Journal of Threatened
Taxa | www.threatenedtaxa.org | 26 May 2026 | 18(5): 28991–28994
ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print)
https://doi.org/10.11609/jott.10462.18.5.28991-28994
#10462 | Received 15 February 2026 | Final received 15 April 2026|
Finally accepted 23 April 2026
First photographic record of
Naumann’s Thrush Turdus naumanni
Temminck, 1820 from Assam, India
1 Centre for the Environment, IIT Guwahati, Amingaon, Assam 781039, India.
1 Balipara Tract & Frontier Foundation, Navin Enclave, Geeta nagar,
Guwahati, Assam 781021, India.
Editor: H. Byju,
Coimbatore, Tamil Nadu, India. Date of publication: 26 May 2026
(online & print)
Citation: Sinha,
V.K., K. Kumar, D. Kumar, I. Ali, R. Tiwary, P. Kumar
& A. Kumar (2026). Theileriosis in a captive Indian Gaur Bos gaurus: a rare encounter. Journal of Threatened Taxa 18(5): 28991–28994. https://doi.org/10.11609/jott.10462.18.5.28991-28994
Copyright: © Sinha et al. 2026. Creative Commons Attribution 4.0 International License.
JoTT allows unrestricted use, reproduction, and
distribution of this article in any medium by providing adequate credit to the
author(s) and the source of publication.
Funding: None.
Competing interests: The author declares no competing interests.
Acknowledgments: I sincerely acknowledge Mr. Langtuk Terang for providing the camera (Nikon Coolpix P900) used to obtain diagnostic photographs, and Dr. Rahul Thaosen for assistance in locating the species in the field. I am grateful to Dr. Rupam Bhaduri and Dr. Leons Mathew Abraham for their valuable suggestions and support in confirming the species identification. I also thank Dr. Dharitri Saikia for her continuous support and motivation during the preparation of this manuscript. Finally, I acknowledge Mr. Rokel Basumatary for his long-term field observations and regular updates on the status of the species.
Naumann’s Thrush Turdus naumanni Temminck, 1820, is a medium-sized (23–25 cm; 63–81 g)
species belonging to the family Turdidae with a
breeding range spanning central and eastern Siberia (Clement & Hathway 2000; Abhinav et al. 2022). Historically,
considered conspecific with Dusky Thrush (T. eunomus),
it was formally recognized as a distinct species (An et al. 2024), though
confusion persists due to hybrid forms (Hatibaruah et
al. 2019). The species winters across southeastern Russia, China, Korea, and
Taiwan (Clement & Hathway 2000), with vagrants
occasionally reaching western Europe and, more rarely, southern Asia.
Within India, T. naumanni remained largely unrecognized until its
formal addition to the national checklist (Praveen et al. 2021). The most
comprehensive assessment by Abhinav et al. (2022) documents only two confirmed records of pure species from India: an
unconfirmed sight record from Ladakh (16 January
1982) and a photographed first-winter female from Shey,
Ladakh (13 December 2021). In contrast, multiple
hybrid individuals (T. naumanni × T.
eunomus) have been documented across the
subcontinent, with an apparent influx during the winter of 2018–2019 in
northeastern India (Abhinav et al. 2022). Within Assam, prior records include a
sight record from Manas National Park, Baksa District (6 January 2006), and an individual of hybrid
or uncertain status from Digboi Oil Fields, Tinsukia
District (17 December 2018) (Hatibaruah et al. 2019;
Abhinav et al. 2022). The present record from Panbari
Village, Dhemaji District (13 January 2026) thus
constitutes the first photographically confirmed record of a pure individual
from the state.
On 13 January 2026, at 0830 h, a single individual of
the species was observed and photographed in grassland habitat mixed with rice
paddy field at Panbari Village, Dhemaji
District of Assam (27.540° N, 94.434° E; elevation ca. 105 m). The bird was
encountered in open grassland interspersed with shrubs, actively foraging on
the ground for invertebrates, a behaviour typical of
wintering thrushes in this region. The bird was observed at the same spot for
more than a month. Detailed photographs were taken to enable diagnostic
assessment of plumage characters. These images (Image 1c–f) were subsequently
submitted to eBird and Indian Biodiversity portal (https://indiabiodiversity.org/)
and BirdCount India (https://birdcount.in/) and
expert members confirmed the species as Naumann’s Thrush, based on the
following key diagnostic features: (1) rufous-orange wash extensively covering
the breast, flanks, and undertail coverts; (2) pale
supercilium extending from lore to nape; (3) brown-rufous (not black) streaking
on the upper chest and malar region; (4) pale brown (not dark brown) upperparts
with rufous tones on the rump and tail; (5) whitish central belly contrary to
the extensive dark markings in Dusky Thrush or Naumann’s × Dusky hybrids; and
(6) absence of the pronounced golden-rufous wing panel diagnostic of hybrids
(Clement & Hathway 2000; Hatibaruah
et al. 2019; Abhinav et al. 2022). Based on the paler and less saturated
rufous-orange colouration on the breast and flanks,
visible pale fringes producing a slightly scalloped appearance on the breast
feathers, and comparatively duller upperpart tones relative to males, the
individual was identified as a female (Clement & Hathway 2000; Abhinav et al. 2022). Furthermore, the
retained median coverts bearing pale buff-white tips contrasting with the
replaced greater coverts, and the moderately worn primaries, indicate this to
be a first-winter (first-year) individual, likely hatched in the preceding
summer (Clement & Hathway 2000). Additionally,
images were posted on the Facebook group ‘Ask ID of Indian Birds’, Assam Bird
Monitoring Network (ABMN) and many Bird ID groups where it was identified as
Naumann’s Thrush with no feature of hybridization. Weather conditions at the
time of observation were clear with moderate temperature (approximately 18–24
°C), following several days of cooler overnight temperatures (5–10 °C), a
pattern typical of trigger conditions for vagrant arrivals in northeastern
India.
Dhemaji District supports high avifaunal diversity, with more
than 334 bird species recorded across the district according to eBird regional data (ebird 2026).
The adjoining locations of the observation site also demonstrate substantial
species richness, with approximately 155 bird species documented from the
specific hotspot (ebird 2026). This record from Dhemaji represents noteworthy distribution data for several
reasons. First, it constitutes the first confirmed photographed record of the
species specifically from Dhemaji District. Second,
it occurs at substantially lower elevation (ca. 105 m) compared to most
previous Indian records, which are concentrated between 1,500 and 3,300 m
elevation (Abhinav et al. 2022), suggesting ecological flexibility regarding
wintering elevations. Third, the timing of this record in mid-January
corresponds to the documented peak occurrence window for the species in
northeastern India (December–February; Abhinav et al. 2022). The record thus
aligns with the hypothesis that this Palearctic species has become increasingly
regular in the region during winter months, particularly in years with severe
continental weather patterns that may trigger irruptive movements southward
(Abhinav et al. 2022).
Future monitoring of open grassland habitats and cultivated
areas in the Brahmaputra Valley during winter months may reveal additional
occurrences of this species and other rare Palearctic thrushes too, further
refining understanding of vagrance patterns and range
dynamics in the eastern Himalayan foothill’s region. The present record
underscores the importance of systematic documentation with photographic
evidence for distinguishing between pure individuals and hybrid forms, a
challenge particularly acute for species recently recognized in the region and
still poorly understood in its distribution ecology in India (Image2).
For
images - - click here for full PDF
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