Basra Reed-warbler Acrocephalus griseldis


Justification of Red List Category
This species was estimated to have undergone a very rapid decline in the past owing to drainage of its breeding habitat, and corroborated by numbers caught at a ringing site during migration.  The population is suspected to have stabilised, but current water management has led to a decrease in its breeding habitat again, in combination with a series of recent droughts; and, additionally, there is uncertainty over future water management.  This suggests that the population may rapidly go into decline in the future again.  Therefore, this species is listed as Endangered.

Population justification
A very crude estimate of the breeding population in Iraq between 2005 and 2011 was 4,500 pairs (Nature Iraq in press).  The authors of this estimate stress caution should be taken with this estimate and so the population is retained in the range of 2,500-9,999 individuals.  This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied.  This estimate is equivalent to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.

Trend justification
A very rapid and ongoing population decline was estimated from declines in ringing records of migrating birds, as well as the loss of the species's marshland breeding habitat.  However, the population is suspected to have been roughly stable since 2005-2011 estimates (M. Salim and L. A. Al-Obeidi in litt. to R. Porter 2016).  Despite this, there have been recent droughts along with water management practices that have led to a reduction, again, in available breeding habitat.  This, in combination with uncertainty over future water management (M. Salim and L. A. Al-Obeidi in litt. to R. Porter 2016), is suspected to be able to cause very rapid future declines.

Distribution and population

Acrocephalus griseldis breeds in the Mesopotamian marshes of south-east Iraq (between Baghdad and Basra, though also observed in 2006 close to the Tigris north of Baghdad) (Maltby 1994; O. Fadhel in litt. 2007) and probably in south-west Iran in the Hawr Al Hawizeh marsh complex of Khuzestan (D. Scott in litt. 2003, M. S. Bagher in litt. 2011, S. S. Mousavi in litt 2013).  Two pairs have recently been found breeding in the Hula Valley, Israel (Shanni and Labinger 2007, Perlman and Shanni 2008).  The highest populations of breeding individuals between 2005 and 2011 were found in Central Marshes, West Hammar Marshes, Hawizeh and Dalmaj, with these populations amounting to c.90% of the total breeding population (Nature Iraq in press).  It winters in Sudan, South Sudan, Ethiopia, south Somalia, south-east Kenya (Urban et al. 1997), east Tanzania, south Malawi (few records) and Mozambique.  It is regular on passage in Saudi Arabia and Kuwait (where it may breed) (Porter et al. 1996); one in Syria in April 2006 was most likely a migrant (Yésou et al. 2007).  Although presumably still common in the breeding habitat that remains (Maltby 1994), and thought now to be common locally due to re-flooding of the marshes following the fall of Saddam's government, there has been a massive loss of its shallow, marshy wetland habitat within its breeding range since the 1950s.  The maximum area of suitable habitat that is estimated to remain within the main Mesopotamian marshlands is 759 km2 (c.7% of the original marshland area, as of the mid-1970s) (UNEP 2003).  At Ngulia ringing station (Kenya), the average decadal ringing total for this species has been declining over the last three decades relative to the average decadal total for all Palearctic passerine migrants (by c.20% per decade) (D. Pearson in litt. 2003), with fewer than 5 ringed in 2014 (Ngulia Ringing Group in litt. 2014).  This suggests that a decline of up to 70-80% may have taken place since the 1970s (D. Scott in litt. 2003; M. Evans in litt. 2003).  However, the ringing methodology has changed somewhat during this period (D. Pearson verbally 2000, in litt. 2003) and even fewer birds might be expected in Kenya given the very high rate of destruction of the Mesopotamian marshes (D. Pearson in litt. 2003).  Following the regeneration of habitat in southern Iraq, surveys indicate that the species increased between 2006 and 2007 (O. Fadhel in litt. 2007), and a total of 180 birds ringed at Ngulia in November-December 2005 was the second highest annual total at the site (R. Porter in litt. 2006), however it is as yet uncertain  whether the species has undergone a genuine recovery.


Acrocephalus griseldis breeds in aquatic vegetation in or around shallow fresh or brackish water, still or flowing, mostly in Typha beds, although it forages extensively in adjacent dense reedbeds Phragmites austoralis (O. Fadhel in litt. 2007).  Newly fledged birds are often observed feeding in Typha along the dry edge of marshes and also in adjacent Tamarix scrub (O. Fadhel in litt. 2007).  It is found in low reeds above water, mangroves and gardens on migration, whilst in winter it has been recorded in dense Typha beds, coastal dense Suaeda monoica saltbushes, moist dense green thickets with tall rank grass and sedges near or over wet or drying ditches, swamps, lakes and flood pools and occasionally in herbaceous woodland undergrowth Walther et al 2004).  It occurs mostly singly or in pairs, but during migration it has been recorded in loose groups (Baker 1997).


