Great reed warbler | |
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Adult at a bird banding station | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Passeriformes |
Family: | Acrocephalidae |
Genus: | Acrocephalus |
Species: | A. arundinaceus |
Binomial name | |
Acrocephalus arundinaceus | |
Range of A. arundinaceus Breeding Passage Non-breeding | |
Synonyms | |
Turdus arundinaceusLinnaeus, 1758 Contents |
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". [3]
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. [4] 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 16–21 cm (6.3–8.3 in) in length, 25 to 30 cm (9.8 to 11.8 in) in wingspan and weighs 22 to 38 g (0.78 to 1.34 oz). [5] [6] [7] 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.
The great reed warbler breeds in Europe and the west Palearctic. It does not breed in Great Britain - where it is replaced by the closely related common reed warbler, Acrocephalus scirpaceus - but is an irregular visitor. Its population has in recent decades increased around the eastern Baltic Sea, while it has become rarer at the western end of its range. It is a migratory bird, wintering in tropical Africa. This bird migrates north at a rather late date, and some birds remain in their winter quarters until the end of April. [1] [8] [9]
While there are no subspecies of this bird, mtDNA haplotype data indicate that during the last glacial period there were two allopatric populations of great reed warbler. The great reed warblers in southwestern and southeastern Europe were at that time apparently separated by the Vistulian-Würm ice sheets and the surrounding barren lands. Though the data are insufficient to robustly infer a date for this separation, it suggests the populations became separated around 80,000 years ago – coincident with the first major advance of the ice sheets. The populations must have expanded their range again at the start of the Holocene about 13,000 years ago, but even today the western birds winter in the west and the eastern birds in the east of tropical Africa. [9]
During 2017–2019, miniature data loggers were used to track migratory flights of great reed warblers, over the Mediterranean Sea and Sahara Desert, between their breeding grounds at Lake Kvismaren, Sweden, and their winter quarters in sub-Saharan Africa. [4] When over the Sahara Desert, some birds would ascend to altitudes exceeding 5 km. As of 2023, these are the highest recorded avian ascents. [10] For comparison, such altitudes are comparable to those of the summits of the highest mountains in Africa and Europe. Possible explanations for such high--altitude ascents include avoidance of predation, reduction of risk of hyperthermia and dehydration, and extension of the visual horizon. [4] [10]
This passerine bird is found in large reed beds, often with some bushes. On their breeding grounds, they are territorial. In their winter quarters, they are frequently found in large groups, and may occupy a reed bed to the exclusion of other birds. [8] Like most warblers, it is insectivorous, but it will take other prey items of small size, including vertebrates such as tadpoles.
The great reed warbler undergoes marked long-term population fluctuations, and it is able to expand its range quickly when new habitat becomes available. This common and widespread bird is considered a species of least concern by the IUCN. [1] [9] Population size can be calculated with a suitability model, but direct counts of territorial males in suitable habitat and sampling the population sex-ratio can be a proper alternative to inference-rich predictive modeling based on imperfect habitat-extrapolation of densities of reed warblers at large spatial scales. [11]
Population densities of Great reed warblers (mean±SD) in European countries | ||||||||||||||||
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Country | Method | Pairs/ha | Birds/ha | Nests/ha | Ref. | |||||||||||
Spain | Transect | - | 1.4 | - | [11] | |||||||||||
Slovakia | Nest | 6.5±6.2 | - | - | [12] | |||||||||||
Poland | Nest | - | - | 2.5±1.8 | [13] | |||||||||||
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. [14] A. arundinaceus has also been reported to eat fruit during non-breeding seasons. [15] Nestlings typically feed on diptera and arachnids, though this may not be their preferred food. [16]
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. [17]
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. [17]
Traditionally, monogamous species of genus Acrocephalus use long, variable, and complex songs to attract mates, whereas polygynous varieties use short, simple, stereotypical songs for territorial defence. There is evidence that long songs have been evolved through intersexual selection, whereas short songs have been evolved through intrasexual selection. The great reed warbler is a notable example of these selective pressures, as it is a partial polygynist and has evolved variable song structure (both long and short) through evolutionary compromise. [17]
In addition to communication, the great reed warbler's song size has been implicated in organism fitness and reproductive success. Though no direct relationship has been found between song size and either territory size or beneficial male qualities, such as wing length, weight, or age, strong correlation has been observed between repertoire size and territory quality. Furthermore, partial correlation analysis has shown that territory quality has significant effect on the number of females obtained, while repertoire length is linked to the number of young produced. [18]
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. [19] Great reed warblers defend their nests using graded alarm calls, directed towards a wide range of enemies, [20] although these alarm calls might reveal the whereabouts of the nest to brood parasites. [21]
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. [22] [23]
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. [24] [25]
The cuckoo, common cuckoo, European cuckoo or Eurasian cuckoo is a member of the cuckoo order of birds, Cuculiformes, which includes the roadrunners, the anis and the coucals.
The dunnock is a small passerine, or perching bird, found throughout temperate Europe and into Asian Russia. Dunnocks have also been successfully introduced into New Zealand. It is the most widespread member of the accentor family; most other accentors are limited to mountain habitats. Other, largely archaic, English names for the dunnock include hedge accentor, hedge sparrow, hedge warbler, and titling.
The Eurasian blackcap, usually known simply as the blackcap, is a common and widespread typical warbler. It has mainly olive-grey upperparts and pale grey underparts, and differences across the five subspecies are small. Both sexes have a neat coloured cap to the head, black in the male and reddish-brown in the female. The male's typical song is a rich musical warbling, often ending in a loud high-pitched crescendo, but a simpler song is given in some isolated areas, such as valleys in the Alps. The blackcap's closest relative is the garden warbler, which looks quite different but has a similar song.
