Historically, the New River may have contained a genetically unique, river-spawning population of walleye (Stizostedion vitreum). Additionally, a number of genetically different walleye stocks have been stocked in Claytor Lake, Virginia. The increasing importance of the walleye fishery led to interest in clarifying key unknowns regarding the biology of the New River walleye stock. A radio telemetry study and genetic evaluation of present-day stocks led to identification of three spawning areas and the characterization of the genetic stock structure of walleye in Claytor Lake and the upper New River. Using radio telemetry to track movements of walleye, I determined that two resident walleye populations co-exist: one within Claytor Lake and the other in the New River above the lake. These populations establish spatially disjunct home ranges, remaining spatially separated throughout most of the year. Although there is no blockage to movement or migration, walleye within Claytor Lake generally spawn at Allisonia, while walleye within the upper New River spawn at Buck Dam. Some walleye from both populations spawn in other areas, such as Fosters Falls. Using allozymes, microsatellite DNA, and mitochondrial DNA marker techniques to examine population structure of walleye, I determined that the walleye within Claytor Lake are a panmictic population. This is the result of years of stocking walleye from different genetic stocks and interbreeding among individuals. The genetic structure of walleye from the New River also shows the presence of more than one genetic stock. Within the New River population, there exists a genetic stock of walleye that is characterized by three mitochondrial DNA haplotypes (43, 44, and 45) that previously have not been seen. This may be indicative of a unique walleye stock that is native to the New River and which has remained spatially or temporally segregated by spawning habits. The co-existence of two different walleye populations in the Claytor Lake / upper New River system justifies different management strategies. I recommend that management of the walleye population in Claytor Lake focus on increasing the exploitation of this non-indigenous stock. Management of the upper New River walleye population should focus on conservation of the unique native stock through supportive breeding and/or strict harvest regulations. / Master of Science

Thesis (MScIng)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Historically, ocelots (Leopardus pardalis) were hunted in large numbers for their fur, causing declines in population abundance across their range. In recent decades protection measures (e.g. CITES) and decreased public demand for ocelot fur resulted in declines in hunting pressure. Do to their elusive nature there is little known about ocelot population size, structure or general ecology. This lack of information hampers our ability to provide protection for this endangered species. Remote cameras were deployed in 7 grids across the landscape to estimate the density of ocelots in 2 habitat types; the broadleaf rainforest and pine forest of western Belize. Camera trapping combined with mark-recapture statistics resulted in densities of 18.91 - 20.75 ocelots per 100 km2 in the rainforest and 2.31 0 3.81 ocelots per 100 km2 in the pine forest habitat. This study examined the issues of camera spacing and animals with zero distance moved and their effect on density estimation. Increased camera spacing resulted in larger buffer sizes (increasing the effective trap area) and decreased density estimates. Inclusion of zero distance animals decreased buffer sizes and increased density estimates. Regardless of these effects, ocelot density was higher in the broadleaf rainforest than the pine forest. The ocelot density estimates in Belizean forests were lower than those in other portions of their range. The camera trapping technique demonstrated ocelots to be mostly active at night, with peaks of activity after sunset and before sunrise, and to travel low-use roads in the wet season and high-use roads in the dry season. Radio telemetry was used in this study to estimate the home range size and density of ocelots in the broadleaf rainforest of western Belize. Six collared ocelots (3 male, 3 female) were collared and tracked from September 2003 - August 2004. Male ocelots had an average home range size of 33.01 km2 (95% fixed kernel) and 29.00 km2 (100% MCP), and female ocelots had an average home range size of 21.05 km2 (95% fixed kernel) and 29.58 km2 (100% MCP). Most ocelots had larger home ranges in the dry season than the wet season. Ocelots showed a large amount of same sex home range overlap; with male-male overlap averaging 25% (100% MCP) and female-female overlap averaging 16% (100% MCP). Ocelot density determined using radio telemetry was 7.79 - 10.91 ocelots per 100 km2. The radio telemetry ocelot densities were lower and their home ranges larger in the Belizean broadleaf rainforests than those in other portions of their range. The camera trapping and radio telemetry techniques were compared against one another and combined in order to test which technique may be more successful in studying certain aspects of feline behavior. Activity budgets and density estimates determined from camera trapping were superior to radio telemetry, whereas camera trapping home ranges showed higher variation and lower resolution than radio telemetry. However, home range estimates determined from camera trapping captured long distance movements, a larger percent of territory overlap, and displayed potential for estimating an animal's core use area. When radio telemetry data were used to create a buffer around camera traps based on the average radius of an ocelots' home range size, the resulting density estimates were smaller than those determined using the current camera trapping methodology. This study provided much needed baseline information on ocelot abundance, home range size, activity patterns, and trail use. While sample sizes were small, this study had the largest number of ocelots captured in Central America to date. Although camera trapping is already a useful tool in felid research, this study highlights the importance of further standardization of the camera trapping methodology, increasing its potential for monitoring and conservation across habitats and study sites. / Master of Science

