Olive spinetail

Olive spinetail
Conservation status
Least Concern  (IUCN 3.1) [1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Furnariidae
Genus:	Cranioleuca
Species:	C. obsoleta
Binomial name
Cranioleuca obsoleta (Reichenbach, 1853)

The olive spinetail (Cranioleuca obsoleta) is a species of bird in the Furnariinae subfamily of the ovenbird family Furnariidae. It is found in Argentina, Brazil, and Paraguay. ^[2]

Taxonomy and systematics

The olive spinetail is monotypic. ^[2] It is closely related to the sister species stripe-crowned spinetail (C. pyrrhophia) and pallid spinetail (C. pallida). ^[3] The olive and stripe-crowned spinetails hybridize in southern Brazil. ^[4]

Description

The olive spinetail is 12.5 to 15 cm (4.9 to 5.9 in) long and weighs 12 to 16 g (0.42 to 0.56 oz). It is a smallish, short-billed, member of genus Cranioleuca. The sexes have the same plumage. Adults have a whitish supercilium, a dull brown band behind the eye, buff and brown streaky ear coverts, and a plain buff malar area. Their forehead is streaked brown and buff, their crown is dull brownish olive, and their back and rump are a slightly richer brown. Their tail is chestnut-rufous; the feathers are graduated and lack barbs at the end giving a spiky appearance. Their wing coverts are dark chestnut-rufous, their primary coverts dark brown, and their flight feathers warm brown. Their throat is whitish, their breast buffy brownish, their belly pale olive-buff, and their flanks and undertail coverts somewhat darker. Their iris is variable, their maxilla black to dark brownish, their mandible pinkish, bluish gray, or whitish with a dark tip, and their legs and feet grayish olive to olive-green. Juveniles have darker upperparts than adults, with variable scaling on the breast. ^{[5] [6] [7]}

Distribution and habitat

The olive spinetail is found from southern São Paulo state in southeastern Brazil south through eastern Paraguay into northeastern Argentina as far as northern Corrientes Province. It inhabits humid forest, both prinary and secondary, and woodlands dominated by Araucaria . In elevation it ranges from near sea level to 1,000 m (3,300 ft). ^{[5] [6] [7]}

Behavior

Movement

The olive spinetail is a year-round resident throughout its range. ^[5]

Feeding

The olive spinetail feeds on arthropods. It typically forages in pairs and often joins mixed-species feeding flocks. It acrobatically gleans prey from bark, moss, and epiphytes. It hitches and climbs along trunks and small branches, mostly in the forest's mid-storey but occasionally to its canopy. ^{[5] [6]}

Breeding

The olive spinetail's breeding season is probably the austral spring and summer; eggs have been noted in October. It is thought to be monogamous. Its nest is thought to be a ball of moss with a side entrance. Nothing else is known about its breeding biology. ^[5]

Songs and calls Listen to olive spinetail on xeno-canto

Vocalization

The olive spinetail's song is a "short series, at first extr. high and hesitant 'tzit-tzit-tzit', and then a short trill ending in a very high '-sfeet-sfeet-sfeet' ". ^[6] Its calls are "tst" and a "short, hard trill" ^[5] ; the second is also described as a "soft, dry, hurried trill" ^[6] .

Status

The IUCN has assessed the olive spinetail as being of Least Concern. It has a large range and an unknown population size that is believed to be decreasing. No immediate threats have been identified. ^[1] It is considered generally fairly common to common though rare in Paraguay and occurs in a few protected areas. However, it has a "relatively small range, within which extensive deforestation has dramatically reduced [the] total area of its habitat". ^[5]

References

1. BirdLife International (2016). "Olive Spinetail Cranioleuca obsoleta". IUCN Red List of Threatened Species . 2016: e.T22702435A93875361. doi: 10.2305/IUCN.UK.2016-3.RLTS.T22702435A93875361.en . Retrieved 14 November 2023.
2. Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (July 2023). "Ovenbirds, woodcreepers". IOC World Bird List. v 13.2. Retrieved July 31, 2023.
3. Derryberry, E. P., S. Claramunt, G. Derryberry, R. T. Chesser, J. Cracraft, A. Aleixo, J. Pérez-Emán, J. V. Remsen, Jr., and R. T. Brumfield. (2011). Lineage diversification and morphological evolution in a large-scale continental radiation: the Neotropical ovenbirds and woodcreepers (Aves: Furnariidae). Evolution 65(10):2973–2986. https://doi.org/10.1111/j.1558-5646.2011.01374.x
4. Claramunt, Santiago (2002). "Variación geográfica en Cranioleuca pyrrhophia y el límite con Cranioleuca obsoleta (Furnariidae)" (PDF). Ornitología Neotropical. 13 (4): 255–266.
5. Remsen, Jr., J. V. (2020). Olive Spinetail (Cranioleuca obsoleta), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.olispi1.01 retrieved November 14, 2023
6. van Perlo, Ber (2009). A Field Guide to the Birds of Brazil. New York: Oxford University Press. p. 216. ISBN   978-0-19-530155-7.
7. de la Peña, Martín R.; Rumboll, Maurice (2001). Birds of Southern South America and Antarctica. Princeton Illustrated Checklists. New Jersey: Princeton University Press. pp. Plate 62, Map 62.18. ISBN   0691090351.