<p>Sexual selection has long been accepted as a widespread force of evolution shaping male traits across taxa. In recent years, biologists have begun to investigate the extent to which sexual selection may also shape traits among females. However, current models of sexual selection have largely been developed using assumptions that--while generally met in males--often do not apply to females. Thus, attempts to apply these contemporary models to the study of sexual selection in females reveal weaknesses in the theoretical framework for sexual selection research. One consequence of this for empirical research is that researchers often infer the action of sexual selection upon evidence of male mate choice. Although male mate choice is increasingly common, it is much less likely to exert selection pressure than its female counterpart. I begin by proposing a conceptual framework that explicitly accounts for ...Next, I investigate a female trait that has recently become an iconic example of sexual selection in females; that is the exaggerated estrous swellings of cercopithecine primates. By combining morphological data collected with a non-invasive photographic method and observational behavioral data with longitudinal ecological and demographic data from the ongoing Amboseli Baboon Research Project, I examine the sources of variance in this exaggerated signal of fertility. Finally, I test the hypothesis that male baboons prefer females with larger sexual swellings because those females have higher fitness. I find no evidence to support this hypothesis. Instead, my results suggest that mate choice among male baboons has evolved to detect, not the intrinsic quality of the female as has typically been proposed, but the quality of a reproductive opportunity.</p> / Dissertation

Darbo tikslas: Išanalizuoti ir palyginti gyvulių elgseną ir kiaulienos technologines bei juslines savybes auginat kiaules ekologinius reikalavimus atitinkančiose ir įprastinės gamybos sąlygose Darbo tikslui pasiekti išsikelti tokie uždaviniai: Įvertinti ekologinių ir įprastinių kiaulių auginimo būdų zoohigienines sąlygas; Atlikti Lietuvoje ekologiškai ir įprastiniu būdu išaugintų kiaulių mėsos juslinę analizę; Nustatyti talpinimo tankio įtaką kiaulių elgsenai ir technologinei mėsos kokybei; Nustatyti skirtingų kiaulių laikymo sąlygų įtaką gyvulių elgsenai ir technologinei mėsos kokybei; Pateikti pasiūlymus neigiamiems aplinkos veiksniams sumažinti siekiant gauti geresnės kokybės kiaulieną. Neskaitant padidėjusio susidomėjimo alternatyviais gyvulių laikymo būdais, šiuo metu atlikta nedaug darbų tyrinėjančių ekologinio kiaulių laikymo būdo įtaką kiaulienos kokybei. Taip pat daugumos mokslininkų atliktų tyrimų rezultatai parodė, kad ekologiškai augintų kiaulių mėsos kokybės rodikliai nėra nuoseklūs, o kartais net prieštaringi. Apibendrinus matyti, kad dauguma tyrėjų analizavo alternatyvių laikymo būdų įtaką tik produkcijos kokybei. Dėl to kartais sunku paaiškinti rezultatų nenuoseklumą. Lietuvoje tokio pobūdžio tyrimai atlikti pirmą kartą. Išnagrinėjus ekologinių ir įprastinių kiaulių auginimo būdų ypatumus ir jų įtaką produkcijos kokybei taip pat, kaip ir literatūroje, gauti nenuoseklūs rezultatai. Tačiau, įtraukus į tyrimus gyvulių elgsenos analizę, buvo galima tiksliau... [toliau žr. visą tekstą] / Object of research: Despite an increased interest in alternative production systems for pig meat there are, to date, few and often inconsistent reports on how these changes in production systems affect pork quality. With a holistic approach, the overall objective of the thesis was to study the effects of production factors and to evaluate their impact on pig’s behavior, performance, technological and sensory meat quality Specific task for the present work were: to evaluate organic and conventional rearing conditions for pigs; make analysis of meat samples which were collected from organic and conventional pig farms from Lithuania; to access the effects of rearing space on growing pig’s behavior, performance and meat quality; to compare indoor and outdoor raising systems for growing/finishing pigs regarding behavior, performance and meat quality traits; to generalize conclusions of an optimized rearing system for pigs. A comprehensive investigation of the most common pig keeping techniques in Lithuania: restricted, spacious, enriched and with access to outside was carried out for the first time. An influence of those rearing conditions on pig’s behavior, performance and meat quality was estimated. It was established that pig rearing conditions has a big influence on animal’s behavior, performance and meat quality. Due to the strict organic animal husbandry regulations, lack of education and information, organic pork is not popular in Lithuania yet. According to the research... [to full text]