Call number: LD2668 .T4 1984 B72 / Master of Science

ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Research on earthquakes and volcanos is of particular importance in seismic instable regions. To improve opportunities of research and civil defence, continuous coverage of seismic activities of a large area at a certain time is necessary. This paper deals with the issues concerning the collecting of environmental data by a number of autonomous field stations and their transmission to central station through a cost effective low bandwidth packer radio data network. This paper deals with the acquisition, preprocessing and transmission of seismic data. Therefore, a prototype system is discussed, which will be developed at the University of Salzburg, Austria.

House cat movements in Canberra suburbs adjacent to grassland and forest/woodland areas were examined using radio-telemetry over 9 months. Information on the composition of vertebrate prey caught by house cats in Canberra was also collected by recording prey items deposited at cat owners' residences over 12 months. Home range areas of 10 suburban house cats, and a colony of seven farm cats, were examined using 95% convex polygons. Nocturnal home range areas of the suburban cats varied between 0.02 and 27.93 ha (mean 7.89 ha), and were larger than diurnal home range areas (range 0.02 to 17.19 ha - mean 2.73 ha). Nocturnal home range areas of cats from the farm cat colony varied between 1.38 and 4.46 ha (mean 2.54 ha), and were also larger than diurnal home range areas (range 0.77 to 3.70 ha - mean 1.70 ha). Activity levels were greater at night than during the day, though diel activity patterns varied seasonally in response to ambient temperature. Four suburban house cats moved between 390 m and 900 m into habitat adjoining the suburb. Movements further than 100-200 m from the suburb edge were always made at night. Polygons describing the home ranges of these animals were strongly spatially biased away from the suburban environment, though the cats spent the majority of their time within the bounds of the suburb. In addition to nocturnal and diurnal effects, home range areas, and subsequently habitat utilisation, appeared primarily determined by the density and spatial distribution of cats utilising separate food resources, and the dominance of individual cats in local social hierarchies, rather than gender or neutering effects. Home ranges of cats in the farm cat colony overlapped extensively, as did those of cats living at the same suburban residence. There was little or no overlap between the home ranges of cats from different residences. Barriers, in the form of busy roads, appeared to also significantly influence home range size and shape. Within home range areas, house cat movements during the day appeared strongly influenced by available cover (drains, tall grass, fences and shrubs etc.), and the location of resting/sunning spots and hunting sites close to home. At night, movement patterns appeared influenced by the location of favoured hunting sites toward the outer edges of home range areas (in this study, tall grass and scrub/forest habitat, and farm buildings). Nineteen hundred and sixty one prey items representing 67 species were reported or collected. Sixty-four percent of the prey items were introduced mammals, with native birds comprising 14%, introduced birds 10%, unidentified birds 3%, reptiles 7%, amphibians 1% and native mammals 1%. Predation appeared to be largely opportunistic with respect to spatial and temporal (daily and seasonal) prey availability and accessibility. All amphibians and 62% of mammals taken by cats not confined at night, were caught at night. In contrast, 70% of birds caught, and 90% of reptiles, were taken during the day (45% of birds between 0600 h and 1200 h, and 61% of reptiles between 1200 h and 1800 h). There was some evidence that small mammals are preferred prey of house cats. The mean number of prey items reported per cat over 12 months - 10.2 � 2.66 (2SE, n=138) - was significantly lower than mean predation per cat per year - 23.3 � 6.16 (2SE, n=138) - estimated by cat owners before the prey survey began. Seventy percent of cats were observed to catch less than 10 prey items over 12 months, but for 6% of cats, more than 50 prey items were recorded. Because counts of the amount of prey caught per house cat per unit time were highly positively skewed, data assumptions and statistical parameters used to extrapolate results from the study sample of cats, to the house cat population of Canberra, had a significant effect on estimates of total predation in Canberra. The precision of the total predation estimate was low (± 25%), from a sample of 0.3% of the Canberra house cat population. The accuracy of such estimates are dependent on how representative the study cat sample is of the wider house cat population, and on the proportion of prey items not observed by cat owners. The total amount of prey taken was not significantly influenced by cat gender, age when desexed, or cat breed. Nor did belling or the number of meals provided per day have a significant influence on predatory efficiency. Cat age and the proportion of nights spent outside explained approximately 11 % of the variation in the amount of prey caught by individual cats. House cat density and distance to prey source areas (rural/grassland habitat) explained 43% of variation in predation on introduced mammals and birds. The impact of predation beyond suburb edges is likely to be most significant on populations of small to medium sized arboreal and ground-dwelling mammals, because of their nocturnal nature, and because they appear to be preferred prey types of house cats. Impacts on diurnally active prey, such as most birds and reptiles, are likely to be confined to within 200 m of residential housing (possibly further where good cover is available). Properly enforced nocturnal confinement should restrict the range sizes of cats that roam widely and utilisation of habitat beyond suburb edges, and also reduce predation on mammals and amphibians. Night-time curfews however, are unlikely to greatly reduce predation on diurnally active species, including most birds and reptiles. Curfews are currently neither widely adopted nor effectively practiced in Canberra. Estimates of predation by house cats, particularly extrapolated estimates, should be treated with caution. They do not necessarily reflect relative impacts on different prey types. Nor do high rates of predation prove prey populations are detrimentally effected, particularly in urban environments. Nonetheless, on a small (backyard) scale in suburban environments, and in habitat within 1 km of residential housing, including isolated private properties, predation by individual cats may threaten populations of native wildlife. Hunting by house cats is particularly undesirable in relatively undisturbed habitat because of fundamental differences in the ecological processes operating in these areas (especially isolated remnants) compared with contrived and modified suburban environments. Adverse impacts on native fauna will always be potentially greatest in undisturbed habitat adjacent to new residential developments

