Waterbird conservation in the Great Rift Valley, Kenya

A small number of lakes in the Great Rift Valley, Kenya, are critical habitats for many endemic and migratory species. From a conservation perspective, waterbirds are particularly important as indicator species for the health of the entire lake community. I am a research associate with the Dept. of Conservation Biology at the Denver Zoo. I work with Birdkeeper Brittney Weaver and Dr. Siva Sundaresan to initiate a waterbird conservation program in the Great Rift Valley, Kenya. We focus on three waterbird species: the lesser flamingo (Phoenicopterus minor), greater flamingo (Phoenicopterus roseus), and great white pelican (Pelecanus onocrotalus).

This project is in collaboration with the Denver Zoo, Soysambu Conservancy, the   Kenyan Wildlife Service, and the National Museums of Kenya.

Photo: With Brittney Weaver, Duncan Ouku, and a greater flamingo at Lake Elmentaita (inset: greater flamingo at Lake Bogoria).

Three lakes in the Rift Valley are disproportionally important for these species: Lakes Nakuru, Bogoria, and Elmenteita. Conservation of these lakes is paramount not only for the persistence of these waterbirds in East Africa, but also for the maintenance of biodiversity within the lake community they represent. Yet, these lakes are subject to anthropogenic impacts, such as pollution, eutrophication, and habitat modification, which threaten these waterbirds. As a first step, we mainly focus on conservation strategies at Lake Elmenteita; however, we foresee this project as a starting point for a multi-year conservation program of Rift Valley lakes in Kenya.

Lake Elmenteita is a natural starting point for the conservation of these waterbirds in the Rift Valley for three reasons. First, given recent mass die-offs of lesser flamingos at neighboring Lake Nakuru, Lake Elementaita stands to be even more important for lesser flamingos in the future and may become threatened by the same anthropogenic impacts (e.g. pollution, eutrophication) as Lake Nakuru. Second, Lake Elementaita was once the key breeding site for greater flamingos in all of Kenya, but nesting has not even been attempted within the last decade. Third, Lake Elementaita is the sole breeding site for great white pelicans in all of East Africa. We are establishing a water quality monitoring program in the Rift Valley and encouraging greater flamingos to resume nesting at Lake Elementaita by constructing artificial nesting sites.

A paucity of good temporal data on water chemistry and algal species composition within the lakes has hampered our understanding of the drivers of lesser flamingo mass die-offs and conservation strategies to mitigate detrimental impacts. By establishing a water monitoring program in the Rift Valley, critical data will be collected on the environmental conditions affecting these waterbirds. The goals are to investigate whether water quality and algal composition differ between human-impacted Lake Nakuru and more pristine Lakes Elementaita and Bogoria (image on left) and attempt to establish a causal relationship between human impacts, water quality, algal species dynamics, and lesser flamingo mortality.

Greater flamingos are nomadic birds, utilizing several residential lakes, but typically nest only at specific lakes. The abandonment of nesting sites at Lake Elmenteita in 2001, therefore, could have long-term detrimental effects on the persistence of greater flamingos in Kenya. During a pilot study in 2011, two existing islands were modified to create artificial nesting sites. These nesting sites are monitored by Soysambu on a monthly basis for any activity. We will construct larger-scale breeding islands and modify several existing islands around Lake Elmenteita during the summer of 2012.

Photo: With Soysambu CEO Kathryn Combes and Brittney Weaver at an artificial nesting island in Lake Elmenteita.

All three of these waterbird species are susceptible to anthropogenic threats. Lesser flamingos have recently experienced mass die-offs at Lake Nakuru, their key residential habitat, likely due to anthropogenic impacts. Greater flamingos have failed to nest at Lake Elmenteita, their former key breeding site, for the last decade. And there are growing concerns about great white pelicans abandoning near-shore nesting islands due to human disturbance. Through this project, we seek to insure the continued persistence of these waterbirds as well as to conserve critical habitats for numerous other unique and often endemic species in the Great Rift Valley.