Yuan, M. L., Jung, C., Bell, R. C., & Nelson, J. L. (2022). Aposematic patterns shift repeatedly 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 remark by coauthor Jessica Nelson, whose staff has been monitoring particular person poison frogs all through their lifetimes as a part of routine care on the Nationwide Aquarium. By working intently and constantly with these animals, she seen a phenomenon that will in any other case be tough to look at within the wild. Their shade patterns change all through their lives!
Poison frogs are well-known for his or her vivid coloration, a warning to predators that the frogs are poisonous. But, the truth that they constantly shift shade sample all through their lives was not nicely documented by scientists. Someday 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 shade 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 remark into this analysis examine? Fortunately, the care staff had been taking standardized pictures all through the lives of those frogs to assist determine people and observe their development. Though not initially taken for the needs of this examine, these photographic information have been repurposed to permit us to characterize adjustments in shade sample. Simply goes to indicate, that you just by no means know the way knowledge could be used for sooner or later!
In complete, we analyzed pictures of 114 inexperienced poison frogs, 91 dyeing poison frogs, and 68 yellow-banded poison frogs. An issue with frog photographs is that they have an inclination to have a little bit of glare. Frogs are, in any case, moist animals. Thankfully, new picture analyses software program akin to 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 shade sample knowledge from our pictures. We discovered that in all three species the colour sample modified as a person aged. Particularly, the relative space of vivid shade decreased and the relative space of black elevated. This typically led to adjustments in sample components, like the looks of latest black patches or the fusion of current patches.
Human care and the wild are, after all, completely different settings and we can’t be sure that the colour sample adjustments we noticed listed here are vital for the biology of untamed people. However we do know that shade patterns play vital roles in poison frogs, from warning predators about their toxins to attracting mates. Thus, we name on future work to explicitly take a look at the implications of age-related adjustments in shade 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 position of zoos and aquariums in offering vital insights into the biology of animals that will in any other case be ignored 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