Moose populations in southern Manitoba have declined. Although the primary cause of this decline is unclear, wolf predation is considered a main contributor because wolves have limited moose populations elsewhere. To help understand the role of wolf predation in limiting moose populations we reconstructed the proportional diet of wolves using stable isotope analysis and a Bayesian stable isotope mixing model (MixSIAR). We tested the assumptions of MixSIAR by running sensitivity analyses on trophic discrimination and prior information. We observed differences in wolf diet in areas where moose and deer coexist and are spatially separated, with changes both seasonally and annually. Our results suggest white-tailed deer were preyed on during winter, even in areas where deer are locally rare, suggesting prey catchability is more important than local prey density. Seasonal changes in prey accessibility strongly affect wolf predation rates, and manipulating alternative prey populations could mitigate predation impacts on moose. / October 2015

Eco-evolutionary dynamics integrates the reciprocal interactions betweenecology and evolution. These two branches of biology traditionally assumethe other as static for simplicity. However, increasing evidence shows thatthis simplification may not always hold because ecology and evolution canoperate in similar timescales. This thesis theoretically explores how thereciprocal interactions may influence ecological and evolutionary outcomesin four different eco-evolutionary contexts.Many species of non-social animals live in groups. Aggregating ingroups often has both benefits and costs that depend on group size. Thanksto the benefits of aggregation, population growth likely depends positivelyon population density when it is small. This phenomenon, the Allee effect,has been hypothesized to explain the evolution of aggregation behavior. Ifind that the Allee effect alone does not lead to the evolution whenpopulation dynamics is explicitly accounted for. Some other mechanisms,such as frequent needs for colonizing new patches or anti-aggregation,should be invoked to explain why aggregation behavior could evolve.Phenotypic plasticity is the ability of a genotype to express distinctphenotypes when exposed to different environments. Although it is oftenshown to be adaptive and not costly, highly plastic organisms are rare. Paststudies demonstrated some potential reasons. I test another possibility; costsmay arise from sexual selection because highly plastic individuals may beless preferred as a mate. I show that, even in the absence of the direct cost ofplasticity, the level of plasticity remained low at intermediate strengths ofassortative mating. This pattern is robust across wide ranges of parametervalues.Ecological speciation occurs when ecologically divergent selectionbetween environments causes reproductive isolation between divergingsubpopulations. Several verbal models of ecological speciation emphasizethe roles of phenotypic plasticity in promoting speciation. The complexprocesses involved in speciation, however, are difficult to be evaluated byverbal accounts. I quantitatively test the proposed idea in a mechanisticmodel of ecological speciation in the presence and absence of plasticity. Ifind conditions under which plasticity can promote or hinder ecologicalspeciation. Plasticity facilitates speciation by producing a gap in thedistributions of expressed phenotypes, which serves as a barrier to gene flowin an assortatively mating population.Ecosystem ecology and evolutionary biology are the least integratedfields in ecology and evolution. Natural selection operating at the individuallevels on traits governing ecosystem functions may affect ecosystemproperties, which may feedback to individuals. I reviewed this idea anddemonstrate the feedback loop by using a simple consumer-resource model.

I characterized dusky dolphin (Lagenorhynchus obscurus) underwater bait-balling behaviors and acoustic signals, and compared data between Argentina and New Zealand (NZ) to investigate the roles of ecology versus social learning. I quantified prey herding and capturing behaviors from video footage, and I analyzed acoustic signals from narrowband recordings. In both locations, I related bait-balling behaviors and acoustic signals to group and prey ball sizes. In NZ, I also related dolphin behaviors to prey ball escape behaviors and acoustic signal parameters to examine proximate functions. Observed herding behaviors typically involved dolphins swimming around or under a prey ball using a side body orientation, while dolphins typically captured fish from the side of a prey ball using a ventral orientation. Coordinated prey-capture behaviors may have made it easier for dolphins to capture fish by trapping fish between dolphins. Signals were categorized as click trains, burst pulses, and combinations due to a bimodal inter-click interval distribution. I observed 3 whistle-like chirp-screams, but no whistles. Sequences of burst pulses also occurred that contained 2-14 burst pulses that aurally and visually appeared closely matched. Similarities between locations suggest that ecological context related to broad behavioral and acoustic parameters, while social learning differences may occur on a finer scale. In NZ, prey balls exhibited horizontal and vertical movements, but the only behavior that preceded escape was “funneling”, the brief formation of a ball shape where the height was at least twice the width. Dolphin behaviors that related to prey balls ascending were type of herding pass, location of prey-capture attempts, and body orientation during attempts. These behavioral parameters may also be used to counter vertical prey escape behaviors. In NZ, all signal categories had a direct or indirect role in capturing prey. Click train-burst pulses were likely used for echolocating on prey, burst pulses and sequences appeared to have communication roles, and the role of click trains was ambiguous. No signal categories appeared to have a herding function, but the sheer number of signals emitted may have caused fish to cluster together more tightly and therefore facilitated capture.

