1. Previous evidence demonstrates that closing force decreases proportionally as fiddler crab claw size increases. Larger crabs do have greater absolute closing force, but less than would be expected if claw proportions were isometric. In the Mud Fiddler Crab, Uca pugnax , this is explained by a decrease in mechanical advantage with increasing claw size. 2. We here re-measure mechanical advanta...

Fiddler crabs are intertidal brachyuran crabs that belong to the genus Uca. Approximately 97 different species have been identified, and several of these live sympatrically. Many have species-specific body color patterns that may act as signals for intra- and interspecific communication. To understand the behavioral and ecological role of this coloration we must know whether fiddler crabs have ...

Numerous avian species prey on fiddler crabs, yet the ecological relationships involving Minuca osa crabs and their predators remain poorly understood. We report first documented cases of M. predation by White Ibis, Eudocimus albus. Three distinct events were observed: June 3rd, 2021, November 10th, 2022, 25th, in Gulf Montijo, Veraguas, Panama. Examination E. albus feces provided confirmation ...

The current phylogenetic hypothesis for the evolution and biogeography of fiddler crabs relies on the assumption that complex behavioral traits are assumed to also be evolutionary derived. Indo-west Pacific fiddler crabs have simpler reproductive social behavior and are more marine and were thought to be ancestral to the more behaviorally complex and more terrestrial American species. It was al...

To reduce the potential costs of combat, animals may rely upon signals to resolve territorial disputes. Signals also provide a means for individuals to appear better than they actually are, deceiving opponents and gaining access to resources that would otherwise be unattainable. However, other than resource gains, incentives for dishonest signalling remain unexplored. In this study, we tested t...

Courtship displays are often energetically and temporally costly as well as highly conspicuous to predators. Selection should therefore favour signalling tactics that minimize courtship costs while maintaining or increasing signal attractiveness. In fiddler crabs, males court females by waving their one greatly enlarged claw in a highly conspicuous and costly display. Here, we investigate wheth...

Polarisation vision is used by a variety of species in many important tasks, including navigation and orientation (e.g. desert ant), communication and signalling (e.g. stomatopod crustaceans), and as a possible substitute for colour vision (e.g. cephalopod molluscs). Fiddler crabs are thought to possess the anatomical structures necessary to detect polarised light, and occupy environments rich ...

In tropical regions, different species of fiddler crabs coexist on the mangrove floor, which sometimes makes it difficult to define species-specific habitat by visual inspection. The aim of this study is to find key environmental parameters which affect the distribution of fiddler crabs and to determine the habitats in which each species was most abundant. Crabs were collected from 19 sites wit...

Although conspicuous courtship displays are an effective way of attracting the attention of receptive females, they could provide valuable information to rival males on the location of these females. In fiddler crabs, males that see a receptive female wave their single, greatly enlarged claw in a highly conspicuous courtship display. We test whether other males use this courtship display to ale...

In this paper, we present a new paradigm of biomorphic robot which is based on capabilities of animals such us grasshoppers or fiddler crabs. Biomorphic robots seem to be the future in exploration of hazardous environments. As has been proved in recent works, multi-robot platforms are the best solution for exploration of unstructured environments. In the forthcoming years, planetary missions mu...