Snake Skin as Protection Against Predators

February 17, 2015 by  
Filed under Features

Birds use all sorts of materials to build and pad their nests with, and are very good in general at adapting whatever is at hand to suit their needs. Some birds even use the shed skins of snakes in their nest building, raising the question as to whether the snake skin is merely a handy and comfortable material to line a nest with, or whether it is actually intended to scare predators off. A study carried out by Arkansas State University ornithologists concluded that some bird species clearly use the snake skin to deter predators by incorporating it into their nests in some way, or by prominently displaying a snake skin near the nest, or both.

The Tufted Titmouse (Baeolophus bicolor) and Blue Grosbeak (Passerina caerulea) are among the bird species that include pieces of snake skin in their nests, while Great Crested Flycatchers (Myiarchus crinitus) are known to display a snake skin outside their nesting cavity, as well as using an entire coiled snake skin in the nest. These will remain there throughout the incubation and fledgling stage of breeding. The study noted that the main predators of the eggs of Great Crested Flycatchers are rat snakes and flying squirrels – the latter being fond of bird’s eggs and the former preying on both birds and their eggs, as well as on flying squirrels. It was also noted that flying squirrels and Great Crested Flycatchers have a very similar geographical spread, and as all three species favor cavities as habitats, it is likely they will encounter one another. As the flying squirrel does its best to avoid the rat snake, it has been suggested that the shed skin of the snake acts as a deterrent to the squirrel.

A test carried out by the researchers confirmed that to be so. Using 60 nest boxes in which quail eggs were placed, researchers added snake skins into 40 of the boxes, with 20 boxes having no snake skin in them. All of the 40 boxes with snake skins were left untouched, while up to 20 percent of the nests without snake skins were raided by flying squirrels – evidence that some birds use snake skins specifically to ward off predators, and it appears to work.

Evening Grosbeak (Coccothraustes vespertinus)

February 9, 2009 by  
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The Evening Grosbeak (Coccothraustes vespertinus) is a lovely little bird which lives in North America. Although other Grosbeak species are found in Europe and Asia, the Evening Grosbeak is uniquely American. Originally the range of this sweet little finch was the Canadian Rockies, but today it is seen in Labrador and Newfoundland. Join us as we discover more about these wonderful birds.

Evening Grosbeaks are plump finches measuring about 7-8 inches in length. Most notable is their brilliantly adapted conical bill, relatively large for such a small bird. Male Evening Grosbeaks are an amazing yellow color with a gold band around the forehead which stands out. Feathers around the crown and neck are a glossy brown. Jet black feathers adorn the wings and tail of the male and white patches decorate the shoulder. Female Grosbeaks are much less striking. Their body feathers are a pale gray with yellow on the nape, rump and sides. Like the male, the wings and tail are black but have white patches. In the winter months the thick bill of the Evening Grosbeak is bone colored whilst in spring it transforms into a green color like that of newly showing deciduous buds. This provides ideal camoflage as it hides in the trees. Its little head resembles a young balsam cone. When in flight, the Evening Grosbeak can be spotted by its undulating flight pattern and rapid wing-beats. The little birds are very noisy and have an extensive call vocabulary.

Evening Grosbeaks prefer coniferous forest but will also reside in mixed deciduous localities. As seed-eaters, Evening Grosbeaks dine on the seeds of cones from pine, spruce and balsam fir. They will also feast on deciduous plant seeds. Whilst feeding, the Grosbeak is adept at shearing husks from seeds. Carefully maneuvering the seed into the correct position they are able to munch on the tasty inner contents of the seed. Evening Grosbeaks have also been known to feed on budworms in their various life stages and are thus a great asset in pest reduction. These lively birds will often frequent bird feeders, devouring sunflower seeds.

Not much information is known about the Evening Grosbeak’s breeding habits. Nests are constructed out of twigs, grass, moss and so forth. About 3 to 4 green, splotched eggs are laid in breeding season. Be sure to look out for this cute little creature when bird watching.

Rose-breasted Grosbeak (Pheucticus ludovicianus)

February 9, 2009 by  
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The Rose-breasted grosbeak or as it is scientifically called, Pheucticus ludovicianus, is about 7.25 inches long and has a large, cone shaped, pale colored bill. The female grosbeak looks similar to the female-plumaged Black-headed grosbeak but has an orange-brown breast with streaks only on the side of its body. The Grosbeak lives near open woodlands that are near to water. It also likes thick brush or small trees, large trees, marsh borders, gardens, parks and overgrown pastures.

The adult male Rose-breasted Grosbeak has a rose red, triangular shape patch on its white breast. The upper parts of its body and head are all black and the under parts are white. The wings have white patches and are lined with rose red. His black tail feathers are speckled with white spots. In winter and autumn the male becomes browner and dull in colour. The juvenile bird has a similar coloring to the male’s winter and autumn colour.

The adult female Grosbeak has black and white stripes on its crown above its eyes. The under parts of the bird are white with extensive streaking, whereas the upper parts are a dark grey. Where the male has a rose red lining the female has a more yellow to yellowish-orange wing lining. The juvenile has an orangey-brown breast and the juvenile female has similar coloring to the adult female.

The Grosbeak mating system is monogamous and so the male and female will pair off and have between three to five pale green, blue eggs. During the courtship the male will fly after the female while singing to her; he will then crouch down and spread and droop his wings; spread his tail, withdraw his head with his nape against his back; once in position he will start singing and waving his head and body in an erratic dance.

The cup-shaped nest is made up of loose twigs, rough plant material and then lined with thin twigs, hair and rootlets. The nest is normally 5-15 feet above the ground and is built by the female with help from the male Rose-breasted Grosbeak. The incubation of the eggs takes up to two weeks and will be looked after by both the male and female bird. The development of the chicks is altricial, which means that they are immobile and eyes closed. Once the young hatch it takes just less than two weeks before they will leave the nest.

Birding in Madera Canyon, Arizona

November 7, 2007 by  
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The beautiful Madera Canyon, located in the Santa Rita Mountain Range in southern Arizona, is considered by many to be a bird-watcher’s paradise. The terrain on the approach to Madera Canyon is grasslands, which gives way to mountain forest. The area is renowned for its abundance of bird species and the relatively easy access to watch and photograph birds that are generally not seen elsewhere.

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