This Woodchuck is doing what Woodchucks do this time of year – eating fast and furiously, and putting on fat equaling about a third of their weight (granted, an apple has only a tiny fraction of a gram of fat, but every bit helps). Accumulation of fat is essential if they are to survive months of hibernation. It’s not known what stimulates this increase in appetite, but most likely photoperiod (length of day) plays a part.
Soon these rodents will seek shelter in their winter burrows, where their heart rate is reduced from 100 beats per minute to 15 and their temperature drops from 96 F. degrees to 47 F. degrees. During hibernation, they lose roughly 20% to 47% of their body weight. Those Woodchucks not able to accumulate sufficient fat reserves may not survive the three or four months of hibernation that take place in the Northeast. (Photo by Erin Donahue)
Thanks to Pat Nelson’s sharp eyes, I realized I had mislabeled the bug in yesterday’s blog. It was an Ambush Bug, not an Assassin Bug. While both are predators and in the same family (Reduviidae), Assassin Bugs are usually dark colored and have long, narrow heads compared to Ambush Bugs. Ambush Bugs are usually quite stout and typically have bright colors such as yellow, red or orange. They also have thickened front pincer-like legs with teeth-like structures that hold the prey while it is being consumed. Although small (usually less than ½ inch), an Ambush Bug’s prey may be as large as a bumblebee, wasp or butterfly.
At this time of year when most flowers have gone by, Canada Goldenrod (Solidago canadensis) is a primary source of pollen and nectar for bees, beetles, butterflies, flies and many other insects. Consequently, goldenrod flowers are a popular place for insect-eating predators to linger.
Recently I spied an Ambush Bug that had captured a fly and had its proboscis inserted into it, contentedly sucking away the fly’s innards while I photographed it. Unbeknownst to me or the Ambush Bug, another predator, a Bald-faced Hornet, had spied the bug with its prey. Although adult hornets consume liquids, usually sugars like the juice of fruits or nectar, their larvae are raised on a diet of insects, so adults are constantly looking for prey. Suddenly, out of nowhere, the hornet flew in, tussled with the Ambush Bug and flew off with the fly in its mandibles, landing on a nearby branch with the object of its thievery.
White-tailed Deer are ruminants. The process of rumination (gathering a lot of food at once and then digesting it later by chewing one’s cud) is fully developed by the age of about two months, or roughly by the end of July. Fawns can be completely weaned and survive without milk at this time, but does often don’t wean them until 3 to 4 months. It’s not unheard of to see a fawn born in May or June still nursing, or attempting to, in October. It stands to reason that it’s hard to give up this valuable source of nutrition, for deer milk is richer in fat, protein and energy than cow’s milk. (Photo taken by Erin Donahue on September 2nd.)
With birds, molting refers to the loss of old, worn feathers and the growth of new ones. A molt can involve all of the bird’s feathers (complete molt), or just some of them (such as wing or tail feathers – a partial molt). Most birds have a complete molt once a year (chickadees, hummingbirds, owls, etc.), or one complete molt and a partial molt before the breeding season (buntings, tanagers, warblers, etc.), or two complete molts per year (Bobolinks, Marsh Wrens).
Complete molts often occur in late summer and early fall, after the breeding season is over. When you think about it, the timing of this “prebasic” or “postnuptial” molt makes a great deal of sense. Growing new feathers takes an inordinate amount of energy; food is plentiful now, the demands of breeding are over and for many birds, migration isn’t quite under way. It is the perfect time to look for molted feathers on the ground. (Photo: molted Red-tailed Hawk tail feather)
Congratulations to Rinky Black, who was the first person to accurately identify the Mystery Photo as a Monkey Slug!
Some of our dullest-looking moths started their lives out as colorful, bizarrely-shaped caterpillars. In particular, there is a family of caterpillars (Limacodidae) known as “slug caterpillars” which come in all kinds of unusual forms and colors. They can be naked or densely hairy, and they usually have stinging hairs. The Hag Moth (Phobetron pithecium), found throughout eastern North America, is one such moth. Whereas the adult moth is a dull brown, the caterpillar stage is anything but dull. Known as the Monkey Slug, the caterpillar stage of this moth has three pairs of long “arms” and three additional pairs about half as long. Its appearance has been likened to a tarantula (many of our insectivorous birds winter in the tropics, where there are tarantulas (which the birds avoid), and therein lies the reason for the caterpillar to look like one). Although most photographs make Monkey Slugs look large, they measure only about an inch in diameter. Adult moths bear a slight resemblance to bees and wasps.
What is eye-catching about Monkey Slugs (as well as other slug caterpillars), besides their bizarre appearance, is the way in which they move. Monkey Slugs glide – instead of the typical prolegs (located behind six true legs) they have suckers (see bottom right inset). This gliding is responsible for its being classified as a “slug” caterpillar, for it moves much like a slug does. The Monkey Slug is one of the slug caterpillars that does not sting, so you can handle it safely should you find one. (Thanks to Kathy and Geoff Marchant for photo op.)
Who’s peeking over this leaf??? Go to the Naturally Curious blog and scroll down to “Comments” to enter your response. Imaginative answers welcome. This mystery will be solved in Wednesday’s 9/4/19 post.