What do Coyotes eat in January? Once again, our little urban fragment has provided some surprising insights. It began with a scat (animal poop), that reliable source of information on mammal diets. And there wasn’t just one, but in true coyote style, a whole series of them, placed at strategic intervals on the trail. The first was just below the front parking area, less than 200 feet from the Louisville Nature Center front door. Though there’s nothing unique about urban coyotes anymore, the strikingly uniform contents of these scats tell an interesting story.
Dear reader, I have until now refrained from posting a lot of scat pics – it’s not everyone’s thing. But having observed this particular coyote dietary quirk for a number of years, I must finally share what I’ve learned. The pic below is from the winter of 2013 – it was the first time I’d noticed such large white seeds in a coyote’s scat. I was so impressed by the size of it that I laid down my pen to indicate scale.
Of course it’s my duty as a naturalist to point out these leavings to people on the trail. Asked to guess at the seed’s identity, several hikers ventured that they might be pistachios. But thanks to a vivid childhood memory, I knew exactly what they were. Who knows why certain events from our distant past remain so vivid, while millions of others fade away? In this case my memory was bolstered by a particularly nauseating odor, like a blend of dog poop and vomit, emanating from a slippery layer of pink-brown fruits rotting on the sidewalk. For several weeks in winter, my mother and I had to pick our way through this mess twice every day, on the walk to and from my nursery school.
Guessed it yet? The seeds and their fruit-like seed covering are the products of that widely planted city tree, Ginkgo biloba. Though naturally occurring now only on small isolated sites in southwest China, 56 million years ago several species of ginkgo were widespread across the northern hemisphere. Scientists are intrigued by the fact that such a hardy, pest free and long-lived tree has been reduced to such a tiny range in the wild. Ancient climate change was a big factor, as advancing glaciers ground over much of its ancient territory.
If you’ve encountered a female ginkgo tree that’s dropped its seeds, you know how prolific they are. So why couldn’t Ginkgo biloba repopulate its former range in China when the climate improved? Not only did the relict populations not expand, but the tree might have gone extinct had the Chinese not revered it, and planted it around temples and in gardens. Recent research has focused on finding actual wild populations of ginkgo in China: https://harvardmagazine.com/2011/11/the-living-dinosaur
But wait a minute – what does all this have to do with the coyote? This hugely successful mesopredator that’s practically an omnivore has had no problem expanding its own range, even in the face of active human persecution. Its ability to eat something as seemingly revolting as rotten ginkgo fruit has likely been a big part of that success.
But it’s also likely coyotes don’t just tolerate the flavor, they actually savor it. “The smell isn’t offensive to all animals”, as Teris A. van Beek notes in his book Ginkgo Biloba: “… reports of carnivores consuming whole Ginkgo seeds and defecating intact nuts, raises the possibility that the foul smelling [seeds] may be attracting these animals by mimicking the smell of rotting flesh …. ”
And another of the ginkgo’s problems is just this – as a species it outlived the animals that were adapted to eat and disperse its seeds. (In fact, researchers think certain dinosaurs may have been among them!) But most surely there were also mammals, perhaps little mesopredators with broad palates, who liked the ginkgo seed’s fleshy outer coating because it tasted like rotten meat. These days, the carrion eating Chinese leopard cat and the Masked palm civet fill the dispersal role for ginkgos in China. Yet the trees don’t pop up easily from seed, relying more often on suckers produced at the base of old trees. Seed production doesn’t even start until female trees are 30 to 40 years old.
But I happen to know where the coyotes of this forest are finding their ginkgo “fruits” (more ancient than a true fruit, the outer coating is called a sarcotesta). Less than half a mile from this little fragment is the Louisville Zoo, with many planted ginkgos bordering the large parking lot. Apparently the fruits are abundant enough to be a primary coyote food at this season, since all the scats I’ve seen lately contain the seeds.
And why am I seeing so many coyote scats? It happens every year as mating season approaches. Coyote hormones ramp up, and defending territory becomes more important with pups on the way. Scats placed at regular intervals on the trail send a message to interlopers that it’s part of a pair’s territory.
I’m really curious to know how many Ginkgo trees will result from these scats. Having already spotted a few seedlings here and there in the forest, the mystery of how this came to be is finally solved. Novel ecosystems are becoming more the norm, particularly near human environments, and I for one would welcome Ginkgo trees to this forest. There seems to be little chance of them being another obnoxious invasive plant. Besides, to take the long view, they would just be returning after a seven million year absence. Quoting Corinne Kennedy at the Seattle Japanese Garden, “This prehistoric tree has left its imprint on our state at Vantage, in eastern Washington. Rare specimens of petrified ginkgo trees were discovered in 1932, and are displayed there in both indoor and outdoor exhibits. Ginkgo Petrified Forest, now a registered National Natural Landmark, is recognized as one of North America’s most diverse fossil forests.”
Maybe North America’s very own wild dog will help the Ginkgo reclaim a tiny bit of its ancient haunts…