Old World warblers

(Sylviidae)

Class Aves

Order Passeriformes

Suborder Passeri (Oscines)

Family Sylviidae

Thumbnail description
Very small to medium-sized, often dull-colored, songbirds with thin, pointed bills

Size
3.1–9.8 in (8–25 cm); .1–2 oz (4–56 g)

Number of genera, species
60 genera; 350–391 species

Habitat
Highly varied. Largely arboreal, but many species inhabit wetlands, grasslands, thickets, scrub, and riparian zones

Conservation status
Endangered: 10 species; Critically Endangered: 3 species; Vulnerable: 29 species; Near Threatened: 13 species; Data Deficient: 9 species

Distribution
Subfamily Sylviinae: Palearctic region, Africa, Asia, Australasia, Oceania. Two genera, Regulus and Phylloscopus, reach Nearctic. Subfamily Polioptilinae: New World, from South America to the northern United States.

Evolution and systematics

The taxonomy of the Passeri, the suborder of oscine passerines (the songbirds) that contains the Sylviidae (Old World warblers), has long been debated. Much of the controversy focuses on the delineation of the apparently closely related families Muscicapidae, Turdidae, Timaliidae, and Sylviidae. Currently available molecular data suggest that widely used, traditional family classifications do not represent the evolutionary history of this large and complex group of birds. Sibley and Ahlquist place the Sylviidae within a large superfamily, the Sylvioidea. This superfamily also contains members of the following traditional families: Sittidae (nuthatches), Certhiidae (creepers), Troglodytidae (wrens), Paridae (tits), Aegithalidae (long-tailed tits), Hirundinidae (swallows), Pycnonotidae (bulbuls), Zosteropidae (whiteeyes), and Timaliidae (babblers). The molecular data do not support the long-held belief that the Sylviidae are closely related to the Turdidae (thrushes) and the Muscicapidae (Old World flycatchers), for these two families fall into a separate superfamily, the Muscicapoidea. The data do, however, support the inclusion of some of the babblers (Timaliinae) and laughing thrushes (genus Garrulax) in the Sylviidae family.

The classification used in the present work is based upon the traditional definition of the Sylviidae. The genera may be divided into six groups, based on molecular evidence of their taxonomic affiliation. The first of these are the gnatcatchers and gnatwrens (Polioptila, Microbates, and Ramphocaenus), which comprise the Sylviid subfamily Polioptilinae, but are placed by Sibley and Ahlquist within an expanded Certhiidae, including both creepers and wrens. The remaining five groups are considered to be within the sylviid subfamily Sylviinae. These are: (1) the kinglets (Regulus), regarded as a separate family by Sibley and Ahlquist and others; (2) the cisticolas and allies (Cisticola, Prinia, Apalis, Camaroptera), and other allied genera, a distinct group that Sibley and Ahlquist regard as a separate family, and most authors regard as a subfamily, Cisticolinae, of the Sylviidae; (3) the Sylvia warblers (Sylvia, Parisoma), a group that, according to Sibley and Ahlquist, is more closely related to the timaliine babblers than to traditional sylviids; (4) the grassbirds and allies (Megalurus, Bowdleria, Cincloramphus, Megalurulus, Chaetornis, Gramnicola, Schoenicola), and other allied genera, which comprise the subfamily Megalurinae in the Sibley and Ahlquist system; (5) the remaining genera of the traditional Sylviidae, most of which appear to fall within a clade represented by Sibley and Ahlquist's Acrocephalinae subfamily. Groups three, four and five above, plus the Garrulax laughing thrushes comprise Sibley and Ahlquist's more restricted Sylviidae, hereafter referred to as Sylviidae sensu strictu.

Little is known about the evolutionary history of passerines. The prevailing opinion has been that passerines arose in the Tertiary, specifically in the early Eocene, then underwent a dramatic diversification during the Miocene. The oldest putative passerine fossils are from early Eocene Australia (ca. 54 million years ago), lending support to a Southern Hemisphere origin, since passerine fossils do not appear in the Northern Hemisphere until the Oligocene. By the lower Miocene, passerine fossils greatly outnumber all other taxa in many Northern Hemisphere sites. A recent molecular study suggests that the passerine divergence may be much older and that passerines

evolved on Gondwana, the Cretaceous supercontinent in the southern hemisphere. If this is the case, oscine passerines may have diverged from suboscine passerines when Australia separated from Gondwana, radiated on Australia, then dispersed throughout the Old World when Australia came in contact with Southeast Asia.

Within the Sylviidae sensu strictu, the first divergence was probably between Sibley & Ahlquist's Acrocephaline sub-family (Acrocephalus, Hippolais, Phylloscopus, Seicercus, Sylvietta, Sphenoeacus, etc.) and the lineage leading to the other three subfamilies. Next to diverge was Garrulax, the laughingthrushes, which diverged from a lineage leading to the Timaliine babbers and Sylvia and Parisoma warblers. The genus Sylvia is thought to be at least 12-16 million years old. The Phylloscopus radiation is about as old as Sylvia, while the Acrocephalus/Hippolais radiation is only about half as old. These estimates place much of the sylviid radiation during the Miocene and Pliocene epochs of the mid-Tertiary, consistent with the passerine radiation in the fossil record.

Physical characteristics

The traits that have been used to characterize Sylviidae sensu latu are: unspotted young (as opposed to the Old World flycatchers and thrushes); rictal bristles at the base of the bill (a widespread adaptation for insectivory); thin, pointed bill; hatchlings naked or only partially downy; ten primaries; scutellate tarsi; and lack of strong sexual dimorphism (Sylvia is a notable exception). Most genera have twelve tail feathers, but there are a few exceptions. Wing shape and length ranges from short and rounded in sedentary species, to longer and more pointed in long-distance migrants. Moult timing and pattern are highly variable.

Sylviids are typically dull in color; often in shades of brown, green, yellow, and gray. The family includes some of the tiniest songbirds in the world, the kinglets, as well as some small wren-like birds, many small warblers, and the medium-sized marsh warblers and grassbirds. The smallest sylviids, the kinglets, weigh only a few grams. The largest, the marsh warblers Acrocephalus and the grassbirds Megalurus can weigh close to 2 oz (60 g). A comprehensive summary of longevity data is unavailable, but many species live at least 8–12 years.

While most species do not have distinctive breeding plumages like those of the New World warblers (Parulidae), a few sylviids show a marked contrast between breeding and nonbreeding plumages. A striking example is the red-winged warbler (Heliolais erythroptera), the only member of a genus apparently closely related to Prinia. While breeding red-winged

warblers of both sexes have dark gray upperparts and tail, they become predominantly tawny-brown in nonbreeding plumage. A somewhat less striking example is the genus Cisticola. Members of this genus undergo two moults each season, and most have shorter tails and slightly different plumage coloration during the breeding season. A few members of the genus Prinia have similar distinct seasonal plumage variation.

Distribution

The Old World warblers are extraordinarily widespread, occuring on every continent except South America and Antarctica. If the Polioptilinae are included, there are representatives of Sylviidae sensu latu in South America as well. Most of the sylviid diversity occurs in the African and Oriental faunal regions, with a less diverse, but widespread group of species in the Palearctic. Nearctic and Australian species represent recent invasions from Siberia and Southeast Asia, respectively.

