Recent observed changes in bird distributions provide an unprecedented opportunity to gain a deeper understanding of the processes that influence species' persistence. By modelling presence-absence data from the North American Breeding Bird Survey, we found evidence that the breeding range of the western burrowing owl has contracted at its northern, western, and eastern boundaries since 1967. We suggest that the species' breeding distribution is also expanding southwards to former wintering grounds into northern Mexico, facilitated by the appearance of new breeding habitat created by irrigated agriculture in the arid areas of southwestern United States and northwestern Mexico. This dissertation explores the hypothesis that burrowing owls from northern migratory populations have become resident breeders in areas of northwestern Mexico that were formerly used only by migratory owls during winter, contributing to both population declines near the northern extent of the species' breeding range and population increases in the southern half of the species' range. We used novel DNA microsatellite markers to test patterns of gene flow predicted by this migration-mediated range-shift hypothesis. We genotyped 1,560 owls from 36 study locations in Canada, Mexico, and the United States. Analyses of molecular variance provided evidence that burrowing owl populations in both northwestern Mexico and Canada are genetically different from the rest of the populations in the breeding range, lending some support to the migration-mediated range-shift hypothesis. We found evidence of subtle genetic differentiation associated with subtropical irrigated agricultural areas in southern Sonora and Sinaloa, demonstrating that land use can produce location-specific population dynamics leading to genetic structure even in the absence of dispersal barriers. We also used stable isotopes 2/H, 13/C, and 15/N in feathers to test philopatry and breeding dispersal patterns predicted by this migration-mediated range-shift hypothesis. Burrowing owl populations near the northern edge of the species' breeding range had a high proportion of immigrants compared to interior populations, while other populations had high levels of philopatry. Stable isotopes also provided evidence of breeding dispersal events from Canadian populations to northwestern Mexico in support of the migration-mediated range-shift hypothesis, but similar isotope signatures in nestling feathers between these two regions prevent stronger inferences.

Os lagostins de água doce sulamericanos (Família Parastacidae) são representados por três gêneros: Parastacus Huxley, 1879, Samastacus Riek, 1971 and Virilastacus Hobbs, 1991. Esse grupo é distribuído no Sul do Brasil (Rio Grande do Sul and Santa Catarina), Uruguai, Argentina e Chile. Os objetivos dessa tese foram revisar a taxonomia do gênero Parastacus e investigar a sua monofilia e relações filogenéticas entre suas espécies e entre os outros gêneros sulamericanos. Para esse propósito, várias coleções e museus ao redor do mundo foram analisados (Brasil, Argentina, Uruguai, Chile, Estados Unidos, Alemanha, Holanda, Inglaterra e França) em adição a coletas realizadas entre Março de 2013 a Setembro de 2016. Os espécimes foram analisados em estereomicroscópio e os desenhos foram preparados com auxílio de camara lucida. Para as análises genéticas, uma abordagem multigênica foi utilizada com dois marcadores mitocondriais (Cox1 e 16S) e um nuclear (28S). A análise filogenética foi realizada por Inferência Bayesiana e a distância genética p também foi calculada. Adicionalmente, o risco de extinção foi assessado para algumas espécies de acordo com o sub-critério B1 da IUCN que leva em consideração a estimativa da Área de Extenção de Ocorrência. Oito espécies foram redescritas: Parastacus brasiliensis (von Martens, 1869), P. defossus Faxon, 1898, P. laevigatus Buckup & Rossi, 1980, P. pilimanus (Von Martens, 1869), P. pugnax (Poepigg, 1835), P. promatensis Fontoura & Conter, 2008 e P. varicosus Faxon, 1898. Um novo gênero foi proposto para alocar a espécie P. nicoleti (Philippi, 1882) que também foi redescrita. Treze novas espécies foram descritas. Assim como, chaves de identificação, descrições, diagnoses, sinonímias e mapas de distribuição foram providos. As árvores filogenéticas resultantes corroboraram com a monofilia de Parastacus e do clado sulamericano, além de dar suporte para o estabelecimento de um novo gênero e novas espécies. Com essa tese, o aumento da riqueza específica para Parastacus é de mais de 150% e as novas informações sobre habitat e distribuição trarão suporte para futuros estudos de conservação e manejo. / South American freshwater crayfish (Family Parastacidae) are represented by three genera: Parastacus Huxley, 1879, Samastacus Riek, 1971 and Virilastacus Hobbs, 1991. This group is distributed in Southern Brazil (Rio Grande do Sul and Santa Catarina), Uruguay, Argentina and Chile. The goals of this thesis is to review the taxonomy of the genus Parastacus and to investigate the monophyly and phylogenetic relationships within Parastacus and among South American crayfish genera. For this purpose, several collections and museums around the world were analyzed (Brazil, Argentina, Uruguay, Chile, United States of America, Germany, Netherlands, England, and France) in addition to collectings carried out from March 2013 to September 2016. Specimens were analyzed under a stereomicroscope and drawings were prepared with the aid of a camara lucida. For genetic analysis, a multigenic approach was used with two mitochondrial (Cox1 and 16S) and one nuclear (28S) markers. Phylogenetic analysis were performed with Bayesian Inference and genetic p-distances were also calculated. In addition, the extinction risk was assessed according to the sub-criterion B1 of IUCN that estimates the Extent of Occurrence (EOO) for some species. Eight species are redescribed: Parastacus brasiliensis (von Martens, 1869), P. defossus Faxon, 1898, P. laevigatus Buckup & Rossi, 1980, P. pilimanus (Von Martens, 1869), P. pugnax (Poepigg, 1835), P. promatensis Fontoura & Conter, 2008 and P. varicosus Faxon, 1898. A new genus is proposed to encompass the species P. nicoleti (Philippi, 1882) and this species is also redescribed. In addition, 13 new species are described. Identification keys, descriptions, diagnoses, synonymies and distribution maps of the genera and species are provided. Phylogenetic trees corroborated the monophyly of Parastacus and the South American crayfish clade, and give support for the establishment of a new genus and new species. With this thesis, the increase in specific richness for Parastacus is more than 150% and new information about habitat and distribution will bring support for future conservation and management studies.

