Public health and economic benefits of spotted hyenas Crocuta crocuta in a peri‐urban system

Social-ecological predictors of spotted hyena navigation through a shared landscape

Human-wildlife interactions are increasing in severity due to climate change and proliferating urbanization. Regions where human infrastructure and activity are rapidly densifying or newly appearing constitute novel environments in which wildlife must learn to coexist with people, thereby serving as ideal case studies with which to infer future human-wildlife interactions in shared landscapes. As a widely reviled and behaviorally plastic apex predator, the spotted hyena (Crocuta crocuta) is a model species for understanding how large carnivores navigate these human-caused 'landscapes of fear' in a changing world. Using high-resolution GPS collar data, we applied resource selection functions and step selection functions to assess spotted hyena landscape navigation and fine-scale movement decisions in relation to social-ecological features in a rapidly developing region comprising two protected areas: Lake Nakuru National Park and Soysambu Conservancy, Kenya. We then used camera trap imagery and Barrier Behavior Analysis (BaBA) to further examine hyena interactions with barriers. Our results show that environmental factors, linear infrastructure, human-carnivore conflict hotspots, and human tolerance were all important predictors for landscape-scale resource selection by hyenas, while human experience elements were less important for fine-scale hyena movement decisions. Hyena selection for these characteristics also changed seasonally and across land management types. Camera traps documented an exceptionally high number of individual spotted hyenas (234) approaching the national park fence at 16 sites during the study period, and BaBA results suggested that hyenas perceive protected area boundaries' semi-permeable electric fences as risky but may cross them out of necessity. Our findings highlight that the ability of carnivores to flexibly respond within human-caused landscapes of fear may be expressed differently depending on context, scale, and climatic factors. These results also point to the need to incorporate societal factors into multiscale analyses of wildlife movement to effectively plan for human-wildlife coexistence.

Ecosystem services provided by striped hyenas in the human-dominated landscape of Rajasthan, India

In human-dominated landscapes, quantifying ecosystem services in terms of economic benefits could contribute to establishing peaceful coexistence between humans and large carnivores. In this study, we estimated the monetary value of scavenging benefits provided by striped hyenas (Hyaena hyaena) in an anthropogenic landscape in the semi-arid region of Rajasthan, India. We converted the value of domestic livestock carcasses consumed by striped hyenas from opportunity costs to quantify the value of this important ecosystem service to local people. We determined the monetary value of carcass disposals using two methods, including (1) electric cremation, and (2) pyre burning of animal carcasses. To determine the minimum number of striped hyenas, present in the study area, we employed a photo-capture approach, and we used scat analysis to determine the livestock consumed by striped hyenas. We estimated that striped hyenas removed 23.13 tons (4.4 %) of livestock carcass waste from the total of 525.68 tons of waste generated per year in the Intensive Study Area (ISA). The annual monetary value of livestock carcass waste removal by striped hyenas in the ISA was estimated to be ~US$ 7095 for electric cremation and US$ 49,665 for pyre burning. Our study demonstrates the economic benefit of scavenging services provided by striped hyenas in areas where anthropogenic food is abundant. In such areas, as hyenas scavenge anthropogenic food, local communities benefit from waste management. Using alternative carcass disposal methods without striped hyenas would be expensive and likely environmentally damaging.

A synthesis of carcass decomposition studies conducted at a tropical (Aw) taphonomy facility: 2013-2022

Decomposition studies have been conducted in several regions of the world, but relatively few have investigated taphonomy in tropical environments. Even fewer have explored carcass decomposition during multiple tropical seasons, leaving the relationships between season and decomposition in tropical environments poorly understood. Ten decomposition studies using 30 carcasses were conducted in Honolulu, Hawaii, USA to start addressing this knowledge gap. These studies show that some postmortem processes were observed regardless of season. Carcass temperature and chemistry were spatiotemporally variable. Fly larval masses were consistently observed within 3 days (∼75 ADD) postmortem and carcasses lost 60%-90% of mass by 10 days (∼250 ADD) postmortem (Total Body Score ∼26). Season had a significant effect on decomposition, yet the warmest and most humid seasons did not always result in the most rapid and extensive decomposition. Seasonal variation appears to be less pronounced than at other tropical decomposition sites.

Growing Up Urban: Hyena Foraging Groups and Social Structure at a City Waste Dump

Urban spotted hyenas (Crocuta crocuta) in Ethiopia are a prime example of large carnivores coexisting with little to no conflict with people in a human-dominated landscape, providing a valuable waste-removal service. To gain insight in how this urban lifestyle persists across generations, we studied hyena group composition at the city waste dump of Mekelle, a regional capital in northern Ethiopia. We found that hyena cubs and sub-adults foraged with adults in groups of highly variable composition. Young urban hyenas already take part in a fission-fusion dynamic that is also characteristic of hyenas in non-urban environments. They do not seem to learn from only one or few close reference adults. Social network analysis revealed no clusters among these dump-visiting hyenas. The number of counted hyenas is furthermore larger than any hyena clan in non-urban areas. All individuals were more or less equally connected to each other, and each hyena had a few connections, but to different individuals. All cubs and sub-adults were connected to each other, over a maximum of four links. Hyenas shared the abundance of food at the waste dump without overt aggression. A much larger number of urban hyenas shares this waste dump at night than would fit into a single forest fragment, such as those associated with orthodox churches where small groups of hyenas have often been observed to rest at daytime. Hyenas appear to commute from different dens and resting sites located around the city, but we have no information on their behavior and group composition away from the dump. We observed no defense of any part of the dump area by any of the foraging groups. In absence of territorial behavior at this city site, the clan concept does not seem to apply to these urban hyenas. Similar to what has been observed in other urban carnivores, individuals at the waste dump behaved as members of conflict-free foraging groups ostensibly sharing food without aggression. Perhaps this is what most strikingly defines their urbanity.