The centers of distribution for some major sylviid genera are as follows. Sino-Himalayan Region: Bradypterus, Cettia, Phylloscopus, Seicercus, Prinia; Southeast Asia: Megalurus and allies, Orthotomus; Temperate Asia (Palearctic): Locustella, Acrocephalus, Hippolais; Africa: Cisticola and allies; Mediterranean/Middle Eastern (Palearctic) region: Sylvia. Relatively little exchange has occurred between Northern (Palearctic) and Southern (Oriental and African) Hemisphere faunas in the Old World, perhaps due to the East/West orientation of major barriers, including the Sahara and Gobi deserts, the Himalayas, the Alps, the Atlas, Caucasus, and other mountain ranges, and historically, the Tethys sea, which separated Africa from what is now the Palearctic. Conversely, in the Americas, where the major barriers are oriented North to South, many Neotropical migrant families originated in South America, then spread north to the Nearctic. Voous (1977) is of the opinion that all Old World sylviids arose in either the Indo-African region or the Sino-Himalayan region. While these are areas where the largest radiations have taken place, it is not clear where the common ancestor of the modern Sylviidae arose.

Habitat

The Old World warblers occupy an astonishing variety of habitats, from montane and riparian forests to arid scrublands to marshes and river floodplains to city parks and backyards. Sylviids are found in all extremes of water availability with the exception of open water and harsh deserts. The family is represented at a wide range of altitudes, from lowlands at or near sea level to montane forests and dwarf scrub as high as several thousand meters. Considerable habitat adaptability is

demonstrated by the varied habitats occupied by Acrocephalus warblers that have colonized oceanic islands.

Habitat partitioning is widespread among sylviid warblers. An example of foraging height segregation is found in the Sylvietta crombecs. The long-billed crombec is restricted to undergrowth in areas of sympatry with red-faced and redcapped crombecs. In other areas, the long-billed crombec is found at higher levels in the forest, demonstrating that competition limits the ability of this species to fully exploit its potential niche. Habitat partitioning also occurs in syntopic species of Sylvia, but there is considerable overlap, leading to interspecific territorial interactions.

Exploitation of topological niches within a habitat has been suggested as an important step in ecological and morphological divergence of closely related species. Adam Richman and Trevor Price have shown, in a 1992 study, that such a scenario has apparently occurred among a group of sympatric Phylloscopus warblers in the Himalayas. A related phenomenon is replacement, the presence of closely related species in different habitat types, with little overlap. Replacement is essentially habitat partitioning on a larger scale. Many Afrotropical genera contain closely-related species that occupy similar ecological niches in dissimilar habitats.

Behavior

Sylviids range from highly arboreal to almost entirely terrestrial. They are generally very active but often quite secretive and skulking. Most species inhabit dense vegetation, and are most easily located and identified by voice. The carriage of many of the Old World warblers is more or less horizontal. Flight ranges from very weak in some sedentary Afrotropical species, to strong and sustained in long-distance migrants. The gait is typically a hop, but some species run.

Vocalizations

The Old World warblers are one of the most vocally diverse bird families in the world. Most species have well-developed songs, with parameters that vary greatly both within and between genera. Song ranges from the unmusical, repetitive sounds of Prinia to the melodious warbles of Sylvia and Phylloscopus, to the amazingly complex, multi-element songs of some Acrocephalus species.

Song is an important component of territorial defense; and the variety of habitats occupied by sylviids have probably contributed to their vocal diversity. Species inhabiting relatively open grasslands, marshes, and brushlands often engage in song-flight displays. Daily and seasonal singing patterns are highly varied as well; Cettia cetti sings all day, for most of the year, sometimes at night. Night singing is common in Acrocephalus, Bradypterus baboecala and Locustella.

Most Sylvia warblers appear to use subsong, typically a longer, lower, more complex and melodious version of the territorial song, in courtship, but it is also given on the wintering grounds. A few sylviids incorporate mimicry into their songs as well. The marsh warbler Acrocephalus palustris learns its song components, from many dozens of other species it hears on both the breeding grounds in Europe, and the wintering grounds in Africa. Some of the Hippolais warblers (H. icterina, H. languida, H. polyglotta) incorporate mimcry of other species into phrases of their own songs. Mimicry also occurs in Eremomela and Sylvia.

Duets are thought to be involved in pair-bond maintenance, synchronization of sexual activity, or cooperative territorial defense, and are generally associated with monogamous species that maintain territories year-round. A Prinia subflava female occasionally adds her own complementary rattle to the notes of a singing male, creating a duet. The female Prinia bairdii is known to duet during territory advertisement. A few Cisticola species (C. hunteri, C. chubbi, C. nigriloris) also engage in duetting. Apalis flavida duets, but not for territory defense. Other genera with species that duet include: Bathmocercus, Bradypterus, Drymocichla, Schistolais, and Spiloptila.

Migration and dispersal

The Sylviidae exhibit a wide range of movement tendencies. There is even considerable variation within some species, like the fan-tailed warbler (Cisticola juncidis), blue-gray gnat-catcher (Polioptila caerulea), and Cetti's warbler (Cettia cetti). Each of these species includes some populations that are migratory, and others that are mostly sedentary. The true long-distance migrants are typically Palearctic species that escape the northern winter by travelling to sub-Saharan Africa or Southern Asia. These long-distance migrants undertake their movements at night.

Many Asian species are altitudinal migrants, moving between elevations, including the Tesias, several Phylloscopus andSeicercus species, and many Cettia species. Many African species undertake local and semi-local movements to moister areas during the dry season. Cisticola juncidis and other species of southern affinity tend to erupt northward after mild winters. Philopatry (tendency to remain near the home area) predominates in the great reed warbler, Acrocephalus arundinaceus, and is predicted by genetic diversity.

Territorial and social interactions

Almost all Old World warblers are territorial. Typically, the male defends a territory with song, display, and sometimes chasing and fighting. The majority of antagonistic behavior in migratory species occurs in the early spring during initial territory settlement and mate acquisition. In several monogamous species the female shares in territorial defense, sometimes by antagonistic behavior, and occasionally by song or duetting with her mate. Among polygynous species, females sometimes defend feeding and nesting areas within a male's territory against intrusion from neighboring females. Many African species defend territories year-round. Wintering and breeding ground site fidelity is often high in migratory and resident species. Family groups are common in many genera after the breeding season has ended.

Many species are interspecifically territorial. Hippolais icterina aggressively defends its territory and nest from many other species. Others, such as Cisticola anonymus, are only aggressive toward other species near nest. Some sylviids, such as the barred warbler Sylvia nisoria, preferentially associate with certain species of shrikes (Lanius) whose vigilance and anti-predator aggression result in higher reproductive success for the barred warbler.

Feeding ecology and diet

The diets of all members of the family consist primarily of insects, other arthropods, and especially spiders. Other prey items include crustaceans, snails, and harvestmen (Opiliones). Sap (golden-crowned kinglet) and nectar (several African and Asian species, especially Prinia) are occasionally consumed. Prinia hodgsonii and Orthotomus sutorius are known to carry pollen attached to the feathers of the throat and forehead; it and other nectar-feeding species may be important pollinators in the tropics. Some of the larger reed-warblers (including Acrocephalus arundinaceus, A. rufesecens, and A. stentoreus) occasionally take small frogs and fish. Young sylviids are fed almost exclusively arthropods, usually soft-bodied larvae and small insects, but in some cases receive berries as well. Variation in prey size and type is found among sympatric foraging guilds. During the pre-migratory period of Palearctic Sylvia warblers, individuals shift their diet from largely insects to largely berries and fruits in order to accumulate fat for migration.