The common reed warbler is an Old World warbler in the genus Acrocephalus. It breeds across Europe into the temperate western Palaearctic where it is migratory, wintering in sub-Saharan Africa. It is also a resident species over large parts of Africa.
The sedge warbler is an Old World warbler in the genus Acrocephalus. It is a medium-sized warbler with a brown, streaked back and wings and a distinct pale supercilium. Sedge warblers are migratory, crossing the Sahara to get from their European and Asian breeding grounds to spend winter in Africa. The male's song is composed of random chattering phrases and can include mimicry of other species. The sedge warbler is mostly insectivorous.
The aquatic warbler is an Old World warbler in the genus Acrocephalus. It breeds in temperate eastern Europe and western Asia, with an estimated population of 11,000-15,000 pairs. It is migratory, wintering in west Africa. After many years of uncertainty, the wintering grounds of much of the European population were finally discovered in Djoudj National Bird Sanctuary, Senegal, with between 5,000 and 10,000 birds present at this single site. Its south-westerly migration route means that it is regular on passage as far west as Great Britain and Ireland.
The marsh warbler is an Old World warbler currently classified in the family Acrocephalidae. It breeds in temperate Europe and the western Palearctic and winters mainly in southeast Africa. It is notable for incorporating striking imitations of a wide variety of other birds into its song.
Blyth's reed warbler is a species of reed warbler belonging to the family Acrocephalidae, which also includes the tree warblers. Blyth's reed warbler breeds across the Palearctic zoogeographical region and winters in South Asia. The species has been expanding its range westwards in Europe.
The moustached warbler is an Old World warbler in the genus Acrocephalus. It breeds in southern Europe and southern temperate Asia with a few breeding in north-west Africa. It is partially migratory. South-west European birds are resident, south-east European birds winter in the Mediterranean breeding range, and the Asiatic race migrates to Arabia, India and Pakistan.
The European pied flycatcher is a small passerine bird in the Old World flycatcher family. One of the four species of Western Palearctic black-and-white flycatchers, it hybridizes to a limited extent with the collared flycatcher. It breeds in most of Europe and across the Western Palearctic. It is migratory, wintering mainly in tropical Africa. It usually builds its nests in holes on oak trees. This species practices polygyny, usually bigamy, with the male travelling large distances to acquire a second mate. The male will mate with the secondary female and then return to the primary female in order to help with aspects of child rearing, such as feeding.
The zitting cisticola or streaked fantail warbler is a widely distributed Old World warbler whose breeding range includes southern Europe, Africa, and southern Asia down to northern Australia. A small bird found mainly in grasslands, it is best identified by its rufous rump; in addition it lacks any gold on the collar and the brownish tail is tipped with white. During the breeding season males have a zigzagging flight display accompanied by regular "zitting" calls that have been likened to repeated snips of a scissor. They build their pouch nest suspended within a clump of grass.
The magnolia warbler is a member of the wood warbler family Parulidae.
The American redstart is a New World warbler. It is unrelated to the Old World (common) redstart.
The black-throated blue warbler is a small passerine bird of the New World warbler family. Its breeding ranges are located in the interior of deciduous and mixed coniferous forests in eastern North America. Over the cooler months, it migrates to islands in the Caribbean and Central America. It is very rarely found in western Europe, where it is considered to be a non-indigenous species. The black-throated blue warbler is sexually dimorphic; the adult male has a black face and cheeks, deep blue upperparts and white underparts, while the adult female is olive-brown above and light yellow below.
The Australian reed warbler is an Old World warbler in the genus Acrocephalus and is the only Acrocephalus species native to Australia. It has also been observed in Papua New Guinea and nearby islands. The name Acrocephalus refers to the peaked crown found on reed warblers in this genus and can be translated to mean "topmost head" in Greek. The species name australis is translated to mean "southern" in Latin, and refers to the species range, Australia. In its western range the Australian reed warbler is also known as "Koordjikotji" in the local Aboriginal language of Perth and its surrounds.
The Seychelles warbler, also known as Seychelles brush warbler, is a small songbird found on five granitic and corraline islands in the Seychelles. It is a greenish-brown bird with long legs and a long slender bill. It is primarily found in forested areas on the islands. The Seychelles warbler is a rarity in that it exhibits cooperative breeding, or alloparenting, which means that the monogamous pair is assisted by nonbreeding female helpers.
The Oriental reed warbler is a passerine bird of eastern Asia belonging to the reed warbler genus Acrocephalus. It was formerly classified as a subspecies of the great reed warbler of the western Palearctic.
The polygyny threshold model is an explanation of polygyny, the mating of one male of a species with more than one female. The model shows how females may gain a higher level of biological fitness by mating with a male who already has a mate. The female makes this choice despite other surrounding males because the choice male's genetics, territory, food supply, or other important characteristics are better than those of his competitors, even with two females on the territory.
Polygyny is a mating system in which one male lives and mates with multiple females but each female only mates with a few males. Systems where several females mate with several males are defined either as promiscuity or polygynandry. Lek mating is frequently regarded as a form of polygyny, because one male mates with many females, but lek-based mating systems differ in that the male has no attachment to the females with whom he mates, and that mating females lack attachment to one another.
The Nauru reed warbler is a passerine bird endemic to the island of Nauru in the Pacific Ocean. It is one of only two native breeding land-birds on Nauru and it is the only passerine found on the island. It is related to other Micronesian reed warblers, all of which evolved from one of several radiations of the genus across the Pacific. Related warblers on nearby islands include the Caroline reed warbler, with which the Nauru species was initially confused, and the nightingale reed warbler, which was formerly sometimes considered the same species.