Waterfowl Vulnerable When Molting
All North American birds replace their old, worn plumage with new feathers at least once a year, a process known as molting. Most birds have what is called a “sequential molt,” in which their flight feathers are lost one at a time (from each wing). This allows many birds to continue flying while molting. However, during their annual molt, waterfowl undergo a “simultaneous wing molt,” losing all of their primary wing feathers at once, preventing them from being able to fly for a month or more while their new primaries are growing in. During this period, they are extremely vulnerable, as this photograph testifies to. If you look closely at the remains of the Canada Goose’s wing on the right in the photograph (dark feathers), you’ll see that the new primaries have almost, but not quite, grown out of their sheaths, making them not yet functional. It’s apparent that this bird was unable to take flight during its molt in order to escape its predator.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Nursery Web Spiders Hatching
Nursery Web Spiders look a lot like Wolf Spiders, and the females of both families carry their respective egg sacs around with them until they hatch, but they do so in a different manner. Wolf Spiders grasp their egg sacs with the spinnerets (silk nozzles) located under their abdomen, whereas Nursery Web Spiders carry their egg sacs with their mouthparts. When hatching is imminent, the female Nursery Web Spider lashes leaves together with silk to form a protective shelter, or “nursery web,” for her egg sac and hatching offspring. The mother stands guard over her spiderlings, aggressively defending her young until they have had their first molt, after which both the spiderlings and the adult female disperse.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Spiny Witch Hazel Galls
Aphids are responsible for the formation of two different galls (abnormal plant growths caused by insects, fungi, bacteria and viruses) on Witch Hazel (Hamamelis virginiana). A cone-shaped gall forms on leaves and a second type of gall covered with spiny points grows from branches. The latter gall, referred to as the Spiny Witch Hazel Gall, provides many aphids (Hamamelistes spinosus) with both food and shelter while they are developing inside the gall. (Their two-year life cycle involves birches as their next host.) The pictured Spiny Witch Hazel Gall has split open enough to allow ants to discover and have access to the aphids. Once the ants enter the gall, they stroke the resident aphids with their antennae, stimulating the aphids into producing droplets of tasty “honeydew” from the tips of their abdomens, which the ants find irresistible. In return, the ants protect the aphids from predators.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
What a Snake’s Eyes Can Tell You
You can tell a lot about a snake just by looking at its eyes. Snakes that burrow underground usually have relatively small eyes compared to those that live above ground. The size of the eye and the shape of the pupil can often tell you if the snake is diurnal or nocturnal – typically diurnal snakes have comparatively small eyes with round pupils and nocturnal snakes have larger eyes with elliptical pupils. Both of these characteristics have to do with maximizing or minimizing the amount of light that enters the eyes. The larger the eye, the more light it can gather. The reason for the difference in pupil shape is that round pupils can close very tightly, to a pinpoint opening, shutting out bright sunlight very effectively. Elliptical pupils can open wider than round pupils, and consequently collect more light. (Photo is of a Common Gartersnake.)
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Blue-headed Vireos Begin Migration
Blue-headed Vireos (formerly called Solitary Vireos) are fairly distinctive birds, given their white “spectacles” or eye-rings. (Trying to make their heads blue seems to be a bit of a stretch, however.) They are the latest species of vireo to migrate, beginning about now and peaking at the end of September/beginning of October. After spending the winter in southern U.S. or Central America, they will head north, one to two weeks earlier than any other species of vireo.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Downy Rattlesnake Plantain Flowering
Downy Rattlesnake Plantain (Goodyera pubescens) is an evergreen plant (each leaf lives for about four years) belonging to the Orchid family. It has broad, rounded leaves (like plantain) that bear a design somewhat reminiscent of snake skin. For the latter reason, it was used by Native Americans to treat snakebites. Botanists think it must have been used on bites from non-poisonous snakes, for medicinally it does not cure a venomous snake bite. This is the most common species of rattlesnake-plantain in New England, and can be identified easily by the broad central stripe down the middle of each leaf. At this time of year its tall flower stalk is bedecked with tiny, delicate, white orchids, each the size of a baby finger nail, which are well worth examining through a hand lens.
Damselfly Reflections
Taken 10 minutes ago — sometimes no words are necessary. Have a glorious late summer weekend!
