Within the Australian wet tropics bioregion, only 900 000 hectares of once continuous rainforest habitat between Townsville and Cooktown now remains. While on the Atherton Tableland, only 4% of the rainforest that once occurred there remains today with remnant vegetation now forming a matrix of rainforest dispersed within agricultural land (sugarcane, banana, orchard crops, townships and pastoral land). Some biologists have suggested that remnants often support both faunal and floral communities that differ significantly from remaining continuous forest. Australian tropical forests possess a relatively high diversity of native small mammal species particularly rodents, which unlike larger mammalian and avian frugivores elsewhere, have been shown to be resilient to the effects of fragmentation, patch isolation and reduction in patch size. While small mammals often become the dominant mammalian frugivores, in terms of their relative abundance, the relationship that exists between habitat diversity and structure, and the impacts of small mammal foraging within fragmented habitat patches in Australia, is still poorly understood. The relationship between foraging behaviour and demography of two small mammal species, Rattus fuscipes and Melomys cervinipes, and food resources in fragmented rainforest sites, were investigated in the current study. Population densities of both species were strongly related with overall density of seed resources in all rainforest fragments. The distribution of both mammal species however, was found to be independent of the distribution of seed resources. Seed utilisation trials indicated that M.cervinipes and R.fuscipes had less impact on seed resources (extent of seed harvesting) than did other rainforest frugivores. Experimental feeding trials demonstrated that in 85% of fruit species tested, rodent feeding increased seed germination by a factor of 3.5 suggesting that in Australian tropical rainforest remnants, small mammals may play a significant role in enhancing germination of large seeded fruits. This study has emphasised the role of small mammals in tropical rainforest systems in north eastern Australia, in particular, the role that they play within isolated forest fragments where larger frugivorous species may be absent.

I examined small mammal demography and habitat associations in 4 forest cover types on Quantico Marine Corps Base, VA. Study sites included clearcut, shelterwood, mature-riparian, and mature-upland habitats. My primary objective was to determine whether the abundance, species composition and demographic characteristics (density, survival, reproductive effort) of small mammals varied with respect to forest cover type. Secondarily, I was interested in identifying patterns of small mammal habitat selection and the factors that influence those patterns at micro- and macroscales. Small mammals were captured from May 1997-January 1999 on 10 sites (2 clearcut, 4 shelterwood, 2 riparian, and 2 mature) using a combination of Sherman live-traps and pitfall traps. Small mammal abundance and demographic characteristics were examined across forest cover types using a combination of statistical analyses, including Chi-square tests, Kruskal-Wallis tests and repeated measures ANOVA. I surveyed microhabitat features at individual trap stations (n=1000) using variable sized plots and the point quarter method and used these data to determine macrohabitat characteristics for sites (n=10). I examined species-habitat relationships at micro- and macro-spatial scales using Kruskal-Wallis tests, Wilcoxon Rank Sum tests, simple linear regression, stepwise multiple regression and stepwise logistic regression. Fourteen species of small mammals were captured over 7 trapping occasions. Five species including white-footed mice (Peromyscus leucopus), northern short-tailed shrews (Blarina brevicauda), eastern chipmunks (Tamias striatus), meadow voles (Microtus pennsylvanicus), and woodland voles (Microtus pinetorum), accounted for approximately 95% of the total number of individuals captured. Overall relative abundance and species composition of small mammals differed significantly across forest cover types. Catch per unit effort was greatest in shelterwoods followed by riparian, clearcut and mature forest cover types. I found significant differences in the abundances of white-footed mice and eastern chipmunks across forest cover types but not in those of northern short-tailed shrews, meadow voles or woodland voles. Shelterwood stands provided the highest quality habitat for white-footed mice and eastern chipmunks while clearcut stands provided high quality habitat for northern short-tailed shrews. Assessments of habitat quality for other species were based on weak evidence or inconclusive. Microhabitat preferences for the 5 small mammal species with > 100 captures were generally consistent with those previously reported in the literature. White-footed mice, eastern chipmunks and northern short-tailed shrews were associated with woody debris and brushy microsites, while meadow voles were associated with grassy vegetation and woodland voles with the presence of soft mast and woody stem densities. For each of these species, microhabitat was able to predict presence at individual trapping stations at a level better than expected by chance. For white-footed mice and woodland voles, however, habitat selection was found to be dependent upon macrohabitat, suggesting that habitat selection for these species is dynamic. Macrohabitat features were related to the abundance of several small mammal species. In general, the habitat characteristics important to individual species at microscales tended to be important at macroscales as well. The results of this study suggest that current even-aged forest management practices on Quantico Marine Corps Base are compatible with the maintenance of native populations of small mammals. Disturbances created by harvesting, at least temporarily, resulted in favorable microhabitat conditions for a variety of small mammal species. Species such as southern flying squirrels, however, were sensitive to disturbance, although it is likely that successional changes allow rapid recolonization of disturbed sites. / Master of Science

