The Earth's most extensive living space is found in the bathypelagic zone of the oceans, yet research in these areas is scant. The micronekton of the bathypelagic zone in the eastern Gulf of Mexico (EGOM) was investigated with the goals of comparing its community structure and trophic interactions with those of the well-studied overlying mesopelagic micronekton. Significant changes in faunal structure were found, including shifts in dominant families as well as species. Compared to the mesopelagic zone, the bathypelagic community had increased abundance and biomass contributions from the Gonostomatidae, Oplophoridae,and Eucopiidae, with a simultaneous decrease in the importance of the Myctophidae and the Dendrobranchiata. The changed faunal structure within the crustacean assemblage includes a distinct difference in reproductive strategies. There is increased prevalence of taxa which feature egg brooding and abbreviated larval development. In addition, the bathypelagic zon e was characterized by relatively large biomass contributions from rare but large species, particularly those within the families Oplophoridae and Nemichthyidae. The faunal shifts, in combination with a high percentage of bathypelagic species absent from mesopelagic samples (~50% of crustacean and ~37% of fish species), suggest the bathypelagic zone is home to a distinct pelagic community, with a biology and ecology fundamentally different from that of the mesopelagic zone. The broad zoogeographic distributions of bathypelagic species suggest the EGOM assemblage is possibly similar to that of other geographic locations at similar latitudes. Diet analysis was performed on several prominent species and revealed 2 major feeding strategies based on diet composition and prey size. Species of Cyclothone and Eucopia preyedon small planktonic crustaceans, while the decapods examined were primarily piscivorous. The fraction of fish in the diets of decapods was greater than in their mesopelagic counterparts. It is suggested the primary trophic players in the system are oplophorid shrimps, followed by Cyclothone spp.

Understanding how environmental variation affects fitness and population dynamics is a central goal in modern population biology. Using a multilevel path model, I simultaneously examined the effects of food and temperature on multiple stages of the breeding cycle, and their relative contribution to annual variation in reproductive success in two tree swallow (Tachycineta bicolor) populations over the same 35 year period. In one population where food abundance peaked during the laying and incubation portion of the breeding season, the primary driver of annual reproductive success was laying period food abundance, which directly influenced clutch size and the proportion of eggs hatched. In the second population, food was relatively low during the first half of the breeding season, and the primary driver of annual reproductive success was temperature during the nestling period, which directly influenced nestling survival. My results show that understanding the factors that influence reproductive performance requires linking environmental variables to reproductive events throughout the entire breeding period and clearly demonstrate how climate change can have opposite effects on two populations less than 35 km apart

According to traditional theory, superior competitive ability in plants generally requires a relatively large plant body size. Yet, within natural, crowded vegetation, most resident species are small, and species size distributions are right-skewed at virtually all scales. I aim to provide a potential explanation for this paradox: small species are able to coexist with and outcompete larger species because smaller species have greater ‘reproductive economy’—the ability for some seed production despite severe size suppression when under intense competition. Tracey and Aarssen (2011) found an isometric relationship between minimum reproductive threshold size (MRTS) and maximum resident plant size (MAX); however, a more accurate measure of maximum potential body size (MPBS) was needed (without competition), as typically the effects of competition are size-dependent. An isometric relationship, similar to Tracey and Aarssen (2011) was seen. Tracey and Aarssen (2011) also found that, contrary to the predictions of traditional theory, larger species were not more abundant (based on plot occupancy) in an old-field community. A more accurate measure of abundance was obtained by locating random 1 x 1 m plots and counting the number of ramets for each species in the plot. A significant negative relationship was seen between abundance and MRTS. This suggests that the most abundant plants in communities are not those that are bigger, or smaller, they are those with the smallest MRTSs. To test whether this relationship exists in other habitats, plots were located in different old-field, shrub-land and wood-land communities. Ramets for each species within the plots were counted, and the largest plant of each species was measured. Significant negative relationships between abundance and MAX plant body size were seen in the shrub-land and woodland sites; however, no relationship was detected in this old-field site. The data support the idea that smaller species have greater reproductive economy, but the mechanism remains unknown. These results suggest that a smaller plant body size results in more effective gene transmission into future generations in all habitat types and stages of succession and indicates a suggested paradigm shift in the predicted selection effects of competition on the evolution of plant body size. / Thesis (Master, Biology) -- Queen's University, 2012-07-30 11:56:23.999

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Good estimations of habitat preference and activity of bats in different habitats are of great importance when planning for conservation or assessing consequences of exploitation. The objective of this study was to compare two different methods for abundance estimation: line- transects (active taxation) and point taxation by autobox recordings (passive taxation), and correlation analyses were made between data from these methods. The species used was Eptesicus nilssonii, which is easy to identify and one of the most common bat species in Sweden. Differences in abundance between edge zones and non-edge zones were tested. The equations from the correlations would allow the use of passive taxation data for abundance estimates. Using the equations produced in the correlation analysis, and data collected in other projects at different sites in southern and central Sweden, an estimation of the total number of E. nilssonii in southern and central Sweden was made. This data was also used in order to test differences in abundance between habitats close to and further away from water. However, no differences in abundance between different habitats could be seen. Significant correlations were found between active and passive taxation data. The total number of E. nilssonii individuals in southern and central Sweden was estimated in two different ways: 1. by using the total number of passive taxation observations, to about 5 million individuals and, 2. by using the number of five minute period containing at least one observation, to 4 million individuals. How to increase the precision of these figures are discussed.

