Yuan, M. L., Jung, C., Bell, R. C., & Nelson, J. L. (2022). Aposematic patterns shift constantly all through the lifetime of poison frogs. Journal of Zoology, vol. 317, pp. 241– 248. https://doi.org/10.1111/jzo.12977
This examine was born out of an statement by coauthor Jessica Nelson, whose group has been monitoring particular person poison frogs all through their lifetimes as a part of routine care on the Nationwide Aquarium. By working carefully and persistently with these animals, she observed a phenomenon that may in any other case be troublesome to look at within the wild. Their coloration patterns change all through their lives!
Poison frogs are well-known for his or her brilliant coloration, a warning to predators that the frogs are poisonous. But, the truth that they persistently shift coloration sample all through their lives was not properly documented by scientists. In the future whereas visiting the Nationwide Aquarium, Jessica talked about her observations to 2 of us – Michael Yuan and Rayna Bell. We have been surprised and excited having by no means heard of this phenomenon earlier than. We determined in that room that we must always quantify the change in coloration sample all through particular person lifetimes in three species stored on the Nationwide Aquarium: the inexperienced poison frog (Dendrobates auratus), the dyeing poison frog (Dendrobates tinctorius), and the yellow-banded poison frog (Dendrobates leucomelas).
How did we go about turning this statement into this analysis examine? Fortunately, the care group had been taking standardized pictures all through the lives of those frogs to assist determine people and monitor their development. Though not initially taken for the needs of this examine, these photographic data have been repurposed to permit us to characterize adjustments in coloration sample. Simply goes to point out, that you just by no means understand how information may be used for sooner or later!
In whole, we analyzed photos of 114 inexperienced poison frogs, 91 dyeing poison frogs, and 68 yellow-banded poison frogs. An issue with frog photographs is that they have a tendency to have a little bit of glare. Frogs are, in spite of everything, moist animals. Thankfully, new picture analyses software program reminiscent of patternize can be utilized to resolve these beforehand intractable issues. Undergraduate extraordinaire, Catherine Jung, got here in to develop a protocol for utilizing this software program to gather coloration sample information from our photos. We discovered that in all three species the colour sample modified as a person aged. Particularly, the relative space of brilliant coloration decreased and the relative space of black elevated. This generally led to adjustments in sample parts, like the looks of recent black patches or the fusion of current patches.
Human care and the wild are, in fact, totally different settings and we can’t be sure that the colour sample adjustments we noticed listed below are essential for the biology of untamed people. However we do know that coloration patterns play essential roles in poison frogs, from warning predators about their toxins to attracting mates. Thus, we name on future work to explicitly check the implications of age-related adjustments in coloration patterns for pure populations. We expect that there’s a lot to be discovered from opening up this new avenue of analysis. Moreover, our work highlights the potential function of zoos and aquariums in offering essential insights into the biology of animals that may in any other case be neglected within the wild. We hope that our work will encourage new collaborations between academia and zoos and aquariums. In case you are ever visiting the Nationwide Aquarium in Baltimore, we hope that you’ll come see the poison frogs that impressed this examine.
Michael Yuan, Catherine Jung, Rayna Bell, and Jessica Nelson