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 systematic drainage of the southern marshes of Iraq, its main breeding habitat. 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 (such as the building of dams) projects and the impact of climate change. As such, the population may very rapidly go into decline in the future again. Therefore, this species is listed as Endangered.

Population justification
A crude estimate of the breeding population in Iraq between 2006 and 2011 was 4,500 pairs (Nature Iraq 2017). The authors of this estimate stress that caution should be taken with this estimate, and so the population is placed in the range of 2,500-9,999 individuals. This is equivalent to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.

Trend justification
In the past, a very rapid and ongoing population decline was suspected from declines in ringing records of migrating birds, as well as the loss of the species' marshland breeding habitat. 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 from 2006 to 2011 show a population of c. 4,500 pairs (Nature Iraq 2017), 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), and it is clear that the species has undergone a genuine recovery (Nature Iraq 2017; M. Salim, S. A. Abed and R. Porter in litt. 2020). The population is suspected to have been roughly stable since 2006-2011 estimates (M. Salim and L. A. Al-Obeidi in litt. to R. Porter 2016), and it is clear that the species has undergone a genuine recovery (Nature Iraq 2017; M. Salim, S. A. Abed and R. Porter in litt. 2020), whilst there is also evidence of birds moving to alternative, marginal habitats (M. Salim and S. A. Abed  in litt. 2020).
However, since 2010 there have been droughts of various severity, some of which have coincided with the species' breeding season (M. Salim and S. A. Abed  in litt. 2020). This, in combination with uncertainty over future water management (M. Salim and L. A. Al-Obeidi to R. Porter in litt. 2016), including building of dams in Turkey that restrict the flow of feed-water to the marshes from the Tigris and Euphrates, as well as the effects of global warming, is thought to reduce available breeding habitat in the future (N. Fazaa and R. Porter in litt. 2020). Therefore, although the current population trend is considered to be stable, it is suspected that the potentially significant impact from future threats could cause very rapid declines in the next ten years.

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 in south-west Iran in the Hawr Al Hawizeh marsh complex of Khuzestan where the species breeds in small numbers (D. Scott in litt. 2003, M. S. Bagher in litt. 2011, S. S. Mousavi in litt. 2013, K. Hafezi in litt. 2020). Two pairs have recently been found breeding in the Hula Valley, Israel (Perlman and Shanni 2008). The highest populations of breeding individuals between 2006 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 2017). 
The species 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 breeds) (Porter and Aspinall 2010); one individual in Syria in April 2006 was most likely a migrant (Yésou et al. 2007). Presumably the species is still common in the breeding habitat that remains (Maltby 1994), and now common locally due to re-flooding of the marshes. The maximum area of suitable habitat within the main Mesopotamian marshlands was 759 km2 (c.7% of the original marshland area, as of the mid-1970s) (UNEP 2003). However, this has increased to c. 70% in 2007 (Nature Iraq 2017) and fluctuated since. The surveys of the Iraq Marshes (Nature Iraq 2017) further identified the main breeding IBAs as follows: Hindiya Barrage 10 pairs; North Ibn Najm 10 pairs; Ibn Najm 30 pairs; Dalmaj 500 pairs; Gharraf River 30 pairs; Auda Marsh 20 pairs; Hawizeh 500 pairs; Central Marshes 2,000 pairs; West Hammar 1,000 pairs; East Hammar 300 pairs; and Fao 100 pairs.


The species 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). Although there is little data on diet, the species likely feeds mostly on insects (Dyrcz 2020).


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 (G. Backhurst in litt. 2003, M. Evans in litt. 2003, D. Pearson 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 at the time (UNEP 2003). Following the 2003 invasion of Iraq, a major project aiming to restore the marshes began, and in conjunction with major snow melts in Türkiye and Iran (Richardson 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 Türkiye, 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 to R. Porter in litt. 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). Further dam projects are however planned for the future in Türkiye (N. Fazaa and R. Porter in litt. 2020). Reed harvesting may additionally be affecting the population (Nature Iraq 2017). 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).  

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. In 2016 UNESCO declared the Marshlands of Iraq as a World Heritage Site, where nearly 4,000 pairs of the species are estimated to breed in the designated area. A large-scale restoration of the Mesopotamian marshes began following the 2003 invasion and successfully re-inundated large areas of habitat; up to 70% of the former area. However, these successes are threatened by drought and upstream dam projects. Dedicated studies of the population in the Iraq Marshes by the Iraq Organisation for the Conservation of Nature have recently been started (M. Salim and S. A. Abed to R. Porter in litt. 2020). In 2011 a high level meeting resulted in the launch of the Tana Delta planning initiative in Kenya, 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 Proposed

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). Continue to monitor migrating birds at Ngulia (Kenya) to assess population trends (M. Evans in litt. 2003, D. Pearson in litt. 2003, D. Scott 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
Fernando, E.

Abed, S., Al-Obeidi, L., Backhurst, G., Bagher, M., Benstead, P., Callaghan, D., Capper, D., Evans, M., Fadhel, O., Fazaa, N., Group, N., Hafezi, K., Khwaja, N., Mahood, S., Martin, R., Mousavi, S., O'Brien, A., Pearson, D., Porter, R., Salim, M., Scott, D., Shutes, S., Symes, A., Temple, H. & Westrip, J.R.S.

Recommended citation
BirdLife International (2024) Species factsheet: Acrocephalus griseldis. Downloaded from https://datazone.birdlife.org/species/factsheet/basra-reed-warbler-acrocephalus-griseldis on 24/02/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org on 24/02/2024.