Widespread anthropogenic invasions have prompted concerns that naturalized organisms could threaten biodiversity. In particular, invasive weeds can negatively affect native biota through a variety of means, including disrupting mutualisms. This thesis was designed to observe and test dispersal mutualisms in a native forest during autumn when the majority of plant species are fruiting. In this thesis I examined whether the invasive plant barberry (Berberis glaucocarpa) was influencing the behaviour of a native frugivore bellbird (Anthornis melanura) and a range of dispersal related services in a native forest, Kowhai Bush near Kaikoura. To test these 18 banded bellbirds were followed through autumn 2011. These observe bellbirds were split between control and test bird. Barberry fruit was removed from the test bird territories. I recorded whether bellbirds changed their territory sizes, foraging and daily behaviours. During 52 hours of observations, bellbirds were never observed feeding on barberry fruit. No significant changes to bellbird behaviour or territories were observed after the removal of barberry fruit. Bellbird diet overall was dominated by invertebrates (83% of foraging observations), with smaller contributions from fruit (16%, nearly all on Coprosma robusta), nectar and honeydew. Since bellbirds did not eat barberry fruit, removal of this weed is unlikely to negatively affect bellbirds during autumn. Which other bird species were dispersing barberry was recorded. I recorded 242 hours of videotape footage on 24 fruiting plants. A total of 101 foraging events were recorded of 4 different bird species: silvereyes (Zosterops lateralis) 42 visits, blackbirds (Turdus merula) 27 visits, song thrush (Turdus philomelos) 29, and starlings (Sturnus vulgaris) 3 visits. The species differed in the mean length of time they spent in plants, so the overall contribution to barberry fruit removal was 32.6% silvereyes, 24.3% blackbirds, 42.9% song thrush and 0.1% starlings. To find out the relative contribution of exotic and native birds to dispersal of fruits in Kowhai Bush, I mist-netted 221 birds of 10 species and identified any seeds in the 183 faeces they deposited. A total of 21 plant species were observed fruiting in Kowhai Bush during this time. A total of 11 different plant species were identified from 1092 seeds. Birds were further observed feeding on 3 other plant species which were not observed in faecal samples. This left 7 plants with unobserved dispersal vectors. There were likely four main dispersers, bellbirds, silvereyes, song thrush and blackbirds and five minor, brown creeper (Mohoua novaeseelandiae), tui (Prosthemadera novaeseelandiae), fantails (Rhipidura fuliginosa), dunnock (Prunella modularis) and starlings. However there was considerable variability between these bird species dispersal abilities. Introduced birds’ song thrush and blackbirds were observed dispersing naturalized plant seeds at higher than expected rates in comparison to native frugivores bellbirds and silvereyes. I also measured the gape sizes on mist netted birds and on samples of fruit from Kowhai Bush. Both silvereyes and bellbirds were found to be eating fruit larger than their gape, but despite this two native (Hedycarya arborea and Ripogonum scandens) and three exotic plants (Vitis vinifera, Taxus baccata and Crataegus monogyna) had large fruit that were probably mainly dispersed by song thrush and blackbirds. Hence, introduced birds were important seed dispersers for large fleshy fruited seeds in Kowhai Bush. Demonstrating that interactions among native and exotic flesh fruited plants and frugivores is important within forest communities.

O Brasil é um dos países com a maior riqueza de aves do mundo (1.677 espécies). A Ordem Passeriformes detém 56% desta riqueza, incluindo o sabiálaranjeira Turdus rufiventris e o pardal Passer domesticus (introduzido), espécies cuja composição, padrão e estrutura da comunidade de helmintos foram investigadas nesta pesquisa. As aves (N=160 de cada espécie) foram capturadas com o auxílio de alçapões e de redes de neblina em paisagens urbanas e rurais da Região Metropolitana de Porto Alegre, RS. Quinze espécies de helmintos foram encontradas no sabiá-laranjeira (sete nematóides, quatro digenéticos, três cestóides e um acantocéfalo), com riqueza média de 2,92 espécies/hospedeiro. No pardal, a riqueza média foi de 0,19 espécies/hospedeiro e cinco espécies de helmintos foram encontradas (dois digenéticos, dois nematóides e um cestóide). Nove espécies foram dominantes, cinco co-dominantes e uma subordinada na comunidade de helmintos do sabiá, enquanto para o pardal, quatro espécies foram dominantes e uma co-dominante. Machos e fêmeas adultos das duas espécies hospedeiras apresentaram comunidades de parasitos semelhantes. Os sabiás-laranjeira adultos, por sua vez, tiveram uma maior riqueza de parasitos do que os juvenis. A fauna parasitária encontrada nestas espécies hospedeiras reflete em grande parte a dieta das aves, considerando que muitas das espécies de helmintos são adquiridas através da ingestão de hospedeiros intermediários infectados. As variações na prevalência apresentada por algumas espécies de helmintos entre as diferentes estações do ano e na riqueza da helmintofauna entre as paisagens rural e urbana são compatíveis com possíveis diferenças na disponibilidade de invertebrados e/ou de outros itens alimentares (tais como frutos) nestas épocas e/ou paisagens dominadas por ambientes distintos.

