Posts Tagged ‘Nathan Emery’

Birds are Technical Wizards

October 9, 2019

This post is based on “The Genius of Birds”, a book by Jennifer Ackerman. There are many accounts of birds using found objects as tools—to contain water water or scratch their backs, wipe themselves down or lure prey. For example, white storks bring water to their chicks in a clump of damp moss and then wring it out to fill their beaks. African greys arrest bail water from their dish with a tobacco pipe or bottle cap. American crows ferry water in a Frisbee to dampen its dried mash, and another one secured a plastic Slinky toy onto its perch and used the free end to scratch its head. A Gila woodpecker fashioned a wooden scoop out of tree bark to carry honey home to its young. A blue jay used its own body as a napkin to rid ants of their noxious formic acid spray, making them fit for eating.

Birds also use objects as weapons. An American crow lobbed three pinecones at a scientist’s head as he climbed up to its nest. A pair of ravens defending their nestlings from two intruding researchers used similar tactics but harder weaponry. A raven took a rock in its beak and with a quick flip of its head tossed the rock down to the target. It was followed by six more one after another, assaulting the scientists who were trying to study them.

Several kinds of birds use objects as lures to draw fish. Green herons are expert bait fishers, drawn to entice their prey with bread, popcorn, seeds, flowers, live insets, spiders, feathers, and pellets of fish food.

For the burrowing owl, dung is the decoy of choice. These owls scatter clumps of animal feces near the mouth of their nest chambers and wait motionless like muggers for unsuspecting dung beetles to scuttle toward their trap.

Nuthatches hold bark flakes or scales in their bills to level the bark from trees, exposing the bugs beneath.

Black palm cockatoos regularly use sticks, twigs, and branches as drumsticks to thrum a hollow tree for territorial display or to direct a female’s attention to a possible breeding holes. These items are used as back scratchers (as well as head, neck, and throat scratchers by yellow-crested cockatoos and African grey parrots. Bald eagles used a stick to bludgeon a turtle with a stick held in its bill.

Behavioral biologist Sabine Tebbich did a detailed study of a woodpecker finch to see how birds acquire their use of tools. At first the finch showed little interest in objects. When he was almost two months old, he began to play with flower stems and small twigs, twiddling them in his beak and holding them at right angles to his bill. He soon was investigating everything around him with great curiosity, tweaking buttons, nibbling pencils, yanking hair through the small ventilation holes in a slouch hat, prying apart toes with his beak and tools inspecting ears and earrings. Within three months, he was an accomplished tool user and had broadened his toolkit, probing cracks with twigs, a feather, fragments of water-worn glass, wool slivers, shell pieces, and the hind leg of a large tree grasshopper. He also inserted a twig between a sock and a boot.

The New Caledonian crow leads in terms of artful toolmaking and tool use in the wild. Ms. Ackerman writes, “when it comes to the nuts and bolts of too crafting, only chimps and orangutans match or exceed the sophistication of the New Caledonian crow, and not even these hotshot primates can make hook tools, These crows make not one but two kinds of hook tools—one from live twigs and the other from the barbed edges of leaves of pandas trees, or screw pines.

One wonders whether birds play? Do they do things just for fun? Nathan Emery and Nicola Clayton suggest that larger-brained, altricial species of birds do play as do many mammals. It does seem to be relatively uncommon in birds, seen in only 1% of the approximately 10,000 species and is largely restricted to species with an extended developmental period, such as crows and parrots. Emery and Clayton say that play may reduce stress, aid social bonding and induce pleasure. They explain “Birds, like us, may also play because it is fun; it produces a pleasurable experience—releasing endogenous opioids.”