Ashy flycatcher
| Ashy flycatcher | |
|---|---|
| |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Passeriformes |
| Family: | Muscicapidae |
| Genus: | Fraseria |
| Species: | F. caerulescens
|
| Binomial name | |
| Fraseria caerulescens (Hartlaub, 1865)
| |
| Synonyms[2] | |
The ashy flycatcher (Fraseria caerulescens) is a species of bird in the Old World flycatcher family Muscicapidae. It is found throughout sub-Saharan Africa, excluding the drier areas of South Africa, Botswana, and Namibia, where it inhabits subtropical or tropical dry forest, subtropical or tropical moist lowland forest, and savanna. It has a disputed generic placement, with different authorities variously putting it in Muscicapa, Fraseria, or other genera. Ashy flycatchers are mostly grey in colour, with pale grey or white underparts.
The species has a small, thin, and pointed beak adapted for eating insects. Its diet is mostly insectivorous, although it also eats berries and small geckoes. The birds are very active, foraging singly, in groups, or in mixed-species flocks. They forage in the upper levels of the canopy, with prey being caught with small circular flights, from foliage, and being gleaned from the bark and leaves. The species breeds in solitary pairs, with each pair maintaining a territory of 1–4 hectare and raising young alone. A variety of vocalisations are used by the species, and there is very little geographical variation in calls.
Taxonomy and systematics
The ashy flycatcher was originally described as Butalis caerulescens by the German ornithologist Gustav Hartlaub in 1865, based on specimens from South Africa.[3] The name of the genus, Fraseria, is in honour of the English zoologist Louis Fraser. The specific name of the species refers to its colour, meaning dark blue or cerulean in Latin.[4] Ashy flycatcher is the official common name designated by the International Ornithologists' Union (IOU).[5] Other common names for the species include ashy alseonax, blue-grey flycatcher, bluegrey flycatcher, blue-grey alseonax, little blue flycatcher, and white-eyed flycatcher.[2]
The ashy flycatcher was long placed in the genus Muscicapa, but a 2016 study of DNA sequences of Muscicapa flycatchers by Gary Voelker and colleagues found that the genus was paraphyletic. The same study found that the ashy flycatcher was most likely sister to Tessmann's flycatcher, and that these two species were most closely related to the olivaceous flycatcher.[6] As of 2022[update], the ashy flycatcher's current generic placement is disputed.[7] The IOU and The Clements Checklist place it in Fraseria, along with Tessmann's flycatcher, while the IUCN continues to place it in Muscicapa.[5][7] The authors of the 2016 study suggested placing both of these species in either Cichlomyia or Butalis, depending on which one has priority.[6] A more recent molecular phylogenetic study published in 2023 supports the species's placement in Fraseria.[8]
Subspecies
There are six recognised subspecies:[5]
- F. c. caerulescens (Hartlaub, 1865): The nominate subspecies, it is found in Mozambique, South Africa and Eswatini.[7]
- F. c. brevicauda (Ogilvie-Grant, 1907): Found from northern Benin and southern Nigeria to South Sudan, western Kenya, southern Democratic Republic of the Congo (DRC) and northwestern Angola. It is generally darker than the nominate and has slate-grey upperparts with grey underparts.[7]
- F. c. nigrorum (Collin & Hartert, 1927): Found from Guinea to Togo. It is slightly paler than brevicauda, with mouse-grey upperparts and more uniformly grey underparts.[7]
- F. c. cinereola (Hartlaub & Finsch, 1870): Found in Somalia, Kenya and Tanzania. It is intermediate in appearance between brevicauda and impavida.[7]
- F. c. vulturna (Clancey, 1957): Found from Malawi and Mozambique to northern South Africa and Eswatini. It is paler than the nominate, with the throat and belly being purer white.[7]