Since the 1950s there has been considerable loss of its shallow, marshy wetland habitat due to large-scale hydrological projects throughout the Euphrates and Tigris river-basins (Maltby 1994).  The Iran-Iraq War (1980-1988) resulted in extensive damage to reedbeds in the main Mesopotamian marshes in southern Iraq (Maltby 1994).  In the 1980s, the construction of upstream dams smoothed out the annual flood pulse from the Zagros Mountains snow-melt which until then was probably an important factor affecting reedbed distribution and growth from year to year (D. Pearson in litt. 2003; M. Evans in litt. 2003; G. Backhurst in litt. 2003).  Large-scale hydrological engineering works in the main Mesopotamian marshes had, by 1993, prevented water from entering up to two-thirds of the area, with huge expanses of lake drying up (Evans 1993; Pearce 1993).  Improvement in access to the region, with consequent increases in settlement, has resulted in increased disturbance and water pollution (Maltby 1994).  Until 1997 perhaps as much as one third of the original extent of suitable habitat remained on the Iran-Iraq border where the dominant water supply to the area (unregulated rivers from Iran) had not yet been controlled or reduced (Maltby 1994).  By 2000, however, the main Mesopotamian marshes had been reduced to just 1,294 km2 (UNEP 2003), and by 2003 a further third of this area had been drained, leaving a maximum of 759 km2 of wetland extant (UNEP 2003).  The amount of suitable reedbed habitat within this wetland area is probably significantly smaller (M. Evans in litt. 2003).  Following the 2003 invasion of Iraq a major project aiming to restore the marshes began, and in conjunction with major snow melts in Turkey and Iran (Richardon and Hussain 2006), as of late 2006 58% of the original marshes had been reinundated.  However, recent drought and continued upstream dam construction and operation in Turkey, Syria and Iran have reduced the marshes to around 30% of their original size by 2009 (Anon. 2012, M. Salim and  L. A. Al-Obeidi in litt. to R. Porter 2016), but the species may be able to use alternative reed beds, such as along rivers during droughts (M. Salim in litt. to R. Porter 2016).  Reed harvesting may additionally be affecting the population (Nature Iraq in press). The 130,000 ha Tana River Delta in Kenya, a key wintering site, is threatened by large-scale conversion for agriculture (food and biofuels), including Kenyan based organisations wanting to establish huge sugar cane plantations on over 70,000 ha of land, companies from Canada and the UK wanting to grow oil seed crops on over 60,000 ha, possible mining in the sand dunes and prospecting for oil and gas.  Kenya's National Environment Management Authority (NEMA) approved these projects after considering their Environmental Impact Assessments, and if they go ahead they will convert an area of over 110,000 ha into plantations (RSPB 2012).  In 2011 a high level meeting resulted in the launch of the Tana Delta planning initiative, with the process to take place over the forthcoming 18 months and the output to be a long-term strategic land use plan representing a truly sustainable future to the Delta, informed by Strategic Environmental Assessment (RSPB 2012).

Conservation actions

Conservation Actions Underway
CMS Appendix II. The population in Israel is being monitored intensely and the population in the Lower Marshes of Iraq is also subject to a monitoring program. A large-scale restoration of the Mesopotamian marshes began following the 2003 invasion and successfully re-inundated large areas of habitat, however these successes are now threatened by drought and upstream dam projects.

Conservation Actions Proposed
Confirm whether Acrocephalus griseldis breeds in the marshes of Khuzestan, Iran (D. Scott in litt. 2003; M. Evans in litt. 2003). Continue to monitor migrating birds at Ngulia (Kenya) to assess population trends (D. Scott in litt. 2003; D. Pearson in litt. 2003; M. Evans in litt. 2003). Conduct surveys to assess whether the species now breeds in sub-optimal habitats, e.g. further up the Euphrates/Tigris north of Baghdad (M. Evans in litt. 2003). Investigate possibilities for habitat restoration.


18 cm.  Large, rather dull reed-warbler.  Upperparts dark brown and underparts mostly whitish, flanks creamy yellow.  Head pattern strong with whitish supercilium and contrasting dark eyestripe.  Similar spp. Best told from Great Reed-warbler A. arundinaceus by more slender, long pointed bill, lower mandible is paler and often pinkish contrasting with the upper mandible, shorter less graduated tail, lack of rufous tones in plumage and paler underparts.  Best told from Clamorous Reed-warbler A. stentoreus by its greater primary extension and the pale fringes of exposed primaries.  Voice  Male's song is kaka-kee, kaka-kee, kaka-kee.  Call is a harsh chaarr.


Text account compilers
Shutes, S., Khwaja, N., Martin, R, Westrip, J., Temple, H., Capper, D., Benstead, P., Symes, A., Evans, M., Mahood, S., O'Brien, A.

Salim, M., Backhurst, G., Mousavi, S., Callaghan, D., Al-Obeidi, L., Scott, D., Porter, R., Pearson, D., Evans, M., Bagher, M.

Recommended citation
BirdLife International (2022) Species factsheet: Acrocephalus griseldis. Downloaded from http://www.birdlife.org on 12/08/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 12/08/2022.