Foraging strategies among the Old World warblers are diverse. Some species forage singly or in pairs, while others forage in groups of several family members or other conspecifics. Still others readily join mixed-species foraging parties, especially in the nonbreeding season. Cisticola nigriloris forages in groups of 5–8 birds, apparently keeping in contact by group-singing. Many African and nontropical species, join foraging parties in the nonbreeding season.

The typical foraging mode is perched gleaning (also known as standpicking) from the ground or from vegetation. Sallying and hawking of aerial insects is also used by many species, including the flycatcher warblers (genus Seicercus). Bradypterus sylvaticus forages on the ground by scratching up litter and humus with its feet, or by disturbing the humus with its wings and tail, in a motion reminiscent of dust-bathing. Tesias, Macrosphenus kretschmeri, and other terrestrial warblers feed in a similar manner. Even some Phylloscopus warblers, members of a genus composed mostly of arboreal species, have adapted to ground-feeding. Kemp's longbill Macrosphenus kempi climbs about on undergrowth, probing its bill into dead wood.

Reproductive biology

Most Old World warblers are either socially monogamous or polygynous. Monogamous warbler species may have a pair bond that lasts for either a single nesting, a single season, or more frequently the pair may remain monogamous for several years. Polygyny occurs when a single male maintains pair bonds with two or more females, each with her own nest and young. Classical polyandry (sex-role reversal) does not occur in this family. Serial monogamy is fairly common among the sylviids, with pair bonds lasting for only a single nesting. This is the case in Cisticola juncidis, a species in which most males mate sequentially with three or four females (as many as eleven) per season. Despite the implications of the term, many socially monogamous species engage in extra-pair copulations in order to enhance their reproductive success. Polygyny has been intensively studied in Acrocephalus reed warblers. Other genera with polygynous species include Cettia, Cisticola, and Phylloscopus. The duration of the pair bond is in part determined by the movements of a species.

Courtship

Some species have elaborate courtship displays that may or may not be accompanied by vocal activity. During the courtship dance of Camaroptera brachyura, the male repeatedly jumps 12–16 in (30–40 cm) into the air from his perch, while whirring his wings and giving a precisely timed call each second, corresponding with the jumps. Some Cisticola species use similar courtship dances, while others attract females and defend their territories with remarkable aerial song-displays. Many species, including the wood warbler (Phylloscopus sibilatrix) and the melodious warbler (Hippolais polyglotta), use a special flight style, often called flutter-flight or butterfly flight when pursuing a female. A characteristic of Sylvia courtship is the building of several cock nests (partial nests decorated with spider silk, flower petals, etc.) by the male. The female apparently uses these partial nests to assess male quality. Courtship displays are diverse, and utilize full song, subsong, calls, posture and flight displays, nest building, and presentation of objects.

Nests

The Old World warblers build some of the most interesting nests in the avian world. They range from simple, open cups to intricately woven domed and rounded structures, to highly camouflaged balls of moss and lichens. Nests may be located on the ground, in low vegetation, or in shrubs and trees as high as 80 ft (26 m) or more. Support may be provided by grass and sedge clumps, tree branches, or other vegetation. Alternatively, the nest may be hanging or nearly pendulous, attached to living leaves, woven into surrounding grasses, or built as a lining inside an abandoned nest of another species. Nests of the Orthotomus tailorbirds are famous for their sewing abilities. The female pierces green leaves with her bill, then draws them together with 'threads' of plant fiber, making several stitches, and sometimes knotting the ends of the fibers. The resulting sac is lined with spider silk and plant fibers. Similar nests are made by Artisornis, Calamonastes, Camaroptera, and Schistolais. The nests of most sylviids are built by both sexes, but in some species, especially polygynous ones, the female builds alone.

Care of young

Sylviids generally lay between one and 12 eggs per clutch. The young are usually incubated and brooded by the female, but in some species including Abroscopus, Seicercus, and Sylvia, the male shares in the task. Feeding of the young is usually done by both parents in socially monogamous species, but there is much interspecific and intraspecific variation in the degree of paternal involvement. In socially polygynous species, males tend to take a smaller role in feeding the young. Aquatic warbler (Acrocephalus paludicola) males take no role in incubation and rearing of their young. The altricial young, which are usually naked but may be downy, remain in the nest for 10–21 days. In many species, the fledglings are dependent on their parents for an additional 1–4 weeks after leaving the nest. Broods of fledglings often roost in groups to conserve warmth and receive food from the parents. Most northern species are usually single-brooded, but occasionally raise a second brood if conditions permit. Many tropical and sub-tropical species, on the other hand, are double-brooded.

Some sylviid taxa engage in cooperative breeding. Helpers have been reported in Acrocephalus vaughani, Prinia bairdii, Cisticola anonymous, C. nigriloris, and most of the Eremomelas. It is not clear, however, whether the helpers in these species are related to the breeding pair, nor is it known whether mating of helpers with breeders occurs. The only known case of true cooperative breeding (a monogamous pair helped by nonbreeding kin) among the Sylviidae is the Seychelles warbler (Acrocephalus sechellensis). Most of the helpers are females, since males tend to disperse and attempt to set up their own territories. In high quality territories, the presence 1–2 helpers increases the reproductive success of the resident pair, while the presence of 3 or more helpers creates too much competition and decreases reproductive success. Breeding pairs have been shown to facultatively manipulate the sex ratio of their eggs to maximize their future reproductive success.

Conservation status

Several species of Sylviid face serious threats. Many of these species are greatly range-restricted, with small populations inhabiting a single island or tiny patch of isolated habitat. Nearly one third of these threatened species are found in tropical Africa. About as many are endemic to small oceanic islands. The genera with the largest number of threatened or Near Threatened species are: Acrocephalus (15), Apalis (7), Bradypterus (6), and Cisticola (5).

The reed-warblers (Acrocephalus), are among the most widespread of the Sylviid genera, but their colonization of island habitats makes them vulnerable to anthropogenic and climatic threats. Acrocephaline species that have large ranges are presumably able to survive loss of habitat. However, island populations, and those species with small or already fragmented ranges are susceptible to habitat destruction and introduction of nonindigenous species. The aquatic warbler has probably suffered dramatic population declines due to destruction of its riverine marshland habitat in Eastern Europe and Western Siberia. IUCN lists it as Vulnerable.

The Seychelles warbler is an island species whose population had drooped precipitously to a mere 26 birds occupying the small Cousin Island in the Seychelles. Intensive management of the island resulted in a dramatic increase over the past thirty years, with the island reaching apparent carrying capacity in the early 1980s. Recent translocation efforts have expanded the range of the Seychelles Warbler to include two more islands.

The millerbird (Acrocephalus familiaris) is the only Sylviid to colonize the Hawaiian Archipelago. Historically, two populations, which were usually regarded as separate species or subspecies, inhabited the islands, one on Laysan and one on Nihoa. The Laysan form became extinct in the early twentieth century, after much of the native vegetation was destroyed by rabbits. The Nihoan form persists on the steep, rocky slopes of this tiny volcanic island. The Nihoan millerbird is listed as a Federally Endangered species in the United States. A 1996 USFWS population estimate was 155 individuals.

Many of the Endangered African species are found in threatened East African forests. A bird that may once have inhabited natural forest clearings, Artisornis moreaui, is limited in its dispersal ability by very weak flight. Forest clearing in its very small range may lead to the extinction of this highly local and poorly known species. Six species of Apalis, most found only in the highland forests of one or a few mountain groups of East Africa from Kenya to Mozambique, face serious conservation risks, as do rare species of Bathmocercus, Chloropeta, Cisticola and Eremomela.

