In the fight for attention from researchers, there are winners and there are civets. That's what researchers found when they analyzed almost 16,500 published papers about animals from walruses to weasels. They saw clear trends in which animals are the most popular to study. And it matters because the most popular animals aren't necessarily the ones most in need of attention. Zoe Brooke, a researcher at the Zoological Society of London, and her coauthors looked at every peer-reviewed paper they could find that was published between 1900 and 2010 about an animal in the order Carnivora. This is a set of 286 mammal species that all—as their name suggests—eat meat, at least sometimes. Medical papers that used animals to model a disease were excluded (sorry, lab mice). Papers on pets were also left out, though feral cats and dogs were fair game. Winners: Big Guys There are 15 families within Carnivora. Some of those families contain many more species than others, so the authors ranked the families by the average number of published papers per species. Bears (family Ursidae) crushed the competition, averaging more than 250 papers per species. The closest runner-up was the walrus family (Odobenidae, which is actually just one species), with only 145 papers. Both walruses and bears would squash their competition in another way—which is to say literally, because they're huge. The researchers found that across all families, body size was correlated to how many papers were published on an animal. Broken down by species, the top 20 most-researched animals included three kinds of bear, as well as the lion, tiger, cheetah, puma, hyena, and elephant seal. Even the relatively smaller animals in the top 20, like wolves and raccoons, are nothing to mess with. There were 28 species of Carnivora that didn't appear in a single published paper. Out of those species, 27 weigh 2.4 kilograms or less—the size of a small chihuahua.
Losers: Homebodies Animals with a larger geographic range were also more likely to be studied. Those that stick to just one place were less popular. The family Eupleridae, for example, was the second-least studied; these animals live only in Madagascar and include things like mongooses and fossas. It might seem that the losers are really the animals that are hardest to find—how many scientists are able to travel to Madagascar and track down a fossa? But Zoological Society of London researcher Chris Carbone, the study's senior author, doesn't think easy access is the whole story. "I think some of the best studied species are not easy to study," Carbone says. "They are often very rare and very elusive." Other animals that would be easier to study are sometimes "simply overlooked." As an example, he cites the serval, "a smaller African cat, very beautiful but with very few studies published. It would be relatively easy to study but people are too focused on lions, cheetah, leopards, hyenas, etc." Losers: Omnivores Animals with more varied diets—omnivores that can get by on just about anything—were studied less often than strict meat-eaters. The authors point out that since these species are so adaptable, they're often common and widespread—not the "rare and elusive" animals Carbone thinks scientists are more excited by. Winners: Charmers and Pests The word "charismatic" may seem better suited to Jon Hamm than an elephant seal. But scientists use it to describe certain big, attention-grabbing animals—think pandas, tigers, or anything that draws a crowd at a zoo. Charisma may be part of the explanation for why some animals steal more of scientists' attention. "Just today, I had someone in the office asking to get genetic material [to study] cats," Carbone says. "He specifically wanted the big, rare, charismatic species!" The least-studied family in the study was Nandiniidae, which includes only one species: the apparently uncharismatic African palm civet, subject of just four papers in over a century. Even animals that aren't charming can seize humans' attention by getting in a fight with us. The authors write that many of the most-studied species are in conflict with humans, maybe over food or habitat or because they carry diseases: wolves, coyotes, raccoons. Nothing Special: Endangered Species Finally, the authors broke down species by their status as endangered, threatened, and so on (labels applied by the International Union for Conservation of Nature). Zoe Brooke explains that the results here were mixed. Looking at average numbers of papers suggested that the less threatened species were better studied. But averages can be skewed by extreme numbers for some animals; when the authors ran the numbers using median values instead, it looked like endangered and critically endangered animals were the most studied. Either way, Carbone says, "threat status was not a significant factor" overall. Body size and geographic range mattered much more to an animal's popularity. This means scientists may be missing their chance to study some animals before they disappear from the earth altogether. For example, the unloved Eupleridae of Madagascar include one endangered species, three that the IUCN lists as vulnerable, and three near threatened. Conserving the animals that are most vulnerable may mean adjusting our focus. Carbone says researchers should start paying more attention to small carnivores—and so should the editors of journals where those papers will be published. Organizations that fund research can help by offering funds only to study certain animals, he says; a group called Panthera is already trying this with its Small Cat Action Fund. "Gradually, the perspectives are changing."
An African civet says, "Why don't you like me?"
Brooke, Z., Bielby, J., Nambiar, K., & Carbone, C. (2014). Correlates of Research Effort in Carnivores: Body Size, Range Size and Diet Matter PLoS ONE, 9 (4) DOI: 10.1371/journal.pone.0093195