Implications of background variation on color variation within a population of Carolina grasshoppers


SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY
2021 VIRTUAL ANNUAL MEETING (VAM)
January 3 – Febuary 28, 2021

Meeting Abstract


P34-9  Sat Jan 2  Implications of background variation on color variation within a population of Carolina grasshoppers Gilbert, FR*; Brandley, NC; College of Wooster egilbert252@gmail.com

Classical natural selection theory suggests that a camouflaging species should resemble their environment. However, what if a species inhabits an area that frequently varies in background color? The Carolina grasshopper (Dissosteira carolina) is a generalist species that inhabits many different backgrounds. Notably, within the same population D. carolina individuals may vary in color including on a brown to grey spectrum. How do these alternative colorations perform on the variety of backgrounds present within their habitat? To explore this question, we measured reflectance of grasshoppers collected in northeast Ohio. Using bird visual modeling, we examined how well the grey (n=23) and brown (n=27) colorations matched various natural backgrounds. Each coloration appeared advantageous against some backgrounds. The brown grasshoppers matched dirt better than grey grasshoppers (color distance for brown= 0.03 and grey= 0.045; p=0.006; smaller values indicate better match) and grey better matched grass (brown=0.13 and grey= 0.12; p=0.0001) and grey rocks (brown=0.095 and grey=0.065; p=0.003). This suggests each coloration within D. carolina populations could have some camouflage advantage on different backgrounds. This supports the notion that background matching can lead to the persistence of alternative colorations in variable environments. However, research on which background each variant spends more time would provide some much-needed insight on whether this is advantageous.

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