What clues or knowledge causes you to believe that the road is often an actual boundary vs. just a path of travel?
A number of factors. Both first hand personal observations and research. The coyote is one of, if not
the most studied animals in North America. For a number of reasons, but primarily the economic impact coyotes have on agricultural producers and the fact the the Fed. gov't largely took over control efforts after Richard Nixon banned the use of compound 1080 in 1972 (Ronald Regan later reintroduced it's use on an extremely limited basis). Suffice to say, there has been an ENORMOUS amount of research done on the coyote. I have a library of this research material. I even have some pure raw data from studies that haven't been completed or written yet - provided to me directly by people involved. It's well documented that coyotes territories are freqently bounded by roads when present. Some of the raw data I have is GPS tracking data from collared coyotes on the Idaho National Laboratory reservation (a close friend is involved - there is some really fascinating stuff in that GPS data!). That data clearly shows territorial coyotes on either side of certain roads rarely, if ever crossing those roads - obviously separating their home territories. And, it is something I have observed in behavior numerous times over the years.
Worth noting, also present in that GPS data is a particular alpha female who, during denning season, made daily trips across multiple other territories to a water source. She never used the same route twice in a row, but always went in as straight line/short a path as possible after entering those neighboring territories. Part of what makes this so interesting, is that there was another water source MUCH closer to her den, but apparently she didn't feel safe visiting it for whatever reason, so had to take great lengths making an 8-9 mile round trip to get water for her pups every day.
All that said... A territorial boundary is almost by definition also a regular travel route. The reverse is not true though. Many regular travel routes are NOT related to spacial distribution. The amount, distribution pattern and relative age of scat and tracks along a travel route are what I go by to decide if I think it's a boundary or not. When I see a lot of tracks both old and fresh, going both directions, a lot of scat, over a distance, with regular marking stations where there is fresh scat on top of old scat on top of really old scat, I think I'm looking at a boundary. Just a few tracks, mostly headed in one direction, with a few scats here and there, I think I'm probably looking at a garden variety travel route.
And all
that said... It is very important to note that in the fall of the year when numbers are highest, about 70% of a typical exploited (hunted etc.) coyote population is made up of non-territorial transient coyotes (note - there are very significant differences in the population dynamics and spacial distribution patterns of exploited vs. non-exploited coyote populations!). The only truly
territorial coyotes are the breeding alpha pair that control and defend a territory where they raise their young. They may have one or two betas from previous litters (usually female) they allow to live in a territory with them, but strange coyotes (either sex) aren't welcome. The degree of territoriality varies significantly with time of year, being greatest during the mating/breeding/whelping season when an alpha won't tolerate a strange coyote anywhere within it's territory. Mating season is about a month away now, coyotes are just starting to pair up now and starting to show more interest in other coyotes. A month ago, they might chase an intruder off from their core area, but probably wouldn't have bothered with coyotes on the fringes. Later when pups are in the ground, either parent won't tolerate another coyote anywhere near the den.
Secondly, this core area is a great way to put it.... How often have you found this core area to be the site of a den/birthing place? I believe that coyotes don't typically den up for long periods of time except during birthing.
You are right, coyotes do not use dens or live in holes or caves except during whelping season. Once pups are able to follow on hunts the den is abandoned. And even during denning season, the adults don't spend much time in the actual den. But during denning season, the area around the den
is the core area. And this is also when it can be easiest to locate that core area, if you know what you are doing and so inclined. Personally, I tend to just leave them alone altogether during denning season though. Disturbing the den area has a very high chance of causing the female to relocated her pups to a new location - I'd just as soon not put the stress on them at that time.
The rest of the year the core area tends to be anywhere within the territory offering good cover, near food resources. And this may or may not be near the denning area - often it is not. Food resources and their location may change a good bit through the year and the core area frequently changes to follow suit. But in many habitats, the core remains fairly constant. Just depends. Also very worth noting, is that unless the habitat or environment changes, once you have pinpointed a core area, it is likely to hold coyote
at that same time of year every year. Primo habitat will always fill back in with coyotes if the current alphas get killed or relocate - it goes back to that 70% transient population, some of them eventually become territorial alphas. I have a lot of places I don't have to do any scouting, I KNOW before I get there pretty much exactly where the coyotes are going to be hanging out.
And "just depends" is probably the single most important thing to really understand about coyotes. They are extraordinarily adaptable. There simply is no such thing as "always" or "never" with coyotes. They are very individualistic and will do what they need to in order to survive. You can never be too sure just what they'll do!
Fascinating critters, I think...
- DAA