Several threatened species in the genera Acrocephalus, Bradypterus, Cettia, Megalurulus, Megalurus, Locustella, Phylloscopus, and Orthotomus occur on islands in Southeast Asia and Australasia.

Among the kinglets, there has been only a single subspecies faced with serious conservation threats. Regulus calendula obscura was endemic to a highly restricted area of cypress groves on the island of Guadalupe. The species was last seen in the 1970s and is considered Extinct.

Among the Polioptilinae, only one species, the creamybellied gnatcatcher, Polioptila lactea, is is Near Threatened.

This species inhabits lowland coastal forests (to 500m) of Brazil, Argentina, and Paraguay, primarily in the Paraná basin. Its habitat has been severely reduced and deforestation continues to pose a threat to its remaining small habitat.

Significance to humans

Their small size, inconspicuous coloration, and preference for inhabiting vegetation make the Old World warblers unlikely candidates for human attention. However, the songs of many species are complex and well-developed. Since many species inhabit Europe and the Mediterranean, these songs have been familiar to Western civilization for thousands of years.

Sylviids are largely insectivorous, and are thus invaluable agents of pest control, not only in agricultural and suburban areas, but in evergreen and hardwood forests. These small songbirds are part of a natural balance that man repeatedly threatens with pesticide use, introduction of alien species, and planting and maintenance of monocultures in farming and timber production. Along with spiders and other natural enemies, sylviid warblers are part of an already extant system of insect control awaiting utilization by man. In many tropical areas, warblers are major consumers of mosquitos, helping to limit the number of vectors for insect-borne disease.

Species accounts

List of Species

Long-billed gnatwren

Ramphocaenus melanurus

subfamily

Polioptilinae

taxonomy

Ramphocaenus melanurus Vieillot, 1819.

other common names

French: Microbate à long bec; German: Schwarzschwanz-Degenschnäbler; Spanish: Chirito Picón.

physical characteristics

4.75 in (12 cm); .3–.4 oz (8.5–10 g). A small, distinctive bird with a long, cocked tail and long, pale slender bill. Tawny brown above, whitish below, with buffy wash on face, sides of breast and flanks. Tail dusky black, with white-tipped outer feathers.

distribution

Neotropical. Lowlands (to 4,900 ft [1500 m]) from Yucatan south through Central America and northern South America to central Brazil, also east coast of Brazil, west of Andes to coastal Ecuador.

habitat

Undergrowth and thickets in deciduous forest and forest edges, and humid forest interior; vine tangle.

behavior

Very active. Solitary or in pairs. Song is a clear musical trill. Male tail fanning and lateral tail movements probably function as territorial or mate-attraction displays.

feeding ecology and diet

Forages for insects in low undergrowth, sometimes joins mixed foraging flocks.

reproductive biology

Nest is loose, deep cup of leaves, grasses and other plant materials located near the ground. Both parents incubate the two eggs (17 days), and feed the young. Fledging occurs after 12-15 days.

conservation status

Not threatened.

significance to humans

None known.

Blue-gray gnatcatcher

Polioptila caerulea

subfamily

Polioptilinae

taxonomy

Polioptila caerulea Linnaeus, 1766. Seven to nine subspecies recognized.

other common names

English: Cat-bird; French: Gobe-moucherons Gris-bleu; German: Blaumükenfänger; Spanish: Perlita Grisilla.

physical characteristics

4–4.5 in (10–11.5 cm); 0.18–0.25 oz (5–7 g). Tiny grayish bird with a distinct white eye ring, and a long tail, often cocked. Upperparts blue-gray, underparts whitish, outer tail feathers white, inner tail feathers black. Breeding male has black 'forehead' stripe extending from base of bill to just above and behind the eye.

distribution

Nearctic. Breeds throughout much of United States and Mexico south to Belize. Winters from extreme southern United States to Baja, Honduras, and Cuba.

habitat

Swampy deciduous or pine woods and riparian lowlands in eastern United States. Arid scrub, pinyon-juniper, and open woodland in western United States. Scrub, wood edges, thorn forest, and clearings on wintering grounds.

behavior

Usually solitary or in pairs. Call is a thin buzzy whine, the male song, a rather soft series of such notes, interspersed with chips and whistles. In migratory populations, males arrives first and sing to defend their territories. Some populations in Mexico and Bahamas are permanent residents, but most are migratory between April and September.

feeding ecology and diet

Will take a wide variety of insects, spiders. Usually gleans while perched, but also hover-gleans and hawks for insects.

reproductive biology

Monogamous. During courtship, the male leads the female to potential nest sites. The nest, built by both sexes, is a neat cup of plant fibers often camouflaged and placed high on a branch or fork of a tree or shrub. Four or five eggs are incubated by both parents for 11–15 days. Female broods the nestlings, but later both sexes feed young. Fledging occurs after 10–15 days.

conservation status

Not threatened.

significance to humans

None known.

Golden-crowned kinglet

Regulus satrapa

subfamily

Sylviinae

taxonomy

Regulus satrapa Lichtenstein, MHK, 1823.

other common names

French: Roitelet à couronne dorée; German: Satrap; Spanish: Reyezuelo Corona Dorada.

physical characteristics

3–4 in (8–11 cm); 0.1–0.3 oz (4–7.5 g). Among smallest of all songbirds; olive-green with two whitish wing bars, and a white eye line surmounted by black lateral crown stripes and a yellow

crown. Male has orange central crown feathers that are usually concealed.

distribution

Breeds from Nearctic boreal zone south through New England and Appalachians in eastern United States, Rockies, Cascades, Sierra Nevada, Chiricahuas in West. Resident populations in mountains of Mexico, Guatemala. Winters south to Northeastern Mexico.

habitat

Dense conifers above 6,560 ft (2,000 m) in Mexico. Sometimes in deciduous forest in winter.

behavior

Very active, often hangs upside down. Voice includes a high thin call note and song, given by both sexes, consisting of a series of ascending notes, sometimes followed by a descending warble. Male defends territory with song, and song-displays (crown raised, tail and wing flicking). Often joins mixed-species flocks in fall and winter.

feeding ecology and diet

Mostly small insects, spiders, and arthropod eggs; occasionally sap, rarely fruit. Occasionally hover-gleans.

reproductive biology

Serially monogamous. Pair bond is maintained through breeding season. Nest, built by both sexes, is a deep hanging cup of moss, lichens, bark, spider webs and other plant material, attached to hanging twigs near trunk, placed high in conifer. Eight to nine (sometimes 5-11) eggs. Incubation by female only (14-15 days). Nestlings are fed by both parents, and leave the nest after 14-19 days.

conservation status

Not threatened.

significance to humans

None known.