Reintroduction of captive-bred Western Burrowing Owls (Athene cunicularia hypugaea) in the Nicola Valley, British Columbia, has had limited success in increasing the local breeding population. Traditionally, yearling captive-hatched Burrowing Owls that were paired and released into artificial burrows in the field, held overnight, and provided with supplemental food throughout the breeding season (hard release) have had high post-release dispersal and mortality. In 2005 and 2006, I used an alternative soft-release technique to test for an improvement upon the hard-release technique. The soft release followed the same procedure as the traditional hard release but also included enclosures around burrow entrances to contain the owls for a 2-week period in the field prior to release. I compared immediate post-release dispersal, seasonal survival, and reproductive success for 37 hard-released and 30 soft-released pairs. I radio-tagged 39 of these released owls in order to accurately monitor their activities, regardless of whether they remained at release sites or dispersed. The soft-release technique led to 20% more owls remaining at the release sites, 14% more owls surviving the breeding season, and 20% more owl pairs fledging juveniles. In addition to investigating adult survival and reproductive success, I examined post-fledging juvenile survival, local recruitment, and habitat use, and adult prey consumption behaviour in order to assess the potential of these aspects to limit the success of the reintroduction. Survival and local recruitment rates of the juveniles of captive-bred adults released with two different techniques were similar to that of juveniles of wild adults in the same study area or in other parts of the Burrowing Owl's range. Juvenile habitat-selection analyses identified the importance of rangeland, and comparisons of prey consumption revealed the rapid development of foraging abilities by captive-bred Burrowing Owls. I concluded that these aspects of the owl's ecology were not negatively affected by a captive upbringing, and therefore not likely limiting the success of the reintroduction. Overall, the use of an enclosure-based soft-release technique addresses major limitations to the success of releases, and shows promise for increasing the breeding population in this region. This approach can also be applied to recovery efforts throughout the Burrowing Owls' range, and provide guidelines for other species' reintroduction programs.

The western burrowing owl, Athene cunicularia hypugaea, is a Federal Species of Concern, whose numbers and range have been drastically reduced from historic levels in Texas. Burrowing owls roost and forage in agricultural areas, and it has been hypothesized that exposure to insecticides may be a factor in the decline of their population. Burrowing owls wintering in southern Texas use agricultural culverts in cotton fields as roost sites, which may increase their risk of exposure to agricultural chemicals, either through ingestion of contaminated prey or through dermal exposure to agricultural runoff. Simulation modeling was used to characterize the risks to individual burrowing owls wintering in agricultural landscapes in southern Texas due to effects of exposure to insecticides or other agricultural chemicals. The simulation model was created using Stella® VII software (High Performance Systems, Inc., New Hampshire, USA). The model is broken into four submodels simulating (1) foraging behavior of burrowing owls, (2) chemical applications to crops, (3) chemical transfer and fate in the crop soil and prey items, and (4) chemical exposure in the burrowing owl. This model was used to evaluate (1) which components of the model most affect the endpoints, (2) the relationship between increased concentrations of agricultural chemicals in culverts and subsequent lethal and sublethal effects from dermal exposure to agricultural runoff, and (3) which agricultural chemicals have the greatest potential to cause adverse effects in burrowing owls. Model results suggested (1) the half-lives of agricultural chemicals in birds caused the most variation in the results, and data gaps exist for several important model components (2), exposure to increased concentrations of agricultural chemicals in culverts is unlikely to result in lethal effects, but is likely to lead to sublethal effects in burrowing owls, and (3) the chemicals with the greatest potential to negatively affect burrowing owls wintering in southern Texas are the OP insecticides chlorpyrifos, dicrotophos, and disulfoton, the oxadiazine insecticide indoxacarb, the herbicide trifluralin, and the defoliants tribufos and paraquat. The results of this model demonstrate the usefulness of simulation modeling to guide future research related to the conservation of burrowing owls.