O Brasil é um dos países com a maior riqueza de aves do mundo (1.677 espécies). A Ordem Passeriformes detém 56% desta riqueza, incluindo o sabiálaranjeira Turdus rufiventris e o pardal Passer domesticus (introduzido), espécies cuja composição, padrão e estrutura da comunidade de helmintos foram investigadas nesta pesquisa. As aves (N=160 de cada espécie) foram capturadas com o auxílio de alçapões e de redes de neblina em paisagens urbanas e rurais da Região Metropolitana de Porto Alegre, RS. Quinze espécies de helmintos foram encontradas no sabiá-laranjeira (sete nematóides, quatro digenéticos, três cestóides e um acantocéfalo), com riqueza média de 2,92 espécies/hospedeiro. No pardal, a riqueza média foi de 0,19 espécies/hospedeiro e cinco espécies de helmintos foram encontradas (dois digenéticos, dois nematóides e um cestóide). Nove espécies foram dominantes, cinco co-dominantes e uma subordinada na comunidade de helmintos do sabiá, enquanto para o pardal, quatro espécies foram dominantes e uma co-dominante. Machos e fêmeas adultos das duas espécies hospedeiras apresentaram comunidades de parasitos semelhantes. Os sabiás-laranjeira adultos, por sua vez, tiveram uma maior riqueza de parasitos do que os juvenis. A fauna parasitária encontrada nestas espécies hospedeiras reflete em grande parte a dieta das aves, considerando que muitas das espécies de helmintos são adquiridas através da ingestão de hospedeiros intermediários infectados. As variações na prevalência apresentada por algumas espécies de helmintos entre as diferentes estações do ano e na riqueza da helmintofauna entre as paisagens rural e urbana são compatíveis com possíveis diferenças na disponibilidade de invertebrados e/ou de outros itens alimentares (tais como frutos) nestas épocas e/ou paisagens dominadas por ambientes distintos.

O Brasil é um dos países com a maior riqueza de aves do mundo (1.677 espécies). A Ordem Passeriformes detém 56% desta riqueza, incluindo o sabiálaranjeira Turdus rufiventris e o pardal Passer domesticus (introduzido), espécies cuja composição, padrão e estrutura da comunidade de helmintos foram investigadas nesta pesquisa. As aves (N=160 de cada espécie) foram capturadas com o auxílio de alçapões e de redes de neblina em paisagens urbanas e rurais da Região Metropolitana de Porto Alegre, RS. Quinze espécies de helmintos foram encontradas no sabiá-laranjeira (sete nematóides, quatro digenéticos, três cestóides e um acantocéfalo), com riqueza média de 2,92 espécies/hospedeiro. No pardal, a riqueza média foi de 0,19 espécies/hospedeiro e cinco espécies de helmintos foram encontradas (dois digenéticos, dois nematóides e um cestóide). Nove espécies foram dominantes, cinco co-dominantes e uma subordinada na comunidade de helmintos do sabiá, enquanto para o pardal, quatro espécies foram dominantes e uma co-dominante. Machos e fêmeas adultos das duas espécies hospedeiras apresentaram comunidades de parasitos semelhantes. Os sabiás-laranjeira adultos, por sua vez, tiveram uma maior riqueza de parasitos do que os juvenis. A fauna parasitária encontrada nestas espécies hospedeiras reflete em grande parte a dieta das aves, considerando que muitas das espécies de helmintos são adquiridas através da ingestão de hospedeiros intermediários infectados. As variações na prevalência apresentada por algumas espécies de helmintos entre as diferentes estações do ano e na riqueza da helmintofauna entre as paisagens rural e urbana são compatíveis com possíveis diferenças na disponibilidade de invertebrados e/ou de outros itens alimentares (tais como frutos) nestas épocas e/ou paisagens dominadas por ambientes distintos.

