O Colículo Superior (SC) é conhecido por apresentar diversas funções que modulam a caça predatória. Neste estudo, investigamos as funções do SC em ratos expostos a caça de insetos. Primeiramente, verificamos que o comportamento predatório induz uma distinta ativação da porção lateral do SC (SCl). Para entender as potenciais funções dessa região colicular, foi analisado o comportamento predatório antes e após lesões bilaterais iontoforéticas por NMDA do SCl. Animais com SCl lesados ficaram menos motivados a perseguirem as baratas, falharam para se orientarem na direção do movimento das presas e quando tentaram capturar as presas, eles apresentaram sérios déficits para capturá-las e segurá-las eficientemente. Por outro lado, animais com lesões da porção medial do SC (SCm) apresentaram apenas um aumento da latência para iniciar a caça, enquanto os outros parâmetros não diferiram significantemente dos animais intactos. Posteriormente, examinamos as conexões eferentes do SCl e do SCm usando como traçador anterógrado a leucoaglutinina do Phaseolus vulgaris. Notamos projeções densas do SCl para a região rostral da coluna lateral da matéria cinzenta periaquedutal (PAGl), um setor criticamente envolvido no controle dos aspectos motivacionais relacionados aos comportamentos de caça predatória e forrageamento. Além disso, o SCl se projeta densamente para o tálamo dorsal, especificamente para os núcleos ventral lateral, central medial e paracentral do tálamo, os quais sabemos que se projetam para setores estriatais ou para áreas motoras corticais, que provavelmente estão envolvidas no ajuste da ação motora durante a captura das presas. O SCm, por sua vez, aferenta densamente a coluna dorsolateral da PAG, núcleo cuneiforme, e núcleos reticulares mesencefálico e pontino, que são setores envolvidos na elaboração de respostas defensivas, além disso, o SCm se projeta esparsamente para os núcleos posterior lateral e suprageniculado do complexo geniculado medial / The superior colliculus is classically known to present a number of functions that fit hunting behavior. In the present study, we investigate the potential roles of the superior colliculus in rats displaying insect hunting. First, we have found that predatory hunting induces a distinct activation of the lateral region of the intermediate layer of the superior colliculus (SCl). To understand the potential roles of this collicular region, we analyzed the hunting performance before and after iontophoretic NMDA lesions bilaterally placed into the SCl. Animals with SCl lesions were clearly less motivated to pursue the roaches, failed to orient themselves toward the moving prey, and whenever the SCl-lesioned rats tried to catch the roaches, they presented serious deficits to capture and hold them efficiently. Next, we examined the SCl efferents connections using Phaseolus vulgaris leucoagglutinin as an anterograde tracer. Of particular relevance, we noted that the SCl projects to the rostral lateral periaqueductal gray, a site critically involved in controlling motivational drive to chase prey and forage. In addition, the SCl also present particularly strong projections to the dorsal thalamus, aimed at the ventral lateral, ventral medial, central medial and paracentral nuclei of thalamus, all of which known to project either to striatal sites or to cortical motor areas, likely to be involved in adjusting the motor action during prey capture. Therefore, the SCl, which seems to present cells responding to prey displacement in the temporal field, presents important arms to the periaqueductal gray and dorsal thalamic sites, influencing, respectively, the motivational drive and the motor skills to hunt

Ácaros fitoseídeos são eficientes predadores de ácaros pragas em algumas culturas. A precisa identificação das espécies é o passo inicial na seleção de inimigos naturais em um projeto de controle biológico. Os ácaros são geralmente identificados com base nas características morfológicas, mas aspectos biológicos e ecológicos, e mais recentemente características moleculares vêm sendo usadas nesse processo. Populações dos fitoseídeos identificados como Euseius citrifolius Denmark & Muma provenientes de Arroio do Meio-RS, Campinas-SP e Petrolina-PE, e Euseius concordis (Chant) procedentes de Arroio do Meio, Jaguariúna-SP, Petrolina, Pontes e Lacerda-MT e Viçosa-MG foram estudados em relação a morfologia, compatibilidade reprodutiva e características moleculares. A caracterização