A troop of banded Mongoose are getting ready to leave their den under a concrete drainage pipe at the town's edge in Botswana. The cat-sized animals move from the shade to the light to search for danger signs and opportunities to eat in a more crowded area.Researchers at the College of Natural Resources and Environment have new insights into how and why animals behave differently in relation to humans. This knowledge can also impact the spread of infectious diseases.Researchers used genetic tools to determine changes in movement behavior between mongooses in urban areas and natural areas. This provided important insight into how to better model disease transmission in wild animals that live in complex environments. The journal Ecology and Evolution published the results of the study funded by a grant from National Science Foundation's Ecology and Evolution of Infectious Diseases Program.Kathleen Alexander, the William E. Lavery Professor at the Department of Fish and Wildlife Conservation said that "the question has always been: how can we predict what's going be happening once an infectious disease arises?" We can learn more about disease dynamics by using systems that are easily understood, such as urbanization and host behavior.One system that is simple to implement is the social groupings of mongooses (also known as troops), who live in both urban and rural areas of Botswana. Alexander founded the Chobe Research Institute (a non-profit organization) and CARACAL (a research institute). They have been studying the behavior of mongoose soldiers in urban areas like Kasane and Chobe National Park over the past 20 years.Botswana's banded monkeys are excellent study subjects. They live in territorial social groups throughout the landscape and are infected in northern Botswana with a novel tuberculosis virus closely related to human tuberculosis."We are looking for dispersal behavior and movement of mongooses which may allow disease transmission between these mongoose troop," explained Professor Eric Hallerman who is a specialist in population genetics. This species is more likely to be found in troops that are resistant to other troops' immigration, so it's crucial to understand how they move across the landscape and interact.Hallerman, who is also an affiliate of Virginia Tech’s Fralin Life Sciences Institute, said that they are a difficult species to track on the ground. "They look very similar, unlike cheetahs which can be identified individually by their spots." You can attach ear tags or other markings to them, but it is often lost, making it difficult for individuals to be tracked across different troops. These problems can be solved by genetic approaches.The researchers required samples to do this. Kelton Verble, who earned his master's degree at Virginia Tech in fisheries, wildlife sciences in 2018, stated that fresh stool samples were the best way to try to capture as much genetic diversity as possible from troops. He improved the sample collection process, including tracking mongooses in different landscapes and collecting fecal samples of a variety of troops.He said that they also examined the health of the mongooses who moved between the study troops. "Our data previously indicated that tuberculosis infected animals tend not to disperse. Data from this study supports this finding."Verble was able to use genetic data from microsatellite markers in the genome sequence of each animal to identify individuals who had moved between troops during their lives and also to characterize the general genetic makeup across the different troops. This allowed Verble, not only can Verble determine how individuals were connected and what would be the impact on disease transmission.Alexander, an associate of the Fralin Life Sciences Institute’s Center for Emerging, Zoonotic, and Arthropod–Borne Pathogens, stated, "With this study, it was really important to explicitly investigate dispersal and clarify how troops were using land type." We found that urban environments were changing not only foraging behavior, aggression, den use, and disease transmission potential, but also dispersal behaviors.Researchers discovered that mongooses who live in urban areas are more likely to spread to other troops on this type of land, increasing the risk of spreading tuberculosis. Soldiers closer to cities were more likely to share their dens and have overlapping home ranges because of the greater availability of human-associated food sources.Verble said that the banded mongoose was often regarded as a "philopatric" species. This means that they are born to a troop and stay there for their entire lives. Verble is currently pursuing a doctorate of genomics at University of Alabama. We discovered that there was more movement between troops than previously thought, which is critical for understanding the spread of disease.These findings are important not only because they reveal the transmission of disease among animals, but also because they help to understand how zoonotic diseases such as COVID-19 can be transmitted from animals to people and how urbanization may impact this spread.Alexander stated that "we've never been very adept at predicting disease-emergence event events." Alexander said that it is impossible to predict when a pathogen might emerge and that it will be difficult to predict what will happen as there are many factors. It will become increasingly important to understand how animals react to and are affected by changing landscapes and urban growth. This information is critical for improving our toolkit to tackle public and animal health problems.###Written by David Fleming