White Baneberry Fruits Mature
All parts of the White Baneberry plant (as well as Red Baneberry) are highly toxic. The fruit, called “doll’s eyes” for obvious reasons, is the most poisonous part, known to cause respiratory paralysis and cardiac arrest in humans. It does not have this effect on all mammals, however. White-tailed deer are known to browse on baneberry, and small rodents such as mice, squirrels and voles feed on the fruit. Geometrid moth larvae (“inchworms”) burrow into the fruits and their seeds while they (the fruits) are still green. A wide variety of birds, including American Robins and Yellow-bellied Sapsuckers, eat the fruit, helping disperse the plants when they excrete the brown, wedge-shaped seeds (insert). Ruffed Grouse also eat the fruits, but the seeds are destroyed in the digestive process. Oddly enough, Native Americans used the juice of Red Baneberry to gargle with as well as to poison their arrows.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
A Frog’s Tympanum
A frog’s tympanic membrane, or tympanum, is the circular patch of skin directly behind its eye that we commonly call its eardrum. It functions much like our eardrum does –the tympanum transmits sound waves to the middle and inner ear, allowing a frog to hear both in the air and below water. In addition, this membrane serves to keep water and debris from entering a frog’s ears. In some species of frogs, such as the Green Frog, American Bullfrog and Mink Frog, their gender can be determined by the size of their tympanum relative to their eye: the male’s tympanum is larger than its eye, the female’s is equal in size or smaller than its eye.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Butterflies Obtain Nutrients From Scat
Nectar from flowers and sugar from running sap (especially at Yellow-bellied Sapsucker holes) or overripe fruit provide most, but not all, of the nutrition that butterflies need. The males of some species will also drink at muddy puddles or damp earth for mineral salts and on scat or animal carcasses to get amino acids and other vital nutrients. This added nutrition is needed for them to generate spermatophores, the packets of sperm and nutrients that are transferred to the female during mating. (Photo is of a White Admiral, Limenitis arthemis arthemis, feeding on blackberry seed-laden Raccoon scat.)
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Woodland Jumping Mouse Succumbs
Usually animals that have been killed don’t last long enough for humans to discover them unless the human disturbs the predator right after it’s killed its prey. This may well have been the case when I came upon this Woodland Jumping Mouse. It is actually fairly unusual to set eyes on a jumping mouse, dead or alive, as they are quite secretive. This remarkable one-ounce rodent has long hind feet and a distinctly long tail, which makes up more than half of its total length of eight to ten inches. Using its hind limbs for propulsion and its tail for balance, the Woodland Jumping Mouse is able to make large leaps of up to eight feet or more to escape danger. (More often it walks around on all fours, or uses short hops for greater speed.) Another survival strategy that jumping mice use is to remain motionless for up to several hours, relying on their coloration and cover for protection. Apparently neither adaptive behavior was effective enough to spare this mouse’s life.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Sundews Capture Their Meals
Sundews (Drosera spp.) are carnivorous plants often found in acidic bogs, fens and cedar swamps. They have numerous small leaves arranged in a circular, or rosette, pattern and they are covered with reddish, glandular hairs, or tentacles, that exude a sticky secretion at their tips. Insects, attracted to the glistening sticky droplets which resemble dew, land on a leaf and become stuck. The movement of the struggling insect triggers cell growth in the glandular hairs and they begin folding over the insect within 60 seconds. An anesthetic is released by the plant’s hairs, causing the insect to become motionless. Digestive enzymes are then secreted which liquefy the insect’s internal organs so that they can then be absorbed by the plant’s hairs. Although insect prey is not vital to sundews, the nitrogen the plants receive from the insects enables them to thrive in environments where nitrogen is in short supply. The damselfly pictured has been captured by a Round-leaved Sundew’s glandular hairs which have rendered it motionless and have started to grow and fold over the tip of the damselfly’s abdomen and its wings.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Clean Antennae Necessary for Sensory Perception
Insect antennae are among the most sensitive and selective chemical-sensing organs in the animal kingdom. They detect information crucial to an insect’s survival, including odors, sounds, humidity, changes in water vapor concentration and air speed. Antennae are capable of these feats because of the sensory receptors covering them which bind to free-floating molecules. Experiments with cockroaches, ants and flies confirm that insects engage in antennal grooming — removing foreign materials from the surface of their antennae with their mandibles — primarily to maintain acute olfactory reception. Pheromones, chemical signals that are vital to insect communication, are used to convey alarm, attract a mate, mark territory and lay out trails, among other things, and clean antennae enhance these messages. (Photo is of a Sword-bearing Conehead Katydid cleaning its antenna.)
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Wild Turkey Taking a Dust Bath
A friend, Jim Block, who is a professional photographer in the Upper Valley (http://www.jimblockphoto.com/) , sent me his delightful photograph of a Wild Turkey actually taking a dust bath, and I am thrilled to be able to share it with you.
