The Visayan babbler (Sterrhoptilus nigrocapitatus) also known as the Visayan Black-crowned Babbler. is a species of bird in the family Zosteropidae. It is endemic to the Philippines. It is found on Samar, Leyte and Bohol. Its natural habitat is tropical moist lowland forest. It was formerly conspecific to the northern population of the Calabarzon black-crowned babbler but has since been split as a species due to differences in its yellowish throat and whiter belly.

Visayan babbler
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Zosteropidae
Genus: Sterrhoptilus
Species:
S. nigrocapitatus
Binomial name
Sterrhoptilus nigrocapitatus
(Steere, 1890)
Synonyms
  • Sterrhoptilus nigrocapitata

Description and taxonomy

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Ebird describes it as "A fairly small bird of lowland and foothill forest and edge; endemic to Samar, Leyte, and Bohol, though lumped with Calabarzon Babbler under “Black-crowned Babbler” by some taxonomies. Has a gray back and cheek with fine pale streaks, dark wings and tail with white outer tail feathers, white underparts, a pale rufous throat, and a black crown. Note the slender black bill. Voice includes a medium-pitched “poo piuu!” with the second note downslurred."

Subspecies

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Two subspecies are recognized:

  • S.n. nigrocapitatus- Found on Samar and Leyte
  • S.n. boholensis - Found on Bohol

It was formerly conspecific with the Calabarzon babbler but is differentiated by it is differentiated from its northern counterpart by having a less orange chin and whiter belly. Its validity as a species were also further validated by sequencing its mitochodrial DNA.[2]

Ecology and behavior

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Diet is assumed to primarily be insects, berries and vegetable matter. They are spotted foraging alone, in pairs or in mixed flocks with other species. [3] It is often observed in mixed-species flocks that include Yellow-bellied whistler, Visayan fantail, Chestnut-tailed Jungle Flycatcher, Short-tailed drongo, Black-naped monarch, celestial monarch, Rufous paradise flycatcher, Philippine leaf warbler, Yellow-wattled bulbul, tailorbirds and sunbirds. [4]

Breeding season is believed to from April to July, which is the general breeding season for most Philippine forest birds. One nest was found that was cup shaped made out of moss and woven together with roots with small twigs just one meter above the ground. This nest contained 3 eggs but this single nest is not enough to assume average clutch.[2]

Habitat and conservation status

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Its natural habitats are tropical moist lowland forest, tropical mangrove forest, and tropical moist shrubland with most records under 1,150 meters above sea level. It is often found foraging in the understorey and lower parts of the canopy.

IUCN has yet to assess the Visayan babbler as it only recognizes the Black-crowned babbler which it has assessed as least-concern with the population believed to be decreasing. It is believed that among the two, the Visayan babbler has gone a more dreastic decline. Extensive lowland deforestation on all islands in its range is the main threat. Most remaining lowland forest that is not afforded protection leaving it vulnerable to both legal and Illegal logging, conversion into farmlands through Slash-and-burn and mining. There is only 4% forest remaining in Bohol and around 400km2 of primary forest combined in Samar and Leyte with no respite in deforestation.

This occurs in a few protected areas such as Rajah Sikatuna Protected Landscape and Samar Island Natural Park however protection is lax.[5]

References

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  1. ^ BirdLife International (2016). "Sterrhoptilus nigrocapitatus". IUCN Red List of Threatened Species. 2016: e.T22716204A94484596. doi:10.2305/IUCN.UK.2016-3.RLTS.T22716204A94484596.en.
  2. ^ a b Collar, Nigel; Robson, Craig (2023). "Calabarzon Babbler (Sterrhoptilus affinis), version 1.0". Birds of the World. doi:10.2173/bow.bkcbab3.01species_shared.bow.project_name. ISSN 2771-3105.
  3. ^ Arlott, Norman. Birds of the Greater Sundas, the Philippines, and Wallacea.
  4. ^ Collar, Nigel; Robson, Craig (2023). "Visayan Babbler (Sterrhoptilus nigrocapitatus), version 1.0". Birds of the World. doi:10.2173/bow.bkcbab10.01species_shared.bow.project_name. ISSN 2771-3105.
  5. ^ IUCN (1 October 2016). Sterrhoptilus nigrocapitatus: BirdLife International: The IUCN Red List of Threatened Species 2016: e.T22716204A94484596 (Report). International Union for Conservation of Nature. doi:10.2305/iucn.uk.2016-3.rlts.t22716204a94484596.en.
  • Collar, N. J. & Robson, C. 2007. Family Timaliidae (Babblers) pp. 70–291 in; del Hoyo, J., Elliott, A. & Christie, D.A. eds. Handbook of the Birds of the World, Vol. 12. Picathartes to Tits and Chickadees. Lynx Edicions, Barcelona.