In the zebra finch (Taeniopygia guttata), song and its social context play an important role in female mate selection. The song of the zebra finch is unique in that it can only be produced by males, which makes the species ideal for analyzing the components of male song that influence female song preference and mate selection. There are three consistent features of zebra finch song that affect female mate preference: 1) the amount of time a male sings, 2) the size and complexity of his song repertoire, and 3) the structural conformation to species or population norms (reviewed in Nowicki et al. 2002). During courtship, male zebra finches often express ‘static-visual’ and ‘dynamic-visual’ elements in sync with song (Morris 1954), which would suggest that such behaviors also play a role in influencing female mate preference. However, with courtship comes the competition between males for the attention of potential mates. These agonistic interactions between males act settle disputes over access to mates, and as such, are also likely to influence female mate selection. As follows, we predict that, at the initial onset of courtship, there would be a higher prevalence of male-to-female courting interactions and singing behavior in comparison to male-to-male agonistic tendencies if female mate selection is fundamentally determined by song preference. However if female mate selection is more complicated than simple song preference, we would expect to initially observe a higher number of agonistic interactions between males as they compete for dominance. This hypothesis was tested by recording and analyzing the behavioral interactions between male and female zebra finches in the context of song complexity. We found that different males scored higher for song complexity than those for expression of courtship behaviors, which indicates that different elements of male courtship display likely influence female mate preference. Our data comparing male-to-male interactions and male-to-female interactions within the first 30 minutes after introduction was statistically insignificant, suggesting that female mate selection is more complicated than simple song preference. This preliminary research can be used as a basis for future studies using quantitative movement tracking analysis, which would further strengthen these initial observations. By increasing our understanding of the influence the male song has on female mate selection, we can better expound upon the nature and function of the favored traits that male songbirds possess and the benefits that females and their progeny might gain from choosing a male with these particular attributes.

<p>High-resolution bio-logging tools were used to examine the fine-scale foraging behaviors of humpback whales (Megaptera novaeangliae) in the coastal waters of the Western Antarctic Peninsula during the austral autumn of 2009 and 2010. Discrete feeding events (i.e., lunges) were inferred from the biologging records of thirteen whales, including a mother and her calf. In general, humpback whales exhibited efficient foraging behaviors that allowed them to maximize energetic gains and minimize energetic costs as predicted by optimal foraging theory. They fed at a continuous and high rate in the upper portion of the water column (< 100 m) from approximately dusk to dawn when their prey (Antarctic krill, Euphausia superba) were most vulnerable and less costly to acquire (i.e., near the surface). When forced to dive to greater depths, they adjusted their behaviors (e.g., descent and ascent rates) so that they could maximize their foraging durations and increase their lunging rates. In addition, humpbacks appeared to accept short term (i.e., dive by dive) costs associated with depleted oxygen stores in favor of maximizing long term (i.e., daily) energetic gains. Such efficient behaviors are particularly beneficial for mother-calf pairs who have additional energetic costs associated with foraging, such as lactation (mother), growth (calf), and maintaining proximity. In addition, because the physiology of humpback whales is poorly understood yet critically important for predicting their behaviors in response to fluctuations in their environmental conditions, foraging behaviors inferred from the bio-logging records were used to estimate their metabolic rates, oxygen storage capacities, and oxygen replenishment rates under the framework of optimal foraging theory. This research suggests that the current techniques used to estimate humpback whale oxygen stores is appropriate but that the estimation of metabolic rates of humpbacks while foraging and while traveling need to be addressed further. This work aims to increase the current understanding of humpback whale foraging behaviors along the Western Antarctic Peninsula so that appropriate measures can be taken to aid in their recovery and in the sustainability of the Antarctic marine ecosystem.</p> / Dissertation

