A predação de ninhos naturais vem sendo sugerida a principal causa do declínio de populações de aves, influenciando na estrutura e no funcionamento das comunidades. Devido à dificuldade de localização e monitoramento dos ninhos naturais, os ninhos artificiais são utilizados como uma rápida alternativa para avaliar o sucesso reprodutivo da avifauna. Os estudos com ninhos artificiais são amplamente difundidos em ambientes temperados e o que conhecemos sobre a predação de ninhos são provenientes destes ambientes. Nos trópicos, os estudos com ninhos artificiais ainda são escassos e no Brasil são quase inexistentes. O presente trabalho tem como objetivo suprir a carência de informações sobre as aplicabilidades e limitações do uso de ninhos artificiais e buscar por padrões de predação de ninhos em um ambiente tropical. O primeiro capítulo foi desenvolvido na Ilha Anchieta que apresenta uma alta densidade de mamíferos e répteis predadores de ninhos. Alguns aspectos metodológicos foram investigados referentes à localização dos ninhos artificiais e o comportamento seletivo dos predadores, por diferentes tipos de ovos utilizados, nos experimentos de predação. Os mamíferos foram os principais predadores de ninhos e os ovos sintéticos foram bons substitutos dos ovos das aves silvestres. No segundo capítulo foi analisada a variação na predação de dois tipos de ninhos artificiais (aéreo e solo) em diferentes ilhas, fragmentos e aéreas continuas. As ilhas apresentaram a maior predação de ninhos, especialmente naquelas que possuem espécies introduzidas, que os fragmentos e as áreas contínuas. Em relação ao tipo de ninho (aéreo e solo) verificamos que os ninhos no solo foram mais vulneráveis a predação nas ilhas e nas áreas contínuas. As ilhas e os fragmentos, apesar de estarem isolados geograficamente, não apresentaram um padrão semelhante na predação de ninhos no solo. Sugerimos que diferentes fatores podem influenciar nos padrões de predação das ilhas e dos fragmentos, como o histórico e a permeabilidade da matriz em que se insere o fragmento. O uso de ninhos artificiais, apesar da sua limitação, é uma ferramenta importante para a compreensão dos padrões de predação de ninhos na avifauna silvestre e pode auxiliar no diagnóstico do estado de conservação nesses ambientes. / The natural predation of the nests has been suggested as the principal cause to the decline of bird population, acting on the performance and community structure. Due to the difficulty of natural nest localization and monitoring, the artificial nests are used as a fast alternative to check the avian reproductive success. The artificial nest studies are widely known in temperate environments where most of the nest predation information has been gotten. In the tropics, the artificial nest studies have still been scarce and in the Brazil, there are few studies about this subject. This work has as a goal to give information about the use and the limitation of artificial nest predation. It also checks some nest predation patterns in tropical environments. The first chapter had been developed in Anchieta Island which has a higher density of mammal and lizard nest predators. Some methodological aspects were investigated related to the artificial nest localization and the selective behavior of the predators by different kinds of eggs used in the predation experiments. The mammals had been the main predators of nests and the plasticine eggs had been good egg substitute of the natural wild eggs. The second chapter, the variation in the predation, of two kinds of artificial nests (on the ground and shrub) in the different islands, fragments and continue areas, had been studied. The islands showed a higher level of nest predation, mainly in those which have exotic species, than the fragments and continue areas. Related to the kind of nest (shrub and ground), it was checked that the ground nests were more vulnerable to depredation in the islands and in the continues areas. The islands and the fragments, besides being geographically isolated, didn?t show the similar pattern in the ground nest predation. It is suggested that different factors can interfere in the predation patterns of the islands and the fragments, as the historical and permeability of the matrix where the fragment is located. The use of artificial nest, besides its limitation; it is a useful tool to understand wildlife avifauna nest predation patterns and can help checking the situation of conservation in different environments.

