Poisonous birds. Pesticide poisoning

It is difficult to imagine that among the poisonous animals there are also birds. But nothing is impossible in nature. It turns out that among birds there are individuals who are ready to cause great trouble to those who touch them.
Among the few representatives of these dangerous representatives of the animal world, one stands out: Pitohui dichrous, or blackbird flycatcher. This small and not very noticeable bird from the genus of passerine birds (the family of Australian whistlers) has one ominous feature - it is the most poisonous in the world.
It was only recently discovered that the blackbird flycatcher is poisonous. This discovery was accidental and occurred in 1989. Ornithologist Jack Dumbacher, disentangling these same birds from the web, scratched his finger, which he then, instead of basic medical treatment, put in his mouth and immediately felt that his lips, tongue and entire mouth were numb. The degree of his reaction to this poison turned out to be small, and such “communication” did not harm him much. But the ornithologist's discovery was very significant for the scientific community.
Zoologists became aware of the peculiarity of this bird, which lives in New Guinea, not so long ago, just over half a century.
Pitohu is slightly smaller in size than the common jackdaw. Its head, wings and tail are black, but the rest of the plumage is reddish-brown.
Like many representatives of the passerine order, its size does not exceed 20-25 centimeters. There are also larger individuals up to 30 centimeters long. Birds weigh 400-500 grams.
Bright black-orange or blue-orange coloring, like many brightly colored animals, is a warning signal that its owner is poisonous. Initially, it was believed that males have brighter colors, but females are not at all behind them, either in brightness of color or in size.
The pitoh's diet consists of small invertebrate animals and small fruits. Pitokha most often build their nests, which resemble a bowl, in rock crevices or in trees. They lay 1 - 4 olive or white with dark spots. The clutch is incubated for 16 - 18 days, and then the chicks can fly out of the nest on the 13th - 16th day.
This bird is completely saturated with poison - batrachotoxin, which causes disturbances in heart rhythm and scattered and uncoordinated contraction of the muscle fibers of the heart muscle (fibrillation).
It is found everywhere - in feathers, on the skin and even in internal organs. In addition to this bird, poison dart frogs that live in South America, but unlike them, its concentration in the bird’s body is much lower.
Why is Pitohu so poisonous? The fact is that they belong to the so-called secondary poisonous animals, which accumulate exogenous poison. This poison enters the bird's body along with food - one of the types of poisonous beetles (Choresine pulchra), in the body of which a high concentration of batrachotoxin is found.
The pitohus themselves have fully adapted to the poison; it is completely harmless to them, but other species may suffer from it. The poison accumulates in the feathers and skin, as well as in certain internal organs of birds. Its composition is similar to the venom of snakes and scorpions, and is 100 times stronger than strychnine!
As scientists have found, the concentration of poison in the body of the blackbird flycatcher can change. It turns out that if you remove this poisonous bug from their diet, then within a fairly short period of time they lose their deadly properties. As they say, no poison - no danger. But they are still not eaten; they say that their meat is very bitter.

Bicolored Blackbird Flycatcher

Blue-capped Ifrita

Poisonous birds - representatives of the class Birds (Aves), whose bodies contain substances that are toxic to humans or other animal species. Birds are passively poisonous animals, that is, the toxin (poison) is not synthesized in their bodies, but only accumulates in them, being integral part some of the objects of their diet.

Long time Scientists believed that there were no poisonous species among birds. The first poisonous bird was discovered in 1989. It became a two-colored thrush flycatcher, or pitahu ( Pitohui dichrous). During an ornithological study in the tropical forests of New Guinea, birds were captured. Caught thrush flycatchers scratched the hands and pecked at the researchers. People involuntarily brought itchy skin lesions to their mouths and moistened them with saliva. As a result, my lips instantly became numb. Later, when studying these birds, a zootoxin similar to batrachotoxin, characteristic of South American dart frogs, was discovered in their skin, feathers and internal organs.

Later, the list of poisonous birds expanded significantly. Currently, five poisonous species have been identified that belong to the genus of thrush flycatchers ( Pitohui; Lesson, 1831) from the order Passeriformes.

Another type of poisonous bird is the blue-capped ifrit ( Ifrita kowaldi), the toxicity of which was discovered in 2000. It is endemic to the tropical rainforests of New Guinea.

Not always poisonous birds

Spur goose

Other poisonous species whose toxicity is not constant and occurs only when sources of toxins appear in their diet are the spur goose ( Plectropterus gambensis), native to tropical sub-Saharan Africa, and the common quail. The toxicity of the spur goose is associated with feeding on poisonous blister beetles (Meloidae), etc.

Various sources describe numerous cases of poisoning by common quail meat. The causes of poisoning were unknown for a long time, although the first information about them was published in the literature back in the 17th century. “Description of Ukraine from the borders of Muscovy to the borders of Transylvania, compiled by Guillaume Levasseur da Beauplan” (translation of 1660), contains the following lines: “In this area there is a special kind of quail with blue legs and deadly to those who eat it.” Beauplan's assumptions that poisonous quails belong to a “special genus”, distinguished by the color of their legs, are erroneous.

