Author: Ofer Eitan
Publisher:
ISBN:
Category : Fiddler crabs
Languages : en
Pages : 82

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Author: Daniela Perez
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The evolution of diverse sexual signals and traits in animals is a promising yet challenging field in behavioural ecology. Sexual features are under the influence of a multitude, and often cryptic, mechanisms. In addition, the composition and strength of selection varies for each study species. Fiddler crabs are ideal subjects for investigating the evolution of diverse sexual traits. Males possess one sexually dimorphic enlarged claw. The structure is used as a weapon in conflicts over territory and signaled in the form of wave displays as courtship to females and warning to intruders. The displays are diverse on the interspecific level, characterized by species-specific movement patterns. In this thesis, I explore the forces behind the evolution of sexually dimorphic claws and the great diversification of fiddler crab signals. In the first two chapters of my thesis I search for a clearer understanding of sexual selection in shaping the species-specific diversity of wave displays in fiddler crabs. First, I investigate if wave displays are cues for species identity in sympatric populations. I use robotic crabs in my experiments and verify that females are able to choose the conspecific over a heterospecific wave movement. In chapter II, I direct my focus to female natural choices and identify their preferences on wave displays and claw size. This final approach allows me to reveal other selective mechanisms, such as constraints from natural selection in male signaling effort. In the second part of my thesis, I expand my approach to the level of social context and its effects on fiddler crab sexual traits. In chapter III, I look into the laterality of the sexually dimorphic claw and examine the different fight endurances when opponents are same- or different-handed. I point out how distinct handedness ratios in fiddler crab populations set contrasting selective pressures in male-male coalitions. In chapter IV, I explore differential social situations in the production of wave signals, and take a step further to explore the social contexts that stimulate the emergence of a rare signal phenomenon, the synchronous waving. Finally, in chapter V, I look into signal diversity from a wider perspective by applying comparative approach to understand the evolution of the wave displays. I gather structural and temporal information of the wave displays of 28 species to predict the likelihood and evolutionary paths of presenting waves in synchrony. Lastly, I indicate how the phenomenon may stem from the particularities of a species mating systems and ecological adaptations.

Author: J. Emmett Duffy
Publisher: Oxford University Press
ISBN: 0195179927
Category : Science
Languages : en
Pages : 519

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Book Description
Understanding of animal social and sexual evolution has seen a renaissance in recent years with discoveries of frequent infidelity in apparently monogamous species, the importance of sperm competition, active female mate choice, and eusocial behavior in animals outside the traditional social insect groups. Each of these findings has raised new questions, and suggested new answers, about the evolution of behavioral interactions among animals. This volume synthesizes recent research on the sexual and social biology of the Crustacea, one of the dominant invertebrate groups on earth. Its staggering diversity includes ecologically important inhabitants of nearly every environment from deep-sea trenches, through headwater streams, to desert soils. The wide range of crustacean phenotypes and environments is accompanied by a comparable diversity of behavioral and social systems, including the elaborate courtship and wildly exaggerated morphologies of fiddler crabs, the mysterious queuing behavior of migrating spiny lobsters, and even eusociality in coral-reef shrimps. This diversity makes crustaceans particularly valuable for exploring the comparative evolution of sexual and social systems. Despite exciting recent advances, however, general recognition of the value of Crustacea as models has lagged behind that of the better studied insects and vertebrates. This book synthesizes the state of the field in crustacean behavior and sociobiology and places it in a conceptually based, comparative framework that will be valuable to active researchers and students in animal behavior, ecology, and evolutionary biology. It brings together a group of internationally recognized and rising experts in fields related to crustacean behavioral ecology, ranging from physiology and functional morphology, through mating and social behavior, to ecology and phylogeny. Each chapter makes connections to other, non-crustacean taxa, and the volume closes with a summary section that synthesizes the contributions, discusses anthropogenic impacts, highlights unanswered questions, and provides a vision for profitable future research.

Author: Huon 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: 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: Catherine Elaine deRivera
Publisher:
ISBN:
Category :
Languages : en
Pages : 314

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Author: Douglas J. Emlen
Publisher: Macmillan
ISBN: 0805094504
Category : Nature
Languages : en
Pages : 288

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Book Description
Emlen takes us outside the lab and deep into the forests and jungles where he's been studying animal weapons in nature for years, to explain the processes behind the most intriguing and curious examples of extreme animal weapons. As singular and strange as some of the weapons we encounter on these pages are, we learn that similar factors set their evolution in motion. Emlen uses these patterns to draw parallels to the way we humans develop and employ our own weapons, and have since battle began.

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

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Book Description
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: Theodore Garland
Publisher: Univ of California Press
ISBN: 0520261801
Category : Nature
Languages : en
Pages : 752

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Book Description
This volume summarizes studies in experimental evolution, outlining current techniques and applications, and presenting the field's range of research.

Author: Charlie Arreza Yparraguirre
Publisher:
ISBN:
Category : Fiddler crabs
Languages : en
Pages : 248

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Book Description