ZOOLOGY STUDY GUIDE - Ye. O. Nevedomska - 2013

LECTURE 17. CLASS BIRDS (Aves)

Did you know that

- According to one version, the lesser coat of arms of Ukraine—the trident—is a stylized depiction of a peregrine falcon swooping down on its prey. The princes of Kyiv sought to embody strength, speed, and courage in this emblem.

- Small passerines cover 50-100 km a day, while ducks fly 100-500 km. American wood-warblers, migrating over the ocean, can fly non-stop for 3-4 thousand km during 60-70 hours of continuous flight.

- The ancestors of domestic chickens were wild red junglefowl. They were domesticated in India about 4 500 years ago. Through long-term selective breeding, humans have developed many chicken breeds.

- The domestic duck descends from the wild mallard, the ancestor of domestic goose breeds was the greylag goose, and the domestic pigeon originates from the rock dove.

- Many victims of shipwrecks died of thirst, as humans cannot drink salty seawater. However, tubenoses drink it with no ill effects. How do they manage this? Their excess salt is excreted by specialized glands through nasal openings connected to thin tubes.

- Some birds fly in a V-formation during migration. The strongest bird flies at the front, cutting through the air. The other birds position themselves to maintain the sharp angle of the V. This happens instinctively, as this formation minimizes aerodynamic drag.

From the world of science

- It was previously believed that Arctic birds dive for prey to depths of up to 10 m. However, Romanian scientists in their bathyscaphe spotted a loon diving for a fish. And at what depth do you think the bathyscaphe was? 80 m! This happened during a cold spell when fish descend deeper to warmer waters, and loons dive after them. Yet, king penguins broke all records, sometimes diving to depths of up to 200 m in search of food.

- Experimental studies show that migratory birds are capable of celestial navigation: choosing the correct flight direction based on THE POSITION OF the sun, moon, and stars. In overcast weather or when the starry sky pattern was altered during planetarium experiments, the birds' ability to orient themselves deteriorated significantly.

- Experiments have shown that birds' sense of time has an accuracy of 1015 minutes.

The evolutionary process

- According to traditional views, the evolution of birds began in the Jurassic period. In this version, Archaeopteryx (Archaeopteryx lithographica) is considered the oldest known bird species. In this context, birds are viewed as specialized theropods, closely related to other feathered dinosaurs of the maniraptoran group.

At the same time, several authors adhere to an alternative version, according to which the first reliable bird fossil is the highly controversial Protoavis from the Late Triassic. According to this theory, both birds and theropods originated from a single, earlier group of archosaurs.

Today, several different hypotheses regarding the ORIGIN AND EVOLUTION of birds have been proposed, but there is no universally accepted phylogeny.

For the curious

- Some dreamers of the past made wings like those of birds but could not take flight. How can the adaptation of birds to flight be explained from the perspective of physics? A bird's body is streamlined, which reduces drag. Air sacs, filling the spaces between Internal Organs, also reduce friction between them during flight and lighten the bird's body. For wing movements, a

rigid support is required, which is why most of the trunk bones are fused together. Body mass reduction is aided by: the absence of Teeth on the jaws, the lightness of the skeletal bones, most of which have air-filled cavities (pneumatic bones), rapid Digestion and excretion of waste, and the absence of a Urinary Bladder.

It is known from physics that the surrounding air exerts pressure on all objects. If the pressure on the upper surface of a body is less than on the lower surface, lift is generated. The wings of birds (and airplanes) create such a pressure difference. A bird's wing consists of two parts, somewhat different in their Functions. The part closer to the body generates the lift that keeps the bird in the air. The part further from the body provides forward propulsion. A crucial role in this is played by the primary flight feathers located at the wingtips. They are not rigidly fixed to the wing but are connected by a flexible membrane and move quite freely. The leading edge of each of these feathers is narrower than the trailing edge. When the wing is lowered, air resistance twists the primary flight feathers. As a result, for a brief moment, they turn at an acute angle to the rest of the wing and the direction of flight. The tilted feather pushes the air backward and downward, propelling the bird forward.

The lift of airplane wings is adjusted by flaps. In birds, an alula is located at the junction of the two PARTS OF THE wing. Like airplane flaps, the birds' alulae alter the lift of the wings during takeoff and landing.

