Vol. 18: #3 • Tidbits Soars with the BIRDS

They're around us everywhere, gracefully gliding through the air, nesting in trees and pecking at crumbs on your patio. Birds are formidable creatures, and whether you find them fascinating or not, this week Tidbits hatches up some interesting information about our feathered friends that we'll bet you never knew, along with some facts you'll find downright interesting!

• Ornithologists have identified about 10,400 different bird species, which is more than twice the number of mammal species in existence. The number of individual birds on earth are about 300 billion, working out to a ratio of some 45 live birds for every human on the planet.

• There are two types of birds. Precocial birds are capable of leaving the nest within a day or two of hatching, such as ducks, chickens, and geese. The word “precocial” comes from the same Latin root word that gives us “precocious.”

• Altricial birds are completely helpless when they hatch and must be fed and protected by their parents until they fledge weeks later. “Altricial” comes from the Latin root meaning “to nourish.” About 80% of bird species are altricial, and altricial birds also end up with brains that are bigger than their precocial counterparts.

BIRD SMARTS

• The hippocampus is that part of the brain re-sponsible for memory and spatial learning. The more neurons there are in this region, the better the memory. Research has found that chickadees living in harsh climate areas (Alaska, Maine) have a larger hippocampus than those that live in milder climates (Iowa, Kansas).

Chickadees living at high elevations have a larger hippocampus than those living just 1900 feet lower. In harsh climates, a good part of survival depends on how well birds can remember where they stashed the seeds. In climates where food is readily available year-round, memory is not so critical.

• In primates, the larger the social group the bigger the brain. In birds, however, the opposite is true. Birds in large flocks have been found to have smaller brains than birds in small groups. It seems that forming close alliances with a small number of others is a more demanding task for birds than having a casual relationship with many others.

• A study done at the University of Washington showed that not only do crows recognize and remember human faces, but they also pass that information on to their offspring.

• In one experiment, teams of people wandered through several neighborhoods in Seattle. Some were wearing different sorts of masks, some had no masks on, and some were wearing scary caveman masks. The people wearing caveman masks captured several of the crows, releasing them unharmed after several minutes.

• Several years later, another group of researchers wandered through the same neighborhoods wearing the same masks. Only those wearing caveman masks were mobbed and dive-bombed by crows, including young crows that had not even been born at the time of the original experiment. Crows up to half a mile away also joined them and mobbed the “cavemen” though they had not even previously been in that vicinity.

HOMING ABILITIES

• White-crowned sparrows migrate from Alaska and northern Canada to southern California and Mexico. Researchers captured a flock of 30 in Seattle. They were then shipped 2,300 miles to New Jersey, where they were released. Would they be able to find their way to California? The adults who had migrated several times did. The juveniles who had never migrated before did not.

• The arctic tern spends summers in Greenland and Iceland and winters off the coast of Antarctica, making a round-trip journey of 44,000 miles every year. If a tern lives 30 years, it flies the equivalent of three trips to the Moon and back.

• The pigeons that you see in cities descended from homing pigeons brought on ships with European settlers beginning in the 1600s. Homing pigeons descended from rock doves that lived on the cliffs surrounding the Mediterranean Sea. Rock doves forage in the fields during the day and return to their nests at night, displaying a strong homing ability.

• Homing pigeons which are transported in a circular route inside rotating drums with no outside visual reference are still able to find their way back. Even pigeons whose eyes are covered are able to find their way home.

• In 2014, researchers outfitted a flock of golden-winged warblers with GPS units to study their migration. The birds were fitted with the units just as they arrived at their summer nesting ground in Tennessee after flying in from Colombia.

• Suddenly, the entire flock took off helter-skelter flying in all directions, some going as far as 500 miles away. A few days later, a huge supercell storm slammed the area, spawning 84 tornadoes that killed 35 people. After the storm passed, the entire flock returned to their original nesting site and took up where they left off. Somehow, in a way that baffles scientists, they had sensed the danger of the approaching storm while it was still hundreds of miles away and flew to safety.

BIRD TOOLS

• Some bird species have shown remarkable abilities for reasoning. For example, research-ers have found that New Caledonian crows not only manufacture useful tools such as hooks and spears out of leaves and branches, but they keep those tools with them to use over and over, even carrying them to new locations when they decide to move.

• A curious ornithologist in Arizona was closely observing a feeding station. Normally the crows would come in first, eat their fill, and then leave, whereupon the waiting jays would then move in for their meal. One jay was impatient with the length of time a crow was taking at the food station. It flew off to a nearby tree, where it pried off a sturdy straight stick. It then dive-bombed the crow, using the stick as a spear. As the ornithologist watched, the crow fought back, causing the jay to drop the stick. The crow quickly picked up the spear and flew after him, taking menacing jabs at the fleeing bird using the jay's own weapon.

Other examples of birds using tools:

• A white stork carries damp moss to its nest and wrings it out with her claws to provide water for her chicks.

• A crow uses a Frisbee to ferry water to an awaiting flock.

• A Gila woodpecker makes a scoop from tree bark and uses it to carry honey home to its nest.

• A blue jay scrapes ants against its feathers, removing their coating of toxic formic acid, rendering them safe to eat.

• A crow uses pine cones as missiles against predators to defend its nest.

• A burrowing owl scatters animal dung at the entrance of its burrow and waits for dung beetles to come along, providing a free meal.

• Green-backed herons float insects on the water as bait to lure in fish, which they quickly snatch for their meal.

• Nuthatches use flakes of bark as a lever to pry bark off tree trunks, exposing insects.

• A chickadee uses a thorn to pry seeds out of a suet feeder.

• A cockatoo uses a heavy stick to beat on a hollow tree trunk to mark its territory and attract a mate.

• Many birds use twigs, leaf stems, thorns, or cactus spines to pry insects from holes too deep for their beaks to reach.

• A crow was filmed sliding down a snowy roof while riding atop a jar lid, which he carried up to use as a snowboard. □

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