The Effects of Sexual Selection on the Interaction of Foraging and Social Behavior in the Gulf Coast Fiddler Crab, Uca Panacea PDF Download

Author: Halina Elizabeth Caravello
Publisher:
ISBN:
Category : Fiddler crabs
Languages : en
Pages : 184

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Author:
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ISBN:
Category : Electronic journals
Languages : en
Pages : 832

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A refereed, broad-spectrum journal publishing basic research in diverse disciplines in biology and varied taxa.

Author: Huon Clark
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Producing offspring is the most important aspect of an animal's life. Reproductive success is the cornerstone of evolution, but successful mating is a complex process that we are only starting to understand. This thesis examines five aspects of reproductive success in a fiddler crab, Uca mjoebergi. This is an ideal study species since the crabs are tractable, abundant and amenable to manipulation. In the first chapter, I examine the natural mate-searching behaviour of females and show, for the first time in any species, that there is a mosaic of preferences: females prefer males of different sizes depending on where they are in the tidal zone, and when they are mate-searching in the tidal cycle. This level of complexity in female preferences can partly explain the 'lek paradox'.In the second chapter, I examine assortative mating and show that there is a strong correlation between the size of males and females in mated pairs. I show that neither mate availability nor mating constraints can explain the pattern. Since both males and females preferentially mate with larger partners, sexual selection explains the high level of size-assortative mating. In chapter three, I revisit earlier work on this species showing that claw loss and subsequent regeneration strongly disadvantages males in terms of reproductive success. By substantially increasing the sample size, I show that males with regenerated claws are not at a mating disadvantage. This study highlights the importance of large sample sizes in behavioural studies. In chapter four, I examine the effect of temperature on mating success. Males can live in the sun or shade. There are advantages to living in the shade: males can be active for longer periods and they are less likely to dehydrate or overheat. Females that chose to mate with males living in the shade, however, would incubate their eggs at approximately 3'C lower than females incubating in sunny territories. I show that this difference in temperature does not affect the timing of crucial reproductive events and does not prevent the females from releasing their fully-formed larvae at the optimal time.In chapter five, I examine the potential consequence of habitat loss and subsequent overlap between species distributions. We can already observe this: a larger, lower-living fiddler crab is invading the habitat of Uca mjoebergi, increasing the competition between these species. I show that the disadvantages experienced by male U. mjoebergi from having a heterospecific neighbour is not necessarily as severe as common sense may suggest.

Author: Michelle Anne Duval
Publisher:
ISBN:
Category : Fiddler crabs
Languages : en
Pages : 310

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Author: Luc-Alain Giraldeau
Publisher: Princeton University Press
ISBN: 0691188343
Category : Science
Languages : en
Pages : 379

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Although there is extensive literature in the field of behavioral ecology that attempts to explain foraging of individuals, social foraging--the ways in which animals search and compete for food in groups--has been relatively neglected. This book redresses that situation by providing both a synthesis of the existing literature and a new theory of social foraging. Giraldeau and Caraco develop models informed by game theory that offer a new framework for analysis. Social Foraging Theory contains the most comprehensive theoretical approach to its subject, coupled with quantitative methods that will underpin future work in the field. The new models and approaches that are outlined here will encourage new research directions and applications. To date, the analysis of social foraging has lacked unifying themes, clear recognition of the problems inherent in the study of social foraging, and consistent interaction between theory and experiments. This book identifies social foraging as an economic interaction between the actions of individuals and those of other foragers. This interdependence raises complex questions about the size of foraging groups, the diversity of resources used, and the propensity of group members to exploit each other or forage cooperatively. The models developed in the book will allow researchers to test their own approaches and predictions. Many years in development, Social Foraging Theory will interest researchers and graduate students in such areas as behavioral ecology, population ecology, evolutionary biology, and wildlife management.

