Sudden flamingo deaths in Kenyan Rift Valley lakes

Abstract

The East African Rift Valley Lakes Bogoria and Nakuru sometimes host around 75% of the world population of lesser flamingos Phoeniconaias minor. In this area, mysterious flamingo die‐offs have occupied researchers for four decades. Recently, cyanobacterial toxins came into the fore as a possible explanation for mass mortalities because the main food source of lesser flamingos is the cyanobacterium Arthrospira fusiformis. We took weekly samples from July 2008 to November 2009 from Lakes Nakuru and Bogoria and analyzed them by high performance liquid chromatography for microcystins. Monthly, samples were cross‐checked using protein phosphatase inhibition assays with lower detection limits and additionally screened for polar toxins. During our study period, three flamingo die‐offs occurred at L. Bogoria and we were able to analyze tissues of 20 carcasses collected at the shoreline. No cyanotoxins were detected either in plankton samples or in flamingo tissues. Accordingly, other reasons such as food composition or bird diseases played a key role in the observed flamingo die‐offs.

Tackling community undernutrition at lake Bogoria, Kenya: The potential of spirulina (Arthrospira fusiformis) as a food supplement

“…Thus, within the limits of the methods used in this study, levels of microcystins at a concentration hazardous to human health in a dried sample of Lake Bogoria Spirulina was not identified. This is in agreement with the findings of Straubinger-Gansberger et al [25], who found no evidence of microcystins in planktonic biomass from Lake Bogoria over a two-year period from 2008-2009. However, it is possible that levels of microcystins present in Lake Bogoria Spirulina vary over time in response to changing environmental conditions, so further studies are needed to investigate this.…”

Reporting of Freshwater Cyanobacterial Poisoning in Terrestrial Wildlife: A Systematic Map

“…With many cases involving large fauna, such as artiodactyls and carnivores, remote sensing techniques are a valuable tool in detecting poisonings. This would enable monitoring of the frequency and intensity of cyanoHABs, particularly in areas where mass mortalities have occurred, such as the lesser flamingos Phoeniconaias minor in Kenya [ 25 , 106 ]. Additionally, as cyanoHABs are linked to climatic fluctuations, coordinating reports of wildlife poisonings among countries would be beneficial in understanding the scale of the impact, as cyanoHABs are likely happening at a regional scale.…”

“…It is unclear in some poisoning events if the ingestion of toxic algae alone leads to intoxication or if co-occurrence with plastic and other types of pollution exacerbates the toxicity. For example, cyanotoxins have been observed to act in concert with other toxic compounds [ 24 , 25 , 26 ]. In some cases, cyanotoxins have been listed as a contributing factor alongside heavy metals and pesticides in wildlife mortality [ 27 ].…”

What influences aggression and foraging activity in social birds? Measuring individual, group and environmental characteristics

“…As carotenoid ingestion is key to the attainment of feather colour, flamingos need to spend time maximising ingestion of high-quality food. The itinerant movements of birds between feeding lakes (Kaggwa, Gruber, Oduor, & Schagerl, 2013;Krienitz, Mähnert, & Schagerl, 2016) and the population die-offs that have been recorded over recent years (Koenig, 2006;Straubinger-Gansberger et al, 2014)-partly attributed to starvation-show the strong link between a flamingo's habitat choice and its specific dietary requirements. Wild flamingos will also maintain specific individual bird distances between themselves and foraging conspecifics whilst filter feeding (Schmitz & Baldassarre, 1992b), and birds will maintain a stable distance from the lake shoreline during feeding (Henriksen et al, 2015).…”