Zitting cisticola

Cisticola juncidis

subfamily

Sylviinae

taxonomy

Sylvia juncidis Rafinesque, 1810.

other common names

English: Fantailed warbler, streaked cisticola; French: Cisticole des joncs; German: Cistensänger; Spanish: Buitrón Común.

physical characteristics

3.9–4.7 in (10–12 cm); 0.3–0.4 oz (8–12 g). Small warbler with warm brown upperparts strongly streaked with black, rufous rump and flanks, short, rounded wings, and short, graduated tail, spotted black and white underneath. Bill short, thin, and slightly decurved.

distribution

Widespread. Southern Europe (Iberian Peninsula, Mediterranean rim), sub-Saharan Africa, Indian subcontinent, Southeast Asia, Australasia.

habitat

Open tall-grass habitat and grassy wetlands, agricultural lands, primarily in lowlands.

behavior

Mostly sedentary, but marked post-breeding dispersal of both adults and juveniles in many populations. Also migratory in Western Mediterranean. Male song is a quick, sharp single note given consistently every 0.5 to 1 seconds. Males are aggressively territorial, especially in vicinity of nest.

feeding ecology and diet

Forages mostly on the ground. Takes insects and insect larvae, particularly Lepidoptera, grasshoppers, spiders, and beetles.

reproductive biology

Serially monogamous with most males mating with 1–11 females over the course of a season. Occasionally simultaneously polygynous. Pair bond lasts for a single nesting. During courtship, male builds several partially complete nests near the ground, and attracts female with song-flight. Nest is pear-shaped bag made by sewing and weaving grasses together with spider web. Two to six eggs incubated by female for 13 days; young leave nest in 11–15 days. Female feeds young 10–20 days after fledging.

conservation status

Not threatened.

significance to humans

None known.

Golden-headed cisticola

Cisticola exilis

subfamily

Sylviinae

taxonomy

Cisticola exilis Vigors and Horsfield, 1827.

other common names

English: Bright-headed cisticola, yellow-headed cisticola, tailor-bird, corn bird; French: Cisticole à couronne dorée; German: Goldkopg-Cistensänger; Spanish: Buitrón de Capa Dorada.

physical characteristics

3.9–4.3 in (10–11 cm). Small warbler, warm brown back, rufous nape, crown, breast and flanks, whitish throat and belly. Strong black streaking on back. Wings and tail short. Bill short, thin, and slightly decurved.

distribution

The only cisticola absent from Africa. Southern Asia, from India and China south through Phillipines, Malay Archipelago, and New Guinea, to Australia.

habitat

Tall, coarse, open grassland. Often in wet areas.

behavior

Usually solitary or in pairs. Scurries through dense grasses in a mouse-like manner. May form loose flocks in nonbreeding season. Male song, given during flight-display, is a nasal wheeze, followed by an explosive, liquid plook note.

feeding ecology and diet

Insectivorous. Forages on or near ground.

reproductive biology

Polygynous. Males with shorter tails have increased reproductive success. Male flight-display consists of characteristic circular flight, singing and a high-speed vertical plummet. Nest is a small, rounded bag of grasses, plant down, and spider silk, attached to grasses or other vegetation. The female builds the nest, sometimes with help from the male, but incubates the 3–4 eggs herself.

conservation status

Not threatened.

significance to humans

None known.

Tawny-flanked prinia

Prinia subflava

subfamily

Sylviinae

taxonomy

Motacilla subflava Gmelin, 1789. Subspecies inornata Sykes, 1832.

other common names

English: Plain prinia; French: Prinia modeste; German: Braunkopfprinie; Spanish: Prinia de Dorsos Castaños.

physical characteristics

5.1–5.5 in (13–14 cm); 0.3–0.4 oz (7–11.5 g). Mmedium to large warbler with short rounded wings and a fairly long, graduated tail. Upperparts uniformly rufous-brown to gray-brown, underparts whitish. Short whitish eye line. Legs long, bill relatively short, slightly decurved.

distribution

Sub-Saharan Africa, southern Asia, from Indian subcontinent to China, Taiwan, most of mainland Southeast Asia.

habitat

Lowlands; grassland and savanna, wetlands, mangroves, scrub, forest clearings and edges.

behavior

Active, vocal and conspicuous. Often in pairs or family groups. Males territorial, defending year-round by singing. Apparently sedentary, but movement may occur in parts of range during dry season. Duetting occasionally occurs.

feeding ecology and diet

Forages in vegetation, gleaning insects and sometimes taking nectar.

reproductive biology

Nest is an oval of woven grasses with a side-top entrance. Two to five eggs are incubated for 13–14 days. Young, fed by both parents, fledge after 13–17 days, but remain with parents 2–3 weeks.

conservation status

Not threatened.

significance to humans

None known.

Yellow-breasted apalis

Apalis flavida

subfamily

Sylviinae

taxonomy

Apalis flavida Strickland, 1852.

other common names

English: Brown-tailed apalis; French: Apalis à gorge jaune; German: Gelbbrust-Feinsänger; Spanish: Apalis de Pecho Amarillo.

physical characteristics

4.7–5.1 in (12–13 cm); 0.3 oz (7–9.5 g). Small warbler, olive-green above, whitish throat and belly separated by broad yellow breast band, with a central black marking in some populations. Tail long and graduated, wings short and rounded. Gray on crown and sides of face.

distribution

Endemic to sub-Saharan Africa.

habitat

Savanna, forest edge, riparian forest and thickets.

behavior

Often in pairs or family groups. Male song individually distinctive. Pairs sing duets. Maintain year-round feeding territories.

feeding ecology and diet

Forages in foliage of trees and thickets. Takes a variety of insects, insect larvae, spiders, and also fruit and nectar. Sometimes joins mixed-species foraging parties.

reproductive biology

Nest is a hanging, domed bag with side-top entrance, constructed largely of lichen bound with spider silk, 3–6 ft (1–2 m) above ground. Two to three eggs incubated 12–14 days by the female; the young, fed by both sexes, fledge after 15–16 days.

conservation status

Not threatened.

significance to humans

None known.

Slaty-bellied tesia

Tesia olivea

subfamily

Sylviinae

taxonomy

Tesia olivea McClelland, 1840.

other common names

English: Slaty-bellied ground warbler; French: Té à ventre ardoise; German: Goldscheiteltesia; Spanish: Trinador de Vientre Pizarro.

physical characteristics

3.5–4 in (9–10 cm); 0.2–0.3 oz (6–9 g). Characterized by an exceptionally short tail with 10 rectrices, a large head, rounded wings, long legs, and a more or less upright posture.

distribution

From south Central Asia through lower Himalayas and Nepal to south China, south to northwest Thailand, north Laos, and North Vietnam.

habitat

Damp areas and stream courses in evergreen forests; usually 3,280–8,860 ft (1,000–2,700 m).

behavior

Keeps to dense cover near the ground. It is skulking, but readily approaches to investigate and scold an intruder. Apparently non-migratory, but descends to lower elevations in winter. Voice a ventriloquial tchirik-tchirik.

feeding ecology and diet

Forages in litter on the forest floor for insects and spiders.

reproductive biology

Little known. Pairs frequently observed.

conservation status

Not threatened.

significance to humans

None known.

Cetti's warbler

Cettia cetti

subfamily

Sylviinae

taxonomy

Cettia cetti Temminck, 1820.

other common names

French: Bouscarle de Cetti; German: Seidensänger; Spanish: Ruiseñor Bastardo de Cetti.

physical characteristics

5.3–5.7 in (13.5–14.5 cm); 0.4–0.6 oz (10–18g) (males), 0.3–0.6 oz (8–16g) (females). Medium-sized, plump warbler with long, graduated, rounded tail with 10 rectrices; short, rounded wings; and a delicate, dark bill. Strongly sexually dimorphic, as measured by wing length and mass. Upperparts dull chestnut to rufous, throat white, breast grayish, and belly and flanks buffy. Characteristic thin, whitish supercilium and eye ring.

distribution

Distribution across Eurasia. In summer, north into Caucasus region of Russia and Uzbekistan, Kyrgyzstan, Kazakstan. Winters along the Indus River in Pakistan. Eastern race (albiventris) migrates to south to Pakistan and Afghanistan.

habitat

Lowlands, usually near water, in dense thickets and reedbeds.

behavior

Skulking. Male territorial song is an explosive series of clear tones. A softer variant is used during courtship. Male song pattern is unique allowing individual recognition. Males aggressively territorial, defending with song, wing-waving display and fighting. In sedentary populations, territories defended all year.

feeding ecology and diet

Forages on or near the ground for insects (especially aquatic invertebrates), spiders, harvestmen, snails, earthworms, and some seeds.

reproductive biology

Often serially polygynous. Male may mate with the same 1–4 females for several successive years. Nest is loose cup of stems and leaves, placed low among tangled vegetation. The nest of each female is placed in her 'range' within the male territory. The 4–5 eggs are incubated by the female. Fledging occurs at 14–16 days, young remain dependent for additional 15 or more days.

conservation status

Not threatened.

significance to humans

None known.