Thesis (Ph. D.)--University of Western Australia, 2004. / Title from PDF t.p. (viewed Feb. 7, 2006). Includes bibliographical references.

No description available.

Os lagostins de água doce sulamericanos (Família Parastacidae) são representados por três gêneros: Parastacus Huxley, 1879, Samastacus Riek, 1971 and Virilastacus Hobbs, 1991. Esse grupo é distribuído no Sul do Brasil (Rio Grande do Sul and Santa Catarina), Uruguai, Argentina e Chile. Os objetivos dessa tese foram revisar a taxonomia do gênero Parastacus e investigar a sua monofilia e relações filogenéticas entre suas espécies e entre os outros gêneros sulamericanos. Para esse propósito, várias coleções e museus ao redor do mundo foram analisados (Brasil, Argentina, Uruguai, Chile, Estados Unidos, Alemanha, Holanda, Inglaterra e França) em adição a coletas realizadas entre Março de 2013 a Setembro de 2016. Os espécimes foram analisados em estereomicroscópio e os desenhos foram preparados com auxílio de camara lucida. Para as análises genéticas, uma abordagem multigênica foi utilizada com dois marcadores mitocondriais (Cox1 e 16S) e um nuclear (28S). A análise filogenética foi realizada por Inferência Bayesiana e a distância genética p também foi calculada. Adicionalmente, o risco de extinção foi assessado para algumas espécies de acordo com o sub-critério B1 da IUCN que leva em consideração a estimativa da Área de Extenção de Ocorrência. Oito espécies foram redescritas: Parastacus brasiliensis (von Martens, 1869), P. defossus Faxon, 1898, P. laevigatus Buckup & Rossi, 1980, P. pilimanus (Von Martens, 1869), P. pugnax (Poepigg, 1835), P. promatensis Fontoura & Conter, 2008 e P. varicosus Faxon, 1898. Um novo gênero foi proposto para alocar a espécie P. nicoleti (Philippi, 1882) que também foi redescrita. Treze novas espécies foram descritas. Assim como, chaves de identificação, descrições, diagnoses, sinonímias e mapas de distribuição foram providos. As árvores filogenéticas resultantes corroboraram com a monofilia de Parastacus e do clado sulamericano, além de dar suporte para o estabelecimento de um novo gênero e novas espécies. Com essa tese, o aumento da riqueza específica para Parastacus é de mais de 150% e as novas informações sobre habitat e distribuição trarão suporte para futuros estudos de conservação e manejo. / South American freshwater crayfish (Family Parastacidae) are represented by three genera: Parastacus Huxley, 1879, Samastacus Riek, 1971 and Virilastacus Hobbs, 1991. This group is distributed in Southern Brazil (Rio Grande do Sul and Santa Catarina), Uruguay, Argentina and Chile. The goals of this thesis is to review the taxonomy of the genus Parastacus and to investigate the monophyly and phylogenetic relationships within Parastacus and among South American crayfish genera. For this purpose, several collections and museums around the world were analyzed (Brazil, Argentina, Uruguay, Chile, United States of America, Germany, Netherlands, England, and France) in addition to collectings carried out from March 2013 to September 2016. Specimens were analyzed under a stereomicroscope and drawings were prepared with the aid of a camara lucida. For genetic analysis, a multigenic approach was used with two mitochondrial (Cox1 and 16S) and one nuclear (28S) markers. Phylogenetic analysis were performed with Bayesian Inference and genetic p-distances were also calculated. In addition, the extinction risk was assessed according to the sub-criterion B1 of IUCN that estimates the Extent of Occurrence (EOO) for some species. Eight species are redescribed: Parastacus brasiliensis (von Martens, 1869), P. defossus Faxon, 1898, P. laevigatus Buckup & Rossi, 1980, P. pilimanus (Von Martens, 1869), P. pugnax (Poepigg, 1835), P. promatensis Fontoura & Conter, 2008 and P. varicosus Faxon, 1898. A new genus is proposed to encompass the species P. nicoleti (Philippi, 1882) and this species is also redescribed. In addition, 13 new species are described. Identification keys, descriptions, diagnoses, synonymies and distribution maps of the genera and species are provided. Phylogenetic trees corroborated the monophyly of Parastacus and the South American crayfish clade, and give support for the establishment of a new genus and new species. With this thesis, the increase in specific richness for Parastacus is more than 150% and new information about habitat and distribution will bring support for future conservation and management studies.

