Squirrel Corn’s Pollination & Seed Dispersal Strategies
Finely dissected leaves, white heart-shaped flowers and small, yellow clustered underground bulblets that look like corn kernels – these are the characteristics that identify the early ephemeral Squirrel Corn (Dicentra canadensis).
Sometimes a plant’s strategies for accomplishing pollination as well as seed dispersal can boggle the mind. Squirrel Corn’s fragrance, nectar and pollen attract queen bumblebees who are out gathering food for the first of their larvae. It is a win-win arrangement: young bumblebees are nourished and pollination is accomplished.
Later in the season Squirrel Corn (and many other ephemerals) achieves seed dispersal by once again attracting insects. Each seed has a tiny packet attached to it (elaiosome) which contains fats and proteins, a highly prized source of food for ant larvae. Ants collect the seeds and bring them underground where they extract the elaiosomes and feed them to their young. They then deposit the seeds into their waste pile, a perfect site for germination as it contains fertilizer in the form of ant frass. This type of mutually beneficial seed dispersal is known as myrmecochory.
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.
Ant Queens & Males Swarming
Ant colonies consist of one or more queens, female workers and males. In most species, only the males and queens have wings. Periodically the winged ants emerge from the colony in large swarms in order to mate. Swarming behavior is usually synchronized with other nearby colonies, so large numbers (hundreds or thousands) of winged ants suddenly appear. After mating, the males die and the queens chew their wings off and use the remaining wing muscles as a source of nutrients during the early stages of establishing a colony.
(Photo: A swarm of ants gathering as they emerge from their ground nest. The pictured (inset) ant has removed three of its four wings and is in the process of removing the fourth wing. Thanks to Alice Trageser for photo opportunity.)
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. (NB: The “Donate” button on the Naturally Curious blog is currently not working. If you would like to donate to this blog, you may send a check made out to Mary Holland to me at 505 Wake Robin Drive, Shelburne, VT 05482.)
Black Bears Foraging
This is the time of year when Black Bears are looking for every available source of food in order to bulk up before entering hibernation. During this period of gorging (hyperphagia) Black Bears consume large quantities of fruits, berries, nuts, grasses, roots and insects.
In particular, they favor the brood (larvae and pupae) of ants, due to their relatively high content of fat and protein. Black Bears find brood by detecting the pheromones and other chemicals such as formic acid that ants use for communication and defense. Research has confirmed that Black Bears will dig up as many as 200 ant colonies a day, flipping rocks, moss and leaf litter over and tearing apart logs, stumps and snags (such as the one pictured), using their canine teeth and claws to gain access to the ants. Once they have torn apart the stump or snag, they use their long, sticky tongues to gather brood. Anthills are avoided except for when Black Bears are extremely hungry, due to the fact that bears prefer not to get a lot of soil or sand mixed in with the brood they’re eating. (Thanks to Virginia Barlow for photo op.)
Ants “Milking” Treehoppers
Certain species of treehoppers (a type of true bug) release a sugary liquid called honeydew, made mostly from excess plant sap that they consume. Ants farm these treehoppers, much as they farm aphids, for their honeydew. An ant grasps a treehopper and strokes it with its antennae, causing a droplet of honeydew to appear at the tip of the treehopper’s abdomen, which the ant then consumes. Both insects benefit from this mutualistic arrangement. The ants get honeydew, and in return, provide protection for the treehoppers from predators. The plant indirectly benefits from the ants, as well, for if the ants were not there, the treehoppers’ honeydew would fall onto the plant, causing mold growth on fruits and leaves. Eggs, nymphs and adult treehoppers can usually all be found in one location. (Photo insert: a treehopper nymph on left, adult treehopper on right) To see a video of ants farming a type of treehopper called a thornbug, go to https://www.youtube.com/watch?v=HoeJn3Imss4.
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.
Black Bears Seeking Protein
Although insects and animal matter make up less than 10% of the annual black bear diet, they are a crucial part of it. Black bears get most of their animal protein from ant brood, hornet larvae, tent caterpillars, march fly larvae, grubs (especially June beetle grubs), and snow fleas. Among the most preferred sources are bee and hornet larvae. Berries and other fruit don’t have a great amount of protein, but they do have some (blackberries = 2 grams of protein per cup). If the summer berry crops fail, insect brood is especially important, especially at this time of year, when bears are seeking protein, fats and carbohydrates, putting on as much as 30 pounds per week to sustain themselves through the coming months of hibernation.
When tearing apart a beehive, yellow jacket nest or bald-faced hornet nest (see photo), bears do get stung, particularly on their ears and faces (their fur is fairly impenetrable). Apparently the reward is worth the aggravation. After filling themselves with brood (and in some cases, honey) black bears shake vigorously in order to rid themselves of any insects that are caught in their fur.(Thanks to Alfred Balch for photo op.)
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.
