Swedish Female Brown Bears Avoided Likely Moose-Kill Ground by Day

STEP 1 · Kill map

Moose were shot nearer roads and in more clearcut

Hunters reported 3136 moose harvest locations from 2016 through 2019 in four management areas of Dalarna, Gävleborg and southern Jämtland. Other units in the study area were left out because brown bears did not use them or because few hunters disclosed kill locations.

Hunters were more likely to shoot moose closer to roads and in a higher proportion of clearcut. Mixed forest and conifer lowered the chance. Young forest did not change the kill odds. The females still selected young forest by day. Our read is that the open cut is a weak place to expect their daytime sign in this sample.

The falls of 2016 through 2019 were split into before hunting, the bear hunt, low-intensity and high-intensity moose hunting, and a pause between the last September harvest and the first October harvest. Moose hunting stopped in that pause to limit disturbance during the peak of the moose rut. The authors used those windows for each year from 2016 through 2019.

Only 6% of the 351 bears legally killed in the study area from 2016 through 2019 were taken after moose hunting began. The authors read that share as little overlap between the hunts. Moose in Sweden are usually hunted with baying dogs that push them toward still hunters, and brown bears are hunted mainly with baying or pursuing dogs. The authors suggest the similar methods kept these bears from separating the two hunts.

STEP 2 · Daylight hours

Avoidance of likely kill ground was strongest by day

Thirty different females contributed 53 bear-years from 2016 through 2019. Males were excluded because only two were monitored. The file held 82,042 hourly locations from 10 August through 21 October before poor fixes and incomplete rows were removed.

Brown bears generally avoided higher moose-kill probability, especially by day. Females with dependent offspring strongly avoided that ground in daylight during the bear hunt and the moose hunt. The paper's summary describes avoidance by day and at night. The detailed results put the strong avoidance in daylight.

Females moved faster and more directionally when traveling through higher kill-probability ground. Our read is that a straight track across shot ground fits passage better than a feeding stop. The track cannot name the bear.

STEP 3 · Night hours

Some females chose middling kill risk after dark

Several female classes selected intermediate moose-kill probability at night in specified periods. Intermediate is the fitted probability of a moose kill in the model. It is not a cover type you can see on the ground.

Females with dependent offspring weakly selected that intermediate probability at night during the low-intensity moose hunt and the pause. Solitary females were more likely to select it at night before hunting, during the bear hunt, during the low-intensity moose hunt and during the pause. Subadult females selected it at night during all hunting periods.

The authors did not find strong support for a night pull toward high kill probability. Missing that support does not show the pull was zero. Their conclusion is that slaughter remains were not strong attractants for these females. The risk map was built from reported harvest locations. Other hunting activity was left out of the model, and the authors say that likely underestimates the disturbance.

STEP 4 · Day cover

Young forest was selected by day in every period

Habitat selection changed through the fall. Some shifts in young forest, clearcuts and distance to the nearest road lined up with bear hunting and moose hunting.

Young forest was selected by day in every period. Solitary females were also more likely to select a higher share of conifer by day in the bear hunt and both moose intensities than in the other periods. The authors read that shift as a move into short and medium conifers that block a side view.

Clearcut was generally avoided by day. At night it was avoided less or used about in proportion to availability. Females with dependent offspring and subadults slightly increased daytime clearcut use during both moose intensities. Solitary females avoided clearcut most strongly during the bear hunt and both moose periods. Our expectation of little daytime sign on clearcuts does not cover those slight increases.

Roads were avoided by day in every period and less strongly at night overall. Daytime road selection barely changed across periods. The study area had 0.7 km of forest road per square kilometer, about 1.1 miles per square mile. The authors suggest a bear there might be unable to move farther from one road without nearing another. Solitary females avoided roads more strongly at night during both moose periods. Females with dependent offspring showed that stronger night avoidance in the moose periods and also during the bear hunt. Subadults did not show that night shift.

The pause coefficients looked like the coefficients from before hunting. The authors suggest moose hunting caused some of the changes because of that resemblance. Our read is that the pause fits their suggestion in this landscape and does not settle cause by itself.

STEP 5 · Local notes

Compare the dressed moose with nearby young timber

Our check is an optional local observation on a moose hunt in country like this sample. Compare the open ground where a moose was dressed with the nearest young regenerating timber. If you can check safely, look once at first light and again late in the day. New sign then falls in either an overnight or a daylight interval. Approach remains cautiously and only in daylight. Tracks, beds, scat and a bear you see show local activity only. They do not measure the paper's kill probabilities, name a collared bear or describe the wider population.

A female with dependent offspring that you actually see can be noted as that class. An unmarked track cannot identify a solitary female or an age class. Count unmarked sign as bear activity on that ground. That note cannot repeat the female-only analysis. Males were not in the models.

Daylight sign that keeps showing up at the dressed moose while the young timber stays clean would drop our read for the bears in front of you. Overnight sign at the remains shows use after dark. It does not show a meal and it does not recover the modeled kill probabilities. A scat with hair or bone shows animal matter was eaten and can include scavenging. It cannot tell a gut pile from an older carcass.

The sample is female brown bears in south-central Sweden from 2016 through 2019, on a dog-hunted boreal landscape with that road density. A hunt without dogs was outside the sample, and so was country with a sparser forest-road network. The authors expect bears from less disturbed landscapes to be less afraid of hunters if a similar study were run there. That expectation is untested. The locations do not measure moose-hunting success.