In the mountain forests of the Andes, some animals rarely make an appearance.
The "elusive" creatures may be small in numbers or might limit their movements to the cover of night.
In Ecuador, researchers studying these animals turned to trail cameras to bolster their research, according to a study published Nov. 20 in the peer-reviewed Biodiversity Data Journal.
Over a 12-year period in the Llanganates-Sangay Connectivity Corridor, areas that connect protected land and provide safe passage for animals, researchers captured thousands of images -- and made an unexpected discovery.
"(Camera trapping) provides insights into the species behavior, spatial distribution occurrence, predation and other ecological features which are difficult to observe directly," researchers said. "Camera trapping allows us to collect information on elusive species, which commonly occur at low densities and whose museum records are scarce."
Snapping photos also allows researchers to see animals with rare traits, including "unusual coloration patterns," brought on by diet or genetic mutation, according to the study.
The cameras were operating 24 hours a day and without the help of bait, researchers said. Photos from the cameras, along with some provided by park rangers, were studied to see if any odd-looking creatures made their way in front of the lens.
"We compiled a total of 57 unusual coloration records encompassing seven different species: black agouti, tayra, clouded oncilla, margay, brown-nosed coati, western mountain coati and southern tamandua," researchers said.
The species were incredibly diverse, as black agouti are a species of guinea pig-like rodents, tayra are species of weasel-like predators, clouded oncilla and margay are small cats, coatis are raccoon-like animals and tamandua are similar to aardvarks.
The animals fell into one of five categories, including animals that had too much melanin, making them darker, or not enough, making them appear to have all-white or white-spotted bodies, according to the study.
Unusual coloration was typically a small percentage of animals of a species, running from 5.2% of animals to below 2%, researchers said. However, almost half of all the clouded oncilla spotted on the cameras were melanistic, meaning they were darker than other individuals.
"Mammals in the tropics are more likely to exhibit dark colorations, and thus, are prone to develop melanism, with factors like temperature, humidity, forest cover and vegetation density being the more influential variables," researchers said.
Brown-nosed coatis exhibited progressive graying, researchers said, while western mountain coatis and black agoutis showed white spotting and yellowing coloration, called piebaldism.
The clouded oncillas were darker than expected, but southern tamanduas had a lighter coloration, according to the study.
Colorations like white spotting and leucism, an all-white coloration that differs from albinism, are commonly determined by genetics, according to the study. This means their rarity may be attributed to the mutation making their life more difficult, and the genes aren't passed down.
"Unusual coloration patterns in mammals can be detrimental to their fitness (i.e. survival rate, reproductive success and energy contribution to the ecosystem), by making individuals more visible to predators, sometimes less sexually desirable, presenting higher heat absorption levels, as well as increasing the predator's exposure to their prey, impacting their survival probability," researchers said.
The Llanganates-Sangay Connectivity Corridor connects the Andes to the Amazon in north-central Ecuador.
The research team includes Elias Viteri-Basso, Juan Pablo Reyes Puig, Carolina Reyes-Puig and Gorky Ríos-Alvear.