O processo de fragmentação florestal, além do isolamento e da redução de hábitat, produz um aumento do microhábitat de borda. Este aumento leva à gradual perda de diversidade devido a alterações abióticas e bióticas fazendo com que remanescentes florestais não comportem a mesma diversidade que hábitats contínuos. O estabelecimento de espécies vegetal depende crucialmente do local onde as sementes são depositadas no ambiente, porém muito pouco se sabe sobre os efeitos da fragmentação florestal para a manutenção das características abióticas e bióticas dos microhábitats e seus efeitos na sobrevivência de sementes pós-dispersas, uma vez que a maioria dos estudos foi conduzida em florestas contínua. Este estudo teve como objetivo avaliar os efeitos da fragmentação florestal na predação de sementes da palmeira Syagrus romanzoffiana (“jerivá”) em três microhábitats (clareira, borda e interior de mata), testando oito fragmentos de Floresta Semidecídua (de 9,5 a 33.845 ha). Os objetivos deste trabalho foram os de avaliar (1) se existe diferenças bióticas e abióticas entre os microhábitats de borda, interior de mata e clareira; (2) se o tamanho do fragmento florestal exerce influência para a manutenção das características do microhábitats amostrados; (3) se os microhábitats testados diferem na sobrevivência de sementes de S. romanzoffiana pós-dispersas; (4) se o tamanho do fragmento influencia na taxa de predação de sementes; (5) quais das características estruturais avaliadas estão relacionadas com a predação de sementes de S. romanzoffiana e (6) quais as características estruturais que estão correlacionadas com o tamanho do fragmento. Foi concluído que fragmentos menores que 20 ha não possuem diferenças abióticas e bióticas por extrapolação da borda da mata a todo o fragmento, não sendo registrada nenhuma semente predada nestas áreas. Fragmentos de 230 a 380 ha possuem alta taxa de predação de sementes, sendo encontradas em todo o remanescente independente do microhábitat à medida que os fragmentos florestais com área superior a 1000 ha possuem uma menor taxa de predação e distinções abióticas e bióticas entre clareira, interior e borda de mata. Para a conservação de populações de jerivá em fragmentos florestais com área inferior a 1.000 ha são necessários planos de manejo, como medidas que visem o desenvolvimento de sub-bosque em fragmentos que estejam inteiramente sob efeito de borda, e a proteção de sementes pós-dispersas em fragmentos onde haja forte pressão de predadores de sementes. Investigações sobre os efeitos das alterações decorrentes do processo de fragmentação florestal na biologia reprodutiva de angiospermas são de suma importância para planos efetivos de planejamento, conservação e restauração, gerenciamento de áreas florestais. / The effects of forest fragmentation, more than isolation and habitat reduction, increase the microhabitat edge. This increasing leads to gradual biodiversity loss because of abiotic and biotic alterations, doing that forest fragments support less species when compared with continuous forest. The establishment of plants depends crucially on the place where their seeds were deposited on the environment, but very little is known about the effects of forest fragmentation on microhabitats abiotic and biotic conditions maintenance and their effects for seed survival, once that most studies have been carried out in large forest. In this study, we evaluate the effects of forest fragmentation on Syagrus romanzoffiana seed predation in three microhabitats (gaps, understory and forest edge), testing eight semi-deciduous forest fragments (9.5 to 33,845 ha). Our objectives were to test (1) if there are abiotic and biotic differences among gap, understory and forest edge; (2) if the size of forest fragment influence the maintenance of microhabitats condition; (3) if the microhabitats differs on S. romanzoffiana seed survival; (4) if forest size influence on seed predation rate; (5) which structure characteristics evaluated are related with S. romanzoffiana seed predation; and (6) which structure characteristics are related with forest fragment area. We conclude that forest with less than 20 ha do not support abiotic and biotic distinction, with the forest edge overspread the whole reminiscent. In these forest fragments, we did not find any seed predated. Fragments with 230 to 380 ha had higher seed predation rates, with no differences among the tested microhabitats. Forest fragments with more than 1,000 ha differ among microhabitats biotic ally and idiotically, and had lower seed predation. We conclude that for Syagrus romanzoffiana populations be conserved in isolated forest areas with less than 1,000 ha are necessaries managing plans, as developing understory at remnants with the whole area under edge effect, and post-dispersed seed protection at fragments with high seed predation. The knowledge of the effects of forest fragmentation on angiosperms reproductive processes is essentially for managing, planning, restoration and conservation of forested areas.