Little rush warbler

Bradypterus baboecala

subfamily

Sylviinae

taxonomy

Bradypterus baboecala Vieillot, 1817.

other common names

English: African bush-warbler, African sedge warbler; French: Bouscarle des marais; German: Sumpfbuschsänger; Spanish: Ruiseñor Africano.

physical characteristics

5.9–7.5 in (15–19 cm); 0.4–0.6 oz (11–17 g). Medium-sized warbler with dark brown upperparts, buffy flanks and breast, whitish underparts, whitish throat streaked or spotted with dark brown, and pale eye line. Tail wide and rounded.

distribution

Sub-Saharan Africa. Widespread, but local in the northern tropics; common throughout much of the south.

habitat

Reedbeds and grasses, near marshes, lagoons, sewage ponds, watercourses.

behavior

Found singly or in pairs. Reluctant to fly. Song an accelerating series of chips, with the tempo of a "bouncing ball." Males defend territory with song and song-flight. Generally sedentary.

feeding ecology and diet

Forages for insects. Also known to take ant eggs.

reproductive biology

Monogamous. Nest is a tight, bulky cup of grasses and reeds, situated in a tussock and supported by sedge or rush leaves over water. The 2–3 eggs are incubated 12–14 days. Fledging period is 12–13 days, both sexes feed young.

conservation status

Not threatened.

significance to humans

None known.

Grasshopper warbler

Locustella naevia

subfamily

Sylviinae

taxonomy

Locustella naevia Boddaert, 1783.

other common names

French: Locustelle tachetée; German: Feldschwirl; Spanish: Buscarla Pintoja.

physical characteristics

4.7–5.1 in (12–13 cm); 0.3–0.6 oz (9.5–18 g). Small grass warbler with olive-brown upperparts, streaked with black, under-parts creamy white, flanks and breast buffy, streaked brown. Short, rounded wings and short graduated tail.

distribution

Breeds from southern Scandinavia, British Isles and France west throughout central Europe and Siberia to Mongolia, Northern China. Winters in Africa and Indian subcontinent.

habitat

Grasslands, low scrub, bogs, fens and marshes, with some shrubs and trees.

behavior

Very secretive; keeps to dense cover. Gait is a run; flight short and low. Song a high, far-carrying trill, common at night. Female sings during courtship.

feeding ecology and diet

Forages in low vegetation and on ground for insects.

reproductive biology

Female builds cup nest of grass and plant material on or near ground in thick vegetation. The 5–6 eggs are incubated 12–15 days by both parents. Young leave nest after 10–15 days.

conservation status

Not threatened.

significance to humans

None known.

Marsh warbler

Acrocephalus palustris

subfamily

Sylviinae

taxonomy

Acrocephalus palustris Bechstein, 1798.

other common names

French: Rousserolle verderolle; German: Sumpfrohrsänger; Spanish: Carricero Poliglota.

physical characteristics

5.1 in (13 cm); 0.4–0.7 oz (10–20 g). Heavy, medium-sized warbler with uniform olive-brown upperparts, creamy under-parts, buffy wash on sides of breast and flanks, white throat, and light line from eye to base of bill.

distribution

Breeds throughout Central and Western Europe, excluding Iberia and British Isles to southern Scandinavia and western Russia. Winters in Southeast Africa.

habitat

Breeds in tall herbaceous vegetation and woody cover, often in moist areas, but also on dry slopes, and in parks and open forest.

behavior

Solitary and territorial in breeding season, some males polyterritorial. Posture somewhat upright. Song a complex, sweet warble learned by mimicry of other birds. Female sings during courtship.

feeding ecology and diet

Gleans insects and spiders from low vegetation. Also takes snails, and rarely berries.

reproductive biology

Mostly monogamous, but serial monogamy and opportunistic polygyny occur. Courtship may include aerial dance involving both sexes. Nest is built by female; cylindrical cup of leaves and plant material 3.3–6.6 ft (1–2 m) from ground in tall vegetation, with rim woven around supporting vegetation. Three to six eggs incubated and young, cared for by both parents, leave nest after 11–12 days, remain dependent 15–19 days.

conservation status

Not threatened.

significance to humans

None known.

Great reed warbler

Acrocephalus arundinaceus

subfamily

Sylviinae

taxonomy

Acrocephalus arundinaceus Linnaeus, 1758. Subspecies griseldis Hartlaub, 1891.

other common names

French: Rousserolle turdoïde; German: Drosselrohrsänger; Spanish: Carricero Tordal.

physical characteristics

7.5–7.9 in (19–20 cm); 0.7–1.8 oz (21–51 g). Large, heavy warbler with strong bill and legs, longish pointed wings. Uniform brown above, whitish below, with buffy wash on flanks, rufous rump, light eyeline.

distribution

Breeds from Iberia and northwest Africa to western Siberia and west China. Winters across sub-Saharan Africa.

habitat

Reedbeds and other emergent vegetation, sometimes in thickets bordering water. Swamps, stream courses and savanna in winter.

behavior

Movements slow and clumsy. Song deep and slow, full of low croaks and rattles. Male defends large territory.

feeding ecology and diet

Insects, spiders, snails, small vertebrates (fish and frogs), some fruits in non-breeding season. Forages in emergent vegetation, trees and shrubs, and water surface.

reproductive biology

Many polygynous, but significant portion monogamous. Pair bond lasts only until nestling stage. Nest is built by female; deep cylinder of reeds and leaves, suspended above water. Three to six eggs incubated 14 days by female; young fed by both parents; fledglings dependent additional two weeks.

conservation status

Not threatened.

significance to humans

None known.

Icterine warbler

Hippolais icterina

subfamily

Sylviinae

taxonomy

Hippolais icterina Viellot, 1817.

other common names

French: Hypolaïs ictérine; German: Gelbspötter; Spanish: Zarcero Icterino.

physical characteristics

4.9–5.3 in (12.5–13.5 cm); 0.3–0.8 oz (8–23 g). Small warbler with olive to gray-olive upperparts, yellowish underparts, pale eye line, and long, thin bill.

distribution

France, Balkans, and Scandinavia east to southwest Siberia. Winters in Southern Africa.

habitat

Open forests, orchards gardens and edges; often in lowlands and river valleys.

behavior

Active and vocal, but usually remains in foliage. Territorial on breeding and wintering grounds. Song rapid, varied, including musical phrases and mimicry.

feeding ecology and diet

Insects, fruit in late summer. Forages in foliage, gleaning insects and sallying to catch aerial prey.

reproductive biology

Monogamous. Nest is neat cup of plant material, decorated on outside with bark, paper, wool, etc., built by female in fork of shrub or tree. Four to five eggs incubated by female for 13–15 days; young, cared for by both parents, leave nest after 12–16 days, independent after 1–2 weeks.

conservation status

Not threatened.

significance to humans

None known.

