Tana time again, mostly to look at grassland vegetation units but it is always good to look at the sky and in the trees. The nice thing is that this year, for the first time since 2006 some flow was left in the river after the empty upstream dams had been refilled. Thus our friends at KenGen (were forced to) release water downstream, enough to cover most of the deltaic floodplains. More detailed observations are to follow soon but the highlights were Madagascar Pratincole, Black Egret and Tana River Mangabey (Cercocebus galeritus). For those of you who have not graduated to mammals yet this last thing is an endangered primate (see Butynski et al. 2008) with very punky white crests sticking out of the sides of its head and that was so far only known from the remaining patches of gallery forest that now probably cover less than 2000 ha between the (inadequate and largely failing) Tana River Primate Reserve (in spite of a 6.7 million $US Worldbank/GEF projet) and the continued eyesore of the failed-rehabilitated-failing Tana Delta Irrigation Project north of the Garsen-Lamu road (Hamerlynck et al. 2010). A group of at least 6 Mangabey were encountered over 20 km south of the road, about halfway to Kipini, i.e. bang in the center of the Tana Delta, a considerable expansion therefore of their known range.

Back to the birds. Two groups of Madagascar Pratincole were encountered. One probably numbering over 1000 (a detailed count from pictures taken still needs to be done) in the floodplains close to Didawarede and a second group of over 150 just north of Bilisa Boka (the central floodplain lake of the delta). The world population is estimated at between 5000 and 10000 of which the Tana Delta now hosts at least 10%.  With regard to the Black Heron (Black Egret would be a better name and a better rhyme with prats) we continuously saw groups of between 4 and 25 travelling at low altitude between the direction of Kipini and somewhere between Lake Moa and Onkolde. All of them adults with bright yellow-orange toes. We suspect these are movements to and fro a nesting site as they occurred throughout the day. We also found some breeding White-breasted Cormorants (over 50 nests with big chicks, detailed count to follow) and Yellow-billed Stork, both species in Ron palm, sometimes sharing the same tree. Other interesting stuff: 8 Black-tailed Godwits, an Ayres’ Hawk Eagle and a probable juvenile Southern Banded Snake Eagle (will have the pics checked by some raptor fundis) next to the Onkolde forest where we confirmed the presence of Red Colobus (Luke & Hamerlynck 2009).

With regard to the future, in addition to the sugar cane, the Jatropha threats, the continued conversion of the terrace woodlands to charcoal, there is now renewed talk of the High Falls dam that, unless it is designed (and managed!!!) to ensure adequate flood releases, will destroy most of the remaining floodplain forests and all delta ecosystems and biodiversity. On the “funny” side, Tarda has done brilliantly again by spending 400 odd million Shillings on rehabilitating the TDIP for maize production, irrigating it as for rice with the first meager harvest unfit for human consumption because of aflatoxin and the second harvest drowning while even the most agriculture-shy livestock keepers have succeeded their near-zero input rainfed maize on the terraces….  

References

Butynski, T.M., Struhsaker, T., Kingdon, J. & De Jong, Y. 2008. Cercocebus galeritus. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.2. <www.iucnredlist.org>.

Hamerlynck, O., Nyunja, J., Luke, Q., Nyingi, D., Lebrun, D. & Duvail, S. 2010. The communal forest, wetland, rangeland and agricultural landscape mosaics of the Lower Tana, Kenya, a socio-ecological entity in peril. In: C. Belair, K. Ichikawa, B.Y. L. Wong, and K.J. Mulongoy (Eds.). Sustainable use of biological diversity in socioecological production landscapes. Background to the ‘Satoyama Initiative for the benefit of biodiversity and human well-being Secretariat of the Convention on Biological Diversity, Montreal. Technical Series no. 52: 54-62.

Luke, Q. & Hamerlynck, O. 2009. A population of the Tana River Red Colobus Procolobus rufomitratus rufomitratus in the Tana Delta, Kenya. Primate Tidings 21:12-14.