A predação de sementes, juntamente com a dispersão, é um dos principais fatores determinantes no recrutamento de novos indivíduos. Espécies de plantas que oscilam na produção de frutos e sementes podem influenciar os predadores e dispersores, alterando a resposta destes em anos de baixa ou alta oferta de recursos. A araucária (Araucaria angustifolia) é o principal elemento da Floresta Ombrófila Mista e as suas sementes, os pinhões, além de amplamente consumidas pela fauna, são uma importante fonte de renda para muitas famílias. Dentre os animais, os roedores são os principais predadores dessas sementes. O objetivo de nosso estudo foi avaliar a relação entre a abundância dos roedores, a disponibilidade de frutos zoocóricos e de sementes da araucária. Avaliamos também se a disponibilidade de sementes influencia nas taxas de remoção e dispersão da araucária. Realizamos o estudo em oito áreas (quatro nativas e quatro de plantação com araucária) na Floresta Nacional de São Francisco de Paula, nordeste do Rio Grande do Sul. Amostramos os roedores durante cinco noites consecutivas em cada estação do ano (abr/outono, jul/inverno, out/primavera e jan/verão). Para avaliar a produção, acompanhamos mensalmente, entre jan/06 a jan/07, todos os indivíduos frutificando ao longo de duas transecções em cada área. Avaliamos também a predação e dispersão de sementes da araucária entre os meses de mai/06 a ago/06. Nossos resultados demonstraram que as sementes da araucária são um importante recurso nas áreas, principalmente no inverno, período em que houve uma queda acentuada na disponibilidade de outros frutos no solo. A abundância dos roedores variou entre as estações do ano, sendo maior no inverno e menor no verão. A remoção de sementes variou entre as áreas nativas e plantadas e entre os meses. Encontramos uma menor remoção nas áreas plantadas, locais de maior disponibilidade de pinhões no solo. A sobrevivência das sementes também foi maior nessas áreas. Nossos resultados indicaram um padrão de predação variando de acordo com a densidade, com uma correlação negativa entre a produção de sementes e a remoção. Nos locais de maior abundância de roedores e maior disponibilidade de sementes encontramos uma menor taxa de remoção, sugerindo uma possível saciação dos predadores. Essa estratégia pode ter conseqüências para o recrutamento e conservação da araucária, bem como para a dinâmica de predação e dispersão, caso não ocorra um manejo dos impactos associados a essa formação, como por exemplo, a coleta das sementes para comercialização e a presença de gado nas áreas. / Seed predation, as well as dispersion, is one of the determinant factors involved in the recruitments of new plant individuals. Plant species that oscillate in their fruit and seed production may influence their seed predators and dispersers, changing their responses in years with high or low resource offer. Araucaria angustifolia is the main element of the Araucaria Forest. Its seeds are largely consumed by the fauna as well as by people, being an important income source for many families. Among the animals that feed upon this seed, the rodents are the main predators. The aim of this study was to evaluate the relation between rodent abundance and fruit availability as well as Araucaria angustifolia seed availability. We also evaluated if the seed production influences the rate of predation and dispersion of araucaria seeds. We conducted the study in the National Forest of São Francisco de Paula, in Rio Grande do Sul state, southern Brazil. In this area, eight forested study sites were selected, four of them were covered by native vegetation (Mixed Ombrophilous Forest) and four were planted with Araucaria. We sampled the rodents at each site during five consecutive nights in each season (autumn, winter, spring, summer). To evaluate the amount of fruit production, we recorded all fruiting individuals of two transects of each area once a month between Jan/06 and Jan/07. We also evaluated the araucaria seed predation and dispersion between May/06 and Aug/06. Our results showed that Araucaria seeds are an important resource in the area, mainly in winter, on which availability of other fruits on the ground was lower. The rodent abundance changed between seasons, being higher during the winter and summer. Seed removal changed between native and planted sites as well as along months. We found low removal rates in planted areas, where overall seed availability on the ground was higher. Seed survival rate was also higher in these areas. Our results indicated a pattern of seed predation changing according to seed density, with a negative correlation between seed production and removal. In areas with higher rodent abundance, we detected lower removal rates, which suggests predator satiation. Such strategy might have consequences for recruitment and conservation of A. angustifolia, as well as for the predation and dispersion dynamic, in case of inadequate management of this species. Additional impacts on seed numbers, such as seed harvest for commercialization and the presence of cattle should be considered in management projects.