Thesis (MSc)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Franklin’s ground squirrels (Poliocitellus franklinii; FGS) are increasingly considered of conservation concern throughout much of their range, yet little is known about this species as compared to their congeners. The main objectives of this thesis were to (1) collate and summarize demographic and life-history data to present an up-to-date account of population characteristics for a FGS population near Delta Marsh, Manitoba, (2) document nest movements wherein female FGS relocate their nests and litter during the energetically demanding lactation period and to investigate proximate factors mediating movements, including intraspecific interaction, ectoparasite burden, and nest habitat associations, and, (3) investigate the influence of ectoparasite infestation on dam and litter attributes. Dams consistently relocated litters during lactation in response to conspecific nest discovery, ectoparasite pressure and habitat type. Relocations may compensate for major costs of ectoparasitism, as beyond the frequency of relocation, only litter sex ratio was influenced by ectoparasite burden in this study. / October 2015

Fishes are widely used by biologist as ecological indicators that measure key elements of complex systems, without having to capture the full complexity of a specific system. The Vaal River in South Africa is classified as Africa’s hardest working river and is home to, two yellowfish species that are socially and economically important. Both these yellowfish species are considered to be sensitive to changes in water quantity and quality, habitat destruction and utilisation pressure and are often used as ecological indicators to manage aquatic ecosystems. Very little however, is known about their movement, response to changing environmental variables and interspecies habitat preferences. This study therefore aims to use radio telemetry as a method to characterise and evaluate how yellowfish behaviour is influenced by changing environmental variables. To characterise the behavioural ecology of the Vaal-Orange River yellowfish species in lentic and lotic ecosystems, Labeobarbus aeneus (n=18) and L. kimberleyensis (n=3) were fitted with externally attached radio transmitters in Boskop Dam (L. aeneus, n=4) and the Vaal River (L. aeneus, n=14) (L. kimberleyensis, n=3). Various methods were used to collect yellowfish species including: gill nets, to target mobile individuals, in deep habitats, electro-fishing (electro-narcosis) to collect yellowfish in shallow habitats and angling techniques in a wide variety of habitats. Thereafter yellowfish species were sedated and tagged with externally attached radio transmitters, before being released back into the system. Yellowfish were monitored for eleven months using a remote monitoring system together with manual monitoring surveys. Analyses of data collected showed that L. aeneus follows distinct behavioural patterns, with some individual variations in behaviour. Labeobarbus aeneus exhibited higher movement that are associated with deeper water during daylight hours (04:00-16:00). During nocturnal periods (20:00-04:00) L. aeneus showed a decrease in movement activity and preferred shallower water compared to daytime. However, L. aeneus in the Vaal River seems to be less influenced by bright daylight and this might be due to the turbidity of the river water. Labeobarbus aeneus in Boskop Dam showed higher movement counts during full moon phases whereas L. aeneus in the Vaal River showed higher movement counts during new moon phases. All tagged fishes in Boskop Dam and in the Vaal River preferred deeper water during full moon phases than during new moon phases. Movement were significantly higher (P<0.05) with increased temperatures and shallower water in summer whereas movement significantly decreased (P<0.05) with a decrease in temperature and increased