Tana River Cisticola

Description 

13 cm 

12-15 grams 

Pale, grey-brown, medium-sized, slender cisticola that is finely and uniformly streaked on the crown and upper back with a long, rounded tail and washed appearance 

Creamy face with a grey-brown cheek 

Crown lightly washed with a rusty coloring that is streaked dark brown merging into grey-brown upperparts that are heavily streaked dark brown on mantle and back 

Grey-brown lower back and rump  

Grey-brown tail with darker subterminal band, buffy tips on all except the central feather pair, and bold black spots that are visible from below and above but don't reach the end of the feathers  

Paler on throat and central belly 

Warm brown iris 

Dark brown bill with a paler base 

Dull pink legs 

Edgings of wings are faintly rusty but not in contrast to upperparts  

Very pale buff/creamy underparts (almost white) with a light grey wash on the sides of the breast and flanks 

Flight feathers and upperwing-coverts are dark brown with ashy margins  

Little to no sexual dimorphism in size (female is slightly larger) with no dimorphism when it comes to color (Birds of the World) 

The Tana River Cisticola looks very similar to the Ashy Cisticola (Cisticola cinereolus) except for the following characteristics:   

Lacks the white bases to the nape feathers 

Rusty wash to the feathers on the crown and nape that separate them from the grey brown back (color of upperparts are uniform on an Ashy Cisticola) 

Narrower dark streaking on upperparts  

Grey wash on the sides of breast and flanks  

Tail is longer, warmer brown, has buffy tips, and black subterminal spots that differ from tails seen on Ashy Cisticolas in Kenya (Traylor, 1967) 

The Tana River Cisticola is similar in appearance to the Rattling Cisticola (Cisticola chiniana) 

The differences between these two species are that the Tana River Cisticola is smaller, paler, and has no rufous wing edgings like her relative 

Due to the lack of sightings and the similarity in appearance, many believe that the Tana River Cisticola is either an aberrant Ashy Cisticola or a hybrid between the Ashy Cisticola and the Rattling Cisticola 

Habitat 

The only specimens were found in the lower Tana River valley in eastern Kenya  

Based on where the specimens were found, many speculate that the bird’s preferred habitat is semi-arid acacia scrub on flat sandy plains and bushland with black cotton soil in the lowlands at 500 m 

The range of the Tana River Cisticola overlaps with that of the Ashy Cisticola and the Rattling Cisticola 

The Ashy Cisticola can be found in Ethiopia, Kenya, Somalia, South Sudan, and Tanzania 

The Rattling Cisticola has a much broader range that includes Angola, Botswana, Burundi, the Republic of the Congo, the Democratic Republic of the Congo, Ethiopia, Kenya, Malawi, Mozambique, Namibia, Somalia, South Africa, South Sudan, Tanzania, Uganda, Zambia, and Zimbabwe 

Like the Tana River Cisticola, both the Ashy and Rattling Cisticolas can be found in dry, arid environments 

The habitats of the Ashy Cisticola includes dry savannah, subtropical/tropical shrub, and subtropical/tropical dry lowland grassland 

The habitats of the Rattling Cisticola includes open savannah and scrub in arid, moist or upland regions, moist savannah and woodland dominated by thorn trees and scrub, miombo and mopane woodlands, the eastern highlands, and East African uplands below 2,000 m  

Other Information 

Vocal behavior unknown with some speculating that it is similar to the Rattling Cisticola 

Diet unknown 

Breeding behavior unknown (Birds of the World) 

Life span- 2.7 years (IUCN Red List) 

The Tana River Cisticola is listed as Data Deficient by the IUCN that made its last assessment in 2020. There is simply not enough data on this species to make an accurate examination of its conservation status. All that we know of this species comes from 7 specimens from 5 localities in the lower Tana River valley in eastern Kenya. The lack of sightings combined with unsuccessful attempts to find the cisticola has only emboldened doubters who contend that the specimens found were aberrant individuals from another species or hybrids. We will not for sure until the bird is found or a DNA analysis is done on the known specimens.  

While we cannot be sure due to lack of data, many speculate that the Tana River Cisticola’s range is limited to the Tana River valley with an extent of occurrence of 5,300 m. Some speculate that this species could also be present in Somalia where there was at least one unconfirmed sighting of this species (IUCN Red List). 

To see a distribution map of this species, click here. 

The Tana River Cisticola was first described by Melvin Traylor in 1967. While examining Ashy Cisticola specimens at the Field Museum of Natural History in Chicago, Traylor found three specimens that were not of that species from the lower Tana River region in Kenya. Three more specimens like these were seen in the Los Angeles County Museum from the same area and were also misidentified as Ashy Cisticolas. Traylor described the bird as a new species and named it the Tana River Cisticola. All of the specimens were collected from the following sites in the lower Tana River basin in eastern Kenya on June 4, 1932 by V.G.L van Someren: Karawa, Garsen, Ijole, Mnazini, Sangole. 

Even though Traylor himself described this bird as a distinct species, there are several points in his analysis where he expresses doubt with his own classification. Despite the similarities in appearance between the Tana River Cisticola and the Ashy Cisticola, Traylor did not think these two species were related because the former does not have any white bases to the nape feathers (a key characteristic in Ashy Cisticolas). On the other hand, he notes that the range of the Ashy Cisticola extends down the Tana to Bura which is only 50 miles away from Ijara (one of the sites where the species was found). This makes it likely that the ranges of the two species could overlap. Furthermore, Traylor observed that, even though the Tana River Cisticola has a longer tail, it is no greater than the tail size during the annual molt of Abyssinian populations of Ashy Cisticolas.  