morfológica correspondeu as medições de estruturas de fêmeas e machos. A compatibilidade reprodutiva foi avaliada através de cruzamentos e retrocruzamentos homogâmicos e heterogâmicos. A caracterização molecular foi realizada com o seqüenciamento dos espaços internos transcritos (ITS1 e ITS2) do DNA ribossomal. Relações significativas foram observadas dentro de cada população entre o comprimento médio das setas e as respectivas amplitudes de variação. Ambos os sexos de E. citrifolius de Petrolina e E.concordis de Jaguariúna tiveram algumas setas mais curtas que as demais populações da mesma espécie; esta última diferiu marcadamente da população de Petrolina. A comparação das medições das estruturas de cada população e dos espécimes tipo de E. citrifolius e E. concordis confirmaram a identificação morfológica preliminar das populações ao nível de espécie. Medições de machos resultantes de cruzamentos heterogâmicos indicaram que essas espécies se reproduzem por pseudo-arrenotoquia. Incompatibilidade parcial foi observada nos cruzamentos heterogâmicos envolvendo fêmeas de E. citrifolius de Petrolina; descendentes produziram poucos ovos e inviáveis quando retrocruzadas com machos das populações parentais. Machos de Petrolina produziram descendentes viáveis quando cruzados com fêmeas de Arroio do Meio e Campinas. Não ocorreu oviposição nos cruzamentos e retrocruzamentos heterogâmicos envolvendo fêmeas de E. concordis de Petrolina. Nos cruzamentos heterogâmicos envolvendo machos de Petrolina a oviposição foi reduzida e somente machos (viáveis) foram produzidos. Cruzamentos de fêmeas de Pontes e Lacerda e machos de Jaguariúna e vice-versa produziram somente machos. Entretanto o fluxo gênico entre essas populações seria possível indiretamente, através de cruzamentos entre essas populações e a população de Arroio do Meio. Populações de Arroio do Meio, Jaguariúna, Pontes e Lacerda e Viçosa pertencem a mesma espécie. Maior variação entre as populações foi observada no espaçador ITS1. O seqüenciamento dos espaçadores ITS1 e ITS2 permitiu discriminar entre os grupos de populações identificadas como E. citrifolius de E. concordis. O seqüenciamento dos ITSs pode ser aplicado como uma ferramenta complementar na identificação de fitoseídeos. Apesar do fato de que alguns tipos de diferenças foram sempre observadas nesta tese entre a população de Petrolina identificada preliminarmente como E. concordis, não é conveniente descrever esta população como uma nova espécie, devido a dificuldade em separar indivíduos dessa população daqueles das populações identificadas como E.concordis. Para uma conclusão, é sugerido que outros estudos de cruzamentos sejam conduzidos com populações morfologicamente identificadas como E. concordis coletadas entre Petrolina e Viçosa, e que a caracterização molecular envolvendo o gene citocromo oxidase seja conduzida. / Phytoseiidae mites are efficient predators of pest mites on several crops. Precise identification is the initial step in the selection of natural enemies in a biological control project. Mites are usually identified by their morphology, but biological and ecological aspects and, more recently, molecular characteristics have also been used in this process. Populations of phytoseiid mites identified as Euseius citrifolius Denmark & Muma from Arroio do Meio-RS, Campinas-SP and Petrolina-PE, and E. concordis (Chant) from Arroio do Meio, Jaguariúna-SP, Petrolina Pontes e Lacerda-MT and Viçosa-MG were studied in relation to morphology, reproductive compatibility and molecular characteristics. Morphological characterization corresponded to measurements of structures of females and males. Reproductive compatibility was evaluated by homogamic and heterogamic crosses and backcrosses. Molecular characterization was done by sequencing the internal transcribed spacers of the ribosomal DNA (ITS1 and ITS2). Significant relationships were observed within each population between mean setal lengths and the respective ranges. Both sexes of E. citrifolius from Petrolina and E. concordis from Jaguariúna had some setae shorter than other populations of the same species; the latter differed most markedly from the Petrolina population. A comparison of the measurements of structures for each population and type specimens of E. citrifolius and E. concordis confirmed the preliminary morphological identification of the populations at species level. Measurements of males resulting from heterogamic crosses