Le développement des activités industrielles et agricoles du siècle dernier a eu pour conséquence le rejet de substances chimiques dans l’environnement, qui contaminent les écosystèmes, et peuvent s’accumuler dans les plantes, les sédiments, et le long des chaînes alimentaires. Il apparait primordial d’effectuer une évaluation du risque écologique associé à la présence de ces composés dans les milieux naturels et les espèces sentinelles sont des outils judicieux pour déterminer l’exposition des individus et évaluer les conséquences sur les organismes. Les amphibiens et les reptiles possèdent des caractéristiques écologiques et biologiques qui les rendent potentiellement intéressants en tant qu’espèces sentinelles. L’objectif des études présentées dans cette thèse est de déterminer la disponibilité de certaines substances dans l’environnement, et d’évaluer les effets de la contamination environnementale sur les organismes en utilisant plusieurs espèces de reptiles et d’amphibiens, (i) en mesurant les niveaux de polluants accumulés dans les tissus d’espèces de reptiles ; (ii) en évaluant l’influence d’un habitat contaminé sur la morphologie d’adultes de crapaud commun (Bufo bufo) ; (iii) en mesurant de manière expérimentale l’impact d’une molécule fréquemment retrouvée dans l’environnement sur le développement de têtards de crapaud commun. Nos résultats montrent d’une part que les reptiles accumulent efficacement les polluants organiques et les éléments traces métalliques dans leurs tissus, et permettent d’évaluer efficacement la contamination globale d’une zone, mais aussi de mettre en évidence des pollutions ponctuelles localisées. D’autre part, nos travaux montrent une influence de l’habitat agricole sur la morphologie du crapaud commun, potentiellement causé par la présence de contaminants dans ces milieux. Enfin, nous avons pu mettre en évidence un effet de concentrations faibles d’AMPA, métabolite principal du glyphosate, sur le développement de têtards de crapaud commun. Les amphibiens constituent donc des organismes efficaces pour étudier l’impact de la contamination de l’environnement sur les caractéristiques individuelles. Nos travaux montrent ainsi l’utilité de certaines espèces de reptiles et d’amphibiens comme espèces sentinelles de la présence de contaminants dans l’environnement et de leur impact potentiel sur les organismes. Les travaux en écotoxicologie qui portent sur ces organismes restent trop rares, et il est impératif de développer la recherche dans ce domaine, pour participer de manière efficace à l’évaluation du risque environnemental. / The development of industrial and agricultural activities over the last century has resulted in the release of chemicals into the environment, which contaminate ecosystems and can accumulate in plants, sediments and across food webs. As such, it is essential to conduct an assessment of the ecological risk associated with the presence of these compounds in natural environments. Achieving this can be aided through the study of sentinel species, which can be used to determine exposure rates of individuals and assess how these subsequently impact wildlife. Amphibians and reptiles display ecological and biological characteristics that may make them particularly attractive as sentinel species. The collection of studies presented in this thesis aims to determine the availability of contaminants in the environment and estimate the effects of this on individual traits of living organisms. Across several species of reptiles and amphibians we, (i) measured levels of pollutants accumulated in the tissues of several reptile species ; (ii) assessed how contaminated habitats impact the morphology of adult common toads (Bufo bufo) ; and (iii) experimentally measured the influence of a molecule frequently detected in the environment on common toad tadpoles’ growth. Results show that reptiles efficiently accumulate organic pollutants and metal trace elements in their tissues, and thereby allow efficient evaluation of the global contamination of an area, as well as the occurrence of localized pollution events. In addition, our work shows an influence of the agricultural habitat on the morphology of adult common toads, which is potentially a consequence of the presence of chemicals in these environments. Finally, we were able to demonstrate an effect of low concentrations of AMPA, the main metabolite of glyphosate, on the development of common toad tadpoles. Amphibians are therefore efficient organisms to study the impact of environmental contamination on individual characteristics. Our work shows the usefulness of certain species of reptiles and amphibians as sentinel species for the presence of contaminants in the environment, and their potential impact on organisms. Ecotoxicological studies on these organisms remain too scarce, and it is imperative to develop research in this field, to participate effectively in the assessment of environmental risk.

