Male-like mudballing behavior of some female fiddler crabs (Uca tangeri)

At each low tide, male and female Uca tangeri remove mudballs from inside their burrows and place them on the surface. Previous studies have shown clear intersexual differences in mudball arrangements. However, we noticed that some females placed their mudballs in an arrangement similar to that of males. In this study, we investigated several factors that may have been responsible for this change in female mudballing behavior. We found no significant effect of the lunar cycle, female size and reproductive state, or burrow features. We briefly discuss the avoidance of sexual coercion or parasite modification of host behavior as possible factors. Our study shows that intersexual differences in mudballing behavior are more complex than previously thought