Made available in DSpace on 2014-06-11T19:30:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-10-26Bitstream added on 2014-06-13T19:19:47Z : No. of bitstreams: 1 castro_er_dr_rcla.pdf: 1176380 bytes, checksum: 2458a65ca174e407c9be76f8a7548b6d (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O palmito Euterpe edulis é uma das espécies de árvores dominates na Floresta Atlântica, e seus frutos constituem uma parte importante da dieta de várias espécies de aves frugívoras. O presente estudo foi desenvolvido em três tipos de Floresta Atlântica (restinga, planície e encosta), na Ilha do Cardoso (Cananéia, São Paulo), durante três anos de observação. Os objetivos foram (1) comparar a fenologia reprodutiva do palmito nos três tipos florestais, e determinar quais os fatores ambientais que estariam influenciando os padrões encontrados; (2) estudar a oferta de frutos e consumo dos mesmos pelas aves frugívoras (em particular, duas espécies de aves Turdus flavipes e Turdus albicollis), e avaliar a relação da abundância destas aves com a oferta de frutos da comuniade arbórea e do palmito E. edulis. Nós avaliamos o consumo de frutos das aves e monitoramos a fenologia de frutificação do palmito e da comunidade arbórea nos três tipos florestais, comparando mensalmente com os dados de censo das aves, de agosto 2001 a julho 2004. Nós também estimamos no mesmo período à produção de frutos e sementes coletados no chão da floresta para o palmito e para a comunidade arbórea. A fenologia de frutificação do palmito foi anual e sazonal nos três tipos florestais, com as fases fruto imaturo e verde correlacionadas com o comprimento do dia, precipitação, e temperaturas, importantes fatores para o desenvolvimento dos frutos. A biomasa de frutos e sementes de palmito coletados no chão diferiram significativamene entre os tipos florestais, sendo maiores estas diferenças entre as florestas restinga e planície. Estas diferenças na produtividade foram relacionadas a densidade do palmito em cada área e a fertilidade de solo. Sobre a dieta das aves... / The palm Euterpe edulis is one of the most common species in Atlantic Brazilian Tropical Rainforest, and its fruits are an important part on the diet of several frugivorous birds' species. This study had been developed in three Atlantic Rainforest types (restinga, lowland and premontane), located in Cardoso Island (Cananéia, São Paulo state), during three years of study. The objectives were: (1) to compare the reproductive phenology of the palm in three forest types, determining which environmental factors could be affecting the patterns found; (2) to study the available number of fruits and the consume of them by the frugivorous birds (mainly, two birds species Turdus flavipes and Turdus albicollis), and to evaluate the abundance relation of these birds with the available number of fruits in the arboreal community and the palm E. edulis. The fruits consume of the birds had been evaluated, and the reproductive phenology of the palm as well the arboreal community in the three types of forest had been monitored. The bird's census data had been compared from August 2001 to July 2004. The palm and the arboreal community production of fruits and seeds taken on the ground of the forest had been estimated during the same period. The reproductive phenology of the palm was annual and seasonal in the three types of forest, having its unripe fruit phases co-related to the day length, precipitation, and temperatures which are important aspects to the fruit development. The palm fruit and seed biomass taken on the ground of the forest differs meaningfully within the forest types, such difference is bigger when considered the restinga and lowland forest. This productivity differences were related to the palm density in each area and the soil fertility. About the bird s diet, 600 records of feeding had been observed, and the families which got the biggest... (Complete abstract click electronic access below)

The song thrush (Turdus philomelos) was introduced to New Zealand from Britain during the mid 19th century and has become one of the most common terrestrial bird species in New Zealand. In this study, I surveyed a range of life-history traits in New Zealand song thrushes for comparison with traits of British thrushes. Clutch size, egg size and nest size have decreased, while the nestling period is shorter and the incubation period longer. This combination of changes suggests birds are investing less energy into each reproductive bout. Birds also appear unable to raise large broods, as nestling starvation is common in New Zealand, which suggests that food is limiting. I experimentally tested the ability of song thrushes to incubate enlarged clutches and broods, but productivity was not higher for enlarged broods and natural 3- and 4-egg clutches produced similar numbers of fledglings. Thus reduced clutch size may be an adaptation to the local environment. Differences in female incubation behaviour, with 3- and 4-egg clutches receiving higher levels of incubation and more visits per hour than 5-egg clutches, also suggest New Zealand thrushes have difficulty coping with clutches as large as those in Britain. The decrease in clutch size between New Zealand and Britain is in the direction and magnitude expected based on the change in latitude, which supports the hypothesis that factors affecting foraging time and food availability, such as daylength, temperature and rainfall, may be selecting for smaller clutches. Egg size was also found to have decreased in New Zealand, though this may be the result of smaller adult size. Hatchling mass was related to egg volume, but I found no effect of egg volume or clutch size on hatching success. However, nests containing more pointed eggs (i.e., abnormally-shaped eggs), had lower survival and hatching/fledgling success. Data from the national nest record database and my study both suggest that differences in song thrush productivity are the result of differential survival of nestlings. Nestling mortality due to starvation was common at Kowhai Bush, but rare in Britain, so either adult condition or food availability may be lowering reproductive success in New Zealand. High rates of nest failure (>65%) could also affect clutch size, but the strong directional selection imposed by food limitation during the nestling period suggests that increases in food supply would result in increased reproductive success even with the same levels of nest failure. When comparing clutch size throughout New Zealand, I found a significant, positive relationship with rainfall, which further suggests that food limitation may be the main factor driving changes in life-history traits of song thrushes in New Zealand.

