Congratulations to Mary Pratt, the first reader to correctly identify the impression a Red Squirrel left in the snow. Red Squirrels are fiercely territorial, and will chase each other furiously in order to defend their territory and their food caches. The photographer, Susan Bull Riley, witnessed this behavior as she watched two Red Squirrels racing after each other in the crown of a maple tree. Suddenly one of them fell to the ground, where sleet and wet snow cushioned its fall and recorded the belly flop landing. No time was lost in the resumption of the chase!
There were many “Flying Squirrel” responses, which makes great sense as they are approximately the same size as a Red Squirrel (just an inch or two shorter in length) and are gliding from tree to tree or from tree to the ground. My assumption is that a Flying Squirrel’s landing impression might show some of the patagium, or membrane, that stretches from a squirrel’s wrists to its ankles, due to the fact that it is extended as the squirrel glides. (Any firsthand Flying Squirrel landing-in-snow impression observations welcome.) Thanks to all who submitted an answer to this Mystery Photo. Many were very amusing!
The pollinated and fertilized white flowers of Red Elderberry (Sambucus racemosa) have recently developed into the red fruit for which this plant is named. Many people are familiar with its relative, Common Elderberry (S. canadensis), which produces dark purple fruit that is used to make jams, jellies, pies and elderberry wine. While Red Elderberry fruit can be used to make all of these, its raw berries are toxic. Red Elderberry’s popularity is greatest with pollinators, birds and four-footed mammals.
The cyanide-producing toxins in its flowers, (raw) fruit, stems, bark, leaves and roots do not seem to discourage wildlife’s attraction to Red Elderberry. The odor of its flowers, its nectar, and its highly nutritious pollen attract many ants, bees, wasps and flies. At least 50 species of songbirds eat the bright red fruits, including red-eyed vireos, ruffed grouse, song sparrows, gray catbirds, brown thrashers, and thrushes. Squirrels, mice, raccoons, and black bears also eat the fruit. Porcupines, mice and snowshoe hares eat the buds and bark in winter. The foliage is usually avoided by herbivores, although white-tailed deer and moose browse on it occasionally.
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.
Naturally Curious is supported by donations. If you choose to contribute, you may go to https://naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
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.)