Often when researching a post, I stumble down a rabbit hole on another topic. Fluffy led me to hair pigmentation and forehead glands. And a comment from a reader regarding scrape activity opened the door to share my obscure findings on the topic.
Deer talk to each other via their nose. Specialized skin glands include nasal, forehead, preorbital, tarsal, metatarsal, interdigital, and preputial. The forehead, tarsal, and interdigital glands produce socially significant scents. The role of the other glands remains a bit of a mystery, at least to us.
Rubs and scrapes are hallmark signposts for deer. They get the most attention during the breeding season and the conversation inevitably revolves around bucks. Sigh…
We’ve written some fun posts about rubs, scrapes, and licking branches over the years. All deer have forehead, tarsal, and interdigital glands and all deer use them to communicate. Forehead glands are most active during the breeding season in both sexes. Pigmentation of the hair on the forehead where the gland is located is associated with testosterone levels and might serve as a visual cue of sexual status.
And social grooming among males is concentrated on the forehead during the breeding season as well. Suffice it to say, deer learn a lot about each other from their foreheads.
Forehead glands are also key in the creation of rubs. Rubs are almost exclusively associated with males, but did you know that dominant females have been observed rubbing their forehead on an antler rub? This was observed over 30 years ago before the advent of trail cameras. I’d bet its more common than we realize.
Scrapes get a lot of attention in the fall…just like antlers. But again, these message boards are not just for the boys. Males and females visit scrapes and they are used year-round.
However, because most people only pay attention to scrapes in the fall, half the population that visits them is often overlooked. There is seasonal variation in scrape visitation. Males visit more in the fall and females visit more in the winter and spring.
And while scrape activity is associated with the rut, peak scrape activity and peak breeding activity are not the same. Peak scrape activity occurs 2-3 weeks before peak breeding. For Pennsylvania, that’s late October. After that, don’t expect to see many trail cam pics of deer at a scrape.
Because there is a little less conversation and a lot more action.
-Jeannine Fleegle
Wildlife Biologist
PA Game Commission
