Urban spotted hyenas show increased abundance with high human density
Contributed by: Gidey Yirga and Lily Johnson-Ulrich
Keywords
War prisoner, African, Black, Black ecologist, Ecology, Consumption, Human-animal interactions, Disturbance, Population Ecology, Population density, Conservation, Terrestrial, Urban, Africa, Animals, Observational
Slides
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Resources
Yirga, G., Leirs, H., De Iongh, H. H., Asmelash, T., Gebrehiwot, K., Vos, M., & Bauer, H. (2017). Densities of spotted hyaena (Crocuta crocuta) and African golden wolf (Canis anthus) increase with increasing anthropogenic influence. Mammalian Biology, 85, 60–69. https://doi.org/10.1016/j.mambio.2017.02.004
Notes
Slide 1: Researcher’s Background
Dr. Gidey Yirga is a professor in the Department of Biology at Mekelle University in Ethiopia. He studies human-carnivore conflict and coexistence in Ethiopia. He completed his PhD in 2013 at Leiden University in the Netherlands and the University of Antwerp in Belgium. The focus of his dissertation was spotted hyena ecology and conservation.
Dr. Gidey Yirga was born and grew up in a small town, Endabaguna, in northwestern Tigray, Ethiopia. He always had a love for biology as a way of understanding nature. Spotted hyenas are the most abundant large carnivores in Tigray and they can be easily seen and heard every night. As opportunistic, intelligent, and powerful predators they are Gidey Yirga’s favorite animal.
PB: Why did you become a biologist?
GY: My high school Biology teacher was excellent in teaching Biology and I liked his way of teaching and was interested so much in the subject. Since then, I am extremely interested in Biology, and become a Biologist. I was fascinated so much by the breath-taking beauty of nature especially the biological diversity on earth.
PB: What is your favorite part about your job?
GY: Talking about the science of the spotted hyena with people. I never thought I would be hyena expert. However, with the help of inspiring role models, I quickly began to study hyenas, and become a professional scientist. It is a unique career, and an amazing job!
PB: What obstacles have you overcome to get where you are?
GY: Ethiopia is a culturally and ethnically diverse country, rich in natural resources, wildlife, and ecology. It is not politically stable, and the country is affected by armed conflict. During the Ethiopia-Eritrea war (from May 1998 to June 2000), I was a high school student, and was not able to continue my education. I had been in jail many times for not joining the armed struggle. After completion of my prison term, I continue my high school education and completed with very great distinction.
PB: What advice do you have for aspiring biologists?
GY: Be hardworking and never be afraid to ask questions. Let your curiosity drive your purpose, and to success.
Slide 2: Research Overview
Take home message of study
In Gidey Yirga’s dissertation research, spotted hyena densities were found to be highest in high human density areas. This is in contrast to previous work finding that human density had a negative effect on carnivore survival (Woodroffe 2000). Furthermore, hyena densities far exceeded the densities recorded inside protected areas elsewhere in Africa. Occurrence and persistence of carnivores like spotted hyena (Crocuta crocuta) in anthropogenic landscapes is associated with availability of human food sources. When these human food resources are abundant and human persecution is low, large carnivores can reach densities even greater than their densities in the wild.
Study system
Spotted hyenas foraging at a trash dump in Ethiopia, photo credit ©Karine Aigner. This study used road transects to record spotted hyena sightings. Spotted hyenas are common carnivores across Enderta district in Tigray, Ethiopia, and can easily be seen almost every night at the outskirts of the city.
Slide 3: Key Research Points
Main figure
This figure shows the numbers of spotted hyenas counted on each road transect. The numbers on the x-axis represent distance from the beginning of the transect. Names on the x-axis represent locations on the transects where there was an urban area with high human densities. Bars with no name indicate rural locations. On all transects, spotted hyena counts are far higher in towns than in unnamed locations (rural areas).
Societal Relevance
Intensive mapping studies can further establish the relationship between spotted hyenas and human inhabitants of urban areas. The results shown here demonstrate a case of coexistence of humans and carnivores at high densities that is not found elsewhere in Africa and has not been reported for other large predators. This coexistence is likely only possible because local communities have a positive attitude towards spotted hyena as they are important in sanitizing the environment by foraging on household waste and removing potentially infected organic waste from human settlements. In addition, spotted hyena survival is almost entirely dependent on human food sources because their natural prey base of the area is highly depleted.