The cause of poisoning is the cumulation (accumulation) of toxic substances in poultry meat after birds eat pikulnik seeds. Alkaloids contained in the seeds of this plant cause blocking of motor nerve endings in striated muscles. The action of many toxins is strictly specific, so quail can feed without harm on the seeds of some plants that are poisonous to humans and domestic animals. The poison is resistant to high temperatures. Heat treatment of quail meat does not destroy it. Poisoning in humans occurs as a result of eating not only the meat of “poisonous” birds and soups made from them, but also potatoes fried in quail fat. The clinical picture of poisoning appears 3-4 hours later, and sometimes 1 hour (in extremely rare cases, 15-20 hours) after consuming toxic meat. The first symptom is general weakness; people can hardly move their legs, and sometimes stop moving at all. A little later, acute pain occurs, localized in the calf muscles, and then - girdling pain in the lower back, back and chest. Breathing becomes shallow and frequent. Then severe pain also occurs in the arms and neck. Movement of the limbs (flexion and extension), especially the arms, becomes impossible due to pain and stiffness occurs. The pain persists from 2 to 12 hours, sometimes up to a day, extremely rarely - 2-3 days. Usually, fatal outcome absent.

There are studies indicating that the cause of quail meat poisoning may be the seeds of hemlock (poisonous hemlock), which the birds feed on. In this case, poultry meat accumulates such amounts of toxin that even a small amount causes poisoning. Common quails are able to feed on hemlock fruits without harm, and in humans, the meat of such birds can cause symptoms of horsemeat poisoning. The latter is similar in its effect on the human body to nicotine, but is characterized by a strong paralyzing effect on the central nervous system and at neuromuscular synapses. In addition to horsemeat, hemlock seeds contain a number of alkaloids and extremely toxic coniceine. The clinic of poisoning by meat of quails that fed on hemlock fruits is manifested in the development of feelings

Pitohui. This strange and funny name is given to an orange and black bird from New Guinea, whose skin, feathers and some organs contain strong poison. Although it is well known that other animals, including a number of snakes, insects and frogs, produce toxins that repel enemies, it was thought that birds did not. Thus, the discovery of a similar adaptation in pitohua has overturned some existing ideas about the defensive strategies and coloration of birds.

The defense mechanism of this bird was discovered by J. Dambecher from the University of Chicago. He felt numbness and a burning sensation in his mouth after licking
hands after holding a crested pitohui, considered a “trash” bird in New Guinea because of the taste of its skin. Dambe Bacher and his colleagues reported that three species of the genus Pitohui—crested, variable, and rusty—produce a toxic substance they identified in 1992.

This substance, homobatrachotoxin, turned out to be identical to the compound contained in South American frogs (Indians poison their arrows with them), which are also distinguished by their aposematic, i.e., warning orange-black color. "I was very surprised," says J. Daly of the National Institutes of Health, who did a chemical analysis of the toxin on these frogs in the 1970s and on the pitohua last year. - Surely we're talking about about the specific evolutionary ability to accumulate this substance. I would prefer the word 'produce', but it is unclear whether it is extracted from food."

Although the pitohui is the first poisonous bird mentioned in literature, stories about inedible birds have been known for a long time. Some experts expected such a discovery. “I’m not at all surprised,” explains ornithologist L. Brouwer of the University of Florida, “especially considering that some insects are poisonous, and birds behave exactly like such insects: they are clearly visible and brightly colored.”

Traditionally, ornithologists have associated birds' striking plumage with courtship and mating success. However, the bright color of the pitohui could serve as a warning to predators. The fact that it is the same in the male and female of this species reinforces such a hypothesis. And just as in the case of the poisonous Danaid butterfly, non-toxic imitators of the appearance of the pitohui are known.

Research conducted in the 1940s and 1950s supports the possibility of an inverse relationship between color and edibility. Zoologist H. Cott of the University of Cambridge observed in Africa that some wasps avoid the carcasses of certain birds, although they feed on others. Cott tested a number of birds using these wasps. The results inspired him to carry out a double-blind gastronomic experience. The wife of one of Cott's colleagues prepared dishes from 200 species of birds. After the lunch given to them, those present confirmed the “Cott’s rule”: the more unattractive the bird, the tastier it is. Species with protective coloring, i.e. the kind that allows them to blend into the background are the most delicious.

“Conversely, some evidence suggests the apparent inedibility of very conspicuous species from many genera; examples include the shelduck, crocodile keeper, magpie and swallow,” writes Cott. However, J. Diamond of the University of California, Los Angeles, reported that his field workers who ate pitohua had no adverse effects.

If we ignore gastronomy, the meaning of color can be twofold: bright plumage is due to both the presence of a toxin and sexual selection. According to Brouwer, these two factors are not mutually exclusive. It is possible that sexual selection initially favored brightly colored males and inconspicuous females. However, if the birds began to eat something containing a toxin, which turned out to be effective means protection from predators, then natural selection, according to Brouwer, could well have led to the appearance of bright colors in females.