Queen Ants Mating & Removing Wings
Ants are social insects and live in colonies consisting of one or more queens, female workers and males. In most species the non-sexually mature female ants are wingless; only the males and the queen(s) possess wings. Periodically, often 3-5 days after a heavy rain, the winged ants emerge from the colony in large swarms in order to mate and create more colonies. Swarming behavior is usually synchronized with other nearby colonies, so large numbers (hundreds or thousands) of winged ants suddenly appear. After mating, the males die and the queens shed their wings and use the remaining wing muscles as a source of nutrients during the early stages of colony development. The shedding of wings is not a passive activity. The pictured ant is in the process of removing her fourth and final wing. She held each wing down with one leg while pulling it out with another. She then crawled off, leaving a pile of wings behind.
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.
Myrmecochory: Seed Dispersal by Ants
As a dispersal mechanism, some plants have fatty structures called elaiosomes attached to their seeds’ coats which are very appealing to ants. After collecting a seed and carrying it back to its underground nest, the ant eats the elaiosome (or feeds it to ant larvae) and discards the intact seed in an area where waste and dead ant bodies are stored. Germination is highly likely in such an ideal environment, making myrmecochory a win-win situation. Trillium, bloodroot and violets are some of the thousands of plants that have elaiosomes attached to their seeds.
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.
Carpenter Ants Huddling
Insects that live in northern New England have different strategies for surviving the winter. Carpenter ants live in the center of both dead and living trees, in galleries that they have chewed throughout their nest. Although wood is a good insulator, it still freezes during the winter. The ants tend to cluster together and enter a state of slowed metabolism called diapause. In addition, carpenter ants also produce glycerol, a compound which acts as antifreeze preventing destructive ice crystals from forming in their bodies.
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.
Some Spiderlings Hatch in the Fall
Have you recently noticed a roundish, flat, papery, 1/4-inch diameter, metallic-looking structure adhering to the top of a rock? If it has tiny bumps in the center, chances are good that it’s a spider egg sac, most likely that of an antmimic spider (spiders resembling ants that often prey on ants), specifically one in the genus Castianeira. One would assume that the contents of the sac that were causing the bumps were eggs that were going to overwinter and hatch once warm weather arrives. This is true for a majority of spider egg sacs, but some, including those of Black-and-Yellow Argiopes and antmimic spiders, hold spiderlings that have already hatched and will remain in the sac throughout the winter. As long as the temperature stays cold, the spiderlings will be safe and secure until spring. If we have periods of cold interspersed with periods of warmer temperatures, or an exceptionally warm winter, the spiderlings will become active when the thermometer rises, and, not having any insects to eat, will be forced to devour each other.
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.
Green Lacewing Larvae Use Corpses as Camouflage
Green lacewings are aptly named for the prominent venation of the adults’ wings. Some species in this insect family even have “ears” in the larger veins that allow them to detect the ultrasonic sounds made by hunting bats. Lacewing larvae and adults are both predators of soft-bodied insects such as aphids. Larval lacewings have long, hollow mandibles with which they puncture prey and suck out the liquefied contents, leaving the woolly husks. Some species of lacewing larvae have hairy backs, and camouflage themselves when in the presence of woolly aphids by sticking aphid husks on these hairs. These “trash packets” camouflage the lacewing larvae from predators, including ants that would otherwise attack the larvae if they recognized that they were lacewings and not woolly aphids.
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.
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.
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.
Hairy Woodpeckers Raising Young
The chipping of hungry Hairy Woodpecker nestlings can easily be detected by human ears, even though it comes from deep within a tree cavity. One is reminded of how beneficial this species is when observing the steady delivery of food by these woodpeckers to their young. More than 75% of an adult Hairy Woodpecker’s diet consists of injurious insects, while the amount of useful insects and cultivated fruits that they destroy is insignificant. Beetle larvae (mostly wood-boring) make up 30% of the insects that are consumed, with ants ranking second, at 17%. Caterpillars, such as those pictured, comprise about 10% of an adult Hairy Woodpecker’s diet, but given this parent’s beakful, one wonders if the percentage is greater for nestlings.
Early Saxifrage Flowering
Early saxifrage (Micranthes virginiensis) is well named – it flowers early in the spring, and is often found growing in or on rocks. (The name saxifrage derives from the Latin words “saxum” meaning rock and “frangere,” to break. When the small seeds of saxifrage lodge in rock crevices and germinate, the plant looks as though it split the rock.) If you look closely you’ll see that early saxifrage’s flower stalk has many hairs – they are glandular and their stickiness is thought to deter ants from taking nectar from the flowers, so that it can attract more efficient pollinators.
Mourning Cloak Butterflies Emerging from Hibernation
A male mourning cloak butterfly basks in the sun on an eastern hemlock while its dark wings act as solar collectors, warming the hemolymph (a circulatory fluid analogous to blood) in the wing veins and returning the warmed fluid to the butterfly’s body until it reaches a temperature sufficient for flight. This butterfly has just emerged from hibernating in a sheltered spot, such as behind loose bark. Because they overwinter as adults, mourning cloaks are one of the first butterflies to be seen in the spring. The adults mate and lay eggs, and the caterpillars that hatch from the eggs will metamorphose into adults in June or July. After feeding for a short time, the adults become dormant (estivate) until fall, when they re-emerge to feed and store energy for hibernation.