Made available in DSpace on 2015-04-22T22:12:46Z (GMT). No. of bitstreams: 1 Jorge Harison Pereira do Nascimento.pdf: 1189534 bytes, checksum: e214c92e030c7e0e83ea285f34b21efb (MD5) Previous issue date: 2011-03-30 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aimed to verify through exposure to short-and long-term, direct and indirect effects of contaminated water from streams Mindu and Quarenta on anuran larvae, hylid Osteocephalus taurinus. Two experiments were conducted over 96 hours of exposure to a gradient of increasing concentrations, we assessed the acute effects of contamination on eggs and larvae in stage 25 larvae free natantia and without the presence of external gills. There was no mortality and no apparent anomalies in the short term for both streams for both stages of egg, as for the larvae. To assess the effects of chronic exposure, larvae were used in stage 25 of Gosn er, where they were exposed to contaminated water until they reach metamorphosis in an experiment using a one-factor control and two treatment using 100% of the concentration of water in their streams. The nitrogen compounds [ammonium (NH ), nitrite (NO ) and nitrate (NO )] produced in the course of the 4+ 2- 3 experiments were always in a higher concentration for the affluent of Mindu in relation to the Quarenta, while the concentrations o f pH , dissolved oxygen and temperature have remained always close between treatments and also taking all individuals received the same feed in two streams of water treatments, a significant difference in the length of larvae, size of metamorphosis and growth rate compared to control. The period of the larvae in Stream Mindu was lower, with the size and growth rate higher than in the control. In the Stream Quarenta, the situation is reversed, there was a period of larvae increased with the size at metamorphosis and growth rate lower than in control. The effects produced by chronic exposure to contaminated water streams are indications that the continuous contamination of streams and / or urban streams can upset the population dynamics of amphibians, carrying, other ecological changes. These results demonstrate possible consequences of contamination by urban sewage on larval amphibian communities of streams and pools of forest land. / Este trabalho teve como objetivo verificar através de exposições a curto e longo prazo, os efeitos diretos e indiretos das águas contaminadas dos Igarapés do Mindu e do Quarenta sobre larvas do anuro, hilídeo Osteocephalus taurinus. Para tanto, foram realizados dois experimentos através de exposições de 96hs a um gradiente crescente de concentrações, se avaliou os efeitos agudos da contaminação, sobre ovos e larvas em estágio 25 larva livre, natante e sem a presença de brânquias externas. Não foi verificada mortalidade e nem anomalias aparentes em curto prazo para ambos os igarapés tanto para os estágios de ovo, como para o de larva. Para avaliação dos efeitos crônicos da exposição, foram utilizadas larvas em estágio 25 de Gosner, onde estas foram expostas às águas contaminadas até alcançarem a metamorfose em um experimento unifatorial utilizando um tratamento Controle e dois outros utilizando 100% da concentração da água dos respectivos igarapés. Os compostos nitrogenados [Amônio (NH ), Nitrito (NO ) e Nitrato (NO )] verificados ao + - 4 2 3 longo dos experimentos mostraram-se sempre em maior concentração para o Igarapé do Mindu em relação ao do Quarenta e, apesar de as concentrações de pH, oxigênio dissolvido e temperatura terem se mantido sempre próximas entre os tratamentos e tendo ainda todos os indivíduos recebido a mesma alimentação, nos dois tratamentos com água dos igarapés, houve diferença significativa na duração do período larvário, no tamanho da metamorfose bem como na taxa de crescimento em relação ao Controle. O período larvário no Igarapé do Mindu foi menor, com o tamanho e a taxa de crescimento maiores em relação ao Controle. Já no Igarapé do Quarenta, a situação se inverteu, foi observado um período larvário maior, com o tamanho na metamorfose e a taxa de crescimento menores que no Controle. Os efeitos crônicos produzidos por exposição à água de igarapés contaminados são indícios de que a contaminação contínua dos igarapés e/ou córregos urbanos pode desequilibrar a dinâmica populacional de anfíbios, trazendo consigo, outras alterações ecológicas. Estes resultados demonstram possíveis conseqüências da contaminação por efluentes urbanos sobre comunidades larvárias de anfíbios de igarapés e poças de floresta de terra firme.