<p>Changing environmental conditions may present substantial challenges to organisms experiencing them. In animals, the fastest way to respond to these changes is often by altering behavior. This ability, called behavioral flexibility, varies among species and can be studied on several levels. First, the extent of behavioral flexibility exhibited by a species can be determined by observation of that species' behavior, either in nature or in experimental settings. Second, because the central nervous system is the substrate determining behavior, neuroanatomy can be studied as the proximate cause of behavioral flexibility. Finally, the ultimate causation can be examined by studying ecological factors that favor the evolution of behavioral flexibility. In this dissertation, I investigate behavioral flexibility across all three levels by examining the relationship between habitat structure, the size of different structures within the brain and total brain size, and behavioral flexibility in six closely-related species of Puerto Rican <italic>Anolis</italic> lizards. <italic>Anolis</italic> lizards provide an excellent taxon for this study as certain species, including those used here, are classified as belonging to different ecomorphs and are morphologically and behaviorally specialized to distinct structural habitat types.</p><p>In order to determine the presence of behavioral flexibility in <italic>Anolis</italic>, I first presented <italic>Anolis evermanni</italic> with a series of tasks requiring motor learning and a single instance of reversal learning. <italic>Anolis evermanni</italic> demonstrated high levels of behavioral flexibility in both tasks.</p><p>To address the pattern of brain evolution in the <italic>Anolis</italic> brain, I used a histological approach to measure the volume of the whole brain, telencephalon, dorsal cortex, dorsomedial cortex, medial cortex, dorsal ventricular ridge, cerebellum, and medulla in six closely-related species of Puerto Rican <italic>Anolis</italic> lizards belonging to three ecomorphs. These data were analyzed to determine the relative contribution of concerted and mosaic brain evolution to <italic>Anolis</italic> brain evolution. The cerebellum showed a trend toward mosaic evolution while the remaining brain structures matched the predictions of concerted brain evolution. </p><p>I then examined the relationship between the complexity of structural habitat occupied by each species and brain size in order to determine if complex habitats are associated with relatively large brains. I measured brain volume using histological methods and directly measured habitat complexity in all six species. Using Principal Component Analysis, I condensed the measures of habitat structure to a single variable and corrected it for the scale of each lizard species' movement, calling the resulting measurement relevant habitat complexity. I tested the relationship between relative volume of the telencephalon, dorsal cortex, dorsomedial cortex, and whole brain against both relative habitat complexity and ecomorph classification. There was no relationship between the relative volume of any brain structure examined and either relevant habitat complexity or ecomorph. However, relevant habitat complexities for each species did not completely match their ecomorph classifications. </p><p>Finally, I tested the levels of behavioral flexibility of three species of <italic>Anolis</italic>, <italic>A. evermanni</italic>, <italic>A. pulchellus</italic>, and <italic>A. cristatellus</italic>, belonging to three distinct ecomorphs, by presenting them with tasks requiring motor and reversal learning. <italic>Anolis evermanni</italic> performed well in both tasks, while <italic>A. pulchellus</italic> required more trials to learn the motor task. Only a single <italic>Anolis cristatellus</italic> was able to perform either task. <italic>Anolis evermanni</italic> displayed lower levels of neophobia than the other species, which may be related to its superior performance.</p><p>In combination, this research suggests that <italic>Anolis</italic> of different ecomorphs display different levels of behavioral flexibility. At the proximate level, this difference in behavioral flexibility cannot be explained by changes in the relative size of the total brain or brain structures associated with cognitive abilities in other taxa. At the ultimate level, the size of the brain and several constituent structures cannot be predicted by habitat complexity. However, behavioral flexibility in certain tasks may be favored by utilization of complex habitats. Flexibility in different tasks is not correlated, rendering broad comparisons to a habitat complexity problematic.</p> / Dissertation

