“Songbirds Learn Their Songs During Sleep”
Zebra finches: Practice as well as sleep may help birds learn new songs. The reorganization of neural activity during sleep helps young songbirds to develop the vocal skills they display while awake, Utrecht University researchers have found.
“Bird Brains Like Human Brains: Episodic Memory Processes Similar”
Clayton, N. S. & Dickinson, A. D. 1998. What, where and when: evidence for episodic-like memory during cache recovery by Scrub Jays. Nature 395: 272- 278.
Birds can remember not only where, but when, they hid food items & even dig up less perishable food if too much time has passed & their favorite worms have probably rotted (Clayton and Dickinson 1998). The study of Scrub Jays (Aphelocoma californica) marks the first demonstration of episodic, or event-based, memory in animals other than humans. This type of memory is referred to as “mental time travel” because it involves mental images of past events. To remember where you put your car keys, you might “see” yourself walking into the house the night before & placing the keys on a table. Previous work had shown that birds can remember what kind of food they had stored & where they had hidden it, even without sensory clues like smell & appearance. But making decisions based on the timing of past events is crucial to episodic memory. In the study, N. S. Clayton (Univ. of California-Davis) & Anthony Dickinson (Cambridge Univ.) allowed Scrub Jays to store their favorite food (wax worms) on one side of a sand-filled tray & peanuts on the other side. Jays retrieved the wax worms if less than four hours old, but birds that had learned that wax worms decompose avoided older worms in favor of peanuts.
“Half-awake to the risk of predation”
Rattenborg, N.C., S.L. Lima, and C.J. Amlaner. 1999. Half-awake to the risk of predation. Nature 397:397.
Birds that are literally half-asleep – with one brain hemisphere alert & the other snoozing – control which side of the brain remains awake. The brain hemispheres take turns sinking into the sleep stage characterized by slow brain waves. The eye controlled by the sleeping hemisphere shuts, while the wakeful hemisphere’s eye stays open and vigilant. Birds also can sleep with both hemispheres resting at once. To check whether birds can control half-brain sleeping, Rattenborg et al. (1999) rows of Mallards napping. Decades of studies of bird flocks led researchers to predict extra vigilance in the more vulnerable, end-of-the-row sleepers. Sure enough, the end birds tended to keep peeled the eye on the side away from their buddies. Mallards snuggled into the inner spots showed no preference for gaze direction. Also, birds dozing at the end of the line resorted to single-hemisphere sleep, rather than total relaxation, more often than inner ducks did. Rotating 16 birds through the positions in a four-duck row, the researchers found outer birds half-asleep during some 32% of snoozing time versus about 12% for birds in internal spots. “We believe this is the first evidence for an animal behaviorally controlling sleep and wakefulness simultaneously in different regions of the brain,” the researchers said. The results provide the best evidence yet for a long-standing conjecture that single- hemisphere sleep evolved as creatures scanned for predators. The preference for opening an eye on the lookout side could be widespread. Useful as half-sleeping might be, it’s only been found in birds and such aquatic mammals as dolphins, whales, seals, and manatees. Presumably, keeping one side of the brain awake allows a sleeping animal to surface occasionally to avoid drowning, explains Rattenborg.
“Bird Brains”
“The level of intelligence among birds may vary. But no living bird is truly stupid. Each generation of birds that leaves the protection of its parents to become independent has the inborn genetic information that will help it to survive in the outside world and the skills that it has learned from its parents.
They would never have met the challenge of evolution without some degree of native cunning. It’s just that some have much more than others.” – David Attenborough
“Opposites may attract, but they don’t make better parents”
Wiebke Schuett, Sasha R.X. Dall, Nick J. Royle. Pairs of zebra finches with similar ‘personalities’ make better parents. Animal Behaviour, 2011; DOI:
A study by experts at the University of Exeter has revealed that couples with similar personalities make much better parents than those with different dispositions — at least in the world of zebra finches.
“Rainy Days Stress Out Birds”
If there’s one thing a rainforest bird shouldn’t mind, it’s rain. But a new study finds that torrential downpours stress out the White-Ruffed Manakin—and that may be why it and other tropical birds migrate up and down slopes.
