For all relevant papers, we also examined articles that cited these papers. For each included paper, we reviewed the bibliography of all articles and identified additional relevant papers.
#Carrion eaters full
If the title or abstract mentioned a scavenger species, the words carrion, adaptation, feeding, behavior, or any other terms relevant to a hypothesized defense mechanism, we then read the full paper.
We first read the title and abstract of every article in the combined output. For each search topic, we narrowed the search by adding additional words until output was fewer than 300 articles more inclusive searches yielded irrelevant articles. We systematically reviewed articles on carrion eaters' adaptations by using the Web of Science database (see PRISMA diagram in Supplementary Material). 2014) 5) avoid rotten food ( Houston 1986) 6) bald heads ( Wink 1995) 7) specialized immune system ( de la Lastra and de la Fuente 2007) and 8) rapid ingestion ( Houston and Cooper 1975).
2009) 4) selective digestive tract ( Wink 1995 Roggenbuck et al. 2014) 3) acid sterilization (Kushawha et al. We created search terms separately for eight previously hypothesized defense mechanisms: 1) taste before eat ( Houston 1986) 2) specialized microbiome ( Roggenbuck et al. We systematically reviewed the literature on potential scavenger defense mechanisms and evaluated available evidence. 2003, 2004), and from a biomimetic perspective ( Benyus 1997), some of their defense mechanisms could potentially be used to improve human and veterinary medicine ( Shaharabany et al. 1979), scavengers play an important role in nutrient cycling in many ecosystems ( DeVault et al. Understanding the diversity of these mechanisms is important because scavengers can disperse pathogens over long distances as they search for their next meal ( Houston and Cooper 1975 Ohishi et al. Eight hypotheses have been suggested to explain how scavengers avoid becoming sick from their diet. Obligate and facultative scavengers are exposed to pathogens and toxic by-products of microbial metabolism. Increased knowledge in these mechanisms may provide biomimetic insights to help combat foodborne illnesses and enhance health. Specialized immunologic defenses and having a low pH have the most support, but the diversity of mechanisms suggests that there is a great opportunity for even more detailed study. There is some support for having a specialized microbiome, having enhanced immunologic defenses, avoiding rotten food, and maintaining a low gastric pH to eliminate pathogens. With the exception of food washing, none of these hypotheses have been properly evaluated as an adaptation to avoid sickness from carrion. We found no support that using urine to sterilize carcasses, having bald heads, eating rapidly, or food-washing behavior reduced disease risk in carrion eaters. We conducted a systematic review of the literature and found correlative support for four of the eight hypotheses but limited evidence of systematic studies of the hypotheses.
Species that scavenge on dead animals are exposed to enhanced disease risks.