An online resource based on the award-winning nature guide

Birds

Bird Nests Revealed

Deciduous leaves have fallen, revealing bird nests that were right under our noses all summer without our even knowing it.  In addition to building in specific habitats and constructing different sized nests, each species of bird uses a combination of building material that is slightly different from every other species. Because of this, the material a bird uses to construct its nest can be diagnostic as far as determining what species built the nest.  Is the nest lined with rootlets? Are grape vines incorporated into the nest? Is moss covering the outside of the nest?  Is there a shed snake skin woven into the nest? The answer to these questions and others can help narrow down the list of possible builders.

This is the time of year to look for nests and try to determine, with the help of a good field guide such as Peterson’s Field Guide to Bird Nests, the identity of the birds that built them.  (Be aware that possession of a bird nest, egg or feather of most migratory birds, even for scientific research or education, is illegal if you do not have a Federal Migratory Bird Scientific Collecting Permit.)

Sometimes you’ll find material in nests that surprise you — some contain man-made, as well as natural, materials. Among the most unusual examples of this are a nest built solely out of barbed wire by a Chihuahuan raven in Texas and the pictured clothes hanger nest built by a crow near Tokyo and photographed by Goetz Kluge.

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


Spruce Grouse Foraging

While Ruffed Grouse are plentiful throughout most of New England, one has to go to northern Vermont, New Hampshire or Maine to see its cousin, the Spruce Grouse.  Associated with boreal forests, this largely herbivorous bird feeds primarily on the needles of pine, spruce and fir (a small amount of animal matter is consumed in the summer as well as ground vegetation). Especially in the winter, a large volume of conifer browse is consumed in order to meet energy demands.

The grouse holds the needle between the tips of its mandibles and breaks it off by flicking its head.  This action, and the fact that Spruce Grouse feed exclusively on needles in the winter, leads to the wearing off of the tip of the bird’s upper mandible by spring.

If you are searching for a Spruce Grouse, you might want to concentrate in the middle of the crowns of trees, as this is where the birds tend to forage. Theories for this preference include the fact that needles in this location have higher nutritive value, branches provide sturdy support, and grouse can see approaching avian predators while remaining partially concealed. (Birds of North America, Cornell Lab of Ornithology). (Photo: male Spruce Grouse browsing on Tamarack needles and (inset) looking for grit on the ground.)

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.

 


Birds Molting Old Feathers And Growing In New Ones

With birds, molting refers to the loss of old, worn feathers and the growth of new ones.  A molt can involve all of the bird’s feathers (complete molt), or just some of them (such as wing or tail feathers – a partial molt). Most birds have a complete molt once a year (chickadees, hummingbirds, owls, etc.), or one complete molt and a partial molt before the breeding season (buntings, tanagers, warblers, etc.), or two complete molts per year (Bobolinks, Marsh Wrens).

Complete molts often occur in late summer and early fall, after the breeding season is over. When you think about it, the timing of this “prebasic” or “postnuptial” molt makes a great deal of sense. Growing new feathers takes an inordinate amount of energy; food is plentiful now, the demands of breeding are over and for many birds, migration isn’t quite under way. It is the perfect time to look for molted feathers on the ground.  (Photo:  molted Red-tailed Hawk tail feather)

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.

 

 


Juvenile Least Bitterns Foraging

The Least Bittern is the smallest member of the heron family, measuring 11-14 inches in length with a 16-18 inch wingspan.  It is so secretive and well camouflaged that it is heard far more often than seen. A soft cooing song is sung by the males in spring, and a variety of calls are given on their breeding grounds. (You can hear both types of vocalizations at www.allaboutbirds.org/guide/Least_Bittern/sounds.)

This elusive bird of freshwater and brackish marshes is foraging for itself soon after it leaves its nest at two weeks of age.  Long agile toes and curved claws enable the Least Bittern to climb and grasp reeds while it looks for frogs, snakes, salamanders, leeches and other prey from on high.

Like its relative the American Bittern, the Least Bittern freezes in place when alarmed, with its bill pointing up, turns both eyes toward the source of alarm, and sometimes sways to resemble windblown marsh vegetation. (A few wisps of white down still remain on young Least Bitterns at this time of year, as is evident in photo.)

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 Loon Chicks Riding High

July on a lake occupied by nesting Common Loons is a birder’s slice of heaven.  Eggs are hatching, day-old fluff balls are riding high on their parents’ backs, parents are busy catching and delivering small fish and crayfish to their chicks, and survival lessons are being given. Recently while watching a pair of two- or three-day-old chicks whose parents were off obtaining their offspring’s next meal I observed a juvenile Bald Eagle, known predator of Common Loon chicks, soaring overhead.  Within a split second both loon chicks dove and stayed submerged long enough for the eagle to give up the ghost. Nature or nurture?

To see a related entertaining phenomenon, go to https://loonproject.org/2019/06/29/unlikely-allies/?fbclid=IwAR0po44dJaElcyYpqKqLwaz9A6gs7RxWfhJRkoB-QleC7sUGnjgElksR5G4.

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.


Changing of the Guard: Pileated Woodpecker Parents Share Parenting Duties

7-1-19 male and female pileated 0U1A0116Recently I had the opportunity to observe nesting Pileated Woodpeckers, and I thought I would devote this week’s Naturally Curious posts to different aspects of my observations. I would like to thank Amber Jones and Dave Bliven for generously sharing their Picidae residents with me.

From start to finish, both Pileated Woodpecker parents are involved in raising their young and all that it entails. Together they excavate a nest cavity, usually in a dead or dying tree. Both have brood patches (areas on their undersides that lack feathers and are well supplied with blood vessels, allowing efficient transfer of body heat to eggs), and both incubate the eggs during the day (the male has night duty). The parents take turns brooding the nestlings and providing them with food. And finally, once fledging take place, both parents provide and help their young find food for several months. (Photo: male Pileated Woodpecker in nest cavity; female Pileated Woodpecker on nesting tree)

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.


Why Do Birds Turn Their Eggs?

5-31-19 C. goose turning eggs 1B0A8783It’s common knowledge that birds periodically turn their eggs when they are incubating them, but have you ever stopped to ask why they do this. One assumes that if this action weren’t critical to the incubation process, it wouldn’t be practiced, and science bears this out. According to Audubon, birds turn their eggs to make sure the embryo gets enough albumen – the white part of the egg that contains water and protein and provides essential nutrients to the developing embryo. Too little albumen leads to an underdeveloped and often sickly chick. (Photo: Canada Goose turning eggs)

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.