour winter.
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While, in my post, I mainly focused on habitat selection at a landscape level as well as landscapes that do not contain vast forest masifs but are already fragmented to some degree, this new study by Johnson-Bice, S.M et al., 2023 might offer additional causes to wolves approaching settlements after logging operations.
For example, habitat selection can be analyzed as second and third order selection.
While individuals might be displaced due to logging on the second order scale (because these areas no longer provide sufficient shelter which is especially true in fragmented landscapes where logging does not create an opening in a forest massif but rather removes a forest massif or reduces its size considerably), the third order habitat selection (selecting features within the home range) could add to the changes in wolf behaviour if wolves selected logged areas to hunt their prey.
The study shows that in Greater Voyageurs Ecosystem which is sparsely inhabited (mainly seasonal lodges) and where logging creates gaps in an otherwise extensive forest system, wolves tend to use linear features (such as roads and trails) for travel and they tend to hunt and kill deer fawns in logged areas as well as near the low-use human infrastructure (possibly because deer aggregate there to utilize more abundant forage).
Thus, where wolves are not displaced entirely and where the following conditions apply:
- logging occurs within an otherwise abundantly forested area with sufficient shelter for wolves;
- logging occurs close to settlements that are not densely populated and that are close to linear features connecting the forested areas and the recently logged sites;
- deer receive supplementary feeding opportunities close to the logged areas which are, coincidentally, close to settlements;
… it might follow that wolves also begin to approach settlements at increased rate because that is where their prey congregates and because logging road access provides them with the opportunity to travel between shelter and relatively exposed areas.
Such changes would mainly concern resident wolves.
As resident wolves tend to have lower conflict rates than dispersing wolves, logging close to settlements might increase these rates.
Logging often occurs near settlements to facilitate the transportation and/or processing of timber.
Notes by Ieva 