VU
Finn's Weaver Ploceus megarhynchus



Justification

Justification of Red List Category
This species has a small, rapidly declining and severely fragmented population as a result of the loss and degradation of terai grasslands, principally through conversion to agriculture and overgrazing. These factors qualify it as Vulnerable.

Population justification
The population is estimated to number 2,500-9,999 mature individuals, based on an analysis of records in BirdLife International (2001) suggesting that the population is unlikely to exceed 10,000 individuals, but may fall short of this. This equates to approximately 3,750-14,999 individuals in total, rounded here to 3,500-15,000 individuals. However, it has also been suggested that the total population could number fewer than 3,000 mature individuals (R. Bhargava per A. Rahmani in litt. 2012).

Trend justification
A rapid and on-going population decline is suspected to be occurring, owing to the conversion of terai habitats for agriculture, as well as the effects of trapping for the cage-bird trade. The recent disappearance of colonies from previously occupied sites supports this projected trend. However, the population trend differs considerably between the two populations. The western population (Delhi, Uttar Pradesh, Uttarakhand, eastern Nepal) seems to be in a rapid decline, as industrial activities within the area have resulted in a loss of grassland habitat (P. M. Laad in litt. 2016). While in 1961, 800 nests were discovered in Uttarakhand, in 2012 only 11 nests could be located (Bhargava 2017). However, the eastern population in Nepal, though historically much smaller, is increasing rapidly: In the Shuklaphanta National Park, the population increased from 11 birds in 1996 and is currently estimated at around 300 individuals (Bhargava 2017). The trend of the southern population (West Bengal) is not clear: In 2008 and 2009, the species had been seen in some locations, but no surveys have been carried out recently. However, there appears to be suitable habitat in the area (Bhargava 2017).

Distribution and population

This species is endemic to the Terai of the northern Indian subcontinent, where it is known from three disjunct populations: The western population occurs in Delhi, northern Uttar Pradesh and Uttarakhand states, India, and adjacent extreme western Nepal where it is a rare breeding resident and summer visitor. The eastern population occurs from eastern Nepal to Assam in India (BirdLife International 2001), and the southern population in West-Bengal. Throughout the range in India, the species was known from 17 locations up to the year 2000. By 2017, the number of sites notched up to 47; however, the species was only present at nine of them. Notably, three of the locations where the species is currently recorded are new locations identified during 2016-2017 (Bhargava 2017). Overall, based on surveys in north and north-east India, the species has become very uncommon (A. Rahmani in litt. 2016).

Ecology

It inhabits Terai marshes and extensive stands of Imperata, Narenga, Phragmites and Saccharum grassland, particularly those that are seasonally inundated, with well-scattered trees, and occasionally interspersed with patchy rice and sugarcane cultivation. It is gregarious, foraging in flocks and breeding (May-September) in colonies. Nests are built in trees, reedbeds, or extensive stands of tall grass. Whilst its movements are poorly understood, populations appear to wander erratically.

Threats

During the last 60 years, the Terai region has been almost totally converted to human-dominated landscape with agriculture, orchards, factories, canals, roads, expanding villages and cities, and very rapid human population growth. The rising population of crows (Corvus splendens and Corvus macrorhynchos), related to garbage and human habitations, is another threat to the nesting colonies (Bhargava 2000, 2017). These threats are compounded by capture for the live bird trade (Bhargava 2017).


 

Conservation actions

Conservation Actions Underway
It is considered Critically Endangered in Nepal (Inskipp et al. 2016). It is protected in India, where trapping and trade of the species has been banned since 1991. It has been recorded in very small numbers from Kaziranga, Orang, Dibru-Saikhowa and Manas National Parks (Assam), Jaldapara Wildlife Sanctuary and Buxa Tiger Reserve (West Bengal), Corbett National Park (Uttar Pradesh), and Suklaphanta National Park and Koshi Tappu Wildlife Reserves (Nepal) (H. Baral and C. Inskipp in litt. 2016).

Conservation Actions Proposed
Conduct widespread interviews with bird-trappers to identify population centres, followed by field surveys in remaining habitat to establish its distribution and status. Conduct surveys outside protected areas to establish whether the species is found in significant numbers outside the protected area network. Conduct a detailed survey of the Brahmaputra Valley for this species (A. Rahmani in litt. 2016). Extend, upgrade, link (where possible) existing protected areas and establish new ones in order to conserve remaining tracts of natural grassland across its range. Control livestock-grazing in protected areas to reduce rates of habitat loss and degradation. Promote conservation awareness initiatives focusing on sustainable management of grassland to maximise both thatch productivity for local people and available habitat for threatened grassland birds. Upgrade its legal protection status to Schedule I of the Indian Wildlife (Protection) Act.

Identification

17 cm. Large weaver with yellow rump, uppertail-coverts, head and underparts and dark ear-coverts. Heavily streaked mantle, back and scapulars. Female is duller with paler, more buff-tinged yellow parts, particularly crown and nape. Similar spp. Female/non-breeding male Baya Weaver P. philippinus is smaller with shorter, narrower bill and lacks dark lateral breast-patch. Voice Song is subdued twit-twit-tit-t-t-t-t-t-trrrrr wheeze whee wee we. Calls a harsh twit-twit etc.

Acknowledgements

Text account compilers
Gilroy, J., Ashpole, J, Hermes, C., Martin, R., Taylor, J., Benstead, P., Westrip, J.

Contributors
Rahmani, A., Inskipp, C., Bhargava, R., Baral, H., Laad, P.M.


Recommended citation
BirdLife International (2020) Species factsheet: Ploceus megarhynchus. Downloaded from http://www.birdlife.org on 27/05/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 27/05/2020.