Black bears engage in various behaviors thought to relate to scent communication. As I’ve discussed before, they mark larger trees by rubbing, biting, and clawing at them, and they mark the ground with their feet by as they walk, sometimes creating well-worn stomp trails. They also mark small trees and bushes with urine by straddling them as they travel, a behavior called straddle marking. Females dribble urine almost constantly, and males may urinate while straddling vegetation.

Identifying Straddle Saplings

Bears probably straddle mark many saplings and bushes, some of which they might never mark a second time. Marked only once, it might bear little visible, lasting sign. A wet urine stain might be seen if examined immediately after marking, or some hair strands may be caught on it. But I have found that some straddle saplings are associated with mark trees and stomp trails, and as part of the marking complex, the sapling is subject to repeated use, just like the tree and the trail. This results in more noticeable damage.

I have found that hemlock used for straddle marking may be missing needles at or near the top, as seen in the photo below. Deciduous straddle saplings and bushes may have torn or creased leaves as shown in this example (the first photo in that article) but I don’t know if the sign on that example was the result of a single marking event or repeated use.

Mark Tree – Stomp Trail – Straddle Sapling Complexes

In Massachusetts, hemlock saplings located near mark trees and stomp trails seem to be a popular choice (perhaps because they are abundant) for straddle marking. This I have learned from my own field experience, and I’ve confirmed it with camera trap photos and videos. Sometimes a bear will mark all three elements, and this is usually a large, mature animal, probably an adult male. Other times, a bear will skip the mark tree but straddle the sapling, or vice versa. Stomping may or may not be evident. All of this marking behavior begins in late April, peaks in May and June (the mating season) and becomes occasional in summer.

Study the two photos below taken in the same location and targeting the same mark tree – stomp trail – straddle sapling complex. Notice:

• The bear is straddling a hemlock sapling as it walks
• Two different bears are using the same straddle sapling
• The bear in each photo has its mouth open, which probably indicates it is gathering and interpreting odor molecules (flehmen response)
• The large light-colored tree at the far right is a mark tree, as evidenced by both fresh and scarred lesions around eye level

Video of Bear Behavior at Marking Complexes

Watch the video below to see several examples of bear behavior at two different mark tree – stomp trail – straddle sapling complexes. These two complexes are about a thousand feet apart on the same bear trail. Notice that there are at last two different bears, and that they don’t always mark all three elements of the complex.

Questions and Comments on Black Bear Straddle Marking

As always, I welcome your thoughts in the comment section. I’m especially interested in observations of vegetation used for straddle marking in different regions. What tree and shrub species are bears using in your area? What kind of sign do you see on them? Have you noticed straddle saplings or bushes in association with mark trees and stomp trails?

Sources

Elbroch, M. and K. Rinehart. Behavior of North American Mammals. New York, NY: Houghton Mifflin Harcourt Publishing Company, 2011.