The effects of variations in the predictability of appetitive events, such as feeding, have rarely been studied in animals in general or primates in particular. Feeding animals on highly predictable temporal schedules often results in the performance of food anticipatory activity (FAA), characterised by increased arousal and activity and thought to be detrimental to welfare. Temporally unpredictable feeding schedules have been interpreted as resulting in improved welfare. However, if feeding is made unpredictable by preceding it with an unreliable signal, it may result in frustration and aggression. It is suggested here that two distinct but overlapping types of predictability exist. 'Temporal' predictability describes whether an event occurs at fixed or variable intervals, whereas 'signalled' predictability relates to the reliability of a signal preceding the event. This thesis examines the effects of each of these types of predictability in relation to feeding. Welfare was assessed in laboratory-housed common marmosets( Callithrix jacchus) using behavioural measures, which were identified in the context of the routine stressor of human handling and weighing. The signalled and temporal predictability of presentation of a desirable titbit was subsequently experimentally manipulated. It was found that temporally unpredictable presentation of food, preceded by an unreliable signal, was associated with substantially increased stress-related behaviours in this species. If no signal was used, stress increased to a moderate level, but if the food delivery followed a reliable signal there were few behavioural changes compared to control animals. Temporally predictable feeding, without a signal, was associated with lower rates of stress-related behaviour than temporally unpredictable, unsignalled feeding. However, deviations from this temporally predictable schedule, representing delays to feeding, resulted in marked increases in stress. The results were confirmed with a further study, worked around existing feeding routines and using a different primate species, the stump-tailed macaque (Macaca arctoides). Based on these findings it is suggested that the most beneficial schedule for feeding captive primates is a temporally unpredictable one, which appears to buffer animals against the negative effects of delays as well as minimising FAA. Presentation of a reliable signal before food delivery appears to minimise the stress intrinsically associated with a temporally unpredictable routine. These recommendations represent a simple and inexpensive method of improving the welfare of captive primates.

<p>Primates in the wild face complex foraging decisions where they must assess the most valuable of different potential resources to exploit, as well recall the location of options that can be widely distributed. While differences in diet and ecology have long been thought to be an important factor influencing brain evolution in primates, it is less well understood what psychological abilities animals actually use when making foraging decisions. This dissertation examines cognitive domains that play a crucial role in supporting foraging behaviors--spatial memory and decision-making--by integrating both psychological and biological approaches to behavior. In particular, the research presented here examines multiple species of primates to address the cognitive skills that different animals use to solve foraging problems (at the proximate level of analysis), as well as why some species appear to solve such problems differently than other species (at the ultimate level of analysis).</p><p>The first goal of the dissertation is to compare closely-related species that vary in ecological characteristics, in order to illuminate how evolution shapes the cognitive skills used in foraging contexts. This component focuses on comparisons between chimpanzees (Pan troglodytes) and bonobos (Pan paniscus), humans' closest extant relatives. In addition, this component reports comparisons amongst strepsirrhines (Lemur catta, Eulemur mongoz, Propithecus coquereli, and Varecia subsp.) to model cognitive evolution in a taxonomic group with greater ecological diversity than Pan. The first two chapters test the hypothesis that more frugivorous species exhibit more accurate spatial memory skills, first by comparing apes' spatial memory abilities (Chapter 2), and then by comparing four species of lemurs on a related set of spatial memory tasks (Chapter 3). In subsequent chapters, I examine apes' decision-making strategies to test the hypothesis that chimpanzees are more willing to pay decision-making costs than are bonobos, due to differences in their feeding ecology. I focus on preferences about the timing of payoffs (Chapter 4); preferences about risk, or the variability in payoffs (Chapters 4 and 5); and preferences about ambiguity, or knowledge about available options (Chapter 6). </p><p>The second goal of the dissertation is to compare the psychological mechanisms that human and nonhuman great apes use for foraging, in order to identify potentially human-unique cognitive abilities. In terms of spatial memory, I examine whether other apes also exhibit human-like patterns of spatial memory development (Chapter 2). In terms of decision-making, I examine whether apes exhibit a suite of human-like biases when making value-based choices. In particular, I test whether emotional and motivational processes, which are critical components of human decision-making, also play a role in apes' choices (Chapters 4); whether apes are sensitive to social context when making economic decisions (Chapter 5); and whether apes are sensitive to their degree of knowledge when making choices under uncertainty (Chapter 6). Finally, I directly compare human and ape preferences on a matched task to assess whether humans use any unique psychological abilities when making decisions about risk (Chapter 7). In sum, this dissertation links studies of mechanism with hypotheses about function in order to illuminate the evolutionary roots of human's unique cognitive phenotype.</p> / Dissertation

Thesis (M.S.) -- University of Montana, 2008. / Title from author supplied metadata. Description based on contents viewed on July 6, 2009. Includes bibliographical references.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2010.

Thesis (M.S.)--University of North Carolina at Wilmington, 2006. / Includes bibliographical references (leaves: 31-35)