Submitted by Jaqueline Silva (jtas29@gmail.com) on 2014-09-04T21:36:39Z No. of bitstreams: 2 Luciano Signorelli Faria Lima.pdf: 6489666 bytes, checksum: ffffa86e79bc4373bbb31a31eac21136 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-09-04T21:36:39Z (GMT). No. of bitstreams: 2 Luciano Signorelli Faria Lima.pdf: 6489666 bytes, checksum: ffffa86e79bc4373bbb31a31eac21136 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-07-28 / Land use activities have been frequently transforming broad native areas into pastures or plantations. This process turned out to be a global problem and is known as one major responsible for declinesin various taxonomical groups. Frogs are one of the most threated groups among vertebrates, from which species with aquatic larvae are more susceptible. Such populations follow metacommunity dynamics and can be structured in function of combined processes, such as patch dynamics, species ordination dynamics, mass effect and neutral dynamics. Nevertheless, the lack of knowledge with respect to anuran species occupation and richness patterns in local and regional scale poses as a threat to their conservation. The aim of my work is to provide relevant information to the conservation of anurans in the Brazilian Cerrado. I investigated regional and local scale patterns and identified factors related to richness and occupation of anuran species that breed in Cerrado ponds. For that, I have collected data in the state of Goiás, which is the only Brazilian state totally inserted in the Cerrado biome and that follows that same tendency of habitat loss as the whole biome (due to agriculture expansion). In Chapter I present the first official list for the whole state of Goiás, with the objective to cover inventory gaps. In Chapter II, I explore local and landscape factors that determine local and regional diversities of anurans. I also assess the effects of area, heterogeneity, productivity and local and landscape habitat complexity over alpha and beta diversities of anurans. In Chapter III, I approach one of the most classic and controversial models for the conservation of the species, known as "SLOSS" (single large or several small). This model should be considered especially when the goal is to preserve as many frog species associated with ponds.Finally, in Chapter IV, I built occupation models to assess the effects of amount of remaining habitats, isolation between remnants as well as local characteristics on the occurrence of some species of amphibians typical Brazilian Cerrado. / As atividades de uso da terra têm transformado grandes áreas naturais em áreas de pastagens ou agricultáveis. Este processo se tornou um problema mundial e é tido como um dos principais responsáveis pelo declínio de espécies de diferentes grupos taxonômicos. Dentre os vertebrados, os anfíbios são um dos grupos mais ameaçados, sendo que as espécies com larvas aquáticas são as mais susceptíveis. Tais populações seguem uma dinâmica de metacomunidades e podem estruturar-se de acordo com uma combinação de processos, conhecidos como dinâmica de manchas, dinâmica de ordenação de espécies, efeito de massa e dinâmica neutra. No entanto, a escassez de informações a respeito do padrão de riqueza e ocupação das espécies de anuros em escala local e regional é um problema para a conservação da diversidade dos mesmos. Tendo como principal objetivo fornecer informações relevantes para a conservação de anuros no Cerrado brasileiro, abordei questões relacionadas aos padrões em escala local e regional, bem como modelos de ocupação de algumas espécies de anfíbios com o intuito de identificar fatores que estão direcionando a riqueza e ocupação das espécies de anuros que se reproduzem em poças no Cerrado. Para isso, coletei dados no estado de Goiás, único estado brasileiro totalmente inserido no bioma Cerrado, e que segue a mesma tendência do restante do bioma em relação a perda de habitat devido ao avanço das fronteiras agrícolas. Com o intuito de cobrir lacunas de inventários para a região, no Capítulo I apresento a primeira lista oficial de espécies de anuros para o estado de Goiás. No Capítulo II, abordo como fatores locais e da paisagem determinam a diversidade local e regional de anuros. Busquei explorar os efeitos da área, heterogeneidade e complexidade de hábitats local e da paisagem e da produtividade sobre a diversidade alfa e beta de anuros. No Capítulo III¸ abordo um dos modelos mais clássicos e controversos para conservação das espécies, que é conhecido como: “muitas pequenas ou uma única grande” ou “SLOSS” (single large or several small). Este modelo deve ser especialmente considerado quando o objetivo é preservar o maior número de espécies de anuros associados a poças. E, por fim, no Capítulo IV, construí modelos de ocupação para ter acesso aos efeitos da quantidade de remanescentes de habitas, isolamento entre remanescentes de Cerrado, bem como características locais sobre a ocorrência de algumas espécies de anfíbios típicas do Cerrado Brasileiro.

