Birdfinding.info ⇒  Locally common in several parts of its range, especially in central and eastern Thailand.  Sites near Bangkok where it can be found consistently include Bang Phra, Chulalongkorn University – Saraburi, Lat Krabang, Nong Chok, Nong Pla Lai, Pak Phli, and Song Phi Nong.  Also common across most of Cambodia, including Phnom Penh.  In Myanmar, seen most often around Bagan; in Malaysia, Chuping; and in Vietnam, Cat Tien National Park and Da Lat.

Plain-backed Sparrow

Passer flaveolus

Family: Passeridae

Southeast Asia, in semiopen and mixed habitats, including towns and farmland.

Central and southern Myanmar east through Thailand, southern Laos, the southern half of Vietnam, and south to peninsular Malaysia around Penang and Terengganu.

Plain-backed Sparrow, male and female.  (Sanam Bin Reservoir Wildlife Refuge, Buri Ram, Thailand; February 9, 2017.)  © Wich’yanan (Jay) Limparungpatthanakij

Identification

A colorful and distinctive sparrow—at least the male, which is mostly olive with chestnut across the back and behind the eye, yellow face and brow, and a black mask and central throat patch.

Often bright yellow-olive over much of its plumage, especially the underparts, but this varies (presumably brighter overall when breeding).

Plain-backed Sparrow, male with yellow underparts.  (Pak Phli, Nakhon Nayok, Thailand; January 21, 2016.)  © Ayuwat Jearwattanakanok

Plain-backed Sparrow, male with olive-gray underparts.  (Pak Phli, Nakhon Nayok, Thailand; January 21, 2016.)  © Ayuwat Jearwattanakanok

Plain-backed Sparrow, male.  (Bang Phra Wildlife Refuge, Chon Buri, Thailand; May 4, 2020.)  © Aladdin

Plain-backed Sparrow, male.  (Cat Tien National Park, Vietnam; February 16, 2018)  © Thibault Riviere

Plain-backed Sparrow, male with yellow underparts.  (Nong Prong, Khao Yoi, Phetchaburi, Thailand; February 24, 2014.)  © Markus Lilje

Plain-backed Sparrow, male with yellow underparts.  (Monywa, Sagaing, Myanmar; March 22, 2018.)  © Stéphane Thomin

Plain-backed Sparrow, male with olive-gray underparts.  (Khao Yai National Park, Thailand; March 2, 2012.)  © Peter Ericsson

Plain-backed Sparrow, male.  (Hot, Chiang Mai, Thailand; February 14, 2016.)  © creaturesnapper

Plain-backed Sparrow, male showing rich chestnut on back and head.  (Lat Krabang, Thailand; January 21, 2018.)  © Bird.soong

Plain-backed Sparrow, male with pale yellow-olive underparts.  (Chuping, Kangar, Perlis, Malaysia; December 12, 2016.)  © Dave Bakewell

Plain-backed Sparrow, male.  (Langkawi, Kedah, Malaysia; November 28, 2018.)  © Tom Reynolds

Plain-backed Sparrow, male with exceedingly yellow underparts.  (Khao Yai National Park, Thailand; March 6, 2011.)  © António Gonçalves

Plain-backed Sparrow, male with yellow underparts.  (Chuping, Kangar, Perlis, Malaysia; December 12, 2016.)  © Dave Bakewell

Plain-backed Sparrow, male.  (Bang Pu, Samut Prakan, Thailand; May 6, 2020.)  © Ben Weil

Plain-backed Sparrow, male showing long black central throat patch.  (Chuping, Kangar, Perlis, Malaysia; November 24, 2019.)  © Neoh Hor Kee

Plain-backed Sparrow, male with yellow underparts.  (Cat Tien National Park, Vietnam; March 9, 2020.)  © Laval Roy

Plain-backed Sparrow, male with exceedingly yellow underparts.  (Chuping, Kangar, Perlis, Malaysia; February 19, 2017.)  © Choy Wai Mun

Plain-backed Sparrow, male with yellow underparts.  (Chuping, Kangar, Perlis, Malaysia; December 12, 2016.)  © Dave Bakewell

Plain-backed Sparrow, male with olive-gray underparts.  (Laem Phak Bia, Phetchaburi, Thailand; March 15, 2013.)  © Marco Valentini

Plain-backed Sparrow, male with olive-gray underparts.  (Cho Lae, Mae Taeng, Chiang Mai, Thailand; September 18, 2015.)  © Ayuwat Jearwattanakanok

Plain-backed Sparrow, male.  (Bagan, Mandalay Region, Myanmar; November 15, 2013.)  © Otto Samwald

Plain-backed Sparrow, male singing and showing black central throat patch.  (Yang Chum Reservoir, Kui Buri National Park, Prachuap Khiri Khan, Thailand; July 2, 2020.)  © Aladdin

Plain-backed Sparrow, male and female.  (Phra Nakhon Si Ayutthaya, Thailand; August 26, 2019.)  © Ayuwat Jearwattanakanok

Females and immatures are mostly tan overall, sometimes tending more toward gray, often with a yellowish wash, especially on the underparts and face.  They have a distinct buffy eyebrow stripe and that extends back turns down toward the nape.

Unlike other female and immature Passer sparrows, they are essentially unstreaked (i.e., plain-backed).

Plain-backed Sparrow, female with a yellowish wash.  (Chuping, Kangar, Perlis, Malaysia; December 12, 2016.)  © Dave Bakewell

Plain-backed Sparrow, female with buffy face and eyebrow.  (Pak Phli, Nakhon Nayok, Thailand; January 21, 2016.)  © Ayuwat Jearwattanakanok

Plain-backed Sparrow, female with drab gray overall coloration and yellowish wash on the throat.  (Chulalongkorn University, Bangkok, Thailand; May 4, 2019.)  © Andaman Kaosung

Plain-backed Sparrow, female with drab gray overall coloration.  (Chiang Mai, Bangkok, Thailand; February 19, 2013.)  © Myron Tay

Plain-backed Sparrow, female with a strong yellowish wash.  (Chuping, Kangar, Perlis, Malaysia; February 19, 2017.)  © Choy Wai Mun

Plain-backed Sparrow, female with a strong yellowish wash.  (Khao Yai National Park, Thailand; October 21, 2007.)  © Ayuwat Jearwattanakanok

Plain-backed Sparrow, female with a subtle yellowish wash.  (Thailand; July 26, 2010.)  © Albert Noorlander

Plain-backed Sparrow, female with drab gray overall coloration.  (Praek Nam Daeng, Samut Songkhram, Thailand; May 1, 2020.)  © Aladdin

Voice.  Typical call is a full-bodied but generic chirp, often repeated: Also a metallic, bisyllabic whistled tsoo-it:Song consists of rambling strings of call notes, interspersed with whistles or other brief phrases:

Notes

Monotypic species.

References

BirdLife International. 2016. Passer flaveolus. The IUCN Red List of Threatened Species 2016: e.T22718194A94572013. https://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22718194A94572013.en. (Accessed October 5, 2020.)

Clement, P., A. Harris, and J. Davis. 1993. Finches and Sparrows: An Identification Guide. Princeton University Press.

eBird. 2020. eBird: An online database of bird distribution and abundance. Cornell Lab of Ornithology, Ithaca, N.Y. http://www.ebird.org. (Accessed October 5, 2020.)

Robson, C. 2002. Birds of Thailand. Princeton University Press.

Xeno-Canto. 2020. Plain-backed Sparrow – Passer flaveolus. https://www.xeno-canto.org/species/Passer-flaveolus. (Accessed October 5, 2020.)