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Posts tagged “Adaptations

Grooming Beaver

Beavers are constantly grooming and oiling their fur to waterproof it. Typically when grooming, a beaver sits upright with its tail curled under its body and extended in front of it between its two hind legs. This allows the cloaca (an opening which contains ducts for everything from evacuation to reproduction, plus oil and castoreum glands) to be exposed. The beaver uses its front feet to retrieve creamy-yellow waterproofing oil from its inverted oil glands and then rubs it carefully over all of its body. Without constant waterproofing the beaver’s fur would soon become soaking wet and the beaver would not be able to tolerate the cold water.


Turkey Vultures Staying Cool

On some of the hot days we’ve had recently, my thoughts have turned to Turkey Vultures and their ingenious way of staying cool. They defecate on their legs and the subsequent evaporation cools the birds while strong acids kill bacteria.


How Snakes Smell

Many snakes, including this Common Gartersnake, use smell to track their prey.  In the roof of a snake’s mouth are two openings, called the vomeronasal  organ, also known as Jacobson’s organ.  Snakes smell by sticking their forked tongue in the air, keeping it constantly moving while they collect particles (mostly pheromones) on it from the ground, air and water.  Next they pull their tongue back into their mouth and insert it into their Jacobson’s organ (one fork in each opening).  Then the particles are analyzed and the snake determines whether prey or a predator is in the vicinity.  


Brown Creepers Nesting

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The Brown Creeper is so well camouflaged that there are many people who don’t even know of its existence. This diminutive bird gets its name from its habit of creeping along tree trunks and spiraling upwards while it probes for insects and spiders hidden in bark crevices with its curved, sharp bill.  At this time of year, brown creepers have already made their fibrous nest behind a loose flap of bark on a tree, and the 5 – 6 nestlings are constantly demanding food.  Unlike some species, both adults care for their young.  These photos illustrate how the male goes off and finds an invertebrate, flies back to the nest and gives it to the female, who then disappears behind bark to feed it to her nestlings.


Delayed Greening of Young Leaves

Many plants practice “delayed greening” of their leaves, including this Red Maple (Acer rubrum).  An initial lack of chlorophyll prevents the leaves from photosynthesizing and making food, which means they have little nutritive value, and thus, appeal, to an herbivore.  Most plants that delay greening have reddish leaves due to the presence of anthocyanin, a pigment which appears reddish.  A majority of herbivorous insects and invertebrates cannot detect colors in the red range of the color spectrum. Young leaves suffer the greatest predation from invertebrate herbivores.  Red leaves would be perceived by these leaf eaters as somewhat dark and possibly dead – not a choice food material.  It is possible that the red coloration of new leaves allows the plant to make them unappealing to the herbivores that would otherwise eat them.


American Bittern

American Bitterns have returned to New England from their southern wintering grounds, and are announcing their presence with a unique song that Sibley describes as a “deep, gulping, pounding BLOONK-Adoonk” that they repeat over and over.  These secret, well-camouflaged marsh birds are almost invisible as they slowly walk through marsh grasses.  When they stand still and point their bill skyward, they are easily mistaken for the reeds they inhabit.

 


Porcupine Foot Pads

Given the amount of time porcupines spend in trees, it’s not surprising to see that their feet are well adapted for climbing.  Long, curved nails that grip the bark, as well as “pebbly” foot pads designed to prevent slipping allow this prickly rodent to climb just about anywhere it wants to.  (Hind foot pictured.)