From Ethnologue (http://www.ethnologue.com/language/ses)
Alternate Names: East Songhay, Gao Songhay, Koroboro Senni, Koyra Senni, Koyra Senni Songhay, Songai, Songay, Songay Senni, Songhai, Songhay, Songoi, Songoy, Sonrai, Sonrhai
Population: 430,000 (2007 SIL), increasing. 300,000 monolinguals (2007 SIL). Ethnic population: 850,000.
Location: Southeast along Niger river from Gourma Rharous to Niger border.
Language Status: (Educational). Recognized language (1982, Decree No. 159 of 19 July, Article 1).
Classification: Nilo-Saharan, Songhai, Southern
Dialects: Fulan Kirya, Gao. Intelligibility good among all dialects on Niger River. Fulan Kirya dialect has more limited intelligibility through heavy lexical borrowing from Fulfulde [ffm] and Humburi Senni Songhay [hmb]. The Gao dialect is dominant in all respects. Closely related languages: Koyra Chiini Songhay [khq], Humburi Senni Songhay [hmb], Zarmaci [dje], and Dendi [ddn]. Lexical similarity: 77% with Gao and Timbuktu dialects; 50% with Tadaksahak [dsq].
Typology: SOV; nontonal
Language Use: All ages. Positive attitudes. Some also use Bamanankan [bam], French [fra], or Tamasheq [taq], but there is no extensive bilingualism (1999 J. Heath).
Language Development: Actively promoted by the government through adult literacy classes and as the language of instruction at the primary level in some experimental schools. Some French literacy. Taught in primary schools. Dictionary. Grammar.
Writing: Latin script.