Time allocations for different activities in the fiddler crab Tubuca rosea (Tweedie, 1937) (Brachyura, Ocypodidae)

Abstract

Investigating the time activity budgets of fiddler crabs is very important to determine the effects of sex and body size on allocating time for different activities. Few previous studies investigated the effects of sex and body size on time allocations in underground mating species. This study determines the effects of sex, size and their interaction on time allocations in a surface mating species (Tubuca rosea (Tweedie, 1937)). The surface activities of large and small, male and female crabs were video recorded. Afterwards time allocations for various activities (e.g., feeding, standing (vigilance), walking, inside burrows, grooming, burrowing, mating, and for males only, fighting and claw-waving) were calculated. All crabs spent most of their time on feeding than on other activities. Smaller crabs spent more time being vigilant, whereas larger crabs spent more time on courtship displays (grooming, and waving), and fighting. Between sexes, females spent more time standing, but less time on walking and grooming than males. Predation risk, reproductive maturation, breeding/non-breeding season, and energy conservation could be important factors for shaping time allocations in T. rosea.

Behavior and activity pattern of Minuca osa (Brachyura: Ocypodidae) from Ponuga, Veraguas, Panama

“…Discrete behavior elements were recorded during field trips based on descriptions in the specialized literature (Crane, 1966(Crane, , 1975Christy and Salmon, 1984;Caravello and Cameron, 1987;Tina et al, 2019;van Himbeeck et al, 2019). To further capture behavior without observer effects, two ground level cameras (Casio, 26mm, 1:2.8-6.5) were placed near active burrow entrances to record video of M. osa individuals.…”

“…One area of research that has received particular attention is their time budgets, which refer to the allocation of time between different activities such as feeding, mating, combat, etc (Altmann, 1974). Time budgets are shaped by a variety of factors, including environmental pressures, social interactions, and predation risk (Lima and Dill, 1990;Koga et al, 2001;Christy, 2007;Neylan et al, 2019;Tina et al, 2019).…”

“…For example, during reproductive bouts, males allocate a significant amount of time to courtship and mate guarding, while females spend more time foraging and mate sampling (Crane, 1975;Christy and Salmon, 1984;Caravello and Cameron, 1987;Backwell and Passmore, 1996;Mokhlesi et al, 2011;Tina et al, 2019). Other studies have demonstrated that there are costs associated to social behavior and that fiddler crabs adjust their time budgets in response to predation risk, increasing their burrowing and flight behaviors under predation risk (Lima and Dill, 1990;Backwell et al, 1998;Koga et al, 1998Koga et al, , 2001Christy, 2007;Takeshita and Nishiumi, 2022).…”

“…Males and females, have been preliminarily observed while performing various activities (e.g., feeding, waving), which creates a context where inter-and intra-specific interaction, especially between males and females, may allow the observation of contrasting adaptive strategies (Christy, 1983(Christy, , 1987Tina et al, 2019;Pardo et al, 2020). This makes fiddler crabs excellent models for studying the selective forces behind their adaptive responses.…”