Os lagostins de água doce sulamericanos (Família Parastacidae) são representados por três gêneros: Parastacus Huxley, 1879, Samastacus Riek, 1971 and Virilastacus Hobbs, 1991. Esse grupo é distribuído no Sul do Brasil (Rio Grande do Sul and Santa Catarina), Uruguai, Argentina e Chile. Os objetivos dessa tese foram revisar a taxonomia do gênero Parastacus e investigar a sua monofilia e relações filogenéticas entre suas espécies e entre os outros gêneros sulamericanos. Para esse propósito, várias coleções e museus ao redor do mundo foram analisados (Brasil, Argentina, Uruguai, Chile, Estados Unidos, Alemanha, Holanda, Inglaterra e França) em adição a coletas realizadas entre Março de 2013 a Setembro de 2016. Os espécimes foram analisados em estereomicroscópio e os desenhos foram preparados com auxílio de camara lucida. Para as análises genéticas, uma abordagem multigênica foi utilizada com dois marcadores mitocondriais (Cox1 e 16S) e um nuclear (28S). A análise filogenética foi realizada por Inferência Bayesiana e a distância genética p também foi calculada. Adicionalmente, o risco de extinção foi assessado para algumas espécies de acordo com o sub-critério B1 da IUCN que leva em consideração a estimativa da Área de Extenção de Ocorrência. Oito espécies foram redescritas: Parastacus brasiliensis (von Martens, 1869), P. defossus Faxon, 1898, P. laevigatus Buckup & Rossi, 1980, P. pilimanus (Von Martens, 1869), P. pugnax (Poepigg, 1835), P. promatensis Fontoura & Conter, 2008 e P. varicosus Faxon, 1898. Um novo gênero foi proposto para alocar a espécie P. nicoleti (Philippi, 1882) que também foi redescrita. Treze novas espécies foram descritas. Assim como, chaves de identificação, descrições, diagnoses, sinonímias e mapas de distribuição foram providos. As árvores filogenéticas resultantes corroboraram com a monofilia de Parastacus e do clado sulamericano, além de dar suporte para o estabelecimento de um novo gênero e novas espécies. Com essa tese, o aumento da riqueza específica para Parastacus é de mais de 150% e as novas informações sobre habitat e distribuição trarão suporte para futuros estudos de conservação e manejo. / South American freshwater crayfish (Family Parastacidae) are represented by three genera: Parastacus Huxley, 1879, Samastacus Riek, 1971 and Virilastacus Hobbs, 1991. This group is distributed in Southern Brazil (Rio Grande do Sul and Santa Catarina), Uruguay, Argentina and Chile. The goals of this thesis is to review the taxonomy of the genus Parastacus and to investigate the monophyly and phylogenetic relationships within Parastacus and among South American crayfish genera. For this purpose, several collections and museums around the world were analyzed (Brazil, Argentina, Uruguay, Chile, United States of America, Germany, Netherlands, England, and France) in addition to collectings carried out from March 2013 to September 2016. Specimens were analyzed under a stereomicroscope and drawings were prepared with the aid of a camara lucida. For genetic analysis, a multigenic approach was used with two mitochondrial (Cox1 and 16S) and one nuclear (28S) markers. Phylogenetic analysis were performed with Bayesian Inference and genetic p-distances were also calculated. In addition, the extinction risk was assessed according to the sub-criterion B1 of IUCN that estimates the Extent of Occurrence (EOO) for some species. Eight species are redescribed: Parastacus brasiliensis (von Martens, 1869), P. defossus Faxon, 1898, P. laevigatus Buckup & Rossi, 1980, P. pilimanus (Von Martens, 1869), P. pugnax (Poepigg, 1835), P. promatensis Fontoura & Conter, 2008 and P. varicosus Faxon, 1898. A new genus is proposed to encompass the species P. nicoleti (Philippi, 1882) and this species is also redescribed. In addition, 13 new species are described. Identification keys, descriptions, diagnoses, synonymies and distribution maps of the genera and species are provided. Phylogenetic trees corroborated the monophyly of Parastacus and the South American crayfish clade, and give support for the establishment of a new genus and new species. With this thesis, the increase in specific richness for Parastacus is more than 150% and new information about habitat and distribution will bring support for future conservation and management studies.

