Both carnivores and herbivores cache, or store, food for later consumption. Black-capped Chickadees tuck seeds into bark crevices. Bobcats may cover their kills with leaves, grass, snow and even hair from their prey’s carcass. Grey Squirrels bury their nuts individually, while Red Squirrels often hide green cones in a pile of cone scales (middens) that accumulate at the site where the squirrels have previously eaten seeds, keeping the young cones moist so that they will retain the seeds within them.
Red Squirrels sometimes go one step further than most animals that cache food — they frequently preserve their food by drying it before storing it. You’ll recognize this when you see it – an apple or mushroom stuck in the crotch of two branches. Sometimes the dried food is collected and cached near their winter quarters, but often it remains lodged in tree branches until eaten. The pictured mushroom, which was hung out to dry, was reduced almost to mush by the torrential rains we’ve had lately. Eventually it will dry out and remain edible into the winter.
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There is no denying that this year’s cone crop is a bumper crop. Just look up at the tops of conifers or down on the ground beneath them and you will see a plethora of cones. This may be the best overall cone crop in five years, and the best spruce cone crop in more than a decade in the Northeast.
Conifers produce cone crops erratically; some years are bountiful, and others are minimal. Part of the reason for this may be that in a year with a bumper crop (mast), predators can’t possibly consume all of the seeds produced, and thus the opportunity for conifers to have their seeds dispersed and germinate is markedly improved. In addition, erratic production may have partially evolved as a strategy to combat insect damage. An unpredictable cycle makes it much more difficult for insects to become a pest.
As to why some years are so productive, weather conditions are certainly influential. Often times people look at the most recent summer’s weather as a forecaster of the coming fall’s hard mast crop (nuts, cones). Although most conifer cones develop in six to eight months, not all do. Most conifers in the family Pinaceae take this amount of time, but cedar cones take a year to mature, and most spruce and pine cones mature in two to three years. Thus, the cone crop we are having this year may in part be a reflection on this year’s weather, but, depending on the species, it could have been influenced by last summer’s weather conditions or even the summer before last.
Regardless of why some years are lean and some plentiful, when we have a bumper cone crop such as this fall’s, the impact is felt far and wide by wildlife. Red squirrels, voles, waxwings, chickadees, nuthatches, grosbeaks, crossbills and siskins reap the benefits. Their resulting reproduction rates soar, and the ripple effect continues to be felt throughout the food chain.
In some circumstances, the ramifications of a bumper crop are evident before the crop even matures. It appears that red squirrels can predict when there is going to be a huge spruce cone year and produce a second litter to take advantage of the large food supply when it matures. It may be that when the squirrels eat the buds of a spruce tree the summer before cones develop (spruce cones take two years to mature — cone buds are produced in the first year and cones develop and mature in the second year) they can discern which buds are going to produce cones and which are destined to produce branches. An abundance of cone buds may be the clue that triggers their extended reproductive activity. (Photo: Red Spruce cones)
Such creative and informed answers to yesterday’s Mystery Photo, and many that were right on the mark! To set the stage, several 2” to 4”-deep holes riddled the ground under a stand of Eastern Hemlocks. Something had obviously been digging for something, but who and what? Close inspection of the holes revealed two things. The animal that had dug the holes had run into some thick hemlock roots, and with a clean 45° angle cut, had snipped them in order to have access to the soil beneath them. Secondly, some of the holes had pea- to marble-size, spherical tan objects that resembled puffballs both lying at the bottom and wedged into the sides of the holes.
Only because I had read Paul Rezendes’s Tracking & the Art of Seeing years ago did I recognize these holes and spherical structures within as the work of an animal looking for false truffles (a genus of fungi) to eat. By putting the various clues together – a hemlock stand, 3” to 6”-wide holes, clean incisor-snipped roots, and a few remnant truffles – the mystery at to what was being sought was solved.
As to who had done the digging, white-tailed deer, squirrels and porcupines all fancy false truffles. Both porcupines and squirrels have incisors that would make a clean cut through the roots. If porcupines had been digging here, there would likely be scat and/or quills lying about, which there were not. Thus, most likely it was a squirrel that had smelled, unearthed and eaten the false truffles.
Rezendes found that the truffles he discovered had dried spores inside them, and assumed that this made them undesirable to the animal that unearthed them and therefore they were not eaten. The spores of the truffles I found were not dried out, so I have no idea why they weren’t eaten, but I’m very glad they weren’t, as their presence allowed me to solve this mystery and see this phenomenon which I’ve been looking for for decades.
It may interest some to know that false truffles and Eastern Hemlocks have a symbiotic relationship. The fungi are attached to hemlock roots, so the minerals and water they absorb are available to the hemlocks. The hemlocks provide the fungi with sugars that they (hemlocks) produce through photosynthesis. Squirrels (and porcupines and white-tailed deer) and eastern hemlocks have a similar mutually beneficial relationship in that hemlocks provide the truffle-eaters with food, and the squirrels, porcupines and white-tailed deer disperse the spores of the truffles they’ve eaten. (Caution: Do not eat false truffles – they are considered toxic to humans.)
An obvious sign of Red Squirrels, especially noticeable if snow is still on the ground, is the remains of their feeding activity. In winter and early spring, when snow may make finding food on the forest floor difficult, Red Squirrels show a preference for conifer buds. Rather than scurrying up a tree and eating the buds, they first prune the branch tip from the tree, eat the buds and then discard the tip onto the ground. Spruces, hemlocks and firs are some of their main sources of buds. If the squirrel feeds for a significant amount of time, the forest floor under the conifer it is feeding in can become littered with branch tips. Nip twigs scattered on the ground beneath hemlocks are also a sign of Porcupine feeding, but the tips they drop are much longer than the 2- to 4-inch tips discarded by Red Squirrels. (Photo: Balsam Fir branch tips; Inset – lateral buds of Balsam Fir branch tip eaten by Red Squirrel)
Red Squirrels have very efficient kidneys, so most of their water requirements are supplied in fruit, buds, fungi and other food that they eat. They are said to rarely drink free-standing water or eat snow, even when it is available. However, both the scat and the chewing marks in the snow surrounding the scat in yesterday’s Mystery Photo were made by a Red Squirrel.
If you live near a stand of Red Oak trees, your chances of seeing a Porcupine this fall are greater than average. At the end of August, when the apple supply has dwindled, Porcupines move on to important new food sources – acorns and beechnuts. While American Beech trees in central Vermont have not produced a bumper crop of beechnuts this year, Red Oaks are experiencing a very heavy mast crop. These acorns provide sustenance for many animals – Black Bears, Red and Gray Squirrels, Eastern Chipmunks and other small rodents, White-tailed Deer and Wild Turkeys, to name a few.
Porcupines are typically one of the first acorn consumers, as they are able to climb oaks and eat the acorns before they drop and are accessible to many of the other animals that are limited to foraging on the ground. If you see the tips of branches nipped off with acorn caps (but no acorns) still attached lying under an oak tree, it’s likely that a Porcupine has been dining in the tree and discarding branches after scooping out and eating the acorns.If the tree is large, the Porcupine may reside in the canopy for several days. (Thanks to Emma for photo op.)