Scarce knowledge of Neotropical small mammal communities prevents experimental inquiry on the mechanisms structuring these communities. In this study, I examined patterns of local assembly of the small mammal communities on the eastern slopes of El Cielo Biosphere Reserve (ECBR) in Tamaulipas, Mexico, at two spatial scales. At the landscape level I tested patterns of species co-occurrences between four sites with a null model. At the local level I addressed floor microhabitat use, vertical structure use and temporal partitioning. I studied these niche axes at two adjoining forest types, Tropical Subdeciduous Forest (TSDF) and Cloud Forest (CF), that had different structural complexity. Total trapping effort consisted of 19,712 trapnights distributed over three years. In 1,365 capture events I recorded 789 individuals representing 14 species. Abundant species, mostly Peromyscus species that are of intermediate body size, co-occurred less often than expected by chance, whereas rare species, mainly Reithrodontomys species of small size, occurred at random over study sites. This pattern suggests that species interactions might be responsible for this non-random structure. Both the TSDF and CF had striking differences in both microhabitat use and temporal partitioning. In the TSDF common species (>8 individuals) organized along a microhabitat gradient from grassy/open areas to closed forest areas. Temporal partitioning for the whole community was less than expected by chance with use of an ad hoc null model. Species from ecotone/open areas avoided use of middle portions of the night whereas the single forest species concentrated activity in this period. So, it is plausible that predator avoidance strategies might have higher impact on temporal partitioning as compared to competitive interactions. In high contrast the CF community was codominated by two Peromyscus species that overlapped heavily in both their microhabitat use and diel activity patterns. Ecological separation of these two species probably occurs along a niche axis not considered in my study or might be facilitated by their body mass difference. Overall, I provide the first account of community patterns for small mammals at ECBR. These patterns can provide the basis for experimental manipulations to ascertain mechanisms responsible for structure at these communities.

Ticks are important vectors of pathogenic agents that cause disease in humans, domestic animals, and wildlife. They are also hosts for a variety of bacterial endosymbionts. However, little is known about the microbial diversity of many tick species, particularly those species that parasitize small mammals in western Canada. In this thesis, I used a combined morphological and molecular approach to identify, to the species-level, ticks that parasitized small mammals from three localities in Saskatchewan and British Columbia. The genetic diversity and phylogenetic relationships of these tick species was also examined. Comparisons were also made of the composition and diversity of bacteria within individuals of each tick species. Questions relating to the biology, systematics, and vector ecology of the vole tick (Ixodes angustus), the rotund tick (Ixodes kingi), the sculptured tick (Ixodes sculptus) and the Rocky Mountain wood tick (Dermacentor andersoni) were also addressed. The results of my thesis work revealed that I. kingi and I. sculptus were the most encountered tick species on northern pocket gophers (Thomomys talpoides) and Richardson’s ground squirrels (Spermophilus richardsonii), respectively, in Saskatchewan, while I. angustus was the most abundant tick on red-backed voles (Clethrionomys gapperi) in Kootenay National Park (British Columbia). At least 40 genera of bacteria were detected in the four tick species; however, there were significant differences in the composition of the bacteria among tick species. Two novel species of Rickettsia and three putative new species of Rickettsiella were also discovered. The findings of this thesis make an important contribution to our understanding of the evolution and ecology of ticks and tick-borne bacteria.

No description available.