- F. c. impavida (Clancey, 1957): Found from Angola east to the DRC, Tanzania, and Mozambique and south to Namibia, Botswana, and Zimbabwe. It is even paler than vulturna, with the upperparts being ashier and less blue in color and the underparts being more uniformly white.[7]
Description
.jpg)
The ashy flycatcher is 13–15 cm (5.1–5.9 in) long. Adults of the nominate subspecies have bluish-grey crowns and upperparts, with very pale grey chins and throats, pale grey breasts and flanks, white bellies and undertail coverts, and grey thighs. They have black loral lines with white stripes above, along with pale, well-defined eye-rings. The flight feathers and tail are brownish-black and the upperwing coverts are brownish-black with grey fringes. The axillaries and underwing coverts are white.[7]
Vocalisations
The ashy flycatcher is a widespread species, but very little variation in vocalisations has been observed through its range. It has a varied repertoire of call types and many different calls. The dawn song consists of 5–7 notes that typically start at a high pitch before going down and then up again. Phrases typically repeat every 3–5 phrases. It is given at dawn in complete darkness for at least 30 minutes from a high canopy level on a fixed perch. After sunrise, birds switch from the dawn song to the day song, which consists of 3–8 short staccato notes. Other songs include the warbling song.[7]
Ashy flycatchers also have a variety of calls, including short peeps and chirps, a high-pitched wheeze, and other notes. A piercing, slightly descending hiss is used as an alarm, often uttered to warn of approaching predators. It is very similar to the alarm calls of other species of birds and is an interspecific call. A distress call, consisting of a shrill, high-pitched, and buzzing note, is given when birds are in panic or stressed. Males also snap wings and bill when observers approach their offspring. Chicks give a high-pitched begging call, which has also been described as a "shrill, short, rattling squeak".[7]
Behaviour and ecology
.jpg)
It is a restless and active bird that is constantly moving and shifting. It has been observed sunbathing on the ground.[7]
Diet
The ashy flycatcher forages singly, in pairs, or in groups of up to seven individuals. It is also known to sometimes join mixed-species flocks while foraging.[9] Foraging is typically done in the upper levels of vegetation, between the treetops and the undercanopy. Ashy flycatchers typically sit upright on exposed perches. Food is caught by making short circular flights to catch flying insects or hovering to catch prey in foliage. It also gleans insects from foliage and bark.[7]
Its diet consists of mostly insects, mainly beetles, flies, grasshoppers, adult and larval moths and butterflies, winged ants, and termites. Prey tend to be 5–35 mm (0.20–1.38 in) in size, with the majority being 15–20 mm (0.59–0.79 in) in size. They have also been observed eating small fruit and berries, and rarely, geckos up to 5 cm (2.0 in) in length.[7]
Breeding
The ashy flycatcher is mainly breeds from September–January, with the exact observed breeding period varying throughout its range; it has also been observed breeding from February–June in the DRC, and in February, May, June, and August in East Africa. Pairs are monogamous, solitary, and territorial, maintaining areas of up to 20 hectare in the non-breeding seasons and territories of 1–4 ha during the breeding season. Nests are generally built at heights of 2–15 m (7–49 ft) in crevices, cavities, or forks in trees, or sometimes in holes or ledges in walls. They are built by both sexes and consist of a sturdy "cup" made of moss, grass, rootlets, shredded bark, fibers, and spiderwebs. Nests have an outer diameter of 11–18 cm (4.3–7.1 in), with an inner diameter of 45–50 mm (1.8–2.0 in) and a depth of 25–28 mm (0.98–1.10 in).[7] Birds have been recorded building over old nests and inhabiting old weaver bird nests.[7][10] Eggs are 19 mm × 14.5 mm (0.75 in × 0.57 in) in size and glossy whitish-buff in appearance, with yellowish-brown or reddish flecking; they are laid in clutches of 2–3 and take 14 days to incubate. After hatching, young are fed by both parents.[7]