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Mas apesar desta grande área de distribuição pouco se sabe sobre sua ecologia, comportamento e relação com os homens. O presente trabalho teve como objetivo geral estudar as relações entre os produtores de peixes localizados em 3 Estados brasileiros (Minas Gerais, Rio de Janeiro e São Paulo) e as lontras, animais estes freqüentemente associados a ataques aos tanques de peixes. Para tal estudo um questionário foi enviado a 50 piscicultores presentes nos estados acima citados, tal questionário continha questões relativas ao levantamento de informações sobre os ataques realizados pelas lontras aos tanques de peixes e se estes geram um conflito entre estas e os piscicultores, assim como questões relativas ao conhecimento dos piscicultores sobre aspectos da ecologia e comportamento das lontras. Os resultados relacionados aos ataques indicam que apesar destes ocorrerem na maior parte das propriedades investigadas, as perdas serem tratadas como grandes pela metade dos investigados e que quanto maior o dano causado maior o sentimento negativo para com as lontras, tais elementos por si só não foram suficientes para a instauração de um conflito entre as lontras e os piscicultores, sendo sim o termo conflito de interesses mais bem colocado, uma vez que a idéia de conflito vem acompanhada de ações danosas entre as partes envolvidas, fato não demonstrado, pois dentre as medidas possivelmente adotadas para a resolução da predação pelos produtores a morte do animal figurou em último lugar. Alguns métodos foram propostos pelos produtores para a solução da predação, em destaque: a utilização de cães, a implementação de cercas e a baixa estocagem de peixes nos tanques. Com relação ao conhecimento dos produtores para com as lontras, estes nos forneceram informações sobre a presença destas em suas propriedades, pequenos córregos e brejos como principais locais de sua ocorrência, tendo as lontras como período de atividade toda a extensão do dia, com picos matutinos e noturnos, sendo animais de hábitos solitários ainda que relatos do avistamento destas em grupos tenham sido freqüentes e com o status atual de sua presença na natureza considerado estável pelos piscicultores que também colocaram que antigamente seu número fora maior. Aspectos de difícil avaliação como a caça e motivos desta também foram avaliados. As 7 abordagens do conhecimento dos produtores de peixes, apresentada neste trabalho foram efetivamente substanciais à obtenção e acréscimo de informações relativas às lontras. Embora exista, obviamente a necessidade de investigar mais detalhadamente algumas das informações obtidas junto aos produtores antes que sua veracidade possa ser atestada, os dados aqui relatados todos a partir do conhecimento dos produtores são uma importante fonte de embasamento e direcionamento para ações conservacionistas a serem desenvolvidas na região, além de contribuírem significantemente para o aumento do conhecimento das relações homem e natureza. / The Neotropical otter (Lontra longicaudis) occur since México toward Argentina, staying among the most widespread species of otter in the world. In spite of this great distribution area a little is known about its ecology, behavior and human relation. The present work aim was to study the relationship between fish farmers placed in three Brazilian States (Minas Gerais, Rio de Janeiro e São Paulo) and the otters, animals frequently associated with fishing tanks’ attacks. For such study, a questionnaire was sent to 50 fish farmers located in the states cited above, containing questions to rise information about the otters’ attack to fishing tanks and if these generate potential conflict between otters and fish farmers, as well as questions concerning the fish farmers’ assessment about otters’ ecology and behavior aspects. The results accounted to attacks shown that, in spite of these attacks occur in the majority of the investigated farms, the losses being threatened as big by the half of investigated and that as larger the damage larger the negative feeling to the otters, such elements by itself were not enough for the establishment of a conflict involving otters and fish farmers, being interest clash the better put term, once that the idea of conflict comes accompanied with harmful actions among the involved parts that in fact, was not verified, cause the dead of the animal figure last in the middle of possible actions adopted by the fish farmers to solve the predation problem. Some fish farmers’ proposed methods to minimize the predation, in prominence: the use of dogs, to implement of fence and low down the stock of fish in fishing tanks. Regarding the farmers’ assessment to the otters, the information supplied by them about otters’ presence in their property, show up small streams and swamps as main place of otters’ occurrence, having as activity period the whole day extension, with morning and night picks, being animals of lonely habits although sighting them grouped reports have been frequent and with current presence status in nature stable by fish farmers that in addition assumed that formerly its number had been larger. Difficult evaluation aspects as the hunt and the reasons of this were also appraised. The approaches of fish farmers’ assessment, presented in this work were substantial indeed to obtaining and increase information about the otters. Although there is, obviously the need of deeper investigation of some information obtained through the farmers before its could be truly attested, the data here reported, from farmers’ assessment onwards, are an important basis and direction source for conservationist actions for being developed in this region, further than significantly contribute to raise the knowledge of human-nature relation.