Author: Huon Lyndon Clark
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Producing offspring is the most important aspect of an animal's life. Reproductive success is the cornerstone of evolution, but successful mating is a complex process that we are only starting to understand. This thesis examines five aspects of reproductive success in a fiddler crab, Uca mjoebergi. This is an ideal study species since the crabs are tractable, abundant and amenable to manipulation. In the first chapter, I examine the natural mate-searching behaviour of females and show, for the first time in any species, that there is a mosaic of preferences: females prefer males of different sizes depending on where they are in the tidal zone, and when they are mate-searching in the tidal cycle. This level of complexity in female preferences can partly explain the 'lek paradox'. In the second chapter, I examine assortative mating and show that there is a strong correlation between the size of males and females in mated pairs. I show that neither mate availability nor mating constraints can explain the pattern. Since both males and females preferentially mate with larger partners, sexual selection explains the high level of size-assortative mating. In chapter three, I revisit earlier work on this species showing that claw loss and subsequent regeneration strongly disadvantages males in terms of reproductive success. By substantially increasing the sample size, I show that males with regenerated claws are not at a mating disadvantage. This study highlights the importance of large sample sizes in behavioural studies. In chapter four, I examine the effect of temperature on mating success. Males can live in the sun or shade. There are advantages to living in the shade: males can be active for longer periods and they are less likely to dehydrate or overheat. Females that chose to mate with males living in the shade, however, would incubate their eggs at approximately 3°C lower than females incubating in sunny territories. I show that this difference in temperature does not affect the timing of crucial reproductive events and does not prevent the females from releasing their fully-formed larvae at the optimal time. In chapter five, I examine the potential consequence of habitat loss and subsequent overlap between species distributions. We can already observe this: a larger, lower-living fiddler crab is invading the habitat of Uca mjoebergi, increasing the competition between these species. I show that the disadvantages experienced by male U. mjoebergi from having a heterospecific neighbour is not necessarily as severe as common sense may suggest.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: Richard Norman Crothers Milner
Publisher:
ISBN:
Category : Animal communication
Languages : en
Pages : 398

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From violence to romance, fiddler crabs are an ideal study system to explore questions and predictions important to behavioural ecology and sexual selection. Fiddler crabs of the genus Uca are members of the Ocypodid family of brachyuran crabs. These highly social crabs occur in dense mixed sex colonies, and display pronounced sexual dimorphism. Males are endowed with one greatly enlarged claw that is used during courtship, as well as a weapon during aggressive interactions. Females lack this claw and instead have two small feeding claws. Fiddler crabs are highly territorial and display both male contest competition and female mate choice. The following nine chapters of this thesis explore the behavioural ecology of fiddler crabs.

Author: Gwendolyn A. Murphy
Publisher:
ISBN:
Category : Animal burrowing
Languages : en
Pages : 198

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Positive rather than negative species interactions dominate in stressful environments like tidal marshes. Fiddler crabs have been shown to ameliorate environmental stress and increase primary productivity through their burrowing behavior. Most notably, bioturbation may facilitate growth of tidal marsh plants by altering soil oxygen concentration, decomposition rates, and soil drainage. In turn, plants provide protection from the elements, refuge from predators and roots provide structural support for burrows in soft substrate. However, dense vegetation may limit the fiddler crab's ability to maneuver on the surface and burrow. Similarly, there may be a threshold where fiddler crab activity becomes destructive to plant growth instead of facilitative. Relatively few fiddler crab and plant interaction studies have been conducted on the Gulf Coast compared to Atlantic Coast. Gulf Coast tidal marshes have distinct climate, dominant vegetation zones and dominant fiddler crab species, and consequently it is likely that community dynamics will differ from Atlantic Coast tidal marshes. To explore interactions between Gulf Coast fiddler crabs and tidal marsh plants, I conducted a seasonal fiddler crab habitat survey and a fiddler crab enclosure study. Both studies were conducted at Grand Bay National Estuarine Research Reserve in Mississippi, across four dominant tidal marsh vegetation zones (salt marsh, brackish marsh, fresh marsh and salt panne). Fiddler crab burrows and associated vegetation were randomly surveyed across the vegetation zones to determine fiddler crab burrow density and habitat preferences. Fiddler crab enclosures were established across the four vegetation zones. Enclosures provided a method to test impacts of fiddler crab burrowing on soil and plant parameters as well as to survey fiddler crab populations. Results of the habitat survey indicated that fiddler crabs utilized all four vegetation zones, but burrow density was statistically higher in the fresh marsh during winter compared to other zones. These results suggest that the fresh marsh may be important habitat for overwintering Gulf Coast fiddler crabs. Additionally, the fresh marsh was found to host higher fiddler crab species diversity and a more balanced sex ratio compared to other zones. The enclosure study established that fiddler crab activity had negligible impacts on plant growth in the salt and fresh marsh yet influenced plant growth in the brackish marsh (positively) and salt panne (negatively). The brackish marsh and salt panne are habitats of intermediate environmental stress for plants and fiddler crabs. Brackish marsh is more frequently inundated than the salt panne and hence bioturbation is likely to be more beneficial in the brackish marsh. Furthermore, brackish marsh below-ground structure is substantial and fiddler crab burrow density was low relative to the salt panne. My work indicates that vegetation abundance and fiddler crab burrow density may balance environmental stresses in tidal marshes and influence nature of fiddler crab and plant interactions.

Author: Naida Deborah Zucker
Publisher:
ISBN:
Category : Fiddler crabs
Languages : en
Pages : 288

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