An online resource based on the award-winning nature guide

Birds

Great Blue Herons Mating

4-15-15  great blue herons copulating2  IMG_8954Great Blue Herons have returned to their nesting colonies in the Northeast and their breeding season is underway. These birds are monogamous for the duration of any given breeding season. A study found that most Great Blue Herons choose a new mate every year. After elaborate courtship displays have taken place, the pair copulates, frequently on the nest, and usually in the early morning or evening, as the female is away from the nest mid-day.

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.


Pied-billed Grebes Returning to Northern Breeding Grounds

4-8-15 pied-billed grebe 1370After wintering from southern New England southwards, Pied-billed Grebes return to the northern freshwater marshes and lakes where they breed and nest on floating platforms of vegetation. It is here, on their nesting grounds, that they are most vocal, with both males and females producing songs (the female’s is a bit softer). At this time of year, you often hear a Pied-billed Grebe before you see it.

When singing, a Pied-billed Grebe submerges its breast and neck to varying degrees. Its primary song has three parts. During the first part, the grebe retracts its head slightly with every note. During second and third parts, it moves its bill up toward the end of each note. David Sibley describes this extremely variable call as sounding something like “ge ge gadum gadum gadum gaum gaom gwaaaaaow gwaaaaaow gaom.” You can hear it and describe it in your own words by going to http://www.allaboutbirds.org/guide/pied-billed_grebe/sounds.

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.


Bald Eagles Nesting

4-9-15  bald eagle and nest 069In the Northeast, Bald Eagles seek out the tallest trees around in which to build their nests. In certain locations in Alaska, coastal California and northern Canada where there are no trees, Bald Eagles will nest on the ground. When building a nest in a tree, eagles will usually build it in the top quarter of the tree, just below the crown, on limbs capable of supporting a large nest. Sticks from the ground are collected up to a mile away from the nest or are broken off of nearby trees. Additional materials are regularly added to the nest throughout the year, including daily additions during the breeding season (see photo).

Many live eagle cams can be found online (in Minnesota, one chick, one egg – http://mnbound.com/live-eagle-cam/ ; in Georgia, older nestlings: http://www.berry.edu/eaglecam/ ; in Pennsylvania, very young chicks: http://www.ustream.tv/decoraheagles ), giving the viewer a window into the incubation, birth and growth of these raptors. Depending on the location of the nest, one can see every stage of development, from eggs to hatchlings to all-but-fledged nestlings. In New England, eggs are soon to hatch, if they haven’t already. (Thanks to Marianne Blake 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.


Early Nesting Hooded Mergansers Seeking Tree Cavities

4-6-15  hooded merganser, male 367In northern New England you are most likely to see Hooded Mergansers in the spring and fall when they are migrating to and from their breeding grounds in northern Canada (some nest in New England, as well). Hooded Mergansers tend to arrive in their breeding areas as soon as the ice starts to melt, and have been known to start laying eggs in March in Massachusetts and April in Vermont. Often some of the earliest eggs laid in a nest will freeze and crack and never hatch.

Hooded Mergansers are cavity nesters, frequently choosing trees that are close to ponds, marshes, swamps or streams. They compete with Wood Ducks for nest boxes put out by humans, and females of both species may lay eggs in the same nest, with one or the other incubating the eggs. Sometimes the duck that initiated the nest does the incubation, but more often the hen laying the majority of the eggs will do so. Because both species have the same incubation period, all the eggs hatch at the same time.

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.


Great Horned Owls Incubating Eggs

4-1-15 GHO2  240Great Horned Owls are said to have the widest range of nest sites of any bird in North or South America. Like other owls and falcons, this raptor does not build its own nest, but rather relies heavily on abandoned stick nests of diurnal birds of prey. Red-tailed Hawk nests are often usurped, as well as those of Bald Eagles, crows, ravens and herons. Nests may be lined with shreds of bark, leaves, downy feathers from the owl’s breast, fur of prey and trampled pellets. In addition to bird nests, Great Horned Owls also raise their one to four nestlings (usually two) in tree cavities and snags, on cliffs, in deserted buildings, in squirrel nests and even on the ground.

The female Great Horned Owl does all the incubating; the male delivers prey to her at intervals throughout the night. These early nesters have incubated eggs successfully when outside temperatures have been as low as -27°F. Hopefully warmer temperatures will welcome the newly hatched owlets in about a month. (photo: mostly hidden Great Horned Owl in Great Blue Heron nest)

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.


Common Grackles Returning

3-30-15 common grackle 083Male Common Grackles have started to arrive on their northeastern breeding grounds (females will arrive in another week or so), having migrated from southern U.S. Common Grackles typically migrate in large flocks containing hundreds of birds, not all grackles. Red-winged Blackbirds, Brown-headed Cowbirds, European Starlings and occasionally American Robins can be found alongside Common Grackles in these migrating flocks. In the early 1990’s, magnetic material was found in the heads and necks of Common Grackles, indicating that the geomagnetic field may play a role in their migratory navigation.

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.


Owls & Humans Share Trait

barred owl 194Birds have three eyelids – an upper eyelid, lower eyelid and a third semitransparent membrane called a nictitating membrane that sweeps across the eye much like a windshield wiper. This membrane keeps their eyes moist, and protects their corneas from being scratched.

In most birds, including owls, the upper and lower eyelids are used to close the eyes when sleeping, and the nictitating membrane is used for blinking. Humans close their eyes mainly by lowering the upper eyelid, where most birds do so by raising the lower lid. Owls (and a few other birds such as parrots, toucans, wrens and ostriches) are more human-like in that their upper lids are usually lowered to close their eyes. Owls also usually close their eyes, partly or entirely, when capturing and transferring prey, scratching their face, preening another owl and copulating. (Note the rows of feathers on this barred owl’s upper eyelids.)

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 3,384 other followers