Distribution and habitat
The ashy flycatcher is found through most of sub-Saharan Africa, from southern Cameroon east through Uganda to southern Kenya and Somalia, and south to Angola, northern Namibia and Botswana, and western South Africa. It is absent from the arid regions of Namibia, Botswana, and South Africa, but is found patchily through West Africa, in Sierra Leone, southeastern Guinea, Liberia, Côte d'Ivoire, southern Ghana, southwestern Togo, extreme southern Benin, Burkina Faso, and southern Nigeria.[7]
The species inhabits a variety of forest and woodland. It occurs near forest edges and enters forest only if it has been logged or opened by roads. It is also known to inhabit open gallery forest, secondary growth, riverine strips, and some plantations. It occurs in peanut and cassava fields with scattered tall trees and borders of shrubs or bushes, along with miombo woodland, dense woodland thickets, open riverine woodland, and thornveld and thorn-scrub. It mainly inhabits altitudes of up to 1,500 m (4,900 ft), although it is known to occur at altitudes of up to 1,800 m (5,900 ft) in eastern Africa.[7]
Status
The ashy flycatcher was listed as being of least concern by the International Union for Conservation of Nature (IUCN) on the IUCN Red List due to its large range, stable population, and occurrence in a number of protected areas. The population in Mozambique is estimated to number over 5,000 individuals.[7]
References
- ^ BirdLife International (2012). "Muscicapa caerulescens". IUCN Red List of Threatened Species. 2012. Retrieved 26 November 2013.
- ^ a b "Muscicapa caerulescens (Ashy Alseonax)". Avibase. Archived from the original on 2011-09-20. Retrieved 2021-11-14.
- ^ Gurney, J. H. (2008-06-28). "A seventh additional list of birds from Natal". Ibis. 7 (3): 267–268. doi:10.1111/j.1474-919X.1865.tb05772.x – via Biodiversity Heritage Library.
- ^ Jobling, James A. (2010). Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp. 83, 262. ISBN 978-1-4081-2501-4. OCLC 1040808348 – via Biodiversity Heritage Library.
- ^ a b c Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (July 2023). "Chats, Old World flycatchers". IOC World Bird List Version 13.2. International Ornithologists' Union. Retrieved 20 July 2023.
- ^ a b Voelker, Gary; Huntley, Jerry W.; Peñalba, Joshua V.; Bowie, Rauri C.K. (2016). "Resolving taxonomic uncertainty and historical biogeographic patterns in Muscicapa flycatchers and their allies". Molecular Phylogenetics and Evolution. 94 (Pt B): 618–625. doi:10.1016/j.ympev.2015.09.026. PMID 26475615.
- ^ a b c d e f g h i j k l m n o p q r s t u Taylor, Barry; Boesman, Peter F. D.; Moura, Nárgila (2020-06-25). Billerman, Shawn M.; Keeney, Brooke K.; Rodewald, Paul G.; Schulenberg, Thomas S. (eds.). "Ashy Flycatcher (Fraseria caerulescens)". Birds of the World. Cornell Lab of Ornithology. doi:10.2173/bow.ashfly1.01.1. S2CID 241261361. Retrieved 2021-09-21.
- ^ Zhao, M.; Gordon Burleigh, J.; Olsson, U.; Alström, P.; Kimball, R.T. (2023). "A near-complete and time-calibrated phylogeny of the Old World flycatchers, robins and chats (Aves, Muscicapidae)". Molecular Phylogenetics and Evolution. 178: 107646. doi:10.1016/j.ympev.2022.107646. PMID 36265831.
- ^ Gordon, Alasdair IV; Harrison, Nancy M. (2010-11-11). "Observations of mixed-species bird flocks at Kichwa Tembo Camp, Kenya" (PDF). Ostrich. 81 (3): 259–264. doi:10.2989/00306525.2010.519514. ISSN 0030-6525. S2CID 85070277.
- ^ Oschadleus, H. Dieter (2018-04-03). "Birds adopting weaver nests for breeding in Africa". Ostrich. 89 (2): 131–138. doi:10.2989/00306525.2017.1411403. ISSN 0030-6525. S2CID 90663983.
External links
- Image at ADW
- Ashy flycatcher - Species text in The Atlas of Southern African Birds.