Common tailorbird

Orthotomus sutorius

subfamily

Sylviinae

taxonomy

Orthotomus sutoria Pennant, 1769.

other common names

English: Long-tailed tailorbird; French: Couterière à longe queue; German: Rotstirn-Schneidervogel.

physical characteristics

5.1 in (13 cm); 0.2–0.4 oz (6–10 g). Small bird with long, thin, decurved bill. Back olive-green, underparts creamy, nape gray, crown rufous, whitish eyeline. Short, spiky tail often held erect.

distribution

Resident throughout India and Southeast Asia to Java and Indonesia.

habitat

Deciduous forest, scrubby clearings, gardens, scrubland, and mangroves.

behavior

Solitary or in pairs. Skulking but restless and active. Flicks tail side to side often. Song a loud, two-syllable phrase repeated in series of three to four calls.

feeding ecology and diet

Insects and insect larvae, flower nectar. Forages on ground, in low vegetation and in trees.

reproductive biology

Nest is lined with spider silk, soft plant fibers, etc.; sewn by female from the leaves of a broad-leaved plant, usually well hidden. Incubation of 3–5 eggs for 12 days and feeding nestlings done by both parents.

conservation status

Not threatened.

significance to humans

None known.

Yellow-bellied eremomela

Eremomela icteropygialis

subfamily

Sylviinae

taxonomy

Eremomela icteropygialis Lafresnaye, 1822.

other common names

English: Salvadori's eremomela; French: Érémomèle à croupion jaune; German: Gelbbauch-Eremomela; Spanish: Eremomela de Vientre Amarillo.

physical characteristics

3.9–4.3 in (10–11 cm); 0.26–0.33 oz (7.5–9.3 g). Small bird with gray head, nape, back, and breast, yellow belly and under-tail. Dark eyeline surmounted by a lighter one; dark gray wing and tail.

distribution

Widespread throughout non-forested sub-Saharan Africa.

habitat

Woodland, forest edge, scrub, gardens, and riparian areas.

behavior

Inconspicuous. Usually in pairs or groups of up to eight birds. Territorial. Song is loud, twittery series of 7–8 notes. Mimicry sometimes included.

feeding ecology and diet

Foraging mostly in canopy and mid-level for small insects. Sometimes joins mixed-species foraging parties.

reproductive biology

Monogamous. Breeds primarily during monsoon season. Nest is deep cup of plant down and spider silk, lined with grass, and suspended from fork of a shrub or tree. One to three eggs are incubated 13–14 days by female; nestlings, fed by both parents, leave after 15–16 days, fed by parents additional two or more weeks.

conservation status

Not threatened.

significance to humans

None known.

Long-billed crombec

Sylvietta rufescens

subfamily

Sylviinae

taxonomy

Sylvietta rufescens Vieillot, 1817.

other common names

English: Cape crombec; French: Crombec à long bec; German: Langschnabelsylvietta; Spanish: Sylvieta de Pico Largo.

physical characteristics

3.9–4.7 in (10–12 cm); 0.3–0.8 oz (8–23 g). Small, nearly tailless bird with brownish gray upperparts, breast and flanks buffy, throat and belly white. Black eyeline surmounted by a light eyeline.

distribution

Endemic resident in Southern Africa.

habitat

Thick brush, Acacia scrub, open and secondary woodland, often in drier areas.

behavior

Solitary or in pairs or family groups. Song a high, variable series of trilled notes. Territorial. Flight bouncy.

feeding ecology and diet

Insects, ticks and grass seeds. Forages methodically from bottom to top of bushes and trees. Often joins mixed-species foraging parties.

reproductive biology

Monogamous. Nest is large, hanging bag of grasses, spider webs, and plant fibers, close to ground and attached to the lower limbs of a tree, often an acacia. One to three eggs incubated for two weeks; nestlings fed by both parents for two weeks before leaving.

conservation status

Not threatened.

significance to humans

None known.

Chiffchaff

Phylloscopus collybita

subfamily

Sylviinae

taxonomy

Phylloscopus collybita Vieillot, 1817.

other common names

English: Common, Eurasian chiffchaff; French: Pouillot véloce; German: Zilpzalp; Spanish: Mosquitero Común.

physical characteristics

3.9–4.3 in (10–11 cm); 0.2–0.4 oz (6–12 g). Small warbler with short, fine bill, olive-green upperparts, white underparts, brownish flanks, a dark line through the eye, surmounted by a light line.

distribution

Breeds from Iberia, British Isles and Scandinavia to Caspian Sea, northern Mongolia, eastern Siberia. Winters in Western Europe, Mediterranean, northwest Africa, Middle East, India and sub-Saharan Africa.

habitat

Open woodland with tall undergrowth, parks, and scrub, typically in lowlands.

behavior

Solitary or in pairs during breeding season. In small groups or mixed flocks in migration and winter. Territorial. Song highly variable; in nominate group it is series of two-note alternating phrases.

feeding ecology and diet

Forages from ground to canopy for insects, gleaning from foliage.

reproductive biology

Monogamous, sometimes facultatively polygynous. Nest is built by the female; dome of dry gr–ss and other plant materials with a side entrance, on or near the ground in thick vegetation. Four to seven eggs, incubated 13–15 days by female;

nestlings cared by female; fledge after 14–16 days. Brood independent after 10–19 days.

conservation status

Not threatened.

significance to humans

None known.

Arctic warbler

Phylloscopus borealis

subfamily

Sylviinae

taxonomy

Phyllopneuste borealis Blasius, 1858.

other common names

French: Pouillot boréal; German: Wanderlaubsänger; Spanish: Mosquitero Boreal.

physical characteristics

4.1–5.1 in (10.5–13 cm); 0.3–0.5 oz (8–15 g). Medium-sized warbler, olive-green above, yellowish-white below, with a yellow wash in some plumages. Thin, clean whitish eye line; long wings with two whitish wing bars.

distribution

Breeds in boreal and subalpine zones from Scandinavia throughout Asia to Japan and Western Alaska. Winters in Southeast Asia, Wallacea.

habitat

Coniferous, deciduous, and mixed forest in taiga zone. Winters in open woodlands, rainforest, forest edge, gardens, and mangroves.

behavior

Arboreal and active, with quick flight and habit of wing- and tail-flicking. Usually solitary or in pairs or small family groups. Territorial; male often defends with song and wing-rattling displays.

feeding ecology and diet

Forages in foliage for insects and larvae, usually high, but occasionally close to the ground.

reproductive biology

Monogamous, occasionally polygynous. Courtship involves song, wing-rattling and wing-flapping displays. Nest is built by the female; dome of dry grass and other plant materials with a side entrance on the ground in thick vegetation. Incubation of 5–7 eggs for 11–13 days by female; fledging takes 13–14 days, young fed by both parents, brooded by female; young independent after two weeks.

conservation status

Not threatened.

significance to humans

None known.

