Researcher Sees Pattern in 'Come-Hither' vs. 'Get-Lost' Animal Colors

Researchers grouped animals that 'come-hither' or 'get-lost' and saw a pattern in the different animal colors in each category.

It should come as no surprise that animals frequently use the same colors for far different purposes given the wide variety of colors used within the animal kingdom.

In strawberry poison-dart frogs (Oophaga pumilio), a male's brilliant red coloration is a stern warning to stay away lest you consume a mouthful of a potent, lethal toxin. Meanwhile, the brilliant red of a male northern cardinal (Cardinalis cardinalis) sends out a message for potential mates to draw closer.

Zachary Emberts, an evolutionary biologist from Oklahoma State University, and John Wiens, a colleague from the University of Arizona, pondered how the same colors could have evolved to serve such disparate functions in various animals.

1,824 Land Vertebrates: Come-Hither vs. Get-Lost

They studied 1,824 species of land vertebrates, classifying their colors as either get-lost or come-hither, and discovered the link that bound each group together.

Birds and lizards are examples of come-hither animals that are descended from diurnal ancestors, or active during the daytime. The get-lost animals, like amphibians and snakes, are related to nocturnal ancestors.

Emberts says that the evolution of a species may have left it with characteristics that are present today. The team conducted two separate analyses using their actual day-night activity and their ancestor's day-night activity to search for evolutionary patterns.

According to University of Arizona News, the researchers discovered that there is no current connection between animal activity during the day and night and coloration; rather, the connection is only ancestral. The evolution of terrestrial vertebrates, which dates back about 350 million years, appears to have shared this trait.

Wiens said that it makes no difference how a species creates its colors. However, this general trend of day-night behavior still holds, even though birds make red in a different way than a lizard does.

Generations of Color

The majority of the animals the researchers studied began life rather plain and dull, which evolved into vivid hues over time. Most of the animals live in environments wherein their vivid colors stand out, according to the analysis done by the researchers.

The most logical explanation is that more animals with brighter colors had a better chance of surviving and passing on their genes to subsequent generations, which sustained the trend.

Speaking in Colors

Red, orange, purple, yellow, and blue were among the colors examined. The researchers discovered that, except for blue, all other colors were fairly evenly split between warning and sex signaling. At this time, it's unclear what could be the cause of that.

Emberts said that it is interesting to note that some hues, like orange, red, and yellow, are used equally frequently for both mate attraction and predator avoidance. On the other hand, blue coloration was much more frequently related to mating than to fend off predators.

The coloration of the diurnal animals makes sense because a flashy animal will be seen by other animals during the day, including potential mates. That might also make them more attractive to predators, but it seems that finding a mate and having offspring are more crucial than avoiding being eaten. These species' females are frequently dull in comparison, making them better at hiding from predators and surviving to raise young.

However, nocturnal wildlife slithers and crawls around at night. If the females can't see it, a male nocturnal snake will not use vibrant colors for sexual signaling.

Wiens said that even species without eyes have evolved warning colors. Since it is doubtful that the majority of snakes and amphibians have color vision, their vivid colors are typically used to attract predators rather than other members of the same species.

Animal coloration may have evolved as a warning to diurnal predators who may come across the sleeping animal to stay away, the researchers contend but further study might turn up more information, Science Alert reports.

The Evolution Angle

The team wants to conduct more in-depth research into the history of vivid colors to determine if their purposes have evolved.

However, the study demonstrates that studying the evolutionary history of animal attributes and behaviors may reveal trends that are no longer the same today.

The study conducted by the group was published in the scientific journal Evolution.