In recent years a push to establish pulpwood plantation forestry in Sarawak, East Malaysia with Acacia mangium has been identified as a means to relieve pressure on the State’s diminishing natural forest resource whilst providing 1) economic wealth for a developing economy 2) community development, and 3) biodiversity conservation outside the protected area network. In a specially designated 504,000 hectare Planted Forest Zone (PFZ) a range of broad-scale landscape planning initiatives have been implemented in an attempt to conserve a representative sample of biodiversity across the plantation landscape. The effects of forest modification and fragmentation have been widely reported in the literature for mammals, and in this study, non-volant small mammals were fitted with tracking spools and/or radio collars and released into small forest remnants outside of their home ranges to measure response to unfamiliar habitats, forest edges and various scales of habitat fragmentation during simulated dispersal events. Medium sized patches exhibited the greatest species diversity and abundance, whereas the largest forest areas hosted the largest population of brown spiny rat (Maxomys rajah); a species that is identified as vulnerable across its natural range. Small forest patches of c.1.00 ha that had been exempt from clearing during plantation establishment are likely to be species poor and host small populations of extant species only. All species were found to make extensive use of downed woody debris for movement, and showed varied responses to a range of habitat edges including forest roads, acacia plantation compartments, old haul trails, clearings and riparian areas. Two species of treeshrew; long-footed treeshrew (Tupaia longipes) and painted treeshrew (T. picta) were shown to be able to move between the forest patch and the acacia forest while the same edges were shown to pose barriers to the brown spiny rat (M. rajah) and large treeshew (T. tana) illustrating the different ways that species may perceive and use habitat features such as corridors. Despite T. picta being common in the PFZ, comparatively little has been published on its ecology and behaviour compared with the other Bornean tupaiids. Therefore this study also reports on the movement and behaviour of this species within its own home territory as revealed from both radio telemetry and spool-and-line tracking. Home range size, dimension, average daily movement distances and nest site construction was found to be similar to other Tupaiids studied in secondary forests in Sabah, and home ranges were found to be dictated by anthropogenic landscape features such as forest roads and open areas across which no movement was recorded. Painted treeshrews were found to favour logs and fallen woody debris as movement substrates and spend the large majority of their movement at ground level. Camera trapping revealed possible interspecific nest sharing between the painted treeshrew and the three-striped ground squirrel (Lariscus insignis), fuelling the debate on whether or not treeshrews construct their own nests or use nests constructed by squirrels.