In the extensive and remote sub-Antarctic forests of South America, birds are the dominant terrestrial vertebrates. Despite considerable efforts to understand the ecology of birds breeding in these forests, our current knowledge for many species is still incomplete. During three breeding seasons (2014 – 2017), I studied the breeding ecology of the five most abundant open-cup forest-dwelling passerines in the sub-Antarctic forest of Navarino Island, Chile (55°04′S, 67°40′W). There were differences in some of the breeding strategies used by birds breeding on Navarino Island versus conspecific populations breeding at lower latitudes. Milvago chimango was the main nest predator of open-cup nesting forest passerines, and the main cause of nest failure. In addition, I found that species built their nests in sites with higher density and taller understory; however, these two factors decreased their nest survival. This mismatch could be due to a change in depredation risk on Navarino Island, and thus, passerines breeding there may be in an ecological trap. In addition, using light-level geolocators, I determined that the migratory connectivity of Elaenia albiceps is weak as a result of the large spatial spread of individuals on the wintering ground, and that the distances among individuals on the breeding grounds are not maintained in the wintering grounds. My study opens further questions about the mechanisms driving differences in breeding strategies among populations. In addition, further research is needed to assess hypotheses that could explain the mismatch between nest-site selection and nest survival and to understand what drives elaenias' movements, not only during winter but throughout their annual cycle.

Birds are a major pest in vineyards both in New Zealand and overseas. There is a need for new behavioural research on birds' foraging habits and feeding preferences in vineyards, as much of the literature to date is anecdotal. Research on cues to birds' feeding will provide a basis on which new deterrent and control strategies can be devised. Spatial-and temporal bird damage in a small vineyard block was mapped to find if damage was correlated with grape maturity and environmental factors. Vineyard and field observations of bird behaviour using video technology combined with preference experiments aimed to establish the relative roles of grape sugar concentration and colour in avian selection. Proximity of vineyards to bird roosts affects damage levels, regardless of differing maturity between locations. The rate of damage tends to increase exponentially once grape maturity has passed a threshold of 13 °Brix. Bunches positioned closest to the ground receive more damage if blackbirds or song thrushes are the predominant pests. Both sugar concentration and grape colour were found to affect birds' feeding preference, but the importance of the two factors varied between years. Black and green grape varieties were differentially preferred by blackbirds (Turdus merula) and song thrushes (Turdus philomelos) while silvereyes (Zosterops lateralis) appeared to have no strong colour preference. It was apparent that there were other, not assessed, grape factors that also affect selection. In small unprotected vineyards that are adjacent to bird roosts the entire grape crop can be taken by bird pests. Besides removing the roosts, which can be beneficial shelterbelts in regions exposed to high winds, growers currently may have no alternative other than to use exclusion netting to keep crops intact. The differential preferences between bird species for variety characteristics suggest that any new deterrents and other strategies to deflect birds from grape crops may need to be species-specific.

