Еуразиялық қамыс торғайы

Eurasian bird

The great reed warbler (Acrocephalus arundinaceus) is a Eurasian bird in the passerine genus Acrocephalus. The genus name Acrocephalus is from Ancient Greek akros, "highest", and kephale, "head". It is possible that Naumann and Naumann thought akros meant "sharp pointed". The specific arundinaceus is from Latin and means "like a reed", from arundo, arundinis, "reed". It used to be placed in the Old World warbler assemblage, but is now recognized as part of the marsh and tree warbler family (Acrocephalidae). Great reed warblers are medium sized birds and are the largest of the European warblers. They breed throughout mainland Europe and the west Palearctic and migrate to sub Saharan Africa in the winter. Great reed warblers favour reed beds as their habitat during breeding months, while living in reed beds, bush thickets, rice fields, and forest clearings during the winter. Great reed warblers exhibit relatively low sexual dimorphism, and both genders of the species are similar in appearance. This species mates both polygynously and monogamously.

The thrush sized warbler is one of the largest species of the former family, the Old World warblers and it stands as one of the largest species in the family Acrocephalidae. It measures in length, in wingspan and weighs The adult has unstreaked brown upperparts and dull buffish white chin and underparts. The forehead is flattened, and the bill is strong and pointed. It looks very much like a giant Eurasian reed warbler (A. scirpaceus), but with a stronger supercilium. The sexes are identical, as with most old world warblers, but young birds are richer buff below. The warbler's song is very loud and far carrying. The song's main phrase is a chattering and creaking carr carr cree cree cree jet jet, to which the whistles and vocal mimicry typical of marsh warblers are added.

A. arundinaceus has a primarily carnivorous diet. Observation of prey collection specifically during breeding season has shown the retrieval of insect larvae, moths, dragonflies, damselflies, beetles, spiders, small fish, and frogs. A. arundinaceus has also been reported to eat fruit during non breeding seasons. Nestlings typically feed on diptera and arachnids, though this may not be their preferred food.

Male great reed warblers have been observed to communicate via two basic song types: short songs about one second in length with few syllables, and long songs of about four seconds that have more syllables and are louder than the short variety. It has been observed that long songs are primarily used by males to attract females; long songs are only given spontaneously by unpaired males, and cease with the arrival of a female. Short songs, however, are primarily used in territorial encounters with rival males. During experimental observation, male great reed warblers showed reluctance to approach recordings of short songs, and when lured in by long songs, would retreat when playback was switched to short songs.

Great reed warbler females lay 3–6 eggs in an open cup nest in reeds. Some pairs of warblers are monogamous, but others are not, and unpaired, so called "satellite" males still father some young. Great reed warblers defend their nests using graded alarm calls, directed towards a wide range of enemies, although these alarm calls might reveal the whereabouts of the nest to brood parasites. A long term study of the factors that contribute to male fitness examined the characteristics of males and territories in relation to annual and lifetime breeding success. It showed that the arrival order of the male was the most significant factor for predicting pairing success, fledgling success, and number of offspring that survive. It also found that arrival order was closely correlated with territory attractiveness rank. Females seem to prefer early arriving males that occupy more attractive territories. These females also tend to gain direct benefits through the increased production of fledglings and offspring that become adults. In addition, male song repertoire length is positively correlated to annual harem size and overall lifetime production of offspring that survive. Song repertoire size alone is able to predict male lifetime number of surviving offspring. Females tend to be attracted to males with longer song repertoires since they tend to sire offspring with improved viability. In doing so, they gain indirect benefits for their own young. Great reed warblers have a short, polygynous breeding cycle in which the male contributes little to parental care. They defend large territories in reed beds where there is reduced visibility, which may allow males to practice deception by moving and attracting a second female. This second female may not realize that the male has already mated. Polygyny of the great reed warbler was assessed in another study that showed the importance of female choice. The differences in territory characteristics seemed to be more important. However, there is also a strong correlation between males and their territory characteristics. Models based on the polygyny threshold and sexy son hypotheses predict that females should gain evolutionary advantage in either short term or long term in this mating system, yet the study did not support this. The data showed that secondary females had greatly reduced breeding success.