Esta dissertação fez parte do projeto temático “Conservação da Biodiversidade em Paisagens Fragmentadas no Planalto Atlântico de São Paulo", que teve como objetivo geral estudar os efeitos da fragmentação da Mata Atlântica sobre diversas comunidades e processos ecológicos na região de Caucaia do Alto, SP. A dissertação está dividida em três capítulos centrais e duas abordagens principais. A primeira delas utilizou dados coletados por mim e outros pesquisadores com o objetivo de testar o uso de uma metodologia de captura de pequenos mamíferos relativamente nova e pouco utilizada nos trópicos, comparando a sua eficiência com a da metodologia mais tradicional de coleta de dados sobre estes animais (capítulo 2). Estudos recentes demonstram que a matriz, conjunto de ambientes alterados que circundam os remanescentes em paisagens fragmentadas, considerada inicialmente inóspita e homogênea, funciona como um mosaico de unidades com diferentes permeabilidades ao deslocamento ou à ocorrência das espécies. Dentro deste contexto, a segunda abordagem desta dissertação corresponde à descrição e comparação do uso, pelos pequenos mamíferos, dos ambientes alterados que envolvem os remanescentes de floresta (capítulo 3) e à utilização deste tipo de informação para o estudo da influência da estrutura da paisagem sobre a distribuição de espécies (capítulo 4). No capítulo 2, para avaliar a eficiência e a congruência entre tipos de armadilhas, amostramos a comunidade de pequenos mamíferos de forma padronizada usando armadilhas Sherman e de queda em 26 sítios, 20 localizados em fragmentos florestais e seis em floresta contínua. Os resultados sugerem que armadilhas de queda, quando constituídas por baldes grandes e profundos e utilizadas nas épocas chuvosas e quentes, não só complementam a diversidade encontrada com o uso de armadilhas tradicionais, como podem triplicar a riqueza por sítio de amostragem, incluindo espécies raras, de hábitos semi-fossoriais e espécies escansoriais/arborícolas geralmente não atraídas pela isca das armadilhas tradicionais. Apesar das diferenças de eficiência, os resultados sugerem que os dados obtidos com os dois tipos de armadilhas são congruentes e que variações de diversidade e abundância entre sítios são semelhantes entre os métodos. As armadilhas de queda também parecem ser essenciais em estudos demográficos, já que capturam indivíduos em uma amplitude maior de peso, incluindo os jovens, raramente capturados nas armadilhas tradicionais. No capítulo 3, para avaliar a qualidade da matriz para os pequenos mamíferos na região de Caucaia do Alto, utilizamos os dados de amostragens padronizadas realizadas em 23 sítios, sete localizados em remanescentes florestais (floresta contínua e fragmentos) e 16 distribuídos nos quatro tipos predominantes de habitats da matriz (vegetação nativa em estádios iniciais de regeneração, plantações de eucalipto, áreas de agricultura e áreas rurais com construções). Houve forte segregação na comunidade de pequenos mamíferos entre a vegetação nativa e demais habitats, indicando a capacidade extremamente reduzida das espécies florestais de ocupar habitats antropogênicos. A vegetação nativa em estádios iniciais apresentou uma razoável permeabilidade para as espécies florestais, sugerindo o potencial da regeneração natural para a restauração de paisagens fragmentadas de Mata Atlântica. Os habitats antropogênicos foram dominados por espécies generalistas, exóticas ou típicas de biomas abertos, sugerindo que paisagens muito alteradas possam ser dominadas por estas espécies, com conseqüências para a regeneração das florestas e para a saúde humana. No capítulo 4, a partir dos resultados da distribuição das espécies de pequenos mamíferos nos habitats do mosaico, informações sobre a qualidade destes habitats foram utilizadas na avaliação da influência da estrutura da paisagem sobre a ocorrência das espécies em 20 fragmentos florestais, com o objetivo de comparar o poder explanatório de métricas que consideram ou não a qualidade da matriz e investigar a importância da escala espacial. Os resultados indicam que a influência da estrutura da paisagem é maior para as espécies que não ocorrem na matriz, ou entre as que ocorrem, para aquelas que não ocupam todos os ambientes da paisagem. Em geral, os modelos com as métricas que consideram a qualidade da matriz apresentaram maior poder explanatório sobre a distribuição das espécies nos fragmentos. Dentre as métricas que consideram a qualidade da matriz, aquelas que incorporam a distância entre as diferentes manchas de habitat mostraram vantagens em relação às que consideram apenas a área das manchas, pois apresentaram maior poder explanatório sobre a ocorrência de um maior número de espécies e menor variação do poder explanatório em relação a mudanças na escala espacial considerada. Esta ultima característica é importante dada a falta de uniformidade observada na resposta das espécies à variação da escala espacial e a escassez de informações que embasem a escolha de escalas espaciais adequadas para espécies tropicais. / This dissertation was developed as part of the thematic project “Biodiversity Conservation in Fragmented Landscapes at the Atlantic Plateau of São Paulo", which aimed at studying the effects of the fragmentation of the Atlantic forest on several communities and ecological processes in Caucaia do Alto, SP. This dissertation is divided in two main approaches that comprise three chapters. In the first approach, I used data collected by myself and by other researchers with the objective of testing the use of a relatively new and little explored methodology to capture small mammals in the tropics, comparing its efficiency to the methodology that is tradicionally ised to collect data about these animals (chapter 2). Recent studies have shown that the matrix of altered habitats surrounding remnants in fragmented landscapes, considered initially as inhospitable and homogeneous, act as a mosaic of units presenting different degrees of permeability to the movement or to the occurrence of species. Within this context, the second approach of this dissertation concerns the description and comparison of use of the altered habitats surrounding forest remnants by small mammals (chapter 3) and to the use of this type of information for the study of the influence of landscape structure on species distribution (chapter 4). In chapter 2, aiming at the evaluation of the efficiency and congruence of different types of traps, we sampled the small mammal community using a standardized procedure, with Sherman and pitfall traps in 26 study sites, 20 located in forest fragments and six in the continuous forest. Results suggest that large and deep enough pitfall traps used during wet and warm periods, not only complement the diversity found using traditional traps, but also leads to an considerable increase in the number of species found at each study site, including rare species, semi-fossorial species and scansorial/arboreal species that are usually not attracted to the bait used in traditional traps. Despite differences in efficiency, results suggest that data gathered with the two types of traps are congruent and that the variation in diversity and abundance among study sites is similar between the two methods. Pitfall traps also seem to be essential in demographic studies because they are able to capture individuals within a larger range of weights, including young individuals, which are rarely captured using traditional traps. In the chapter 3, to evaluate matrix quality for the small mammals in Caucaia do Alto, we used data from standardized sampling in 23 study sites, seven of which were located in forest remnants (continuous and fragmented forest) and 16 were distributed in the four main types of matrix habitats (native vegetation in initial stages of regeneration, eucalyptus plantation, areas of agriculture and rural areas with buildings). There was a strong segregation in the small mammal community between native vegetation and the other habitats, indicating the extremely low capacity of forest species to occupy anthropogenic habitats. Native vegetation in initial stages presented a reasonable permeability to forest species, suggesting the potential of natural regeneration to restore fragmented Atlantic forest landscapes. Anthropogenic habitats were dominated by generalist species, exotic species or species that are typical from open biomes, suggesting that highly altered landscapes may be dominated by these species, with consequences to forest regeneration and to human health. In chapter 4, using the results of the distribution of the small mammal species in the habitats of the mosaic, information on the quality of these habitats was applied in the evaluation of the influence of landscape structure on the occurrence of species in 20 forest fragments, aiming to compare the explanatory power of metrics that consider or not matrix quality and to investigate the importance of spatial scale. Results indicate that the influence of landscape structure is stronger for species that do not occur in the matrix, or for species that do not occur in all habitats in the mosaic. In general, the models using metrics that consider matrix quality presented higher explanatory power on the distribution of species. Among the metrics that consider matrix quality, those that incorporate distance among different habitat patches presented advantages in relation to those that consider only patch area, because they presented a higher explanatory power to the occurrence of a larger number of species and lower variation in the explanatory power in relation to changes in spatial scale. The later characteristic is important given the lack of uniformity observed in species response to variations in spatial scale, and the scarcity of information that could support the choice of adequate spatial scales for tropical species.

