Bobcats select young forests and avoid clear-cut and mature forests in a timber-logged landscape

1. What they did

Clear-cut logging changes forests for decades, helping some wildlife and harming others. The authors tested how logging on Washington’s Olympic Peninsula affects where bobcats move. They caught nine bobcats in cage traps or with hounds between 2021 and 2024 and fitted GPS collars that recorded a location every hour.

Using step selection functions, they compared each bobcat step with 20 possible steps it could have taken, testing forest age since clear-cutting, canopy cover, slope, vegetation greenness and distances to streams, paved roads and logging roads. They also estimated home ranges.

2. What they found

• Bobcats avoided the newest clear-cuts (0 to 5 years old) and older forests (41 to over 150 years), and selected young regenerating forest 6 to 15 years old.
• They preferred gentler slopes, and did not show selection for logging roads.
• Selection for canopy cover rose steadily up to 66% cover and then declined.
• Female home ranges averaged 7.6 km² and male ranges 16.0 km² (excluding one transient male whose range was 738 km²).
• Results were the same with or without the transient male, except that slope dropped out of the best model.

3. What they concluded

• Clear-cut logging appears to benefit bobcats on the Olympic Peninsula by creating young forest with dense understorey, which likely holds more prey such as mountain beavers and snowshoe hares.
• Bobcats seem to prefer intermediate cover, a trade-off between concealment for hunting and other factors.
• Managing logged forests for a mix of stand ages, leaving some undisturbed patches and debris, keeping patches connected and limiting use of the rodenticide chlorophacinone against mountain beavers would likely benefit bobcats and other wildlife.

4. How tracking was or was not used

Tracking was used only to catch the bobcats: cage traps were set where bobcat signs had been seen and where camera traps routinely detected bobcats, and six of the nine bobcats were caught by pursuing them with hounds. Habitat selection itself came from GPS data.

5. Tracker or observer certification

Not reported. The paper does not say who identified bobcat signs or how their skill was assessed.

6. Other technologies, skills or innovations

• GPS collars with drop-off units and rot-off cotton spacers as a backup.
• Cross-validation used as the main test of model performance, because models chosen by information criteria were overfitting.
• Movement data are publicly available on the Movebank Data Repository.

7. Implications for conservation (from the paper)

• Maintaining stands 6 to 15 years old within a mosaic of forest ages, with undisturbed patches and connectivity, would likely benefit bobcats.
• Limiting anticoagulant rodenticide use in timber forests would reduce poisoning risk to bobcats that eat mountain beavers.