indicated that both species reproduce by pseudo-arrhenotoky. Partial incompatibility was observed in heterogamic crosses involving females of E. citrifolius from Petrolina; progeny produced just few, unviable eggs when backcrossed with males of the parental populations. Males from Petrolina produced viable offspring when crossed with females from Arroio do Meio or Campinas. No eggs were produced in heterogamic crosses and backcrosses involving females of E. concordis from Petrolina. In heterogamic crosses involving males from Petrolina, oviposition was reduced and only (viable) males were produced. Crosses of females from Pontes e Lacerda and males from Jaguariúna and vice-versa produced only male progeny. However, gene flow between those population could be possible indirectly, through crosses between those populations and Arroio do Meio population. Populations from Arroio do Meio, Jaguariúna, Pontes e Lacerda and Viçosa belong to a same species. Most of the molecular variation between populations was observed in ITS1. The sequencing of ITS1 and ITS2 allowed the discrimination between the group of populations identified as E. citrifolius from that identified as E. concordis. With the information presently available, sequencing of ITSs can be applied as a complementary tool to identify phytoseiids. Despite the fact that some type of differences were always observed in this thesis between the Petrolina population preliminarily identified as E. concordis and the remaining populations, it is not convenient to describe such population as a new species presently, given the difficulty in separating individuals from that population from those of populations identified as E. concordis. For a conclusion, it is suggested that other crossing studies be conducted with populations morphologically identifiable as E. concordis collected between Petrolina and Viçosa, and that the characterization of the cytochrome oxidase gene be conducted.

Agentes econômicos com posição dominante são capazes de se conduzir de maneira independente na sua atividade comercial. Da mesma forma, possuem todos os incentivos para manutenção desta posição, em detrimento de seus concorrentes, fornecedores e clientes. O presente trabalho visa, inicialmente, em estudo comparado da doutrina e jurisprudência no Brasil, União Europeia e Estados Unidos, identificar os elementos de cognição da teoria do abuso de posição dominante para cinco modalidades de conduta. A partir daí traçamos seus elementos de correlação com o propósito de sugerir uma teoria aplicada ao ordenamento jurídico pátrio, que passa pelo reconhecimento da concorrência como garantia institucional, de forma a estabelecer-se igualdade material segundo a teoria da função social dos meios de produção. A presença constante da concorrência nos mercados deve ser tratada como presunção de bem-estar social. E finalmente, valendo-se destes elementos de suporte, propomos uma teoria da responsabilidade especial para agentes econômicos em posição dominante, que implicaria o dever de autoaplicação dos limites permitidos para sua conduta comercial, cujo descumprimento ensejaria presunção relativa de efeitos deletérios ao mercado, segundo os parâmetros propostos. / Firms enjoying dominant position are able to conduct themselves independently in their commercial activities. Likewise, they hold all due incentives to maintain such position, in detriment of their competitors, suppliers and clients. The present work aims, initially, through a comparative study of the Brazilian, the European Union and the United States\' legal doctrine and jurisprudence, to identify cognitive elements of the abuse of dominance theory, for five different natures of conducts. Subsequently, we identify their elements of connection with the purpose of suggesting a theory applicable to the local legal system, which includes the recognition of competition as an institutional guarantee, so to establish a material equality according to the theory of social function of productive assets. The constant presence of competition on the markets shall be treated as a presumption of social welfare. And finally, based on such supportive elements, we propose a theory of special responsibility for dominant firms that implies in a duty of self-application of the permitted limits for their commercial conduct, and which infringement would entail a relative presumption of harmful effects to the market, pursuant to the proposed parameters.

