Unlucky "Island of the Devils"

In the photo - Bermuda typhoon , or kahou ( Pterodroma cahow ), on Nonsach Island ( Nonsuch Island ) Bermuda 3-3-3302. . This is a classic appearance representative of the family petrels 3-3-3302. , endemic 3-3-3302. for the archipelago.

Bermuda is a small archipelago in the northern Atlantic Ocean about a thousand kilometers from North America. From the very beginning of human development, these islands received notoriety. Sailors who visited this land area lost in the ocean in the sixteenth and seventeenth centuries spoke of the extremely difficult navigation among the islands surrounding the reefs and the otherworldly, devilish screams chasing the ships, especially in stormy weather. For Bermuda for a long time fixed 3-3-3302. nickname "The Isle of Devils". And in the last century, the vicinity of the islands became famous as an ominous place where, for inexplicable reasons, ships and aircraft disappear without a trace. Now the first association that comes to mind at the mention of the archipelago is the ominous Bermuda Triangle .

Whether this section of the sea is really different from other similar places in terms of danger to travelers or is it speculation rooted in popular culture is an open question. However, rumors of demonic voices off the Bermuda shores were justified. These cries were issued by those same kahou (you can listen to them 3-3-345. Here 3-3-3302.). Like a black cat from famous song They were considered messengers of misfortunes for travelers who met with them, but they themselves suffered much more.

Before the discovery by the Spaniards in 1503 there were no people in Bermuda, and about a million kahou nested there. But the active use by seamen and British settlers of bird colonies as an affordable source of meat, as well as the ruin of nests brought by pigs, dogs, cats and rats, quickly led to the disappearance of kahou: the species was considered extinct since 1621. However, a small part of the birds, apparently, was able to survive away from places inhabited by humans. In the first half of the XX century, in Bermuda, they began to find individual birds of this species, which encountered lighthouses and antennas. Finally, in January 1951 on a small rocky islet in Castle Bay (3-3-3351. Castle Harbor 3-3-3302.), A small colony of 18 individuals was opened, which was immediately taken under protection.

Seven-day chick kahou. Photo © J. Madeiros from Recovery Plan for the Bermuda Petrel (Cahow) Pterodroma cahow

Now the number of kahou is still extremely small and 3-3-375. estimated by International Union for Conservation of Nature (3-3-377. IUCN 3-3-3302.), Does not exceed 200 adults. However, even such a deplorable position of the species looks good compared to the fate of many other Bermuda endemic species.

Special studies of the history of the native fauna of these places began recently, at the beginning of the XXI century. They are closely related to the name of the American Storrs Olson , patriarch of modern paleoornithology. For many years, he and his colleagues studied the deposits from caves and faults in the rocks of Bermuda turned into two interesting discoveries in the natural history of the archipelago.

First, Biostratigraphy 3-3-3302. Fresh sedimentary rocks 3-3-3302. Bermuda showed a curious tier corresponding to periods 3–3–389. Pleistocene 3-3-3302. cold snap and shorter interglacial 3-3-3302. . Each new ice age greatly lowered the level of the world's oceans, which resulted in an increase in the area of all known land areas. Bermuda was no exception. The increase in area several times increased the number of habitable places and allowed many species of animals to more successfully colonize the archipelago and separate into separate species. Warming, on the contrary, led to an almost complete flooding of the island, after which many local species disappeared, and survivors were forced to adapt to changing conditions (the same thing happened, for example, on the atoll 3-3-3393. Aldabra 3-3-3302. In the Indian Ocean; see pictures of the day 3-3-3395. Aldabra Atoll 3-3-3302. And 3-3-3397. "Risen" shepherd from Aldabra 3-3-3302.).

A map of Bermuda today (3-3-3305. Black color 3-3-3306.) And during the Pleistocene glacial maxima (3-3-3305. Gray color 3-3-3306.). Figure from an article by S. L. Olson, et al., 2010.3-3r3115. Prodromus of vertebrate paleontology and geochronology of Bermuda

Changes in living conditions in Bermuda in relation to climatic cycles were well reflected in the dimensions of snails of the endemic genus 3-3-3305. Poecilozonites [/i] . These are small gastropod 3-3-3302. make up about 95% of the fossil terrestrial fauna of the islands (snail shells are well preserved, and the abundance of these invertebrates was initially high). A large amount of material suitable for study made it possible to identify several cases of a continuous increase in the dimensions of shells in the Pleistocene within the framework of the history of this genus. Initially, this was due to the expansion of the island area in 3-3-3129. glacial 3-3-3302. periods and an increase in the food supply of mollusks (and they eat almost everything - plants, 3-3-3131. biofilms 3-3-3302. on stones, sometimes even animal corpses). However, Olson and colleagues 3-3-3169. could identify Another important factor. During each glacial, a certain set of predators inhabited Bermuda, and the increase in the size of snails was most likely due to 3–3–3135. co-evolution of with them and the need to protect themselves from eating (large snails had either a more durable shell, or just not every predator crawled into the throat). The predators themselves, apparently, died out during each subsequent interglacial (interglacial), after which another invader took their place. Snails survived interglacial periods, leaving for a smaller dimensional niche (there was enough food for small individuals).