depth in autumn and winter. Seasonal movement data were, however, limited. This study confirms that radio telemetry methods can be used to characterise the behavioural ecology of yellowfish species. In addition, the study has improved the knowledge of how environmental variables may affect the behaviour of yellowfish species. However, due to limited data and our understanding of these species, it is still uncertain how behaviour of yellowfish species can be applied as an ecological indicator of aquatic ecosystems. / Thesis (MSc (Zoology))--North-West University, Potchefstroom Campus, 2013

Fishes are widely used by biologist as ecological indicators that measure key elements of complex systems, without having to capture the full complexity of a specific system. The Vaal River in South Africa is classified as Africa’s hardest working river and is home to, two yellowfish species that are socially and economically important. Both these yellowfish species are considered to be sensitive to changes in water quantity and quality, habitat destruction and utilisation pressure and are often used as ecological indicators to manage aquatic ecosystems. Very little however, is known about their movement, response to changing environmental variables and interspecies habitat preferences. This study therefore aims to use radio telemetry as a method to characterise and evaluate how yellowfish behaviour is influenced by changing environmental variables. To characterise the behavioural ecology of the Vaal-Orange River yellowfish species in lentic and lotic ecosystems, Labeobarbus aeneus (n=18) and L. kimberleyensis (n=3) were fitted with externally attached radio transmitters in Boskop Dam (L. aeneus, n=4) and the Vaal River (L. aeneus, n=14) (L. kimberleyensis, n=3). Various methods were used to collect yellowfish species including: gill nets, to target mobile individuals, in deep habitats, electro-fishing (electro-narcosis) to collect yellowfish in shallow habitats and angling techniques in a wide variety of habitats. Thereafter yellowfish species were sedated and tagged with externally attached radio transmitters, before being released back into the system. Yellowfish were monitored for eleven months using a remote monitoring system together with manual monitoring surveys. Analyses of data collected showed that L. aeneus follows distinct behavioural patterns, with some individual variations in behaviour. Labeobarbus aeneus exhibited higher movement that are associated with deeper water during daylight hours (04:00-16:00). During nocturnal periods (20:00-04:00) L. aeneus showed a decrease in movement activity and preferred shallower water compared to daytime. However, L. aeneus in the Vaal River seems to be less influenced by bright daylight and this might be due to the turbidity of the river water. Labeobarbus aeneus in Boskop Dam showed higher movement counts during full moon phases whereas L. aeneus in the Vaal River showed higher movement counts during new moon phases. All tagged fishes in Boskop Dam and in the Vaal River preferred deeper water during full moon phases than during new moon phases. Movement were significantly higher (P<0.05) with increased temperatures and shallower water in summer whereas movement significantly decreased (P<0.05) with a decrease in temperature and increased depth in autumn and winter. Seasonal movement data were, however, limited. This study confirms that radio telemetry methods can be used to characterise the behavioural ecology of yellowfish species. In addition, the study has improved the knowledge of how environmental variables may affect the behaviour of yellowfish species. However, due to limited data and our understanding of these species, it is still uncertain how behaviour of yellowfish species can be applied as an ecological indicator of aquatic ecosystems. / Thesis (MSc (Zoology))--North-West University, Potchefstroom Campus, 2013