Este estudio constituye una importante fuente de información sobre el potencial de los sírfidos depredadores (Diptera: Syrphidae, Syrphinae) como agentes biológicos para el control de plagas en cultivos agrícolas en Venezuela. Las larvas de los Syrphidae presentan una morfología muy variada y poseen una gran diversidad de modos de vida. La mayor parte de los representantes de la subfamilia Syrphinae, son depredadores de una amplia gama de hemípteros de cuerpo blando aunque también pueden alimentarse de otros artrópodos. Las principales presas de los sírfidos depredadores son los áfidos o pulgones (Aphididae), escamas (Coccoidea), aleuródidos (Aleyrodidae) y trips (Thripidae). Para la realización de la presente Tesis doctoral se realizó un muestreo en los principales cultivos del estado Lara y se revisó la colección del Museo de Entomología José M. Osorio (MJMO = UCOB, según el Biodiversity Collections Index) de la Universidad Centroccidental "Lisandro Alvarado". También se revisaron ejemplares de la colección del Museo del Instituto de Zoología Agrícola (MIZA) de la Universidad Central de Venezuela. Entre los resultados de la tesis, se presenta una base de datos con los sírfidos depredadores estudiados con un total de 2571 ejemplares agrupados en 11 géneros y 59 especies. Del total de especies estudiadas, al menos se identificaron 15 nuevos taxa para la ciencia. Adicionalmente, se realizó un inventario de las presas y plantas asociadas a cada especie de Syrphidae depredador. Se reportaron nuevas especies de presas y plantas asociadas que aumentan de manera significativa el conocimiento de estas relaciones conocidas hasta la fecha en Venezuela. Como ejemplo, para A. exotica, se indican 6 nuevas presas y 23 plantas hospedantes; para P. clavatus se registran 7 nuevas plantas hospedantes. Por último, destacar 26 nuevos registros de presas relacionadas con el género Ocyptamus sobre 33 especies de plantas asociadas, presentando la mayor diversidad de presas de todos los sírfidos estudiados. En función de los resultados obtenidos en el muestreo se procedió al estudio del potencial biológico de Allograpta exotica, Pseudodoros clavatus y Ocyptamus dimidiatus, utilizando como presa al áfido de las leguminosas, Aphis craccivora en condiciones de laboratorio. Los parámetros biológicos de la especie (A. exotica) fueron estudiados en detalle. Las curvas de respuesta funcional de A. exotica se ajustaron mejor y mostraron el valor más alto de R2 para el modelo Polinomial indicando una fuerte correlación entre el aumento de áfidos depredados por A. exotica y las diferentes densidades ofrecidas de A. craccivora. El coeficiente de determinación para el modelo de Holling sugiere que A. exotica responde al Tipo de curva II. De manera complementaria a los estudios anteriores, se procedió al análisis de la morfología preimaginal de los géneros Allograpta, Pseudodoros y Ocyptamus. Además, se estudió la morfología preimaginal de Eosalpingogaster umbra Mengual y Thompson, Salpingogaster nigra Schiner, Leucopodella sp. nov. y xanthandrus bucephalus (wiedemann) aportando las primeras informaciones conocidas sobre su morfología preimaginal y las implicaciones sistemáticas derivadas. Se describen por vez primera el pupario, la larva madura (L-3) y la quetotaxia de O. dimidiatus y O. gastrostactus. También se describen los puparios de Ocyptamus funebris, O. norina, O. phaeopterus O. stenogaster, Ocyptamus lividus, O. tristani y Ocyptamus sp.nov aff. attenuatus. Por último se incluye una clave de identificación diagnóstica de las especies de Ocyptamus cuya morfología preimaginal ha sido analizada en esta memoria. / Consejo de Desarrollo Científico, Humanístico y Tecnológico de la Universidad Centroccidental Lisandro Alvarado (CDCHT-UCLA), financiamiento al proyecto de Tesis Doctoral 003-DAG-2007.