Submitted by PPG Zoologia (zoologia-pg@pucrs.br) on 2018-09-13T17:02:53Z No. of bitstreams: 1 Disserta??o - Escalona - Mois?s.pdf: 3628906 bytes, checksum: a6fc5f6bc6015a1a1a95f67e3c5c5f16 (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-09-14T17:19:08Z (GMT) No. of bitstreams: 1 Disserta??o - Escalona - Mois?s.pdf: 3628906 bytes, checksum: a6fc5f6bc6015a1a1a95f67e3c5c5f16 (MD5) / Made available in DSpace on 2018-09-14T17:46:57Z (GMT). No. of bitstreams: 1 Disserta??o - Escalona - Mois?s.pdf: 3628906 bytes, checksum: a6fc5f6bc6015a1a1a95f67e3c5c5f16 (MD5) Previous issue date: 2018-03-28 / Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Os anuros emitem cantos de an?ncio com o objetivo de atrair parceiros e repelir concorrentes co-espec?ficos. Eu investiguei a associa??o entre o comprimento do corpo, o s?tio de vocaliza??o, o cuidado parental e a varia??o em propriedades ac?sticas do canto (dura??o do canto, n?mero de notas, freq??ncia de pico, largura de banda de freq??ncia e estrutura do canto) em pererecasde-vidro?uma fam?lia de pererecas que habitam florestas neotropicais?controlando para efeitos de ancestralidade compartilhada. Eu tamb?m explorei o tempo e o modo de evolu??o dessas caracter?sticas e as comparei com as de tr?s caracter?sticas morfol?gicas (comprimento do corpo, largura da cabe?a e comprimento da t?bia). Eu gerei e compilei dados ac?sticos para 72 esp?cies de pererecas-de-vidro (46 % da riqueza descrita), incluindo representantes de todos os g?neros, e analisei os dados usando m?todos comparativos filogen?ticos. Descobri que quase todas as caracter?sticas ac?sticas avaliadas tinham sinal filogen?tico significativo, mas geralmente modesto. O pico de frequ?ncia dos cantos ? significativamente associado ao comprimento do corpo, enquanto a estrutura dos cantos ? significativamente associada ao s?tio de vocaliza??o e ao sexo do adulto que desempenha cuidado-parental. Meus resultados sustentam que, al?m das restri??es filogen?ticas, o tamanho do corpo est? associado ? evolu??o dos cantos de an?ncio em Centrolenidae. A diversifica??o de caracter?sticas ac?sticas ao longo da filogenia de pererecas-de-vidro concorda com a radia??o dos taxa na transi??o entre Mioceno e Plioceno. A disparidade estimada para caracter?sticas ac?sticas foi geralmente maior que a de caracter?sticas morfol?gicas, e o pico de disparidade de caracter?sticas ac?sticas geralmente ocorreu mais tarde na evolu??o do grupo, sugerindo um in?cio historicamente recente da pronunciada diverg?ncia ac?stica entre esp?cies deste clado. / Anurans emit advertisement calls with the purpose of attracting mates and repelling conspecific competitors. I investigated the association between body size, calling site and parental care with call variables (call duration, number of notes, peak frequency, frequency bandwidth and call structure) in glassfrogs?a family of leaf-dwelling frogs which inhabit Neotropical forests?while controlling for effects of shared ancestry. I also explored the tempo and mode of evolution of these traits and compared them with those of three morphological traits (snout-vent length, and relative head width and tibia length). I generated and compiled acoustic data for 72 glassfrog species (46 % of described diversity), including representatives of all genera (n = 12), and analyzed the data using phylogenetic comparative methods. I found that almost all acoustic traits evaluated had significant, but generally modest phylogenetic signal. Peak frequency of calls is significantly associated with body-size, while call structure is significantly associated with calling site and with the sex of the caring parent. My results support that, besides phylogenetic constraints, body size is associated with the evolution of advertisement calls in glassfrogs. Diversification of acoustic traits along the phylogeny of glassfrogs is coincident with the radiation of extant taxa at the Miocene-Pliocene boundary. The estimated disparity of acoustic traits was larger than that of morphological traits and the peak in disparity of acoustic traits generally occurred later in the evolution of glassfrogs, suggesting a historically recent outset of the pronounced acoustic divergence in this clade.

