Reproductive and Social Dynamics of a Lek Breeding Bird

Sociality and the unequal apportionment of reproductive success among social individuals is a common characteristic of many vertebrate taxa. To date, our understanding of what factors drive high variance in reproductive success (i.e., intra vs. inter-sexual selection) and which male attributes contribute to that variance, are still fragmentary for most species. Moreover, how social structure interacts with individual behavior and fitness remains understudied despite its potential importance to the evolution of cooperation. This dissertation research focused on understanding this complex synergistic interplay between social and reproductive dynamics in a lek-breeding bird, the wire-tailed manakin. The first chapter examines the complex display ritual of this species of manakin (Pipra filicauda). More specifically, it quantifies and compares the frequency of individual behavior among males of different age and social status. In addition, the first chapter examines in detail the genetic relatedness of male partnerships to test the kin selection hypothesis. The second chapter uses these complex reticulate interactions to build social networks. This chapter details the emergent properties of these networks and examines their role in determining male social ascendancy and access to reproduction. The third chapter uses a combination of molecular tools and network analysis to create a synthetic understanding of variance in male reproductive success. This chapter presents molecular estimates of reproductive skew and examines the social correlates of male reproductive success. Our primary results show 1) that males within leks are not more related than expected by chance, enabling us to reject the role of kin selection in the lek evolution of wire-tailed manakins; 2) that the complex networks of social interactions among males contain the ingredients needed for the evolution of cooperation; 3) that social connectivity of young males was predictive of their later social ascendancy; 4) that the number of male affiliations was strongly predictive of the number of offspring he sired. Overall our findings greatly advance our understanding of social relationships and the role they play in the evolution of cooperation and reproductive variance

UNIFORM SPERM MORPHOLOGY IN THE LEK-BREEDING WIRE-TAILED MANAKIN (PIPRA FILICAUDA)

Abstract ∙ When females copulate with multiple males, selection on spermatozoa can reduce variation in sperm morphology. We describe sperm morphology for a polygynous lek-breeding suboscine, the Wire-tailed Manakin (Pipra filicauda). Total sperm length averaged 41.5 ± 0.7 μm and the among-individual coefficient of variation in total sperm length was 1.8%. Variation was considerably lower than in the other manakin species with known sperm morphology, the Lance-tailed Manakin (Chiroxiphia lanceolata), despite similar promiscuity levels. This result highlights the need for further work on spermatozoa in lek-breeding species. Resumen ∙ Morfología uniforme en el esperma del Saltarín Uirapuru (Pipra filicauda), una especie con sistema de apareamiento de lek Cuando las hembras copulan con más de un macho, selección actuando al nivel del espermatozoide puede reducir la variación en la morfología del esperma. Aquí describimos la morfología del esperma para una especie poligínica de suboscín con sistema de apareamiento de lek, el Saltarín Uirapuru (Pipra filicauda). Los espermatozoides tuvieron una longitud total promedio de 41.5 ± 0.7 μm, y el coeficiente de variación para la longitud total fue de 1.8%. El nivel de variación fue menor que en la otra especie de saltarín estudiada al respecto, el Saltarín Lanceolado (Chiroxiphia lanceolata), aunque ambas especies tienen casi el mismo nivel de promiscuidad. Estos resultados sugieren la necesidad de más estudios sobre especies de aves con este sistema de apareamiento

Sexual selection in a species with exploded leks: the White-crowned Manakin (\u3ci\u3ePipra pipra\u3c/i\u3e)

Understanding what determines male reproductive success is central to sexual selection theory. The main goal of this dissertation was to examine the processes that shape female mate choice and male reproductive success in an exploded lek species: the White-crowned Manakin (Pipra pipra). The first chapter examined if females select males with certain genetic characteristics to gain indirect fitness benefits. Specifically, it tested whether females preferentially mate with unrelated males or males with high overall heterozygosity to increase the genetic diversity of their offspring. The second chapter examined if food resources within territories affect male mating success of territory owners. This chapter evaluated if resources within territories influenced male mating success by increasing (1) the encounter probability among sexes or (2) male attractiveness during mate choice (by increasing male performance or acting as honest signals of male quality). The third chapter examined the effect of male behavioral traits (i.e., intra and inter-sexual selection traits) and territorial characteristics on male mating success. More specifically, it tested if male traits such as vocalization rate, display rate, territory attendance, aggressive interactions, male-male agonistic interaction, territory size and location have an influence in male mating success. My results suggest that female mate choice is the main mechanism affecting male reproductive success in White-crowned Manakins. Moreover, genetic, ecological and behavioral factors interact to influence the outcomes of male reproductive success. Resources within territories were found to influence male advertisement traits (i.e., display) used during mate selection. Further, females appear to use a combination of genetic and behavioral traits as cues during mate choice. These results highlight the importance of considering multiple factors and their interactions when studying male reproductive success