Resize snails 3-3-3305. Poecilozonites [/i] and their relationship with the presence of predators in Bermuda in the Middle and Late Pleistocene. Left - percentage of open land area on the platform of Bermuda and silhouettes of known predators that lived on them in certain periods ( shepherd Rallus recessus flightless duck Anas pachysceles Crane Grus latipes 3-3-3306., tortoise 3-3-3305. Hesperotestudo bermudae 3-3-3306.). In center column - morphotypes of snails demonstrating a connection with glacial and interglacial cycles. Right column indicates fluctuations in sea level over the considered period of time. Drawing from the article S. L. Olson, P. J. Hearty, 2010.3-3r3169. Predation as the primary selective force in recurrent evolution of gigantism in Poecilozonites land snails in Quaternary Bermuda

Secondly, the study of the most recent subfossil 3-3-3302. (not completely petrified) bird remains from Bermuda showed that since the invasion of the human archipelago and 3-3-3179. synanthropic 3-3-3302. (living next to humans) mammals, its avifauna has lost several endemic bird species: 3–3–3305 quack. Nyctanassa carcinocatactes , buzzard Bermuteo avivorus , owl Aegolius gradyi , Shiloklyuvy woodpecker Colaptes oceanicus and taui Pipilo naufragus . Now the islands are stable 3-3-3302 nest. 17 species of birds, but only kahou and the local subspecies 3-3-3205. white-eyed vireon ( Vireo griseus bermudianus ) Are endemic to the archipelago. All species of Bermuda nesting or nesting land birds are of American origin.

Left - Comparison of the bones of the cranium and beak of the Bermuda taui (in all pairs - on the left) and now living red-eyed taui ( Pipilo erythrophthalmus ), Its closest relative and probable ancestor. The length of the scale segment is 2 cm. Photo from the article S. L. Olson, D. B. Wingate, 2012.3-3r3233. A new species of towhee (Aves Emberizidae Pipilo) from Quaternary deposits on Bermuda . Right - red-eyed taui (male) in vivo. The Bermuda taui looked similar, but was slightly larger and had a noticeable reduction in the bones of the wings and keel . Photo © Davey Walters from ebird.org , state Virginia 3-3-3302. , USA 3-3-3307.

The above five are extinct in Holocene 3-3-3302. endemic figures appear in diary observations of travelers visiting the archipelago shortly after its discovery. But the descriptions of these birds are brief and not very informative. So, the British traveler and writer William Streichy ( William Strachey ) In his recollections of his stay in Bermuda in 1609-1610 wrote about "sparrows, fat and chubby, like our oatmeal, but bigger" - apparently, referring to the Bermuda taui, who really have a distant relationship with oatmeal . However, even such fragmentary information allows us to judge that people found these birds, and, most likely, contributed to their extinction. The most disastrous 3-3-33257. anthropogenic factors 3-3-3302. considered introduction of 3-3-3302. terrestrial mammals, which previously were not in Bermuda, and the destruction of primary 3-3-33261. biotopes 3-3-3302. under the needs of man. The number of other Bermuda animals also decreased due to human faults: due to invasive predatory snails and 3-3-33263. planar (as well as rats and ants) the former variety of snails of the genus 3-3-3305. Poecilozonites [/i] decreased to two species, both are on the verge of extinction. Also on the verge of extinction is the only autochthonous species of lizards - Bermuda skink (3-3-3305. 3-33270. Plestiodon longirostris 3-3-3302. 3-3-3306.).

Snail Poecilozonites bermudensis . Photo from Chester Zoo , which runs a program to restore the population of the species in captivity 3-3-3307.

The difficult fate of ecosystems The archipelago with cycles of uplifts and flooding in the Pleistocene, constant impacts of tropical cyclones, and even with an anthropogenic ending in the Holocene makes one involuntarily recall another song, famous in the Soviet years, - “The island of bad luck” . However, an analysis of world experience in studying island ecosystems shows that similar processes took place on almost all isolated oceanic islands. The introduction of species into such ecosystems at a short distance promises paradise life in a stable climate and with low pressure of predators, but at a long distance there is a much higher risk of extinction (which increases with the arrival of a person on the islands) than the existence of living conditions in changeable, dangerous conditions continents.

Photo © Jeremy Madeiros from birdlife.org .

Pavel Smirnov