The earwigs (Dermaptera) contains mostly nocturnal insects, which are considered subsocial due to formation of aggregated family groups and maternal care. Species of Dermaptera have been shown to play an important role as generalist predators in different crop systems worldwide. Despite that, the knowledge about their behavior and insect-plant interactions remains poorly understood. The earwig Doru luteipes (Dermaptera: Forficulidae) is one of the most important generalist predators in different crops, especially in maize (Zea mays ssp. mays) by voraciously consuming eggs and larvae of Spodoptera frugiperda (Lepidoptera: Noctuidae) and Diatraea saccharalis (Lepidoptera: Crambidae), key pests in this crop. Maize is one of most produced cereals in the word. However, great losses are registered annually due to pest attacks, despite the use of pesticides. Studies have demonstrated that domesticated plants such as maize have reduced defenses against herbivores in detriment to intensely selecting for rapid growth and high yield, when compared with their wild ancestors\' species known as teosintes (Zea spp.). This thesis focuses on the study of the trophic interactions which occur in the system \'Zea plants - herbivores caterpillars - predator earwig\' and is divided in four chapters. In the Chapter 1 is present a general introduction and the thesis outline. In the Chapter 2, we studied through scent collection and multiple-choice bioassays, the communication between D. luteipes individuals which influences their predatory behavior. Our results indicate that earwigs can produce and use chemical cues by conspecifics to orientate them towards foraging resources. In the Chapter 3, we investigated the predation behavior of earwigs during photo- and scotophase and their preference for maize volatiles induced by S. frugiperda or D. saccharalis at different time intervals (early and old damage). Behavior, olfactometry bioassays and plant volatile collections were conducted. As was hypothesized, earwigs showed a predation activity only during night. Besides that, they were attracted by maize odors produced by both caterpillars and showed significant preference to early-damage odors over old-damage. Therefore, it is considered that early-damage volatiles (Green Leaf Volatiles-GLVs) could be the key compounds of D. luteipes attraction. In the last part (Chapter 4) was explored how domestication of Zea plants influences insect-plants interactions through plant defense. Experiments about food utilization by caterpillars, olfactometry bioassays and plant volatile collections were conducted. Interestingly, as in the previous chapter, we suggest that GLVs have an important role in earwig attraction. The results show that life-history of Zea plants influences plant defense and consequently the plant-insect interactions. In conclusion, our findings bring a new contribution to the knowledge about plant defenses in a tritrophic context and predatory strategies in D. luteipes, which would promote alternatives to optimize the conservation and biological control of pest by predators in the field. / As tesourinhas (Dermaptera) são em sua maioria insetos noturnos considerados sub-sociais devido ao cuidado maternal e à formação de grupos familiares agregados. Espécies de Dermaptera possuem um papel importante como predadores generalistas em diferentes culturas em todo mundo. Apesar disso, o conhecimento sobre seu comportamento e as interações inseto-planta permanecem pouco estudadas. A tesourinha Doru luteipes Scudder (Dermaptera: Forficulidae) é um dos predadores mais frequentes em diferentes culturas, especialmente no milho (Zea mays ssp. mays), devido ao voraz consumo de ovos e lagartas de Spodoptera frugiperda e Diatraea saccharalis, pragas chave nesta cultura. O milho é um dos cereais mais produzidos no mundo, embora grandes perdas sejam registradas anualmente devido ao ataque de pragas, apesar do uso de agroquímicos. Estudos recentes demostraram que plantas domesticadas tais como o milho têm reduzido suas defesas contra os herbívoros em detrimento à intensa seleção de cultivares de rápido crescimento e alta produtividade, quando comparados com seus ancestrais selvagens conhecidos como teosintos (Zea spp.). Esta tese foca no estudo das interações tróficas que ocorrem no sistema \'plantas Zea - lagartas herbívoras - tesourinhas predadoras\' e foi dividida em quatro capítulos. No Capítulo 1, apresenta-se uma introdução geral e o esboço da tese. No Capítulo 2, a partir da coleta de voláteis de adultos de D. luteipes e ensaios de múltipla escolha, foi estudada a comunicação química entre estes indivíduos que influencia o comportamento de predação. No Capítulo 3 foi investigado o comportamento de predação das tesourinhas durante a foto e escotofase, e a preferência delas pelos voláteis do milho induzidos por S. frugiperda ou D. saccharalis, em diferentes intervalos de tempo (dano recente ou dano tardio). As tesourinhas mostraram atividade predatória apenas durante a noite, e foram atraídas pelos odores do milho atacados pelas duas lagartas. O dano recente (voláteis de folhas verdes-VFVs) contêm os compostos chaves para a atração de D. luteipes. No Capítulo 4 foi explorado como a domesticação das plantas Zea influenciam as interações com insetos por meio das defesas de plantas. Assim como no capitulo anterior, os VFVs apresentaram um importante papel na atração das tesourinhas. Os resultados indicaram que a história de vida do gênero Zea influenciou as defesas das plantas e consequentemente, as interações inseto-planta. Em conclusão, o presente trabalho traz novas contribuições ao conhecimento sobre defesas de plantas num contexto tritrófico, bem como às estratégias de predação em D. luteipes, o qual pode gerar ferramentas para otimizar a conservação e controle biológico de pragas por predadores em campo.