Ecologist S. Temple from the University of Wisconsin discovered a correlation in birds between a fruit-rich diet and aposematic coloration. According to his hypothesis, such food allows the accumulation of substances that can turn into toxins. (Cott doesn't link the birds' diet to their taste.) Temple said he also discovered a poisonous bird, the pink pigeon from Mauritius, but has not yet published his findings. This species appears to extract a toxic alkaloid from its food. “It’s probably still not extinct thanks to this defense mechanism, Temple notes. “The dodo and some other birds of Mauritius were barbarically exterminated.”

Dumbeicher, Daley and their colleagues plan to study the pitohua's potential enemies and see if its toxin repels them. They are also studying this species itself in search of a mechanism that protects against self-poisoning. Homobatrachotoxin opens ion channels in cell membranes, which leads to excessive penetration of sodium into cells. However, creatures are known that are resistant to their own poison. Their ion channels do not respond to it; Daly expects to find a similar mechanism in pitohua.

Did you know that there are poisonous birds? Their name is crested pitohu. But how can a bird poison, because it does not have a sting or a long tongue...

When we talk about the ostrich, we immediately think of the powerful legs of the African bird, with the blow of which it can even knock down a horse. Therefore, during the breeding season, people do not approach males, knowing about their aggressiveness. Australian cassowaries, armed with a sharp claw, are no less dangerous. But hardly anyone has heard of poisonous birds, and it is even more difficult to imagine that touching their feathers can cause the death of a living creature. The fact is that these little birds, no larger than a jay, live exclusively in tropical forests New Guinea.

The Latin name for the crested pitohu is Pitohui dichrous. Scientific name This bird is a bicolored blackbird flycatcher.

There is not much information about the biology and ecology of these birds. detailed information. But about the poisonousness of these birds local residents have known for a long time. Reliable information about poisonous birds with orange feathers became available to Europeans only in the 90s of the last century. Before this, only Covaldi's blue-headed efreet was considered the only poisonous species among birds.

The body size of the pitohu reaches 25 centimeters. There are also larger individuals up to 30 centimeters long. Birds weigh 400-500 grams.

The color of the plumage is dominated by black tones, the beak is long and thin, the head, throat, and wings are also black. The feathers on the back, chest and neck have a contrasting color; they are defiantly yellow-orange. This whole color scheme seems to warn: “Don’t touch me!” The head is decorated with a noticeable crest. Biologists call this provocative coloration a warning; the animal carrying the toxicity seems to apologize for its dangerous qualities and warns predators who may prey on the pita.

This species of bird inhabits the Guinean forests, which are full of a variety of insects, along with its relative, the blue-headed ifrit covaldi. Pitohu is an exclusively insectivorous bird and only in rare cases can it switch to feeding on seeds. But this attractive and at first glance completely harmless bird secretes a very strong poison. Scientists have classified the toxic substance as batrachotoxin BTXs, which is identical to the poison secreted by the skin of dart frogs living in Colombia. This poison is very dangerous, even strychnine, which is used to fight harmful rodents, is 100 times weaker.

In pitohu, the poison is not concentrated to the same extent as in amphibians. For 60-65 g of bird mass there are 15-20 mg of toxin, which is found in the skin and 2-3 mg of the toxic substance is contained in feathers. Dogs, rabbits, toads, mice and frogs die within a short period of time, within minutes. People are only at risk of poisoning or skin burns if they come into contact with the body of a bird. And for clarity, we can give the following figures as an example: the poison contained in the body of a bottom-dwelling tropical bird can infect 800 mice.

Feathers are impregnated with a poisonous substance, internal organs feathered carrier of death. It is still puzzling that the pitoh does not need poison at all to hunt insects. The insectivorous bird deftly collects various small animals with its thin beak without any paralysis by poison. But then the question remains: why such a huge dose of a toxic substance in the body of a small bird?

According to the version proposed by scientists, the bird becomes poisonous after eating nanisani beetles, the body of which contains a huge amount of toxic substances. For the pitoh, these insects are tasty prey and do not cause any negative consequences for the bird. Through pores in the skin, the poison gradually comes out and concentrates in the integument, causing the death of all animals that encroach on the small bird. And another question naturally arises, troubling the minds of curious biologists: why does poison have no effect on the pitoh’s body at all, and self-poisoning never occurs? In general, not a bird, but a continuous tangle of contradictions.

For people, this bird is unlikely to be very dangerous. The crested pitohu lives in too inaccessible places, and it is unlikely that anyone will go to the impenetrable forests of Guinea to get acquainted with such an interesting representative of birds. Only for scientists does this bird serve as an object of careful study; the way of life, reproduction and poisonous qualities of the crested pitot are represented by interesting material for a true naturalist.

Perhaps new ones are waiting for them amazing discoveries. But you still need to know that the animal world on our planet is very diverse, and even among such cute birds there are poisonous individuals, even a simple touch of which can create many problems for human health. Poison causes characteristic features poisoning: numbness of the limbs, burning of the skin, paralysis, therefore the pitohu is considered a potentially life-threatening bird.