Traylor argues that the Tana River Cisticola also looks a lot like the Wailing Cisticola (Cisticola lais) of which the subspecies (Cisticola lais distincta) is found in the Kenya Highlands close to where the specimens of the Tana River Cisticola were collected. This subspecies has well-streaked upperparts that include a crown and nape with a rusty wash similar to the Tana River Cisticola. He even goes as far to say that the Tana River Cisticola is a washed-out version of the richly colored distincta. The main differences between the two is that distincta has a larger, more robust tarsus and is found in highlands and on rocky hillsides at the base of cliffs where there is grass and scattered bush. The habitat where the Tana River Cisticola specimens were found was recorded as arid thorn bush with red sand and a belt of riverine acacia along the Tana. Traylor put forward the idea that the habitat for the Tana River Cisticola is most likely the same habitat as the Wailing Cisticola since the likelihood of two species having completely different habitat preferences is rare among cisticolas (especially if they are related or from the same species). Could it be that the collectors recorded the wrong habitat for the Tana River Cisticola specimens? Could they have confused the habitat for the Tana River Cisticola with another species they collected along the Tana River? Regardless, Traylor does not think there is a close connection between the two species unless the Tana River Cisticola is found or shows similar behavior similar to the Wailing Cisticola.  

Another cisticola that Traylor compares this species to is the Rattling Cisticola. Compared to this species, the Tana River Cisticola is smaller, has a longer tail, and lacks the sexual dimorphism in size. The Tana River Cisticola is also sympatric with the subspecies of Rattling Cisticola known as heterophrys that can be found on coasts from Lamu to Dar-es-Salaam and Kilosa. Heterophrys is plain colored compared to the Tana River Cisticola but does look similar to the Ukamba subspecies of Rattling Cisticola that lives in arid habitats in Kenya. The Tana River Cisticola differs from this subspecies by having a mottled crown with narrower dorsal streaking. This species also does not show the dimorphism of Rattling Cisticolas. Traylor further points out that both Ashy and Rattling cisticolas also like thorn bushes and acacia like the Tana River Cisticola. Could it be that the two could overlap and hybridize? If so, could the Tana River Cisticola be a hybrid? If so, Traylor himself does not propose this theory. Traylor concludes that the Tana River Cisticola is closely related to the distincta subspecies of Wailing Cisticola. He does not go as far as to say that the two are the same species because of the difference in habitat preferences (arid sandy thorn bush instead of rocky, grassy hillsides) (Traylor, 1967) 

The controversy surrounding this bird’s status as a species has only deepened since 1967 due to the fact the bird has only rarely been seen since then. Other than the specimens collected in the early 1930s, the bird has only been seen in 1972. There has been no trace of the bird since. This has fueled speculation that the Tana River Cisticola specimens were no more than aberrant individuals or hybrids of either the Ashy, Rattling, or Wailing species of cisticola. No one will know for sure who this bird is until either more members of this species are found or a DNA analysis is conducted on the known specimens.

According to a study by J.H Fanshawe and L.A Bennun (1991) who analyzed the challenges to environments and wildlife in Kenya, the Tana River Cisticola’s habitat was not threatened in the lower Tana River basin. The issue here is that this study was done in the early 1990s and a lot has happened since then. Since then, a multitude of phenomena currently loom over this bird’s tiny range in Kenya. These threats include human population growth, pollution, deforestation, unsustainable land use, dams, irrigation, and agricultural expansion where precious habitats (including the arid scrub that the species supposedly prefers) continue to be converted into farmland. The fact that we know little about this species only makes the situation more challenging from a conservation perspective. 

Conduct a DNA analysis of the known specimens of the Tana River Cisticola to see if there is enough genetic divergence between this species and the Ashy and Rattling Cisticolas to justify the former’s status as a distinct species.

There have been some surveys over the years in the lower bank of the Tana River and in areas adjacent to it with the goal of finding the cisticola that is the river’s namesake. None of them have been successful. 

One such survey was done by Francoise Dowsett-Lemaire and Robert J. Dowsett in the Kipini Conservancy between October 11-December 26, 2006. The conservancy covers approximately 250 km² between the Tana River Delta and the Witu and Mpeketoni villages in Kenya. They explored habitats such as live dunes, coastal thickets, seasonally flooded grasslands (ziwas), wooded grasslands, thicket-clump savannah, and semi-evergreen rain forest. They did not visit the gallery forest at Kangawati and the Witu forest. While the Tana River Cisticola was found in semi-arid acacia scrub, Rattling and Ashy cisticolas prefer dry vegetation that include thornbush. While none of these habitats were present in Kipini at the time of their survey, they noted that Ashy and Rattling cisticolas were seen on the southern bank of the Tana in Retief's camp by D.A Turner. If both of these species coexist on the southern bank of the Tana, then the Tana River Cisticola could be a hybrid of these two species. Nonetheless, the possibility remains that this bird could still be a distinct species as there still remain areas north and south of the Tana River that remain to be explored (Dowsett-Lemaire and Dowsett, 2014).

Order: Passeriformes 

Family: Cisticolidae 

Genus: Cisticola 

Species: Cisticola restrictus