Šiame darbe analizuojamas Europos Bendrijos ir Lietuvos Respublikos konkurencijos teisės normų, reglamentuojančių piktnaudžiavimą dominuojančia padėtimi nustatant nesąžiningas kainas, taikymas. Analizuojama nesąžiningų kainų sąvoka, išskiriant pagrindines tokių kainų rūšis – nepagristai didelės kainos, „grobuoniškos” kainos, diskriminacinės kainos bei nesąžiningas nuolaidų taikymas. Darbe aptariama Europos Teisingumo teismo, Europos Komisijos bei Lietuvos Respublikos Konkurencijos Tarybos bei administracinių teismų praktika, nagrinėjant nesąžiningų kainų taikymo bylas ir pateikiamos pagrindinės taisyklės, pagal kurias nesąžiningas kainas galima atskirti nuo sąžiningų, taip pat trečiame šio darbo skyriuje įvardijamos pagrindinės šių taisyklių taikymo praktikoje problemos. Paskutiniame skyriuje apžvelgiama konkurencijos teisės normų, susijusių su nesąžiningomis kainomis, įgyvendinimas Lietuvoje po įstojimo į ES, analizuojama konkurencijos politikos įgyvendinimo efektyvumas, kokybė, pateikiami pagrindiniai sprendimai bei išaiškinimai, nustatant piktnaudžiavim�� dominuojančia padėtimi taikant nesąžiningas kainas. / This thesis was set out to analyse the application of competition law on unfair pricing related to the abuse of dominant positions in the European Community and the Republic of Lithuania. Firstly, the study gives a definition of unfair pricing and identifies four types of such pricing: excessive pricing, “predatory” pricing, discriminatory pricing and unfair discounts and rebates. Then, it overviews the practice of the European Court of Justice, the European Commission and the Competition Council and the administrative courts of the Republic of Lithuania in hearing cases on unfair pricing. The author then lists the fundamental rules that may help to distinguish between fair and unfair pricing. The third chapter indicates the main problems faced when applying these rules in practice. The last chapter gives an overview of the application of competition law on unfair pricing following Lithuania’s accession to the EU. The author also analyses the effectiveness and quality of the implementation of competition policy and presents the fundamental judgements on and interpretations of unfair pricing in relation to the abuse of dominant positions.

Conservation in New Zealand has begun to focus heavily on the restoration of degraded mainland ecosystems and the reintroduction of native species that have become locally extinct. In many cases the individuals that are selected for reintroduction are harvested from ‘mammal-free’ offshore islands. This thesis examines the effects of isolation from mammalian predators on the predator avoidance behaviours and predator recognition abilities of New Zealand birds using the North Island robin as a model. It also investigates whether any effects of isolation from mammalian predators has a lasting impact on mainland populations founded by individuals from offshore islands. Nest site selection behaviours were compared across three populations that are exposed to different suites of predators and have differing translocation histories; Benneydale, Tiritiri Matangi and Wenderholm. Point height intercept and point-centred quarter surveys were used to compare habitat availability between the sites and to compare nest sites with the available habitat. Eight nest characteristic variables were also compared across the three sites using a principle component analysis. Benneydale nests were located higher in the trees and were more concealed than nests at the other two sites. Nests on Tiritiri Matangi were supported by large numbers of thin branches and were located toward the periphery of the nest tree. Unfortunately these differences are very difficult to interpret due to a high degree of variation in the habitat types present at the three sites. The anti-predator behaviours initiated in response to a model stoat, model morepork and control were used to test the ability of nesting robins to recognise the threat that each of these treatments might pose to nest success. Behavioural variables were compared between Benneydale, Tiritiri Matangi and Wenderholm using a response intensity scoring system and a principle component analysis. The results indicated that isolation from mammalian predators on Tiritiri Matangi has suppressed the ability of robins on the island to recognise the predatory threat posed by a stoat. They also suggest that the intense mammal control carried out at Wenderholm may have inhibited the ability of local robins to produce strong anti-predator responses when faced with a stoat.