Pileated Woodpecker Winter Droppings Reveal Diet
A pileated woodpecker’s diet often shifts with the seasons. One study found that the primary food of these woodpeckers was fruit in fall, carpenter ants in winter, wood-boring beetle larvae in early spring, and a variety of insects in summer. During the winter, with the help of its impressive beak, the woodpecker pries off long slivers of wood from trees containing carpenter ants and exposes the ant galleries. It then uses its long, pointed, barbed tongue and its sticky saliva to catch and extract ants from the ant tunnels inside the tree. This winter diet can be confirmed by examining the contents of a pileated woodpecker’s droppings. Finding these droppings is simply a matter of locating a tree that has a considerable pile of wood chips at the base, indicating that a pileated woodpecker has spent a lot of time working on the tree – long enough to have deposited droppings in and amongst the chips. The droppings crumble easily and reveal a multitude of tiny, black, shiny carpenter ant body parts. (The whitewashed end is due to uric acid.)
Pileated Woodpecker Feeding Holes
There is no mistaking what bird is responsible for the large holes that a pileated woodpecker makes in an attempt to gain access to the carpenter ants living within a tree. No other bird in North America is capable of excavating holes of this size. Pileated woodpeckers tend to work vertically, and you often find one hole drilled above another. A look inside these holes reveals the galleries that the ants create in order to travel to all parts of their nest located within the dead center of the tree. (Carpenter ants, while omnivorous, do not consume or digest wood; they merely tunnel through it.) A tree’s inner core provides structural support, but is not essential for the tree’s survival. This eastern hemlock’s cambium layer, just inside the bark, is very much alive and the tree may continue to live long after its center becomes hollow.
A Great Christmas Present!
If you’re looking for a present for someone that will be used year round, year after year, Naturally Curious may just fit the bill. A relative, a friend, your child’s school teacher – it’s the gift that keeps on giving to both young and old!
One reader wrote, “This is a unique book as far as I know. I have several naturalists’ books covering Vermont and the Northeast, and have seen nothing of this breadth, covered to this depth. So much interesting information about birds, amphibians, mammals, insects, plants. This would be useful to those in the mid-Atlantic, New York, and even wider geographic regions. The author gives a month-by-month look at what’s going on in the natural world, and so much of the information would simply be moved forward or back a month in other regions, but would still be relevant because of the wide overlap of species. Very readable. Couldn’t put it down. I consider myself pretty knowledgeable about the natural world, but there was much that was new to me in this book. I would have loved to have this to use as a text when I was teaching. Suitable for a wide range of ages.”
In a recent email to me a parent wrote, “Naturally Curious is our five year old’s unqualified f-a-v-o-r-I-t-e book. He spends hours regularly returning to it to study it’s vivid pictures and have us read to him about all the different creatures. It is a ‘must have’ for any family with children living in New England…or for anyone that simply shares a love of the outdoors.”
I am a firm believer in fostering a love of nature in young children – the younger the better — but I admit that when I wrote Naturally Curious, I was writing it with adults in mind. It delights me no end to know that children don’t even need a grown-up middleman to enjoy it!
Ant Mandibles
Ants go through complete metamorphosis, passing through four stages (egg, larva, pupa, adult). Like honeybees, there are queens, female workers and male drones in an ant colony. The female worker ants have a series of “jobs” that they perform in a certain order. A young worker spends the first few days of its life caring for the queen and young. After that she maintains the nest and eventually forages for food. Like most insects, ants lack grasping forelegs and compensate for this by using their mandibles as “hands.” When the nest is disturbed, workers rush to rescue the eggs, larvae (depicted in photograph) and pupae by clasping them in their mandibles and transporting them to safety. They also use their mandibles to carry food, construct nests, and for defense.
Bloodroot Seeds and Myrmecochory
Bloodroot seeds, as well as the seeds of as many as 5% of flowering plants, have a fatty white appendage called an elaiosome attached to them which ants are very fond of. This adaptation benefits both the ants as well as the plant. The ants collect the seeds and take them down into their tunnels where they feed the elaiosomes to their larvae. The actual seeds are discarded underground, often in with ant compost, where their chances of germinating are enhanced. The dispersal of seeds by ants is referred to as myrmecochory. As the photographs indicate, ants don’t always wait until the seeds have dropped out of the seed pod to collect them.Ant Farmers
Certain species of ants have what is called a mutualistic relationship with aphids – a win-win situation for both the ants and the aphids. The ants protect the aphids from predators. In return, the aphids secrete droplets of “honeydew” from their abdomen when stroked by the ants’ antennae, which the ants devour. The act of stroking the aphids is referred to as “milking” them; hence, the ants are referred to as “farmers.”
Naturally Curious with Mary Holland 
What Other Naturally Curious People Are Saying