Si les parasites sont étudiés depuis très longtemps, la plupart des connaissances concernent des parasites présentant un intérêt médical ou vétérinaire. Ainsi, malgré leur omniprésence au sein du monde vivant, le rôle des infections parasitaires sur les populations naturelles est encore très mal maîtrisé. <br />Un objectif de ce travail était d'étudier la pathogénicité de deux groupes de parasites (tiques et Haemosporidae) au sein de populations de Merles noirs. Ces deux groupes de parasites se sont révélés associés aux indices de condition corporelle et de réponse immunitaire des individus. Cependant, l'étude d'une population urbaine ne nous a pas permis de confirmer un effet des Haemosporidae sur la survie et la dynamique de la population de Merles.<br />L'incidence du milieu de vie (structuration spatiale) sur le fonctionnement de la relation hôte-parasite a été également abordée. En effet, le Merle est une espèce ubiquiste. Nous avons montré que les populations de milieu urbanisé présentent des infections parasitaires plus faibles que celles vivant en milieu forestier. Ce résultat pourrait expliquer en partie les fortes densités de Merles en zones urbaines, même si d'autres interprétations restent bien sûr envisageables.<br />Enfin, divers travaux récents suggèrent le rôle des caroténoïdes comme lien entre l'immunité des mâles et l'intensité de leur signaux colorés. Cependant, ces études utilisent des mesures de l'immunité par challenge immunitaire pour « mimer » les infections parasitaires. Cette démarche a été récemment discutée car les challenges pourraient ne pas toujours refléter la résistance parasitaire. Nos résultats vont dans ce sens. De plus, nos travaux semblent montrer que le contexte social module la relation entre immunité et signaux colorés. Ceci pourrait remettre partiellement en cause l'idée selon laquelle les caroténoïdes constituent un mécanisme universel garant de l'honnêteté des signaux.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-10T22:31:41Z No. of bitstreams: 1 NicolasLucianoRuiz_DISSERT.pdf: 1952148 bytes, checksum: 19e4fee0d04c3075a81e4b5f5bbc52f1 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-17T20:26:25Z (GMT) No. of bitstreams: 1 NicolasLucianoRuiz_DISSERT.pdf: 1952148 bytes, checksum: 19e4fee0d04c3075a81e4b5f5bbc52f1 (MD5) / Made available in DSpace on 2016-05-17T20:26:25Z (GMT). No. of bitstreams: 1 NicolasLucianoRuiz_DISSERT.pdf: 1952148 bytes, checksum: 19e4fee0d04c3075a81e4b5f5bbc52f1 (MD5) Previous issue date: 2015-04-16 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Fornecer informa??es sobre aspectos de hist?ria de vida das esp?cies neotropicais ? de fundamental import?ncia devido ? grande lacuna de conhecimentos que existe para essa regi?o, e ? atrav?s do estudo desses aspectos que verdadeiramente se conhece um organismo e se inspiram respostas ?s mais diversas teorias das ci?ncias biol?gicas. Dessa forma, o presente estudo, realizado no extremo norte da Mata Atl?ntica, divide-se em dois cap?tulos complementares com foco na esp?cie Turdus leucomelas (Vieillot 1818), cuja fam?lia ? amplamente conhecida por serem excelentes modelos para estudos ecol?gicos devido a sua ocorr?ncia e distribui??o. O primeiro cap?tulo aborda a biologia reprodutiva, onde estimamos o sucesso reprodutivo atrav?s do protocolo de Mayfield em 7,2 % para 2013 e 4,5 % para 2014, evidenciando uma elevada taxa de preda??o; analisamos sucesso e preda??o, nas fases de incuba??o e ninhego, em fun??o de vari?veis ambientais coletadas; descrevemos padr?o dos ovos e ninhos, triando os materiais que os comp?em; e acompanhamos o desenvolvimento dos filhotes, desde a eclos?o at? a sa?da do ninho. O segundo cap?tulo traz informa??es sobre a sua din?mica populacional acompanhada por quatro anos e analisada atrav?s dos modelos Cormack-Jolly-Seber e Desenho Robusto com o uso do programa MARK; estimamos sobreviv?ncia, detectabilidade e tamanho populacional em fun??o de co-vari?veis externas (tempo, ciclo reprodutivo, chuva e presen?a de cong?nere migrat?rio) e diferenciando indiv?duos adultos residentes daqueles transit?rios e juvenis. As sobreviv?ncias estimadas atrav?s da an?lise CJS para os adultos residentes foram sempre maiores (76,01-93,41%) que os transit?rios (65,47-87,16%) e os juvenis sempre intermedi?rios (72,00-91,43). Identificamos o per?odo reprodutivo como sendo a vari?vel que mais influencia a sobreviv?ncia, enquanto que a densidade do migrante Turdus amaurochalinus influenciou inversamente proporcional as taxas de recapturas. Estimamos valores similares de sobreviv?ncia e taxas de detectabilidade atrav?s do DR e estimamos tipo de movimento, dispers?o tempor?ria e tamanhos populacionais. Verificamos tamb?m que esse ?ltimo par?metro manteve uma rela??o inversa com o per?odo reprodutivo. Nossos resultados estimam as sobreviv?ncias mais altas para o g?nero Turdus e confirmam os padr?es de baixas taxas de recaptura e elevada dispers?o e cuidado parental estendido das regi?es tropicais. Por?m contestam a pluviosidade como principal fator influenciando a sobreviv?ncia, enquanto se refor?a o trade off entre reproduzir e sobreviver nessas latitudes.