The biodiversity on earth is spectacular, with over a million species known to science, and at least 10 times as many species still to be discovered. Biodiversity is amazing in its own right, but is also vital to human well-being, providing resources and services for people, including building materials, pharmaceuticals, clean water and air, as well as recreational areas. Despite the value of biodiversity, many species are threatened with extinction by human activities. Deforestation, overharvesting, and climate change all put species at risk of extinction. Disease increases the vulnerability of species, and when combined with other factors, can wipe out whole populations. Of the species that have already gone extinct, disease was a likely cause for 4% of them. Parasites that cause diseases are also important parts of ecosystems, but when species are threatened by habitat loss and other factors, the natural balance between animals and their parasites can be disrupted, leading to epidemics that can negatively impact threatened populations. In a new article published this month, my colleague, Dr. Charles Nunn, and I reviewed the literature on the links between disease, animal behavior, and conservation. This article is part of a special theme issue of the Philosophical Transactions of the Royal Society, specifically focused on how important understanding behavior is for conservation. We detail many theories and examples of the interplay between animal behavior, disease, and protecting biodiversity. For example, sociality in animals impacts their disease risks. Animals that live in larger groups often have more parasites than those that are solitary or live in small groups. This pattern is not universal, though, and the benefits of sociality likely outweigh the costs of disease. Specifically, living in groups allows wolves to have more successful hunts than those that live alone, despite the risk of transmitting mange among individuals. Living in groups also facilitates ‘herd immunity,’ a principle similar to vaccination in which exposure to disease-causing parasites allows group-living individuals to develop antibodies that make them resistant to the parasites. These behaviors have important implications for conservation. One common method for managing diseases in populations is to remove sick individuals, either by quarantining or culling herds. However, such management practices can have adverse effects, especially when they disrupt natural territories and lead to colonization of managed areas by animals from other places, which can bring diseases with them. Careful management can incorporate aspects of behavior to identify the highest priority animals to treat, and combining vaccination, contraception, and culling can be more effective than any one strategy alone. While the examples above illustrate how behavior affects disease, the opposite is also true – diseases affect behavior. Some of the most fascinating examples include parasites that can directly manipulate host behavior to facilitate their own transmission. Rabies is a classic example, caused by a virus that infects parts of the central nervous system, including the brain, increasing aggressive behavior and salivation. Infected animals bite others, leading to disease transmission. Rabies can have severe impacts for endangered species, such as an epidemic that devastated Ethiopian wolf populations. Toxoplasma is a parasite with multiple hosts in its life cycle. It initially infects small mammals and leads to a decrease in their fear responses to predator cues. For example, infected rodents show no fear to cat urine, and infection leads rodents to be preyed on by cats more often, facilitating the transmission to the cat. These phenomena are important for managing threatened species because the transmission of these parasites can have negative impacts on both predator and prey populations. Policies to manage threatened predators must also evaluate the prevalence of these parasites in the hosts, and multispecies parasites that negatively impact endangered species may persist because they also infect more common hosts. The interplay of behavior, disease, and conservation is especially important now as species are threatened by habitat loss and climate change, which are negatively impacting the geographic ranges and population sizes of many species. To effectively manage threatened species in the future, it will be important to create policies that integrate aspects of how behavior affects disease and vice-versa, and interdisciplinary research will be especially relevant in this context.
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3/2/2021 11:55:48 pm
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3/2/2021 11:57:13 pm
Rabies is a disease that is transmitted from animals to humans caused by the rabies virus. The rabies virus is mainly transmitted through an animal’s saliva when the infected animals bite or scratch someone. Can you tell me that, <a href="https://techealthinfo.com/how-long-does-rabies-vaccine-last/"> how long does rabies vaccine last </a>? Thanks you reading.
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