Our earth is currently undergoing unprecedented human induced climate change, which is expected to drive widespread changes in species distributions and abundances that will affect natural pest suppression. Recent studies have suggested that climate change may cause changes to predator and herbivore assemblages in ways that alter multi-trophic food webs and affect the stability of ecosystems. Moreover, higher temperatures and increased climatic variability are expected to induce differential responses from predators and their prey that will undoubtedly disrupt species interactions. This thesis aims to test how climate change will impact the ability of natural enemies to continue to control pests in agroecosystems, and how they will continue to survive and function. In a field experiment using 13 farm sites across a natural temperature gradient, I found that temperature had direct positive effects on the abundances of the dominant parasitoid (an aphid specialist) and hyperparasitoid species, highlighting the importance of specific species responses in shaping larger communities. I also found that overall community composition was affected by temperature, with composition in warmer sites changing more throughout the season than cooler sites. In a future of inevitable climatic changes this result tells us we can expect arthropod community structure to change, which will have questionable impacts on overall population dynamics. To build on the field experiments, I used laboratory experiments to test differential responses of species to both drought and temperature and found that natural enemies responded to drought and temperature in a non-additive way, suggesting that the interaction between various climate change drivers is more important than their singular effect. Also, different species of natural enemies responded differently to abiotic factors, highlighting the importance of conserving natural enemies that can maintain important functional attributes in the face of climate change. Although biodiversity can be important for ensuring ecosystem functioning, response diversity, rather than species richness, may better promote ecosystem resilience, especially in the face of changing climate. The mechanisms underlying biodiversity effects are often difficult to disentangle, however, by manipulating the diversity of climate responses exhibited by ecosystem service providers, I tested how the rates and stability of prey suppression by predators are affected by climate warming and drought. I found that predator combinations with different individual responses to climate change maintained greater and less variable (i.e. more stable) prey suppression, compared with single predator species or combinations of predators with similar climate responses. This response complementarity became strongest through time and under drought or high temperature treatments. I suggest that response complementarity provides ‘insurance’ effects, which may be more important than previously envisaged for maintaining ecosystem functions such as biological control under global environmental change. Overall, the non-additive effects of different climate drivers, combined with differing responses across trophic levels, suggests that predicting future pest outbreaks will be more challenging than previously imagined.

Hatchery supplementation of declining fish populations is used for increasing year-class strength, particularly when fish are released with knowledge of local predators. The ability of young-of-the-year lake sturgeon (Acipenser fulvescens) to avoid predation, as well as their vulnerability to predation, remains undocumented. The objective of my thesis was to determine: 1) whether hatchery-reared, predator-naive juvenile sturgeon would respond to alarm cues from injured conspecific cues, a reliable indicator of predation risk in other fishes; and 2) if sturgeon would learn to identify unknown predators through a Pavlovian-like conditioning with conspecific alarm cues. Releaser-induced recognition learning is a variant of Pavlovian learning in which recognition of a previously neutral stimulus is acquired through the experience of pairing a behaviourally active releasing stimulus and a novel stimulus. Sturgeon were initially conditioned using a behaviourally active stimulus of sturgeon alarm cue, paired with a behaviourally neutral stimulus of novel northern pike (Esox lucius) odour, or were pseudo-conditioned with distilled water paired with pike odour. Following conditioning, sturgeon were tested for recognition of the predator odour 24 hours later. The first population of fish (Rainy River) showed a dramatic antipredator response to alarm cues from the skin of conspecifics, but failed to exhibit learning of a novel predator through conditioning with alarm cues obtained from the skin of conspecifics. However, when Rainy River fish were conditioned with alarm cues from the whole body of conspecifics, they showed strong learning of the predator. Conditioning Wolf River fish to recognize predators with whole body extract had no effect on response to predator odours. However, when the fish were conditioned multiple times there was evidence of predator learning. These results highlight potential opportunities and limitation to life-skill training of artificially reared sturgeon for future conservation initiatives.