Orientador: José Roberto Trigo / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-23T04:31:56Z (GMT). No. of bitstreams: 1 Mariscal_AdrianoAffonso_M.pdf: 5931496 bytes, checksum: beff506193372fed1f1ae62149a3f37d (MD5) Previous issue date: 2013 / Resumo: O resumo poderá ser visualizado no texto completo da tese digital / Abstract: The abstract is available with the full electronic document / Mestrado / Ecologia / Mestre em Biologia Animal

Le Grand hamster (Cricetus cricetus), l’un des mammifères les plus menacés d’Europe, est en voie d’extinction en France. Toutefois, nous manquons d’information sur les causes de son déclin et sur comment améliorer sa conservation. Durant ma thèse, je me suis intéressée à l’effet des cultures sur la reproduction du hamster. Les principaux résultats indiquent qu’une consommation importante de maïs conduit à une diminution drastique du succès reproducteur en raison d’une carence en vitamine B3. Une autre étude démontre que des associations de cultures (blé-soja ou maïs-tournesol) sont favorables au hamster et devraient être mises en place en Alsace. En parallèle, j’ai développé un tube anti-prédation (TAP) pour améliorer les passages à faune et reconnecter les populations sauvages. Des tests comportementaux ont révélé que les hamsters présentent des comportements audacieux face au prédateur, mais utilisent tout de même le TAP comme refuge, validant sa fonction anti-prédation. Le TAP sera maintenant mis en place dans plusieurs passages à faune en Alsace. Les résultats de cette thèse vont maintenant bénéficier à la conservation du hamster en France et en Europe. / The European hamster (Cricetus cricetus), one of the most endangered mammal in Europe, is on the verge of extinction in France. However, we are still lacking information on the causes of its decline and on how to improve its conservation. During my PhD, I therefore investigated for the nutritional effects of crops on hamsters’ fitness. The main results highlight that elevated maize consumption is severely reducing hamsters’ reproduction because of a major deficiency in vitamin B3. Then, I found that crop associations such as wheat-soybean and maize-sunflower are favorable to the species and should be implemented in the Alsace. I also developed an anti-predation tube (APT) that will serve to upgrade wildlife underpasses and ultimately allow to reconnect wild populations. Moreover, behavioral tests presented in this thesis reveal that hamsters display bold behaviors when facing a predator. Nonetheless, they use the APT as a refuge in such cases, which validated its anti-predatory function. Therefore, the APT will now be implemented in wildlife underpasses in the Alsace. Results of this PhD will now benefit the conservation of the species in France and in Europe.