A bird's tail feathers form an additional surface that presses against the air in flight and helps with braking during landing.

Interesting facts about THE ORIGIN OF bird names

- Great Bustard. Scientists believe that in the Slavic language there was a word "dropi", which meant "to flee" ("to run away"). Indeed, the bustard belongs to birds that run well but do not fly as well, since the bustard is the heaviest of all flying birds (weighing up to 16 kg).

- Woodpecker. The Ukrainian name of this bird shares the same ROOT as "dovbaty" (to peck): the ancient name of the bird was "deltel"—"hollow-carver."

- Crane. The Ukrainian name of this bird originates from the Old Indian "jarate"—"sings," "shouts"—meaning the bird's name originally signified "shouter" or "caller."

- Turkey. This gallinaceous bird was brought from America, but as we know, America was initially mistaken for India. When the famous explorer Christopher Columbus, searching for India, sailed to the islands between North and South America, he believed he had reached the shores of India. Consequently, the inhabitants of America were called "Indians." The bird brought from there was named "indyk" (from the Latin "indicus"—"Indian"). Thus, these birds are "Indian chickens," or "turkeys." The male of these birds is "indyk"—so while his name suggests he is "Indian," by origin, he is American.

- Hen (rooster and chicken). Of these three words, the oldest is "kur" ("rooster"); in many Slavic languages, this word meant "shouter,"

"singer." Later, the name "kura" appeared. The relatively new name for the female of this bird species is "kurka."

- Partridge. There is a noticeable connection between this word and "kura." Indeed, this name comes from "kur"—"rooster"—and the long-lost Slavic word "p'ta"—"bird" (from which we get the well-known "ptashka"). When combined, these two words mean "chicken-like bird."

- Swallow. In Lithuanian, "lakstiti" means "to fly." The Slavic "lasta" meant "flying (one)."

- Swan. The proud name of this beautiful bird is close to the Indo-European "alb," "elb," which means "white." It can be compared to the Latin "albus"—"white"—or to the name of the Elbe River (a river in Germany), which also means "White." It turns out that, at the time, only white birds received this name, as people back then did not know of any others. Therefore, when we say "black swan" today, it is as if we were saying "black white." Our ancestors were only familiar with white birds, which still live in Europe today, as well as in Asia and America. Black swans originate from Australia and are very rare here.

- Peacock. Here we must recall a little etymological tale. Once upon a time, there was a Latin word "papilio," which meant "tent" or "canopy." It had two French descendants: "pavilion"—"gazebo," "kiosk," "canopy"—and "papillon"—"butterfly." How the first word came about is quite clear: there is little difference between a "tent" and a "kiosk." The second word, however, was likely invented by someone with a rich imagination who found something in common between a colorful butterfly and a bright tent-like flower. Nothing extraordinary happened to the second word, but the first one had an interesting adventure. It entered the German language as the name of a beautiful, variegated bird that spread its tail like a luxurious canopy—a "pavilion." To German ears, this word "pavilion" sounded like "pavenkhen" or "pavenkhun"—"peacock hen." When this word reached us, we adopted it as "pavych" (and "pava" for the female bird), completely unaware of its connection to tents, kiosks, canopies, and butterflies.

- Ostrich. Imagine a sparrow and an ostrich side by side. You might say it is hard to imagine, as the ostrich is a true giant (nearly three meters tall and weighing up to 90 kg) compared to the sparrow. Yet, the sparrow can proudly claim that it, too, is an ostrich! The Greek word "strouthos," from which the word ostrich is derived, meant "bird," and sometimes simply "sparrow." The Greeks called the ostrich "strouthos megas"—"large sparrow." The Greeks had another name for the ostrich—"strouthokamelos," meaning "camel-bird" or "camel-sparrow." Indeed, the ostrich looks like a bird but runs instead of flying. It is large and clumsy, with an unsightly HEAD—how is it not a camel? Yet, it has several magnificent feathers on its tail—long, white, and fluffy. Everyone probably knows about them. But no one mentions that the rest of its feathers are gray and unremarkable. This plumage blends in with the sun-bleached grass, often saving the ostrich by allowing it to hide.