This study used an in situ heart preparation to analyze the power and work of spontaneously beating hearts of four anurans (R. marina, L. catesbeianus, X. laevis, P. edulis) and three urodeles (N. maculosus, A. tigrinum, A. tridactylum) in order to elucidate the meaning of relative ventricle mass (RVM) in terms of specific cardiac performance variables. This study also tests two hypotheses: 1) the ventricles of terrestrial species (R. marina, P. edulis, A. tigrinum) of amphibians are capable of greater maximum power outputs (Pmax) compared to aquatic species (X. laevis, A. tridactylum, N. maculosus, L. catesbeianus) and, 2) the ventricles of Anuran species (R. marina, P. edulis, L. catesbeianus, X. laevis) are capable of greater maximum power output compared to aquatic species (A. tigrinum, A. tridactylum, N. maculosus). The data supported both hypotheses. RVM was significantly correlated with Pmax, stroke volume, cardiac output, afterload at Pmax, and preload at Pmax. Preload at Pmax and afterload at Pmax also correlated very closely with each other, suggesting that an increase blood volume and/or increased modulation of sympathetic tone may influence interspecific variation RVM and may have played a role in supporting higher rates of metabolism, as well as dealing with hypovolemic stresses of life on land.

The decline of the Oregon Spotted Frog (Rana pretiosa), a Pacific Northwest endemic now federally listed as threatened, has been attributed to several aspects of ecosystem alteration, primarily habitat degradation and loss. The introduced American Bullfrog (Rana (Aquarana) catesbeiana) has been widely implicated in those declines, but the basis of that contention has been difficult to characterize. The bullfrog occurring at every site of recent Oregon Spotted Frog extirpation has focused concern about its impact. Here, I present a suite of interconnected studies that examine the behavioral ecology of both species to better understand the potential for bullfrog-mediated Oregon Spotted Frog extirpation. I quantified Oregon Spotted Frog anti-predator behavior from the only known population successfully co-occurring with bullfrogs (Conboy Lake) and a population devoid of bullfrog impact (Big Marsh), and compared these behaviors to the predatory traits of the bullfrog. The initial study revealed that captive-reared individuals from the Oregon Spotted Frog population that has successfully co-occurred with bullfrogs respond faster to a predatory stimulus (measured as latency to response) than Oregon Spotted Frogs from a population not to exposed to bullfrogs. Subsequent field investigations of the approach distance allowed by a predator stimulus before taking evasive action (termed the flight initiation distance: FID) conducted with the Oregon Spotted Frog population co-occurring with bullfrogs first demonstrated that FID of recently metamorphosed bullfrogs is consistently greater than that of recently metamorphosed Oregon Spotted Frogs. Further, examination of FID across all post-metamorphic age classes of Oregon Spotted Frogs revealed that older frogs do not allow as close approach as recently metamorphosed Oregon Spotted Frogs. This age class shift in FID did not occur in the Oregon Spotted Frog population not exposed to bullfrogs. In the latter population, FID did not differ among age classes. Since the bullfrog might be driving this age-based change in anti-predator behavior, I