Abstract Rare and elusive species are difficult to study, because they are usually secretive, solitary, occur at low densities and have large home ranges. Wolverines (Gulo gulo) can both hunt and scavenge for food. In Fennoscandia, wolverines co-exist with either wild or semi-domesticated reindeer, which constitute their most important winter food. Approximately half of the 180–220 Finnish wolverines are found in northern Finland within the reindeer management area. However, the other half of the population is distributed in eastern and central Finland, and the ecology of wolverines especially in this area is poorly known. This research examined the habitat selection, diet and population genetics of wolverines in northern and eastern Finland. The results suggest that wolf presence is one of the most important variables influencing the habitat selection of wolverines. This finding supports the speculative idea that wolverines might benefit from being sympatric with wolves through increased scavenging opportunities. Furthermore, both the reproductive status of wolverines and the availability of different prey items were found to affect the wolverine diet. In northern Finland, semi-domesticated reindeer and mountain hare were the most frequently utilized prey species for breeding female wolverines. In eastern Finland, the most important food source for breeding females was moose carrion, whereas males and non-breeding females heavily utilized mountain hares. These results support the predictions of the optimal foraging theory, suggesting that wolverines opportunistically utilize the food source that is most energy-efficiently available. In areas with a low density of medium-sized ungulates, scavenging of wolf- and human-killed carrion plays an essential role in food acquisition by wolverines. According to the results of a population genetics investigation, two wolverine subpopulations exist in Finland: a northern and an eastern one. The overall genetic variability was found to be low, and signs of a recent population bottleneck were detected in both populations. It is likely that the wolverine populations in Finland would benefit from improved connectivity between them, but also with neighbouring populations in Scandinavia and north-eastern Russia. / Tiivistelmä Ahma (Gulo gulo) tunnetaan sekä haaskansyöjänä että keskikokoisia hirvieläimiä ja pienriistaa saalistavana petona. Fennoskandian alueella peuran kesy tai villi muoto on ahman merkittävin saalislaji. Noin puolet Suomen 180–220 ahmasta elää Pohjois-Suomessa poronhoitoalueella, ja loput Itä- ja Keski-Suomessa. Poronhoitoalueen ulkopuolella elävien ahmojen ekologiaa on tutkittu erityisen vähän. Väitöstyössäni tarkastelin ahman habitaatinvalintaa, ruokavaliota ja populaatiogenetiikkaa pääasiassa Pohjois- ja Itä-Suomen alueilla. Tutkimukseni tulokset osoittivat, että suden läheisyys oli yksi tärkeimmistä ahman habitaatinvalintaan vaikuttavista tekijöistä. Tämä havainto tukee hypoteesia, jonka mukaan ahma saattaisi hyötyä susien läheisyydestä suuremman haaskatiheyden ansiosta. Todennäköisesti ahmat elävät mielellään samoilla seuduilla susien kanssa, mutta kaihtavat läheistä kanssakäymistä välttääkseen killansisäisen saalistuksen. Tutkimusteni perusteella sekä ahman lisääntymistila että alueen saaliseläinten saatavuus vaikuttivat ahman ruokavalioon. Poro ja metsäjänis olivat lisääntyvien ahmanaaraiden tärkein ravintokohde Pohjois-Suomessa. Itä-Suomessa merkittävin lisääntyvien naaraiden ravintokohde oli hirvi, jota ahmat hyödyntävät lähinnä haaskojen muodossa, mutta urokset ja ei-lisääntyvät naaraat sen sijaan saalistivat eniten metsäjänistä. Ahmat siis näyttävät hyödyntävän opportunistisesti sitä ravintokohdetta, joka kullakin alueella on energiatehokkainta saavuttaa. Susien ja ihmisten jälkeensä jättämät haaskat ovat merkittävä ravintolähde ahmoille alueilla, joilla keskikokoisten hirvieläinten tiheydet ovat alhaisia. Ahman populaatiogeneettinen tutkimus osoitti, että Suomen ahmat ovat geneettisesti jakautuneet kahteen alapopulaatioon, pohjoiseen ja itäiseen. Ahmakannan geneettinen monimuotoisuus oli pientä, ja molemmissa alapopulaatiossa oli nähtävissä merkkejä äskettäisestä pullonkaulailmiöstä. Populaatioiden välisen geenivirran määrän tulisi olla nykyistä korkeampi, jotta ahmakannan elinvoimaisuuden voisi katsoa olevan turvattu tulevaisuudessa.

Predators exert strong direct and indirect effects on ecological communities by intimidating their prey. Non-consumptive effects (NCEs) of predators are important features of many ecosystems and have changed the way we understand predator-prey interactions, but are not well understood in some systems. For my dissertation research I combined a variety of approaches to examine the effect of predation risk on herbivore foraging and reproductive behaviors in a coral reef ecosystem. In the first part of my dissertation, I investigated how diet and territoriality of herbivorous fish varied across multiple reefs with different levels of predator biomass in the Florida Keys National Marine Sanctuary. I show that both predator and damselfish abundance impacted diet diversity within populations for two herbivores in different ways. Additionally, reef protection and the associated recovery of large predators appeared to shape the trade-off reef herbivores made between territory size and quality. In the second part of my dissertation, I investigated context-dependent causal linkages between predation risk, herbivore foraging behavior and resource consumption in multiple field experiments. I found that reef complexity, predator hunting mode, light availability and prey hunger influenced prey perception of threat and their willingness to feed. This research argues for more emphasis on the role of predation risk in affecting individual herbivore foraging behavior in order to understand the implications of human-mediated predator removal and recovery in coral reef ecosystems.

