Thursday, February 9, 2017

Urban Hyenas in Ethiopia

Hello everyone, I just arrived in Mekelle, Ethiopia two days ago to study the urban hyenas of Ethiopia.

My route of travel from the Maasai Mara on the Tanzanian border, to Nairobi where I flew to Addis Ababa and took a connecting flight to Mekelle in Northern Ethiopia in the Tigray region. (Harar is the little red dot in eastern Ethiopia). 

 Ethiopia is somewhat unique among African countries because the people there believe that hyenas consume bad spirits. Because of this belief hyenas are less persecuted than they are in places like Kenya and has facilitated the rise of the "urban hyena". Almost all large cities in Ethiopia support large populations of hyenas that scavenge from rubbish dumps and domestic animals.

Harar, Ethiopia is the most well known city for seeing these urban hyenas because of the "hyena men" who feed the hyenas nightly as a show for tourists. 

In Mekelle I'm collaborating with a scientist, Dr. Gidey Yirga, who was been studying the urban hyenas of Mekelle. In Mekelle, hyenas congregate around the rubbish dumps on the outskirts of the city and this is where Dr. Gidey has been studying them. Interestingly, the result from a genetic study done by Master's Student Elien Schramme suggests a massive break down of clan structure in Mekelle with little to no genetic structuring despite an extremely high density of hyenas (1.84 individuals/sq km). This density is far higher than any other hyena density on record, the next highest figure is 1.5 individuals/sq km in the Ngorongoro Crater in 1972. 

Though domestic animals almost entirely make up the diet of spotted hyenas, Dr. Gidey has found that the economic loss is minimal. On average hyena depredation of livestock costs households about 0.7% of their annual income (disease in livestock costs 1.6x this much). This is largely because most of the food hyenas obtain is through scavenging at waste dumps, rather than active hunting of domestic animals. The exception to this rule is during the Christian fasting period when hyenas make up the largest part of their diet from hunting donkeys due to reduced waste availability. 

I'm planning on going to the rubbish dumps of Mekelle at night to give these urban hyenas my multi-access box and cylinder detour-task to see how the urban life might affect innovation and inhibitory control! Hypotheses for the evolution of large brains and cognition predict that urban animals will be better problem solvers than rural animals due the demands of surviving in an evolutionarily novel environment.

Disclaimer: I did not take any of these photos! 

Schramme, E., 2015. Social Structure of Spotted Hyena (Crocuta crocuta) Populations around Mekelle city in Tigray, Ethiopia.

Yirga, G. et al., 2013. Spotted hyena (Crocuta crocuta) coexisting at high density with people in Wukro district, northern Ethiopia. Mammalian Biology - Zeitschrift für Säugetierkunde, 78(3), pp.193–197.

Abay, G.Y. et al., 2010. Peri-urban spotted hyena (Crocuta crocuta) in Northern Ethiopia: diet, economic impact, and abundance. European Journal of Wildlife Research, 57(4), pp.759–765.

Yirga, G. et al., 2012. Adaptability of large carnivores to changing anthropogenic food sources: diet change of spotted hyena (Crocuta crocuta) during Christian fasting period in northern Ethiopia. The Journal of animal ecology, 81(5), pp.1052–5.

Audet, J.-N., Ducatez, S. & Lefebvre, L., 2016. The town bird and the country bird: problem solving and immunocompetence vary with urbanization. Behavioral Ecology, 27(2), pp.637–644.

Maklakov, A.A. et al., 2011. Brains and the city: big-brained passerine birds succeed in urban environments. Biology letters, 7(5), pp.730–2.

Papp, S. et al., 2014. A comparison of problem-solving success between urban and rural house sparrows. Behavioral Ecology and Sociobiology, 69(3), pp.471–480.

Preiszner, B. et al., 2017. Problem-solving performance and reproductive success of great tits in urban and forest habitats. Animal Cognition, 20(1), pp.53–63.

Snell-Rood, E.C. & Wick, N., 2013. Anthropogenic environments exert variable selection on cranial capacity in mammals. Proceedings. Biological sciences / The Royal Society, 280(1769), p.20131384.



Nora said...

Wow so cool, Lily!!! Have a great (and successful) time. Can't wait to hear more!

Kay Holekamp said...

Yes, I am very happy you made it there safely! Now you'll have to keep us posted on how things go with the trials!

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