The ecological importance of introduced mammalian predators is well acknowledged in New Zealand, however, little research has focused on the ecology of native avian predators and their role in communities. This study investigated the ecology of moreporks (Ninox novaeseelandiae) on Ponui Island, Hauraki Gulf, New Zealand between August 2007 and April 2008. The primary aim was to investigate the functional response of moreporks to availability of their prey. The contents of regurgitated morepork pellets were compared with relative abundance of prey taxa (invertebrates, small birds and rodents) over the study period. The diet consisted primarily of a range of invertebrate prey, particularly weta (Anostostomatidae and Raphidophoridae) and beetles (Coleoptera). Small numbers of vertebrate prey were recorded including rodents and birds. A positive relationship between the percentage contribution to pellet samples of certain taxa and their relative availability was found, and there were peaks in the occurrence of seasonally abundant taxa including cicadas (Cicadidae), and huhu beetles (Prionoplus reticularis). The tendency of moreporks to prey on abundant taxa indicates that they are unlikely to depress prey populations to low levels, and may have some degree of stabilising influence. A significant increase in the rodent component of the diet in April indicated that the risk to moreporks of secondary poisoning during mammalian pest control operations may vary considerably with the time of year. The secondary aims were to collect data on roost site characteristics and breeding success. Moreporks roosted at a mean height of 4m, and foliar cover at the 4-6m height tier appeared to be the most important characteristic of roost sites when compared with control sites. These findings suggested that moreporks were selecting roost sites with high overhead cover. Possible reasons for this include predator avoidance, avoidance of mobbing passerines, and the microclimate provided. None of three established pairs and two other birds were observed to establish a nest or breed successfully. Additionally, only three juvenile moreporks were sighted or heard across the 90ha study area suggesting low breeding success in 2007-08. This may have been influenced by a range of factors including 1), predation by the high densities of ship rats on Ponui, or other predators 2), a lack of suitable nest sites such as tree hollows in some areas or 3), competition for invertebrate prey with high densities of ship rats and North Island brown kiwi (Apteryx mantelli).

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2006. / Härtill 4 uppsatser.

