Mite load predicts the quality of sexual color and locomotor performance in a sexually dichromatic lizard

• Published in: Ecology and evolution Vol. 10; no. 7; pp. 3152 - 3163
• Main Authors: Orton, Richard W., Kinsey, Chase T., McBrayer, Lance D.
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.04.2020; John Wiley and Sons Inc; Wiley
• Subjects: Animal behavior; Animal reproduction; Body size; Color; Complex variables; Endurance capacity; Evolution; Genetic engineering; Habitats; honest signals; Hypotheses; Infections; Laboratories; Lizards; Maintenance; Males; Mites; Original Research; Parasites; parasite‐mediated selection; Physiology; Predators; Quality; Scrub; selection for handicap; sexual dichromatism; Signal quality; Florida; parasite‐mediated selection; sexual dichromatism; honest signals; selection for handicap
• ISSN: 2045-7758; 2045-7758
• DOI: 10.1002/ece3.5689

Since Darwin, the maintenance of bright sexual colors has recurrently been linked to mate preference. However, the mechanisms underpinning such preferences for bright colors would not be resolved for another century. Likely, the idea of selection for colors that could decrease the chances of survival (e.g., flashy colors that can inadvertently attract predators) was perceived as counterintuitive. It is now widely accepted that these extreme colors often communicate to mates the ability to survive despite a “handicap” and act as honest signals of individual quality when they are correlated with the quality of other traits that are directly linked to individual fitness. Sexual colors in males are frequently perceived as indicators of infection resistance, in particular. Still, there remains considerable discord among studies attempting to parse the relationships between the variables associating sexual color and infection resistance, such as habitat type and body size. This discord may arise from complex interactions between these variables. Here, we ask if sexual color in male Florida scrub lizards (Sceloporus woodi) is an honest signal of resistance to chigger mite infection. To this end, we use linear modeling to explore relationships between mite load, different components of sexual color, ecological performance, body size, and habitat type. Our data show that that the brightness of sexual color in scrub lizards is negatively associated with the interaction between mite load and body size, and scrub lizards suffer decreased endurance capacity with increases in mite load. Our data also indicate that mite load, performance, and sexual color in male scrub lizards can vary between habitat types. Collectively, these results suggest that sexual color in scrub lizards is an honest indicator of individual quality and further underscore the importance of considering multiple factors when testing hypotheses related to the maintenance of sexual color. The data submitted here help to disentangle the convoluted links between color, parasitism, and ecological performance. Collectively, the results suggest that sexual colors in male scrub lizards may be maintained by parasite‐mediated selection.