Posts

THE UNIQUE SPERM WHALES

      Scientists claim that over many millions of years, whales evolved from a kind of land-based, bear-like creatures that slowly adapted to getting food from the oceans, becoming the mammals they are today.  And it seems that, early on, sperm whales diverged from the baleen whales to take advantage of different food sources, other than the baleens' sieving tiny plants and animals from the oceans' surfaces.  Sperm whales evolved different mouth structures and habits than baleen whales, to hunt giant squid, octopi, sharks, rays and larger fish in cold, dark, crushing ocean water over a half mile down.  Sperm whales have 52, cone-shaped teeth on their narrow lower jaws that catch the animals listed above, just like bears and wolves do.        Sperm whales are unique.  They are the only whales that adapted to diving so deep to get food, a practice that took eons to perfect.  They are able to stay submerged for up to two hour...
Post a Comment
Read more

SALMON FOOD CHAINS

      Every July, in recent years, through live cameras and our computer screen, I watch several brown bears catch many mature sockeye salmon swimming up Brooks River in Katmai National Park in Alaska to spawn.  That park is in southern Alaska, at the base of the Aleutian Island chain that juts into the northern Pacific Ocean.         After a few years feeding on small creatures in the Pacific Ocean, hordes of sockeyes swim along the Alaskan Coast until they smell the river they hatched in.  Then they tirelessly push up the river {Brooks River}, day after day, by the hundreds of thousands to the gravelly shallows where they hatched.  They wiggle over rocky shallows, leap ten foot waterfalls and slip swiftly through deeper waters to reach their destination.  But many salmon don't make it to their spawning spots because of the unceasing predations of brown bears.           Brown bears compete with ea...
Post a Comment
Read more

FAVORITE COLOFUL BUTTERFLIES

      Tiger and zebra swallowtail butterflies, monarch and red admiral butterflies and buckeye butterflies have large, colorful wings that make them quite visible sipping nectar from alfalfa and red clover flowers, roadside flowering plants and blooms in backyard gardens in southeastern Pennsylvania, as elsewhere, particularly from mid-July to the middle of September.  Use a field guide to eastern butterflies to see the colors and patterns of these beautiful butterflies.       These common, showy butterflies, my favorites, pollinate those blossoms as they sip nectar, and flutter daintily from one flower to another.  And in that process, they help beautify and enliven the hay fields, roadsides and gardens they patronize to get nectar.  And these kinds of butterflies, like all species, have interesting life histories.          Tiger swallowtails are yellow with black stripes on their wings.  Their caterpi...
Post a Comment
Read more

WHITE-HEADED AND ACORN WOODPECKERS

      Presumably having a common ancestor, all woodpecker species have similar characteristics, including stiff tail feathers that prop them upright on vertical tree trunks, two toes in front of each foot and two in back that allow them to cling to tree bark and dead wood, and prop themselves upright at the same time, and heavy, sharp beaks that chip into bark and wood after invertebrates, and to carve out hollow to raise young in.  And they have attractive feather patterns.        But some kinds of woodpeckers have other food sources, including white-headed woodpeckers and acorn woodpeckers that hail from the American west.  Other food sources decreases competition for food among the adaptable, worldwide woodpecker family of birds.  White-headed and acorn woodpeckers diverged from other woodpecker species by ingesting different kinds of "nuts" from trees.      White-headed woodpeckers have black body feathers and whi...
Post a Comment
Read more

GIANT SOUTH AMERICAN RIVER TURTLES

      I recently became aware, by a TV program of giant South American river turtles living in the large Orinoco and Amazon Rivers in the tropical Amazon Basin of northern South America.  And what impressed me the most about these giant river turtles is the annual gathering of hundreds of female turtles on gigantic flats of soil during the annual drought when river water levels drop dramatically.           Those female turtles come together on the flats to lay their eggs at one time in the two and a half foot holes they dug in the soil with their back feet, one per turtle, on a bit higher part of the large, drying flats.  Each female lays about a hundred eggs in the pit she dug.  Digging a nursery hole a little uphill helps insure the turtle embryos don't drown before they hatch.  Perhaps, in the past, through trial and error, the river turtles that may have deposited eggs to close to the river have no descendants today be...
Post a Comment
Read more

JUNE BEETLES AND DIGGER WASPS

      On the afternoon of July 7, this past, I was sitting in our car in a parking lot and waiting for my wife.  While there, I noticed about a dozen green June beetles zipping back and forth low across a regularly mowed, nearby lawn.  I watched them for a few minutes and remembered they were male and female June beetles seeking mates for mating in the short grass.  Females release pheromones that attract the males.       Adult male and female June beetles emerge from the ground by late June ready to mate.  Males and females are similar in appearance; about an inch long, and dull-green and tan on top and metallic green below, both of which camouflages them.      Adult June beetles are part of several food chains.  They ingest rotting fruit, tree sap and flower nectar.  However, some of these beetles are preyed on by crows, blue jays, American robins, purple grackles and other bird species.    ...
Post a Comment
Read more

MINIATURE STREAMSIDE BEAUTIES

      Late in June, while scanning a shoreline of a sluggish creek with binoculars for wildlife in Lancaster County, Pennsylvania, I saw beautiful bouquets of water forget-me-nots, and several attractive common bluet damselflies.  Those flowers and insects were studies in miniature beauties.        The streambank was grown up with tall reed-canary grass right to the waterline, offering a green backdrop for the blooms and damselflies.  The forget-me-not bouquets of blooms were nestled charmingly, and peeked out coyly, from among the high grasses that swayed in the wind.  Meanwhile, the small, slender damselflies flew back and forth low over the waterway after mates, or flying insect food.  And some of the damselflies perched on soaked mats of algae in the water's surface, or blades of grass on the shore, where they can watch for food, mates, and rivals in the case of the males.             Forg...
Post a Comment
Read more