Researchers have found that Black-backed Woodpeckers play a key role in providing cavities that help other animals repopulate burned forests. The vociferous young leave the nest after about a month, and learn to forage on their own by imitating their parents. Male and female share the work of chiseling out the nest cavity in a dead or dying tree, then incubating their two to six white eggs, and feeding the nestlings once they hatch. Similar to other woodpeckers, from Downy to Pileated, this species is a primary cavity nester, meaning that it excavates its own nest site. Accessible at Primary Pair-upsīlack-backed Woodpeckers stay paired throughout the year. (Audio: Black-backed Woodpecker call by Geoffrey A. Black-backed Woodpecker (Picoides arcticus).The Black-backed Woodpecker's call note, a sharp kyik, is most commonly heard as it forages and interacts. These birds also take advantage of forests denuded by bark beetle outbreaks, but to a lesser extent. Populations are nonmigratory but shift as previously burned forests re-grow and new areas burn. Scream, Rattle, and Snarlĭespite having a wide range across northern North America and in the northern Rockies and Sierra Nevada, the Black-backed Woodpecker has no recognized subspecies. In addition to beetles, grubs, and other insects, this woodpecker sometimes eats berries, acorns, and nuts, but these items make up just a small part of its diet. Patches of exposed orange cambium (inner bark) that stand out against blackened trunks are a sure sign a Black-backed Woodpecker has been at work. With its sturdy, chisel-like bill, the Black-backed Woodpecker scales off large pieces of bark from charred tree trunks. In fact, researchers found that this species has the most shock-absorbent skull in the genus Picoides. A modified skull and rib cage help it withstand the pounding required to excavate deep into wood after its prey. The Black-backed Woodpecker feeds primarily on the wood-boring insects and larvae that infest burnt trees in the wake of fires. The absence of a back toe allows this bird to pivot farther back while preparing to hammer at a tree trunk, making the ensuing blows more forceful. This arrangement differs from the typical woodpecker foot arrangement of two toes forward and two back, as seen in the Red-bellied and Lewis's Woodpeckers. In an interesting adaptation for more efficient excavating, this species, along with the American Three-toed Woodpecker, only has three toes per foot - two facing forward and one back. These dead trees (also known as snags) are also perfect places to excavate cavities for nesting and roosting. A post-fire forest of charred conifers attracts wood-boring beetles and their larvae, as well as other insects, providing a ready woodpecker buffet. The Black-backed Woodpecker's seemingly odd choice of habitat makes a lot of sense when you think about the bird's diet. This species is one of the first to recolonize a forest after a major fire, along with other species such as the White-headed and Hairy Woodpeckers. This glossy-backed bird blends in beautifully with the charred trees it prefers in fact, it's far less likely to be seen away from a burned area than in one. "So that is why even the hardest hits we observed are not expected to cause any concussion," Van Wassenbergh says.Black-backed Woodpecker range map by American Bird ConservancyĪ burned-over forest may look lifeless and dreary to the human eye, but to the Black-backed Woodpecker, it's a veritable welcome mat. Now, it has been confirmed by Van Wassenbergh's high-speed video.Ī woodpecker's brain is about 700 times smaller than a human brain. That idea was suggested in 2006 by Lorna Gibson, a professor of biomechanical engineering at MIT. "An animal that has a smaller size can withstand higher decelerations," he says. That is possible because a woodpecker's brain is protected - not by cushioning, but by its tiny size and weight, Van Wassenbergh says. Yet the woodpecker brain emerges unscathed, even after thousands of impacts in a single day. That means the organ repeatedly experiences deceleration that would cause a concussion in a human brain. "The way we see the head behaving is very rigid, like you would use a hammer hitting wood," Van Wassenbergh says. What the videos did not show is any sign that the woodpecker's brain is somehow cushioned. But they break free almost instantly, thanks to a clever beak design that provides independent motion of the upper and lower beak. The videos also showed that woodpeckers' beaks often get stuck in the wood. The videos, part of a study published in the journal Current Biology, revealed some remarkable details.įor example, "they close their eyes at the moment they impact the wood," Van Wassenbergh says, to protect their eyes from splinters. "We went to four different zoos in Europe where they had woodpeckers and we recorded them at very high frame rates, while they were pecking," he says.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |