Loja tyrannulet

Loja tyrannulet
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Tyrannidae
Genus:	Zimmerius
Species:	Z. flavidifrons
Binomial name
Zimmerius flavidifrons (Sclater, PL, 1860)

The Loja tyrannulet (Zimmerius flavidifrons) is a species of bird in the family Tyrannidae, the tyrant flycatchers. ^[1] It is found in Ecuador and Peru. ^[2]

Taxonomy and systematics

The Loja tyrannulet was originally described as Tyrannulus flavidifrons. ^[3] It was later reclassified as a subspecies of the golden-faced tyrannulet (then Tyrannulus chrysops, now Zimmerius chrysops). Through much of the twentieth century the golden-faced tyrannulet and several other tyrannulets were kept in genus Tyranniscus but a study published in 1977 erected the present genus Zimmerius for them. ^{[4] [5]}

Beyond its transfer to Zimmerius as a subspecies of the golden-faced tyrannulet, the Loja tyrannulet's taxonomy is unsettled. The International Ornithological Committee (IOC) follows a study published in 2008 and splits it from the golden-faced tyrannulet as a monotypic species. ^{[1] [6]} However, the South American Classification Committee of the American Ornithological Society, the Clements taxonomy, and BirdLife International's Handbook of the Birds of the World (HBW) treat it as a subspecies of the Peruvian tyrannulet (Z. viridiflavus). ^{[4] [7] [8]}

This article follows the monotypic species IOC model.

Description

The Loja tyrannulet is about 11 to 12 cm (4.3 to 4.7 in) long and weighs 9 to 10 g (0.32 to 0.35 oz). The sexes have the same plumage. Adults have pale yellowish lores and eye-ring and a dark stripe through the eye on an otherwise grayish olive face. Their crown is darkish olive to grayish olive and their back and rump are bright olive. Their wings are dark dusky with bright yellow-green edges on the coverts and flight feathers. Their tail is dusky olive. Their throat is pale yellow, their breast and flanks pale olive-yellow with some olive markings, and their belly very pale yellow to white. They have a gray to medium brown iris with a tan rim, a small, rounded, bill whose maxilla is gray to blackish and mandible medium gray, and dark gray to black legs and feet. ^{[2] [9] [10]}

Distribution and habitat

The Loja tyrannulet is found in Ecuador west of the Andes from southeastern Chimborazo Province south to western Loja Province and in the extreme southeast in the Zumba region of Zamora-Chinchipe Province. Its range extends into the northern Peruvian departments of Tumbes and Piura. It inhabits the canopy, edges, and clearings of humid forest and woodlands in the subtropical zone. In elevation it ranges between 900 and 2,400 m (3,000 and 7,900 ft) in Ecuador, between 500 and 750 m (1,600 and 2,500 ft) in Tumbes, and between 1,200 and 2,600 m (3,900 and 8,500 ft) in Piura. ^{[2] [9] [10]}

Behavior

Movement

The Loja tyrannulet is a year-round resident throughout its range. ^[2]

Feeding

The Loja tyrannulet feeds on insects; it probably also feeds on small fruits like those of mistletoes (Loranthaceae). It forages singly or in pairs and often joins mixed-species feeding flocks. It feeds mostly in the forest canopy, perching horizontally with its tail cocked and actively moving about and gleaning food while perched or with short flights. ^{[2] [9]}

Breeding

Nothing is known about the Loja tyrannulet's breeding biology. ^[2]

Songs and calls Listen to the Loja tyrannulet on xeno-canto

Vocalization

The Loja tyrannulet's dawn song is "a fast 'ti tuueé' " and its call "a loud and sharp, drawn-out 'truuu-eeé' ". ^[9]

Status

The IUCN follows HBW taxonomy and so has not separately assessed the Loja tyrannulet from the Peruvian tyrannulet. ^[11] The Loja tyrannulet is considered common in Ecuador. ^[9]

References

1. Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (August 2024). "Tyrant flycatchers". IOC World Bird List. v 14.2. Retrieved 19 August 2024.
2. Fitzpatrick, J. W. and D. A. Christie (2020). Peruvian Tyrannulet (Zimmerius viridiflavus), 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.pertyr1.01 retrieved November 13, 2024
3. Sclater, Philip Lutley (1860). List of Additional Species of Birds collected by Mr. Louis Fraser, at Pallatanga, Ecuador in Proceedings of the Zoological Society of London Part XXVIII. Zoological Society of London. p. 69.
4. Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, G. Del-Rio, A. Jaramillo, D. F. Lane, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version 28 September 2024. A classification of the bird species of South America. American Ornithological Society. https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm retrieved September 29, 2024
5. Traylor, M. A. (1977). A classification of the tyrant flycatchers (Tyrannidae). Bulletin of the Museum of Comparative Zoology 148:128–184.
6. Rheindt, F.E.; Norman, J.A.; Christidis, L. (2008). "DNA evidence shows vocalizations to be better indicator of taxonomic limits than plumage patterns in Zimmerius tyrant-flycatchers". Molecular Evolution and Phylogenetics. 48 (1): 150–156.
7. Clements, J. F., P.C. Rasmussen, T. S. Schulenberg, M. J. Iliff, T. A. Fredericks, J. A. Gerbracht, D. Lepage, A. Spencer, S. M. Billerman, B. L. Sullivan, M. Smith, and C. L. Wood. 2024. The eBird/Clements checklist of birds of the world: v2024. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/ retrieved October 23, 2024
8. HBW and BirdLife International (2024). Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 8.1. Available at: https://datazone.birdlife.org/species/taxonomy retrieved August 26, 2024
9. Ridgely, Robert S.; Greenfield, Paul J. (2001). The Birds of Ecuador: Field Guide. Vol. II. Ithaca: Cornell University Press. p. 457. ISBN   978-0-8014-8721-7.
10. Schulenberg, T.S.; Stotz, D.F.; Lane, D.F.; O'Neill, J.P.; Parker, T.A. III (2010). Birds of Peru. Princeton Field Guides (revised and updated ed.). Princeton, NJ: Princeton University Press. p. 406. ISBN   978-0691130231.
11. BirdLife International (2024). "Peruvian Tyrannulet Zimmerius viridiflavus". IUCN Red List of Threatened Species . 2024: e.T22699156A264357859. Retrieved 13 November 2024.