The Western Grebe (Aechmophorus occidentalis, WEGR) is a Species of Special Concern in Alberta, declining in distribution and abundance. I evaluated how environmental variables including emergent vegetation, human developments, and prey availability affected WEGR persistence and abundance on 43 lakes in Alberta that historically supported WEGR. Persistence and abundance of WEGR were correlated, and both were positively associated with shoreline bulrush (Scirpus lacustris) and human development within a 500m buffer surrounding the lake, while inversely associated with surrounding forest. Bulrush provides important habitat for nesting, and WEGR are likely to occur on the same large fish-bearing lakes that humans prefer for recreation. However, this relationship with development puts grebes at risk for disturbance and habitat lossa primary threat to endangered birds. I recommend shoreline vegetation be protected for the success of breeding grebes, and human activity around colonies should be kept to a minimum to curb further WEGR decline. / Ecology

The decline of amphibian populations around the world is a well documented phenomenon. The Baw Baw Frog Philoria frosti belongs to a group of high-elevation, mountain-top amphibians in Australia that have undergone recent population declines, but an understanding of the responsible agents is deficient or absent for most species. The inability to diagnose agents of decline has mostly been attributed to a paucity of knowledge on the natural history of these species. / The discipline of conservation biology provided a scientific basis for commencing investigation into the decline of P. frosti. This thesis examines the pattern and extent of decline, and the autoecology and demography of the species, in order to provide a basis for evaluating conceivable decline-agents, and to establish a platform to commence diagnosis of the decline. (For complete abstract open document)

In 2004, the government of Panama created Ecoparque Panama with the aim of conserving unique habitat and curbing urbanization on the western slope of the Panama Canal. A lack of baseline ecological research in the area prompted the Panamanian National Environmental Authority and the U.S. Forest Service International Institute of Tropical Forestry to fund a camera-trap study to catalog and determine relative abundance of predator and prey species in the Panama Canal region. These infrared-triggered camera-traps allowed researchers to study elusive wildlife that may otherwise remain undetected. Using techniques adapted from previous research, infrared and motion-triggered camera-traps were purposively placed in the 4 km2 Ecoparque (U.S. Forest Service spelling: Eco-Park) Panama study area to gather data on two cervid species, white-tailed deer (Odocoileus virginianus) and red brocket deer (Mazama americana). The study was conducted over a five month period (December 2005-April 2006). Data collected were analyzed using SPSS and Stastix statistical software. Results in the form of inferred relative abundances and densities show that populations currently appear to be within the local carrying capacity. Cervid management recommendations of this study include the continued moratorium on deer hunting and strengthening of the legal protection of the red brocket deer. Given the lack of previous data, the conclusions drawn from this preliminary study will be the foundation for future research in Panama.

Little research has been conducted in the Republic of Panama concerning mammalian predator and prey populations. New Technologies such as remote camera-traps, allow researcher to efficiently monitor elusive wildlife species within dense tropical vegetation. The general goal of this study was to establish concrete evidence of the felid population in EcoParque Panama-a newly designated protected area adjacent to Panama City. The specific objective of the study was to estimate the relative abundance of predators and prey species in order to determine the feasibility of releasing more felids into the area that were to be removed from the Panama Canal Expansion Zone. Camera-traps were purposefully located in likely felid habitat and data were collected for approximately 5 months. Photographs were analyzed according to species and location captured, and abundances were established. Using SPSS and Statistix statistical software, tests for association between likely habitat for felids and time activity periods for prey species were conducted. EcoParque was found to have a robust prey population with relatively few predators. Felid predators present include the ocelot (Leopardus pardalis) and jaguarundi (Felis yaguarondi). Results suggest that felid carrying capacity has not been reached and additional individuals could be released into the area. This preliminary study lays the ground work for further research in EcoParque as well as the rest of Panama concerning predator and prey species relationships.

Presented diploma thesis deals with the topic of colonisation of newly build fishponds by macrozoobenthos organisms. Most of the authors devote to colonisation of running or periodic waters but colonisation of standing waters is more likely neglected topic. Observed locality is placed in the Northern Moravia. Three fishponds in the newly created pond system were sampled from spring till autumn during the first year after building. Qualitative samples of aquatic biota were taken by hand-net. Macrozoobenthos of fishponds was evaluated from the taxonomic structure and abundance point of view. Due to the high proportional representation of Chironomids and a lack of autecological demands of particular taxa, distribution of organism into particular functional groups was not realized. The influence of fish stock as well as short time period from the pond creation were assessed as the main factors of low taxonomic composition and low abundance of macrozoobenthos. Simultaneously, the physicochemical parameters (temperature, dissolved oxygen, pH and conductivity) of water of fish ponds were monitored. Those were assessed as suitable for stated fishponds types and should not eliminate neither the rearing of fish nor the presence of aquatic invertebrates.