explored the variation in strike distance of bullfrogs from the site of co-occurrence in both the field and laboratory to determine the extent of overlap with Oregon Spotted Frog FID. I found that the bullfrog strike distance significantly overlaps the FID of all ages of Oregon Spotted Frogs from the bullfrog-free site but only that of youngest (recently metamorphosed) frogs at the site of co-occurrence. Older Oregon Spotted Frogs from the site of co-occurrence generally escaped at distances greater than the strike distance of bullfrogs. I also collected > 880 bullfrogs from the site of co-occurrence and analyzed the stomach contents to assess their dietary trends. I found that bullfrogs consume Oregon Spotted Frogs at the site, but do not eat the larger (older) frogs. Moreover, the body size ratio between Oregon Spotted Frogs as prey and bullfrogs as predators suggests that nearly all of the adult size distribution of bullfrogs at Conboy would be incapable of preying on adult Oregon Spotted Frogs. Collectively, these studies strongly suggest that bullfrogs have altered the escape behavior of Oregon Spotted Frogs at Conboy Lake and that most adult Oregon Spotted Frogs at Conboy may have a size-based release from predation by bullfrogs. Implicit in this finding is that bullfrogs may pose a real threat via predation to other Oregon Spotted Frog populations with which they might come into contact where the distribution of bullfrog body sizes differ substantially from that at Conboy Lake.

ABSTRACT One cause of declines and extinctions of island species is carnivore introduction. Four carnivores, including the small Indian mongoose (Herpestes auropunctatus), are on the IUCN’s list of 100 of the World's Worst Invasive Alien Species. My thesis summarizes global patterns of carnivore introductions and examines ecological, evolutionary, and management impacts of this mongoose. I study abundances of reptiles and amphibians on mongoose-infested and mongoose-free islands in the Adriatic Sea to determine if factors other than mongoose presence can account for abundance differences. For several reptiles and amphibians, the mongoose is implicated as causing differences. Additionally, I assess species abundance in the small mammal community and activity times of introduced ship rats (Rattus rattus) on the same islands. The mongoose is implicated in a shift in rat activity times, but it is difficult to separate mongoose impacts on small mammal abundance from rat impacts. To manage introduced carnivores, we can exclude, control, or eradicate them. I review literature data on mongoose eradication and control campaigns. I compiled a list of all islands with known mongoose populations and focused on assessing successes, failures, and challenges. The mongoose has been eradicated only on six very small islands. Management at low levels by various techniques has been attempted on many islands, with variable success. On almost all islands of introduction, the mongoose has no potential competitors of similar size. However, on three Adriatic islands where the mongoose was introduced, a similar-sized native carnivore, the stone marten (Martes foina), is present, while on one Adriatic island the small Indian mongoose is the sole carnivore. To see if character displacement occurs in the mongoose when the marten is present, and vice-versa, I examined size variation in the diameter of the upper canine tooth (the prey-killing organ) and skull length in these two species on these islands. Character displacement in both traits was evident for the mongoose but not the marten. Lastly, I developed a simulation model to examine genetic consequences of serial introductions of the small Indian mongoose and found that the potential for population genetic data to determine introduction pathways and sequences is limited.