Conservation in New Zealand has begun to focus heavily on the restoration of degraded mainland ecosystems and the reintroduction of native species that have become locally extinct. In many cases the individuals that are selected for reintroduction are harvested from ‘mammal-free’ offshore islands. This thesis examines the effects of isolation from mammalian predators on the predator avoidance behaviours and predator recognition abilities of New Zealand birds using the North Island robin as a model. It also investigates whether any effects of isolation from mammalian predators has a lasting impact on mainland populations founded by individuals from offshore islands. Nest site selection behaviours were compared across three populations that are exposed to different suites of predators and have differing translocation histories; Benneydale, Tiritiri Matangi and Wenderholm. Point height intercept and point-centred quarter surveys were used to compare habitat availability between the sites and to compare nest sites with the available habitat. Eight nest characteristic variables were also compared across the three sites using a principle component analysis. Benneydale nests were located higher in the trees and were more concealed than nests at the other two sites. Nests on Tiritiri Matangi were supported by large numbers of thin branches and were located toward the periphery of the nest tree. Unfortunately these differences are very difficult to interpret due to a high degree of variation in the habitat types present at the three sites. The anti-predator behaviours initiated in response to a model stoat, model morepork and control were used to test the ability of nesting robins to recognise the threat that each of these treatments might pose to nest success. Behavioural variables were compared between Benneydale, Tiritiri Matangi and Wenderholm using a response intensity scoring system and a principle component analysis. The results indicated that isolation from mammalian predators on Tiritiri Matangi has suppressed the ability of robins on the island to recognise the predatory threat posed by a stoat. They also suggest that the intense mammal control carried out at Wenderholm may have inhibited the ability of local robins to produce strong anti-predator responses when faced with a stoat.

Conservation in New Zealand has begun to focus heavily on the restoration of degraded mainland ecosystems and the reintroduction of native species that have become locally extinct. In many cases the individuals that are selected for reintroduction are harvested from ‘mammal-free’ offshore islands. This thesis examines the effects of isolation from mammalian predators on the predator avoidance behaviours and predator recognition abilities of New Zealand birds using the North Island robin as a model. It also investigates whether any effects of isolation from mammalian predators has a lasting impact on mainland populations founded by individuals from offshore islands. Nest site selection behaviours were compared across three populations that are exposed to different suites of predators and have differing translocation histories; Benneydale, Tiritiri Matangi and Wenderholm. Point height intercept and point-centred quarter surveys were used to compare habitat availability between the sites and to compare nest sites with the available habitat. Eight nest characteristic variables were also compared across the three sites using a principle component analysis. Benneydale nests were located higher in the trees and were more concealed than nests at the other two sites. Nests on Tiritiri Matangi were supported by large numbers of thin branches and were located toward the periphery of the nest tree. Unfortunately these differences are very difficult to interpret due to a high degree of variation in the habitat types present at the three sites. The anti-predator behaviours initiated in response to a model stoat, model morepork and control were used to test the ability of nesting robins to recognise the threat that each of these treatments might pose to nest success. Behavioural variables were compared between Benneydale, Tiritiri Matangi and Wenderholm using a response intensity scoring system and a principle component analysis. The results indicated that isolation from mammalian predators on Tiritiri Matangi has suppressed the ability of robins on the island to recognise the predatory threat posed by a stoat. They also suggest that the intense mammal control carried out at Wenderholm may have inhibited the ability of local robins to produce strong anti-predator responses when faced with a stoat.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.