Wild Birds Unlimited – Omaha, NE

November 29, 2014

Winter Finches

House Finch

In addition to our year-round finches, the House Finch and the American Goldfinch, winter often brings more species of finches into our area. Irruptive migrations of Pine Siskins, Common Redpolls and Purple finches typically occur every two to three years.

Goldfinch in winter plumage

Common Redpolls are small brown-streaked birds with a reddish spot on top of their heads. They have tiny yellow bills and appear to be rather fluffy. The male usually has extensive deep pink color on his chest, while the female has none. Birch thickets and weedy fields are common places to find them.

Common Redpoll

Common Redpolls will quickly gather numerous whole seeds and store them in an expandable section of its throat called the diverticulum. Once the bird has flown to the safety of dense cover, they will regurgitate the whole seed, husk it and re-swallow the nut meat. They will also fill the diverticulum with seed just before darkness in order to provide an extra source of energy to help them survive the night. A study in Alaska documented that Common Redpolls could survive temperatures of sixty-five degrees below zero.

Purple Finch

Purple finches may be found in small flocks in shrubs or open woods. Unlike the House Finch, the male Purple Finch has extensive red color on its head and back. During the winter, Purple Finches will often forage and roost with mixed flocks of Pine Siskin and American Goldfinch. In these flocks the Purple Finch are socially dominant over the Goldfinch, but subordinate to the Pine Siskin. They will visit birdfeeders, but competition with House Finches and House Sparrows my drive them back into the woods.

Pine Siskin

Pine Siskins look like goldfinches disguised as sparrows, with their predominantly brown and white color with darker brown striping. Males sport yellow wing bars. They are found mainly in open coniferous forests or fields of thistle or sunflower. Primarily seed eaters, they will sometimes hang upside down to reach choice seeds. In winter, they often flock with Goldfinches and visit birdfeeders. Their winter migration patterns are very erratic, coming south in great numbers some years and very scarce in other years.

Red-breasted Nuthatch
Not a finch, but also here some winters, are the red-breasted nuthatches. These small birds, about the size of chickadees, have bluish to brownish gray backs and a white belly with a band of rufous between. The head is distinctive, with a black stripe through the eye, making the birds appear to be little bandits when they snatch a seed from your feeder and fly off with it.
So look closely at your feeders this winter and you might just find some visiting winter finches and red-breasted nuthatches.

October 28, 2014

Nuthatches

WBNuthatch_JRC_4c
The name Nuthatch probably results from the corruption of the word “nuthack,” referring to the bird’s habit of hacking away at a seed with its beak until it opens. Nuthatches have short legs, flat bodies and large heads. Nuthatch pairs stay together throughout the year. They hoard seeds and nest in cavities.

Nuthatches have a peculiar way of creeping head first down tree trunks while searching cracks and crevices for insects to eat. A nuthatch’s foot has one big toe (the hallux) that faces backward, while its other three toes face forward. They are able to walk down the trunks of trees head first by moving one foot at a time while the hallux toe on the other foot holds firmly to the bark.

Nuthatches frequently visit birdfeeders. With larger seeds, such as sunflower, they usually select a seed then fly to a tree to eat it. They have stout bills (for pounding) that come to a point (for probing). The nuthatch cracks food open by wedging it into bark and then hammering it to pieces with its bill. Peanuts (out of the shell) and suet are also attractive to them.

In our area, two nuthatch species are the most common, White-breasted Nuthatches and Red-breasted Nuthatches. White-breasted Nuthatches are year-round residents, favoring mature deciduous forests. They are often seen in heavily treed areas within the city as well as in more rural areas.

Nuthatch on Mesh Ball Feeder
The White-breasted Nuthatch is a common visitor to birdfeeders. One study found that they selected shelled sunflower seeds approximately 25% more often than seeds still in the shell. This preference is likely driven by the fact that it takes a nuthatch about half the time to transport and cache a shelled seed than it does a seed in its shell. They’ll often store seeds for later in the same day or as a quick source of food for the next morning.

During winter, White-breasted Nuthatches will often forage together with other birds such as titmice, chickadees and downy woodpeckers in a group known as a foraging guild. Nuthatches are able to recognize the alarm calls of these species, thus reducing their own level of alertness by relying on vigilance of other species. This leaves them with more time to focus on finding food.

However, nuthatches are monogamous and defend a territory from other nuthatches throughout the year. Female White-breasted Nuthatches rarely stray far from their mates and stay in constant vocal contact when they are more than a few yards apart. Females play the dominant role as “watchdog” when they are together, leaving the males to focus on hunting for food.

RBNuthatch on Pnt Fdr
Red-breasted Nuthatches are not year-round residents, and they do not visit us every year. When natural food supplies are scarce in northern Canada, numerous species of birds, including Red-breasted Nuthatches, will “irrupt” into a southern migration in search of food.

The preferred habitat of Red-breasted Nuthatches is an area with many fir and spruce trees. They line the entrance to their nesting cavities with drops of sticky conifer resin. It is thought this may be a tactic to discourage predators or nest competitors from entering the cavity. The nuthatches avoid the resin themselves by diving directly into the nesting cavity without ever touching the sides of the entry hole. Red-breasted Nuthatches very aggressively defend their nesting cavities, especially during the building period. They chase away much larger birds and have even been observed to bully the very aggressive house wren.
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