An online resource based on the award-winning nature guide

Uncategorized

Dragonflies & Damselflies Spear Prey With Lower Lip

7-27 dragonfly mouthpart 077Dragonflies and damselflies are unique among aquatic insect larvae in that they have a greatly enlarged hinged lower lip, or labium, which they can rapidly extend outwards to capture prey. When retracted, the prehensile labium fits like a mask over the face or is folded flat beneath the insect’s head. When hunting for prey, the dragonfly larva uses its labium like a speargun. It shoots forward as far as half the larva’s body length away, and moveable hooks on the front edge grab the prey. There are no muscles at the hinge/joint, leading entomologists to believe that the labium is extended by increased blood pressure caused by abdominal muscle contraction. It unfolds at a right angle, and extends extremely rapidly, faster than most prey can react. (photo: cast skin of dragonfly larva from which adult dragonfly emerged)

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.


Two-month-old Striped Skunks Can Spray!

7-15-15 striped skunk2 058The answer to yesterday’s mystery photo is a lot less original than many of your guesses, all of which could have been true, given my natural curiosity. I am embarrassed to admit that it was the oily, yellow spray of a young striped skunk that covered my spectacles (and my entire head, arms and camera) – even with ample warning, I chose to persevere in order to get the perfect picture. Unfortunately, the skunk was a lot more successful at his mission than I was at mine.

There is a reason why coyotes, foxes and most predators (one exception is the great horned owl), including most sane photographers, keep their distance from striped skunks. Whether newborn or several years old, skunks are capable of using their musk-filled anal glands to ward off anything that threatens them. Skunks are generally reluctant to spray, however, as they only have a few teaspoons (half an ounce) of musk in their glands, and once their supply is depleted (five or six sprays), they are defenseless for about 10 days, while it builds up again. Hence, plenty of warning is given in the form of stomping front feet, erect hair, raised tail, and chattering before a skunk contracts the muscles surrounding its anal glands and shoots a pungent, yellowish spray as far as ten feet away. Only a fool would not heed the warning given…and be forewarned – a skunk’s aim is surprisingly accurate.

The organic compounds that make the smell of skunk spray so offensive are called thiols (mercaptans). Thiols are also found in garlic and onions, and form parts of the keratin in hair. If your dog or you happen to be at the wrong end of a skunk’s partially everted anus, the best combination to neutralize the musk smell is 1 quart of 3% hydrogen peroxide, ¼ cup of baking soda, and 1 teaspoon of liquid dish soap. (Thanks (?) to Tom Ripley 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.


Iridescent Dogbane Beetles Emerging

7-1-15  dogbane beetle170Dogbane beetles (Chrysochus auratus) appear suddenly, usually when the plant which they consume and for which they are named is flowering. Look on the leaves and blossoms of Dogbane, or Indian Hemp, (Apocynum cannabinum) for this blue-green beetle with a metallic copper and crimson shine to it.

The iridescence is a special type of color that shines and changes as the insect changes position or we change position looking at it. It is produced by special body structures and light. The surface of the body parts of this beetle is made up of stacks of tiny, slanting plates, under which is a pigment. Some light rays reflect from the surface of the plates, and other light rays reflect from the pigment underneath. At different angles, the light reflects at different speeds, causing interference and resulting in our seeing different colors that shine.

Although all parts of this plant are toxic to humans, Dogbane is tolerated by Dogbane Beetles, whose larvae reside underground where they eat the roots of Dogbane. When they mature into adult beetles, they climb up the plant to the leaves and flowers, which they then consume.

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.


Moose Antlers Growing

moose antlers 795Antlers grow faster than any other mammal bone — a big bull moose can grow an 80-pound rack in a summer, adding a pound of bone a day. While genetics has an influence on antler growth and size, nutrition is by far the most important factor, and males in high quality habitats grow much larger antlers.

In the early stage of growth, antlers are covered with a fuzzy skin called velvet, which contains a tremendous concentration of nerves and as well as a supply of blood. The velvet nourishes the growing antler for about five months, during which time the antlers are extremely sensitive to touch, and if injured, may be permanently misshapen. Eventually, when the bone stops growing, the velvet is shed. Bull moose then use their antlers to attract and fight for mates, as well as to root plants from the pond floor. A month or two after they have served their purpose of securing a mate, antlers are shed.

In moose, antlers may act as large hearing aids. Moose with antlers have far more sensitive hearing than moose without, and a study of antlers (with an artificial ear) confirmed that the antler behaves like a parabolic reflector.

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.


Sacrificial Honeybee Drones

6-26-15 drone 039A honeybee colony has one (fertile, egg-laying) queen, several hundred male drones and thousands of (sterile) female worker bees. The drone’s one and only function is to mate with and fertilize a queen. (They do no work in the hive, and are fed by workers until fall.) Early in a queen’s life, she makes several mating, or nuptial, flights. On these flights, she mates — in midair about 200-300 feet high — with anywhere from one to more than 40 drones. They are usually not from the queen’s hive, but may be from several other hives. The average number of drones with which a queen mates is 12. The queen stores up to six million sperm from her mating flights, and retains them for the remainder of her life — two to three years, for a long-lived queen. (Recent research shows that the more times a queen mates, the more attractive she is to her worker bees, due to pheromone alterations, and thus, the longer she lives before being replaced.)

While the queen may live several years after mating, the few drones that manage to partner with her do not, for they die after mating. Although brief, honeybee mating is dramatic. The drone inserts his endophallus (internal penis) into the queen’s sting chamber and with great force injects his sperm into her. The force with which this is done is so powerful that it ruptures the endophallus, separating the drone from the queen. The drone dies shortly thereafter. (At this time of year, honeybee hives often swarm due to overcrowding, with the old queen departing with half of the hive; a new, virgin queen then takes her nuptial flights.) Photo: A drone honeybee which lost its life after successfully mating with a queen. Discovered and photographed by Boston Beekeeper Association founder, Sadie Richards Brown.

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.


Barred Owl Chicks Fledging

6-18-15  barred owl fledged 155The fledging of flightless Barred Owl chicks takes place four or five weeks after they hatch. Typically they perch on the rim of the nest cavity before climbing to a nearby branch. If there are no branches close by, the chicks will drop to the ground and climb a nearby leaning tree, where they perch and are fed by their parents. Juvenile Barred Owls begin short flights at approximately 10 weeks of age, attaining longer flights by 12 weeks. They are now learning to hunt, but continue to be fed by their parents until late summer or early fall. (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.


Showy Lady’s Slippers Flowering

showy2  231The month of June can’t go by without a mention of Showy Lady’s Slippers. Just fifty years ago, this orchid could be found over most of the Northeast. Habitat loss and an exploding deer population are considered major factors in Showy Lady’s Slipper’s decline, making it endangered or on the verge of extinction in many areas. Although rare, it is still locally abundant, particularly in fens (peat wetlands that get their water from rainfall and surface water).

As with Pink and Yellow Lady’s Slippers, one of Showy Lady’s Slipper’s three petals is greatly modified into a large inflated pouch called the labellum . (The pouch’s color can vary widely from year to year, depending on the ambient temperature. Cooler conditions appear to produce more intense color.) The petals on either side of the pouch attract pollinators with an alluring odor, but the insects that enter into the pouch are in for a disappointment, as lady’s slippers produce little or no nectar. The structure and positioning of the pistil and stamens are such that they encourage cross-pollination to take place, which is crucial, as lady’s slippers rarely self-pollinate.

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.


Follow

Get every new post delivered to your Inbox.

Join 3,573 other followers