Golden-spectacled warbler

Seicercus burkii

subfamily

Sylviinae

taxonomy

Seicercus burkii Burton, 1836.

other common names

English: Yellow-eyed flycatcher warbler; French: Pouillot de Burke; German: Goldbrillen-Laubsängerl Spanish: Curruca de Burke.

physical characteristics

3.9–4.7 in (10–12 cm); 0.2–0.3 oz (6–9 g). Small, plump warbler, with bright green upperparts, bright yellow underparts, a short, broad tail with white undertail feathers. Crown streaked black and gray, eyering yellow; yellow wingbar.

distribution

Southern Asia, from India to south-central China to Thailand, Cambodia and Vietnam.

habitat

Mid-level undergrowth of evergreen or mixed forest in highlands. Winters at lower elevations.

behavior

Usually solitary or in pairs. Rarely found in canopy. Song of burkii is a loud, clear trill.

feeding ecology and diet

Insects. Often joins mixed-species flocks in non-breeding season.

reproductive biology

Little known. Nest is ball of mosses, grass, and other plant fibers, lined with moss and lichen, and concealed along a bank or slope, often in tree roots. Four eggs are incubated by both parents.

conservation status

Not threatened.

significance to humans

None known.

Little grassbird

Megalurus gramineus

subfamily

Sylviinae

taxonomy

Megalurus gramineus Gould, 1865.

other common names

English: Little marshbird; striated grassbird; little reedbird; marsh warbler; French: Mégalure menue; German: Zwergschilfsänger.

physical characteristics

5.1–5.9 in (13–15 cm). Medium-sized warbler with brownish upperparts, streaked dark; pale grayish underparts finely

streaked with dark brown. Flight feathers graduated, edged with white.

distribution

Southern and eastern Australia.

habitat

Dense vegetation of marshes, reedbeds, swamps, occasionally mangroves.

behavior

Solitary. Skulking. Song is three note, plaintive whistle. Flight is weak. Some movement and nomadism occurs.

feeding ecology and diet

Insects, insect larvae, spiders and other arthropods; also takes aquatic mollusks.

reproductive biology

Courtship involves chasing and wing-fluttering displays. Nest is suspended above water, a deep cup of grass and plant material, lined with large feathers, and rimmed tops. Three to five eggs.

conservation status

Not threatened.

significance to humans

None known.

Blackcap

Sylvia atricapilla

subfamily

Sylviinae

taxonomy

Sylvia atricapilla Linnaeus, 1758.

other common names

French: Fauvette à tête noire; German: Mönchsgrasmücke; Spanish: Curraca Capirotada.

physical characteristics

5.5 in (14 cm); 0.5–0.7 oz (15–21 g). Medium-sized, with plumage ranging from slate gray in adult males to olive or brown in females and juveniles. Crown is distinctive (black in adult males, rufous in females and juveniles). Wings are long and pointed, with long primary projection. Bill is black, relatively long, and pointed. Legs long.

distribution

Breeds from British Isles and southern Scandinavia throughout Western and Central Europe to coastal northwest Africa, Mediterranean, Near East, and west to central Russia and northern Iran.

habitat

Forest with tall undergrowth, from riparian areas, parks and gardens to boreal forest and alpine forest to treeline.

behavior

Arboreal and very active. Males territorial, defending with song, displays, and agonistic behavior. Mimicry of other birds is occasionally incorporated into song. Mixed partial migrant: individuals in northern range migrate south, while individuals in southern range (the Mediterranean area) are residents or partial migrants.

feeding ecology and diet

Feeds in trees and shrubs, gleaning insects and other arthropods from leaves and branches. During migration and on wintering grounds, fruits constitute a large part of the diet.

reproductive biology

Pairs solitary and territorial, generally monogamous. Site-fidelity is high in migratory populations. Courtship involves construction, by the male, of several loose 'cock nests'. The female completes the final nest, a fine cup typically located in dense vegetation of a tree or shrub above ground. Both parents incubate 2-6 eggs (typically 5) for 10–16 days. Feeding young in the nest (8–14 days) and after fledging (for about two weeks) is also shared.

conservation status

Not threatened.

significance to humans

A familiar songbird easily recognized by appearance and voice. It is a model system for the study of the physiology and evolution of bird migration, and for the study of avian diet and energetics, especially as related to movement and seasonal food availability.

Whitethroat

Sylvia communis

subfamily

Sylviinae

taxonomy

Sylvia communis Latham, 1787.

other common names

English: Common whitethroat, greater whitethroat; French: Fauvette grisette; German: Dorngrasmücke; Spanish: Curruca Zarcera.

physical characteristics

5.5 in (14 cm); 0.4–0.9 oz (10–24 g). Medium-sized warbler with gray-brown upperparts, whitish underparts, buffy flanks, gray (male) or brownish (female) cap and side of face, and a bright white throat. Folded wing shows significant rufous edging of coverts, secondaries and tertials. Long tail with white outer tail feathers.

distribution

Breeds in Western and Central Europe, southern and coastal Scandinavia, Turkey, North Africa, and Western and Central Siberia. Winters in sub-Saharan Africa.

habitat

Open scrubland, farmland and forest edges, with mix of herbaceous and low woody vegetation.

behavior

Typically solitary or in pairs. Skulking, but inquisitive. Male song a short, scratchy warble. Territorial. Engages in song-flight display, rising vertically from shrub, then swooping back down.

feeding ecology and diet

Forages in low and mid-height vegetation, gleaning arthropods.

reproductive biology

Monogamous. Male builds 'cock nests'. Nest a loose, deep cup of grasses in dense, low, tangled vegetation. Three to six eggs incubated 11–13 days, mostly by female; young brooded and fed by both parents, leave nest after 10–12 days, remain with parents 2–3 weeks.

conservation status

Not threatened.

significance to humans

None known.

Resources

Books

Ali, Salim, and S. Dillon Ripley. Handbook of the Birds of India and Pakistan, 2nd ed. Vol. 8. Warblers to Redstarts. Delhi: Oxford University Press, 1997.

Baker, Kevin. Warblers of Europe, Asia and North Africa. Princeton: Princeton University Press, 1997.

Cramp, Stanley, ed. The Birds of the Western Palearctic. Vol. 6. Warblers. Oxford: Oxford University Press, 1992.

Kaufman, Kenn. Lives of North American Birds. New York: Houghton Mifflin, 1996.

Parmenter, Tim and Clive Byers. A Guide to the Warblers of the Western Palearctic. Uxbridge, Middlesex: Bruce Coleman Books, 1991.

Shirihai, Hadoram, Gabriel Gargallo, and Andreas J. Helbig. Sylvia Warblers. Princeton: Princeton University Press, 2001.

Sibley, Charles G. and Jon E. Ahlquist. Phylogeny and Classification of Birds. New Haven, Yale University Press, 1990.

Urban, Emil K., Hilary C. Fry, and Stuart Keith. The Birds of Africa. Vol. 5. San Diego: Academic Press, 1997.

Periodicals

Alström, P. and U. Olsson. "The golden-spectacled warbler: a complex of sibling species, including a previously undescribed species." Ibis 151 (1999): 545–568.

Barker, F. Keith, et al. "A phylogenetic hypothesis for passerine birds: taxonomic and biogeographic implications of an analysis of nuclear DNA sequence data." Proceedings of the Royal Society of London, Series B, 269 (2002): 295–308.

Catchpole, Clive K. "The evolution of mating systems in Acrocephalus warblers." Japanese Journal of Ornithology 44 (1995): 195–207.

Helbig, Andreas J. and Ingrid Seibold. "Molecular phylogeny of Palearctic-African Acrocephalus and Hippolais warblers (Aves: Sylviidae)." Molecular Phylogenetics and Evolution 11 (1999): 246–260.

Irwin, Darren E., et al. "Speciation in a ring." Nature 409 (2001): 333–337.

Leisler, B., et al. "Taxonomy and phylogeny of reed warblers (genus Acrocephalus) based on mtDNA sequences and morphology." Journal fur Ornithologie 138 (1997): 469–496.

Matthew J. Sarver, BS