Coordinated display, social hierarchy, and the development of dancing ability in young long-tailed manakins, Chiroxiphia linearis

Although a considerable amount of research has been conducted on the development of bird song, the development of visual displays is still poorly understood. In this thesis, I investigate the coordinated courtship displays of male long-tailed manakins ( Chiroxiphia linearis ). By scoring complex behaviours from video recordings, I characterize the courtship display and dominance hierarchy in detail. I show that courtship is highly stereotyped and that the performance of specific subcomponents of the display can predict courtship success. I also provide evidence of an age-graded dominance hierarchy among young males. Finally, I show that courtship display differs significantly between older and younger males, and that certain display elements may develop over time. My research suggests that social interactions between males may be important in the maintenance of lek dynamics, and that social learning may play a role in the development of coordinated display in long-tailed manakins

The ecology of blue-crowned manakins (Lepidothrix coronata): a comparison study of biometric sexing using discriminant analyses

Blue-crowned manakins (Lepidothrix coronata) exhibit neotenic retention of subadult monomorphic plumage in sexually mature males. Definitively plumaged adult L. coronata are dichromatic, with males displaying a black body and blue crown while females retain green colouration characteristic of Pipridae species. Male neoteny and the reliance on soft tissue colouration to identify females make mature monomorphic L. coronata indistinguishable in the field, presenting research and management difficulties. The application of biometric measurements with discriminant function analysis (DFA) offers a practical methodology to sex L. coronata. Three DFA methods were compared using L. coronata of definitive plumage and known sex to determine the best modelling methodology for future applications. A linear discriminant analysis was performed using biometric measurements and combined with a principal component analyses. Quadratic discriminant analysis was performed using biometric measurements as a comparison to linear methodologies. Linear and quadratic discriminant analyses of biometric measurements produce a 92.86 and 91.2 per cent accuracy sexing definitively plumaged L. coronata, indicating applicability of statistical modelling as a potential solution for future field applications

Property rights of animals

journal articleThe problem here treated includes the property rights and spatial relationships o f animals, with special reference to the land vertebrates. With little work done in the way of collecting and compiling materials pertaining to this field, the references and literature were widely scattered. Sources of information included (1) the Zoological Records, the Biological Abstracts, the Encyclopedia Britannica (14th Edition), (2) books in the fields of social psychology, animal biology, animal sociology, animal ecology, bird territory, bird behavior, animal stories, game management, social evolution and populations; (3) magazines, including Auk, Condor, Birdbanding, Ibis, National Geographic, Birdlore, American Naturalist, Science, Science News Letter, Ecology and Journal of Mammalogy; (4) bulletins and pamphlets on observations o f the vertebrates. Besides these sources of materials, assistance was received from some personal contacts and from access to unpublished notes. The problem was developed for a master's thesis

Invasive Birds: Global Trends and Impacts

This 381-paged book covers the biology, ecology, impact and management of 34 common alien invasive species, with reviews on the history and context of avian introductions and invasions in five major regions (Oceania, Africa, Europe (including the Middle East, Asia and South America)), as well as management challenges and the potential of citizen science for monitoring alien birds. The book pitches at the introductory level and is ideal for readers to gain a quick and comprehensive view of the current status of global avian invasions. It has brought the records and research of avian invasion one step ahead of other alien invasive animal taxa. Many chapters contain distribution maps and data tables on the diet and morphology of the species, providing a good reference for the species and its management issues. Each chapter also contains a rich list of references that could help readers dive further into the topic

Management to conserve biodiversity is likely to increase soil carbon storage in upland Atlantic oakwoods in the United Kingdom

The objective of this research was to determine whether fencing to exclude grazing from upland woodlands to facilitate the natural regeneration of trees is likely to increase soil carbon storage. Permanent sample plots were established along a transect through Young Wood, the highest Atlantic oakwood in England, immediately prior to fencing and exclusion of sheep in autumn 2008. Plots outside the wood contained either heather (Calluna vulgaris), bilberry (Vaccinium myrtillus), gorse (Ulex europaeus), wavy hair grass (Deschampsia flexuousa) or mixtures of these species. The wood is 99% sessile oak (Quercus petraea) with woodland ground flora such as heath bedstraw (Galium saxatile). Soil samples were analysed for carbon and nitrogen content. Results indicated that more carbon is stored in soil under the oaks than in either heather, bilberry, gorse, grass or mixtures of these species. In conclusion, this study showed that fencing and excluding grazing to conserve Atlantic oakwoods at their altitudinal limit in the United Kingdom is likely to have a carbon mitigation benefit as well as protecting and enhancing the biodiversity for which the management was initially intended