The aims of this thesis were to evaluate the effects of agriculture on amphibians in terms of (i) population genetic consequences of agriculture-induced spatial changes of the landscape and (ii) local adaptation and tolerance to frequently used agrochemicals. The study was performed using the common frog Rana temporaria as a model. Abundance, occurrence, genetic diversity and gene flow were negatively affected by agriculture in southern Sweden, but unaffected or even positively affected by agriculture in the central and northern regions, respectively. These test parameters correlated positively with landscape diversity both in the south and in the north. Moreover, the size and occurrence of R. temporaria populations decreased towards the north i.e. the margin of the species’ distribution range. In accordance with theoretical expectations, genetic variability decreased and population substructuring increased as a negative function of (effective) population size. Southern Swedish common frogs are naturally exposed to higher levels of nitrates, and thus have a higher tolerance to high nitrate levels than their northern conspecifics. This suggests local adaptation to naturally varying nitrate levels. Consequently, increased anthropogenic supplementation of nitrate could impact more the northern than the southern Swedish common frog populations. Exposure to the pesticides azoxystrobin, cyanazine and permethrin at ecologically relevant concentrations had small or no effects on R. temporaria tadpoles. The populations with lowest microsatellite variation (fragmented populations) in southern Sweden had considerably lower fitness in terms of survival and growth as compared to those with the highest genetic variability (non-fragmented populations). The results indicate that populations with low levels of neutral genetic variability were phenotypically less differentiated than populations with higher levels of variability. One possible explanation for this is that the degree of population differentiation in low variability populations has been constrained due to lack of suitable genetic variation or inefficiency of selection relative to genetic drift.

Cost and benefits of high individual growth rates are likely to vary across different environments leading to geographic differentiation in growth strategies. In ectotherms, habitats constrained by short growing seasons favour rapid growth and development leading to adaptive latitudinal clines in these traits. Geographic variation in growth strategies should be influenced by physiological variation as well as environmental factors, however many of these mechanisms remain largely unexplored. In my thesis, I studied hormonal correlates of growth strategies, and compensatory responses to phenological variation and environmental stress in anuran tadpoles. I tested the hypotheses that fast growing high latitude common frog Rana temporaria tadpoles have higher growth hormone (GH) expression, and low stress hormone (CORT) elevation in response to predator stress. I found no relationship between GH expression and latitude, but CORT response decreased with latitude after 24 hours of predator exposure. Lower CORT response at high latitude can be adaptive as it may enable the tadpoles to maintain high growth in time constrained habitats. I also found that breeding phenology affected latitudinal variation in growth, development and anti-predator strategies. Northern R. temporaria tadpoles were phenotypically more similar to southern tadpoles when breeding occurred early, suggesting that part of the latitudinal variation is plastic and affected by yearly variation in phenology. When time stress was manipulated by delaying hatching, tadpoles were able to compensate by increasing their development and growth during the larval stage, decreasing the cost of the delayed development. In the final study, I found that northern tadpoles showed stronger compensatory growth during the larval stage than southern tadpoles after being delayed by low food, however, temperature manipulation did not induce differences in the compensatory responses. In general, my results highlight the roles of both environmental and genetic variation in determining individual growth strategies. / Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 735

Mountaintop removal mining and valley filling (MTR/VF) is a common form of land conversion in Central Appalachia and threatens the integrity of stream ecosystems. We investigated the effects of MTR/VF on stream salamander occupancy probabilities and community structure by conducting area constrained active searches for stream salamanders within intermittent streams located in mature forest (i.e., control) and those impacted by MTR/VF. During March to June of 2013, we detected five stream salamander species (Desmognathus fuscus, D. monticol, Eurycea cirrigera, Pseudotriton ruber, and Gyrinophilus porphyriticus) and found that the probability of occupancy was greatly reduced in MTR/VF streams compared to control streams. Additionally, the salamander community was greatly reduced in MTR/VF streams; the mean species richness estimate for MTR/VF streams was 2.09 (± 1.30 SD), whereas richness was 4.83 (± 0.58 SD) for control streams. Numerous mechanisms may be responsible for decreased occupancy and diminished salamander communities at MTR/VF streams, although water chemistry of streams may be a particularly important mechanism. Indeed, we detected elevated levels of specific conductivity, pH, total organic carbon, and dissolved ions in MTR/VF streams. Our results indicate that salamander communities, with other invertebrates, fish, and other aquatic and/or semi-aquatic animals, are susceptible to MTR/VF mining practices.