Magister Scientiae (Biodiversity and Conservation Biology) / Desertification deteriorates the landscape functionality of rangelands, affecting the resilience of biome boundaries which have a cascade effect not only in vegetation composition and characteristics but also in animal communities. The balance between plants and small mammals are essential in maintaining the functionality (i.e. nutrient cycling, soil stability, and water infiltration) of rangeland which includes the arid Steinkopf communal rangeland. However, the landscape functionality of rangelands has not been extensively studied, especially in communal areas where desertification is a serious concern since many people farm with livestock to survive. The aim of this study was to assess landscape functionality along an arid biome boundary and its relationship to small mammal assemblages. This study further aimed to provide a local landscape perspective of the current desertification process and projected expansion of the Desert Biome into more mesic biomes in South Africa. Three replicates for three Desert Biome, ecotone and Succulent Karoo Biome sites (27 sites in total) were selected to assess landscape functionality and survey small mammal assemblages over a one-year period. The change in landscape functionality between the three areas was assessed to determine the resilience of the biome boundary to desertification. For each small mammal survey, 216 live Sherman traps were set up during the summer and winter seasons to account for breeding, mortality, and possible migration. With the data, the body condition index, population density, and diversity were quantified.

This project aimed to reanalyse two large historical data sets from two different locations in New Zealand (Fiordland in the South Island and Pureora Forest Park in the North Island). The data describe populations of mice (Mus musculus), rats (Rattus rattus and R. norvegicus), and stoats (Mustela erminea) collected using standard monitoring techniques from five distinct types of forest habitat. The new analysis methods selected were an index of patchiness and Site Occupancy analysis. The objectives of the analysis were (1) to evaluate whether the patchiness index and Site Occupancy analysis methods might contribute to improved protocols for monitoring small mammal populations in the future, and (2) to use formal tests of five hypotheses to evaluate two of the assumptions made by the conventional density index often used in small mammal studies. I describe the results of the analyses for each species, including any problems encountered (such as the inability of the Site Occupancy method to analyse very sparse data sets). I also describe the results pooled from each of the two study locations and potential consequences for small mammal monitoring and control. This analysis has suggested that in most cases the density index is not a rigorous measure of small mammal populations. However, both the index of patchiness and Site Occupancy analysis provided useful, new information about these populations of rodents and stoats, despite the fact that these historical data sets were not designed for use with modern methods of analysis. Please note: some figures and tables were printed separately and added to the thesis as unnumbered pages. These can be found in the file 03Plates_and_Tables.pdf.

The relationship of vegetation and disturbance factors to the distribution, abundance and diversity of small mammals in the eastern Otway region, Victoria were investigated. Antechinus stuartii, Rattus fuscipes and Rattus lutreolus were widely distributed and occurred in the majority of the eleven floristic vegetation groups identified. Antechinus minimus, Antechinus swainsonnii and Pseudomys novaehollandiae had restricted distributions and were recorded in only two or three vegetation groups. New information on the distribution of the rare species P. novaehollandiae, was obtained and two floristically rich vegetation groups that it preferred were identified. Species-rich small mammal communities occurred in vegetation communities with high numbers of sclerophyll plant species and high structural diversity. Maximum food resources were considered to be provided in these communities. Local habitat diversity was also correlated with species-richness. Small mammal abundance was maximum in non-sclerophyllous canmunities, where high plant productivity was considered to be important. For the first time, the presence of the plant pathogen Phytophthora cinnamomi was shown to affect small mammals. It was associated with small mammal communities of low species richness and abundance, Recovery of small mammal populations after wildfire was slow until the fourth year. Mus musculus reached peak abundance from 2-3 years and then declined rapidly. P. novaehollandiae was the only native species that achieved maximum abundance early in the succession. A. stuartii, R. fuscipes and R. lutreolus approached maximum abundance in mid-succession, while Isoodon obesulus was a mid- to late-successional species. A. minimus survived the fire, but did not persist after one year. The pattern of succession was influenced by attributes of species, such as survival after fire, their ability to disperse and reproduce.