Predator reintroductions are becoming increasingly more common for multiple reasons, including assisting with the conservation of a predator species, the restoration of ecosystem functions and the economic benefits of their reintroduction for ecotourism ventures. There remains however, little knowledge on prey species responses to these predator reintroductions. As such, the reintroduction of cheetah (Acinonyx jubatus) into Samara Private Game Reserve provided an opportunity to investigate prey responses to predator reintroduction across a range of spatial and temporal scales. More specifically, the aim of this study was to investigate the effect of cheetah predation risk on habitat use and behavioural responses of the resident ungulate community. Samara is divided into “predator present” and “predator absent” sections, providing the opportunity to conduct a comparative study investigating the effect of cheetah on prey responses. It was hypothesized that different ungulate species would respond differently to the presence of cheetah, depending on differences in perceived vulnerability to cheetah predation. To address this, shifts in habitat use, and behavioural responses of the ungulate community reflected at landscape and patch scale were investigated. Overall, ungulate species have not shifted habitat use since cheetah reintroduction, this was possibly related to life history strategy constraints and the need for individuals to obtain suitable forage and therefore remain in specific habitats. While no shift in habitat use was observed for the majority of ungulate species, a shift in behaviour was observed for kudu (Tragelaphus strepsiceros) at a landscape scale, where kudu dedicated more time to vigilance and less time to foraging within the predator section. In addition, individuals within smaller kudu groups were observed to be more vigilant than individuals within larger groups of kudu within the predator section. Although the other three ungulate species monitored did not increase time spent vigilant within the predator section, they still maintained relatively high levels of vigilance, potentially as a means of social monitoring. At a patch level, ungulate species responded strongly to a predator cue as a proxy for cheetah proximity, and increased time spent vigilant with a trade-off of lower foraging effort. This vigilant response was strongest for kudu. Differences in perceived predation risk were reflected within eland (Tragelaphus oryx) and kudu species demographic classes, with juvenile eland and kudu, adult female kudu and subadult female kudu spending more time vigilant within manipulated patches than respective males of each species. Kudu were also observed adopting fine-scale behavioural responses to minimize predation risk within patches. The asymmetrical prey species response to perceived predation risk from cheetah supports the hypothesis that different species respond differently to the presence of a predator. Furthermore, this study illustrated the importance of measuring prey responses to predation risk across multiple scales and highlighted the need to replicate this study for a number of different sites where predators have been reintroduced, to better understand the range of factors influencing these predator-prey interactions.

Dasineura sp. is a gall forming midge that was introduced into South Africa for the biocontrol of the Australian myrtle, Leptospermum laevigatum. It causes galls on both the vegetative and reproductive buds of the plant. Although Dasineura sp. was initially regarded as a potentially successful agent, galling up to 99 percent of the buds of the host plant, it has been preyed on by native opportunistic mites, which caused a decline in the performance of the midge as a biocontrol agent of L. laevigatum. This raised a concern about whether this fly will be able to perform effectively in the presence of its new natural enemies. Therefore, the objectives of this study were to: 1) ascertain whether mite abundance has seasonal variations; 2) determine if plant density and plant size have an effect on midge predation by the mites; and 3) determine if midge predation varies in different locations. The study was conducted at three sites in the Hermanus area, Western Cape Province. Every three weeks for thirteen months, galls were collected and dissected so as to count and record the numbers of midge larvae, pupae, adults and mites that were found. Data collected showed that predation varied with season, and the mites were scarce during the flowering season. Predation also varied among the study sites and plant density had an effect on midge predation. Midges in smaller plants (saplings) were more vulnerable to predation than those in the bigger plants (plants from isolates and thickets). It was concluded that although mites have an effect on midge populations, they do not prevent their establishment on the plant. Therefore, a survey should be done in two to three years time to check if the midges are still persisting on the plant, vi and recommendations are that a new agent should be released to supplement the midges.