A forgotten rodent from the Garden of Eden: what really happened to the long-tailed nesokia rat in the Mesopotamian marshes?

Abstract

The greater part of expected mammalian extinctions will be of smaller-bodied mammals, including rats which are more generally known only as pests and carriers of pathogens. We address the long-tailed nesokia rat, which is among the least studied Palaearctic mammals. The species is known from merely five specimens, collected between March 1974 and January 1977 within a radius of 30 km around Qurna inside the seasonally flooded Mesopotamian marshes in southern Iraq. In the 1990s, this extensive aquatic habitat has been deliberately reduced to <15% of its original area and the IUCN expressed fear that such a disaster “almost certainly” caused the extinction of the long-tailed nesokia. Although the interventions after 2003 reversed the shrinking trend and marshes started to expand, the continuous presence of the long-tailed nesokia could not be unambiguously confirmed. We provide meagre evidence suggesting that the rat might be still present in the marshes. Next, our habitat modelling shows that the area of the long-tailed nesokia might be more extensive than expected with a highly suitable habitat covering 15,650 km2 of Mesopotamian marshland in Iraq (between Basra and Salah Ad Din provinces) and the Hawizeh Marshes in the adjacent Iranian Khuzestan.

First Photographic Records and New Distribution Range of the Endangered Long-Tailed Nesokia Nesokia Bunnii (Khajuria, 1981)

“…The photograph of the carcass had not been assigned to the species and was labeled as a "Rat". However, it clearly showed the distinctive morphological features of N. bunnii and was sufficient evidence of the species' persistence in the Mesopotamian marshes of southern Iraq since the last animal had been captured near Bani Mansor in 1977 (Kryštufek et al, 2020). Al-Sheikhly et al (2015) indicated that the current status the species in Iraq is unknown; suggesting that it could also possibly occur in Al-Hawizeh Marsh straddling the Iraq-Iran southeastern borders.…”

“…The species is known from only five voucher specimens collected between March 1974 and January 1977 within a narrow perimeter of 30 km around Qurna, within the Mesopotamian marshes at the confluence of the Tigris and the Euphrates Rivers in Basra Province in southern Iraq (Khajuria, 1981;Kryštufek et al, 2017Kryštufek et al, , 2020 (Tab. 1).…”

“…In a craniometric study, Al-Robaae and Felten (1990) published additional three specimens of N. bunnii (Tab. 1), which are now in the Naturmuseum Senckenberg, Frankfurt, Germany (SMF) (see Kryštufek et al, 2017Kryštufek et al, , 2020. They demonstrated a close resemblance between N. bunnii and N. indica rats, concluding that Erythronesokia is "not more thanif at all-a subgenus of Nesokia, but not a separate genus."…”

“…Similar conclusions were in agreement with a geometric morphometric approach of craniodental structures made by Kryštufek et al (2016). Furthermore, Kryštufek et al (2020) indicated that no further museum vouchers of N. bunnii are known to exist.…”

“…Al-Sheikhly et al (2015) indicated that the current status the species in Iraq is unknown; suggesting that it could also possibly occur in Al-Hawizeh Marsh straddling the Iraq-Iran southeastern borders. It is worth mentioning that attempts by the late Jamshid Darvish, one of the leading rodent experts in Iran, were dedicated to search for N. bunnii in the Khuzestan Province of southwestern Iran, but such efforts yielded no positive results (Kryštufek et al 2020). Based on the habitat suitability model (see Kryštufek et al, 2020), the species is highly expected to occur in Al-Edhe'am Marsh (=Hor Al-Azim), a transboundary monotonic marshy habitat on the eastern side of Al-Hawizeh Marsh in the Khuzestan province in southwestern Iran.…”