Made available in DSpace on 2017-07-10T18:01:54Z (GMT). No. of bitstreams: 1 Tiago Birck.pdf: 505982 bytes, checksum: 4b6847150900887efe0c63ffd60125ee (MD5) Previous issue date: 2015-07-27 / Fundação Araucária / The practice of introducing species has brought great trouble to natural environments as a new species cause imbalance to the ecosystem and evolutionarily established his control has been one of the challenges for ecologists today. Thus, in mesocosms were experimentally analyzed the potential of juveniles of three species of piscivorous fish native (Salminus brasiliensis, Pseudoplatystoma corruscans and Brycon orbignyanus) in population control of Nile tilapia (Oreochromis niloticus) and the role of habitat complexity in this predator-prey interaction. The invasive species Oreochromis niloticus was offered in 2,000L tanks as prey for predators in 1:10 rate (predator:prey) with four levels of habitat complexity (0%, 50%, 100% and natural) without food supply. The number of exemplary preyed was evaluated with 6, 12, 24, 36, 48, 60, 72, 84, 96 and 108 hours after started of the experiment. Salminus brasiliensis showed the highest efficiency of predation, whereas the complexity of habitat did not influence the consumption of prey. In this sense, the sample results indicate that S. brasiliensis species is most effective to control of O. niloticus populations, thus constituting an alternative to implementations of management actions on aquatic environments of the Paraná River. / A prática da introdução de espécies tem trazido grandes problemas aos ambientes naturais, pois a nova espécie causa desequilíbrio ao ecossistema estabelecido evolutivamente e seu controle tem sido um dos desafios de ecologistas na atualidade. Com isso, foram analisados experimentalmente em mesocosmos o potencial de juvenis de três espécies de peixes piscívoros nativos (Salminus brasiliensis, Pseudoplatystoma corruscans e Brycon orbignyanus) no controle populacional da tilápia do Nilo (Oreochromis niloticus) e o papel da complexidade de habitats nesta interação predador-presa. A espécie invasora Oreochromis niloticus foi oferecida como presa para os predadores em tanques de 2.000 L na proporção de 1:10 (predador:presa) com quatro níveis de complexidades de habitat (0%, 50%, 100% e natural). Foi avaliado o número de indivíduos predados em 6, 12, 24, 36, 48, 60, 72, 84, 96 e 108 horas. Salminus brasiliensis apresentou a maior eficiência de predação, enquanto que a complexidade de habitats não influenciou no consumo das presas. Neste sentido, os resultados indicam que a espécie S. brasiliensis é a mais eficiente no controle de populações de O. niloticus, constituindo dessa forma uma alternativa para implementações de ações de manejo em ambientes aquáticos no rio Paraná.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-03-10T18:30:25Z No. of bitstreams: 1 anaameliadesouzapereira.pdf: 7981340 bytes, checksum: 0446c7b651ada497c790051f8b213d35 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-03-13T19:24:03Z (GMT) No. of bitstreams: 1 anaameliadesouzapereira.pdf: 7981340 bytes, checksum: 0446c7b651ada497c790051f8b213d35 (MD5) / Made available in DSpace on 2017-03-13T19:24:03Z (GMT). No. of bitstreams: 1 anaameliadesouzapereira.pdf: 7981340 bytes, checksum: 0446c7b651ada497c790051f8b213d35 (MD5) Previous issue date: 2016-09-26 / O sequenciamento da produção é um processo importante de tomada de decisão usado nas indústrias a fim de alocar tarefas aos recursos. Dada a relevância desse tipo de problema, a pesquisa em programação da produção faz-se necessária. Este trabalho envolve o processo de otimização nos seguintes problemas: máquina única, máquinas paralelas idênticas, máquinas paralelas idênticas com release time, máquinas paralelas não relacionadas com setup time dependente da sequência e das máquinas, e flow shop flexível com setup time dependente da sequência e dos estágios. Além disso, múltiplos e conflitantes objetivos devem ser otimizados ao mesmo tempo na programação de produção, e a literatura vem mostrando avanço nesse sentido. O presente trabalho analisa os objetivos comumente adotados e propõe um conjunto de pares de objetivos. Análise de correlação e árvore de agregação são utilizadas aqui para indicar as possibilidades de agregação entre os objetivos conflitantes. Meta-heurísticas são comumente adotadas para resolver os problemas de escalonamento abordados neste trabalho e duas delas, o Non-dominated Sorting Genetic Algorithm II (NSGA-II) e a Presa Predador (PP), são aplicados aos problemas multiobjetivo propostos a fim de estudar suas adequações aos novos casos. O NSGA-II é um dos Algoritmos Genéticos mais utilizados em problemas de escalonamento. A PP é uma abordagem evolutiva recente para problemas de programação da produção, cada predador é responsável por tratar um único objetivo. Uma generalização para a técnica PP em que os predadores consideram de forma ponderada ambos os objetivos é também proposta. Adicionalmente, a influência da adoção de busca local sobre essas técnicas é analisada. Experimentos computacionais adotando hipervolume como métrica de desempenho foram conduzidos visando avaliar as técnicas computacionais consideradas neste trabalho e suas variantes. / The sequencing of the production is an important process in decision-making and it is used in industries in order to allocate tasks to resources. Given the relevance of this kind of problem, the research in production scheduling is necessary. This study involves the process of optimization in the following problems: single machines, parallel identical machines, parallel identical machines with release time, unrelated parallel machines with setup time dependent on the sequence and on the machines, and flow shop which is flexible with setup time dependent on the sequence and stages. Moreover, multiple and conflicting objectives must be optimized at the same time in production scheduling and the literature has been showing progress in this sense. The present study analyses the commonly adopted objectives and suggests a set of objective pairs. Correlation analysis and aggregation trees are used here to indicate possibilities of aggregation among the conflicting objectives. Metaheuristics are commonly used to solve the sequencing problems addressed in this study and two of them, the Non-dominated Sorting Genetic Algorithm II (NSGA-II) and Predator-Prey(PP), are applied to the proposed multiobjective problems in order to study their adjustments to the new cases. The NSGA-II is one of the most used genetic algorithms in sequencing problems. The PP is a recent evolutionary approach to scheduling problems, where each Predator is responsible for dealing with just one objective. A generalization of the PP technique, in which Predators considered both objectives using weights, is also proposed. In addition, the influence of the adoption of local search on these techniques is analyzed. Computational experiments adopting the hypervolume as a performance measure were conducted aiming at evaluating the computational techniques considered in this study and their variants.

Both the upper and lower temperature tolerances of red fluorescent protein transgenic zebra danios and wildtype zebra danios, Danio rerio, were significantly different via two different methods; however, all differences are small (< 1°C) and probably not ecologically important. The U.S. geographic distributions of both transgenic and wildtype zebra danios will not be restricted by their upper thermal tolerances, but will be limited to the southern and western portions of the U.S. by their lower thermal tolerances. Largemouth bass did not preferentially prey upon transgenic zebra danios compared to wildtype danios or wildtypes relative to a native fish. If transgenic or wildtype zebra danios are released into southern or western U.S. waters, it is possible they could be eliminated by predation.