Arid and semi arid environments are characterised by extreme fluctuations in temperature and low rainfall which present significant challenges to the animals inhabiting these areas. Mammals, such as aardvarks (Orycteropus afer, Pallas 1766), excavate burrows in order to avoid predators and climatic extremes and are termed “ecosystem engineers” as they physically modify their environment and in doing so create new habitats and alter the availability of resources to other species. In this study I assessed the microhabitat conditions (maximum and minimum temperature, relative humidity and seed abundance) of aardvark burrows in relation to paired control sites. In addition, I evaluated the use of aardvark burrows by other vertebrate and invertebrate species and investigated the impact of aardvark burrow mounds on landscape scale floristic diversity. Maximum temperatures were significantly lower (p < 0.05) and minimum temperatures and midday humidity were significantly higher (p < 0.05) inside the burrows at the three study sites, Kwandwe Private Game Reserve (Kwandwe), Mountain Zebra National Park (MZNP) and Tswalu Kalahari Reserve (Tswalu). There were no significant differences between the concentration of seeds, the average numbers of unique individual small mammals, trap success or small mammal species richness recorded inside the burrows compared to outside (p > 0.05). At all three sites, small mammal species diversity was higher in the burrows but this result was also not significant (p > 0.05 for all). Trap success and the number of individuals captured was higher at Tswalu than the other two sites (p < 0.05 for both). The different methods used in this study revealed a total of 25 mammal, seven bird, one amphibian and six reptile species utilising aardvark burrows. There were significant differences in insect community assemblages between the burrows and open control areas at Kwandwe and Tswalu (p < 0.05 for both) but not at MZNP (p > 0.05). The parasitic guild was more prominent inside the burrows than outside but their abundance was not as high as anticipated, possibly due to the placement of traps closer to the burrow entrances than the sleeping chambers. The complex structure of the burrows prevented the placement of traps in close proximity to the sleeping chambers. As expected, the amount of bare earth was significantly higher on active and recently abandoned burrow mounds compared to the old burrow mounds and reference plots at all three sites (p < 0.05 for all), with the exception of the active burrows at Tswalu. Overall, the different plot types were characterised by significantly different plant communities during all the seasons at MZNP, during three of the seasons at Kwandwe and only during winter at Tswalu. The total species richness recorded on the reference plots was higher than on the burrow mounds at all three sites. However, species diversity on the reference plots was not significantly higher than the burrows at any of the sites (p > 0.05 for all sites). Although the results were not significant, the overall species diversity at a site level was greater than the reference patches at Kwandwe and Tswalu (p > 0.05 for both). Aardvarks fulfil the criteria of a significant ecosystem engineer and their presence in arid and semi-arid environments is likely to be critical to the survival of other individual organisms and species, particularly when alternative burrowing animals are either absent or restricted in their activities. Thus, aardvark populations should be considered a conservation priority in arid and semi-arid ecosystems.

abstract: Unmanned subsurface investigation technologies for the Moon are of special significance for future exploration when considering the renewed interest of the international community for this interplanetary destination. In precision agriculture, farmers demand quasi-real-time sensors and instruments with remote crop and soil detection properties to meet sustainability goals and achieve healthier and higher crop yields. Hence, there is the need for a robot that will be able to travel through the soil and conduct sampling or in-situ analysis of the subsurface materials on earth and in space. This thesis presents the design, fabrication, and characterization of a robot that can travel through the soil. The robot consists of a helical screw design coupled with a fin that acts as an anchor. The fin design is an integral part of the robot, allowing it to travel up and down the medium unaided. Experiments were performed to characterize different designs. It was concluded that the most energy-efficient speed from traveling down the medium is 20 rpm, while 60 rpm was the efficient speed for traveling up the medium. This research provides vital insight into developing subsurface robots enabling us to unearth the valuable knowledge that subsurface environment holds to help the agricultural, construction, and exploration communities. / Dissertation/Thesis / Video of Self Burrowing Robot travelling down the medium / Video of Self Burrowing Robot travelling out the medium / Masters Thesis Mechanical Engineering 2020