Ruffed Grouse Dust Bath
During the summer, some species of birds “bathe” in substances other than water. Often dust or sandy soil is the material of choice, but rotten wood and weed particles are also used. Ornithologists believe that this behavior is a means of ridding the bird of parasites such as lice and mites. After sitting down on the ground and scraping the sand all around it into a pile, the bird kicks its feet and beats its wings in the pile, getting the sand in amongst all of its feathers and next to its skin before standing up and shaking it all out. Usually some feathers come out as well, and if you’re familiar with different birds’ feathers, it’s often possible to determine what species of bird has taken a bath. The pictured dust bath is sprinkled with Ruffed Grouse feathers and is located in the midst of many ant hills, which is typical of this species. Another favorite location where Ruffed Grouse often choose to bathe is the entrance of an old mammal burrow.
Correction: Paper Wasps Have Chewing Mouthparts
I misspoke in today’s blog. Of course paper wasps have mandibles adapted for chewing — how else would they successfully turn wood fiber into paper? The reason their diet is liquid is purely because the food won’t fit through their narrow “waist.” My apologies, and thanks to the alert readers who caught this misstatement.
The Give and Take of Food in a Paper Wasp Nest
Like all adult wasps, bees, and ants, adult paper wasps are limited to liquid diets – they have no chewing mouthparts, and the passageway between their head and abdomen, where food is digested, is so narrow that pieces of food wouldn’t fit through it. Wasp larvae (the white grub-like organisms in the upper third of the pictured wasp nest cells) are able to eat a wider range of food, due to mouthparts and their body structure. Adult paper wasps capture and feed caterpillars and other insects to their larvae. The larvae then digest their food and produce saliva rich in nutrients. The adult wasp proceeds to scrape her abdomen across the nest, producing a vibration that signals to the larvae to release some of their carbohydrate-rich saliva which the adult then drinks. (Cells covered with white paper nest material contain wasp pupae.)
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Pinesap Flowering
Pinesap (Monotropa hypopitys), like its close relative Indian Pipe, is a flowering plant which has no chlorophyll, and therefore is not green. Often found under pine trees, Pinesap’s color ranges from yellow to pink, red, orange or brown or some combination of these. Because it has no chlorophyll, it also cannot obtain energy from sunlight. (Therefore, it can thrive in very shady areas.) Pinesap gets its nutrients from other plants’ roots, but not directly. Mycorrhizal fungi are the middlemen, connecting the roots of Pinesap with those of its host plant, allowing nutrients to be passed along from the host plant to the Pinesap. This fungi-dependent relationship is called mycotropism. Similar to Indian Pipe, during fruiting Pinesap’s previously-nodding stem straightens, becoming erect.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Harvestmen
Harvestmen (daddy longlegs) and spiders are closely related and share many characteristics, but they also have significant differences. One such difference is that Harvestmen do not possess venom glands, nor the digestive enzymes capable of breaking down the insides of prey into a liquid. (Some species of Harvestmen are omnivores, eating both plant and animal matter, others are scavengers.) Unlike fellow arachnids (spiders, ticks, scorpions and mites) that drink their food, Harvestmen ingest small particles, breaking them down with their chelicerae, or mouthparts, which resemble miniature, toothed lobster claws. In this photograph, the Harvestman is holding a deer fly with its pedipalps, appendages used to grasp food as well as their mates. Its chelicerae are too small to discern, but they do the job — in the space of about ten minutes, this Harvestman consumed an entire deer fly, bit by bit.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Mutual Grooming
Beavers spend a great deal of time tending to their coats, grooming several hours a day throughout the year. Grooming consists of removing sticks and debris that have become embedded in their fur, as well as applying oil from their anal glands to waterproof their fur. Waterproofing is essential, as it prevents the cold water from penetrating their fur. Typically they sit with their tail between their hind legs, stretched out in front of them, with their anal glands exposed. Beavers procure the oil with their front feet, and use all four feet to comb it through their fur. The two inside nails on both of their hind feet are split, increasing the efficiency with which they can apply the oil. Sometimes two beavers will groom each other, engaging in “mutual grooming.” The male and his offspring begin to groom each other when the kits are only two weeks old, yearlings and kits from three weeks on, and the mother and kits when the young are four weeks old. Mutual grooming continues as long as they are a family unit. ( I am humbled by the response to yesterday’s post. You will each be hearing from me soon. )
What Other Naturally Curious People Are Saying