The Wild Harts Study Area (WHSA) covers an ecological diverse area in northeastern British Columbia that is poorly represented by protected areas. Industrial expansion threatens to fragment the contiguous habitats found in the WHSA — reducing the ability of the area to perform important landscape functions at local and continental scales. I employed a systematic conservation planning approach to prioritize lands for conservation. The software MARXAN with integer linear programming (ILP) was used to produce optimal solutions for conservation, at the lowest cost, and to enforce principles of protected area design. Priority lands for conservation action were those that met science-based targets for a selection of ecological surrogates, displayed low edge-to-area ratios, and represented intact landscapes outside the influence of resource development. The finalized conservation portfolio produced in this research is meant to inform protected area planning in the WHSA.
Moose are a keystone species and play a substantive role in predator-prey systems, nutrient cycling, and forest succession. Following a mountain pine beetle (MPB) spread across British Columbia, I quantified seasonal home-range selection, home-range size and daily movements, and within home-range selection of GPS-collared female moose in three study areas. I used case-matched logistic regressions with individual seasonal home-ranges, and mixed-effects logistic regressions for seasonal locations of female moose to determine habitat selection at two spatial scales. Individual variation was evident at both home-range and within-home-range scales. Female moose selected lodgepole pine-leading stands at both spatial scales regardless of mass die-off due to MPB. Clear-cuts following the MPB outbreak were avoided in drier locations, and trade-offs between cover and browse were evident where disturbance due to salvage logging was highest. My findings indicate that MPB salvage-logging reduced moose habitat, and thereby, influenced selection by female moose.
Females from a wide variety of taxa display elaborate ornaments and aggressive behaviours that are similar to those expressed by males. Although recent empirical investigation has demonstrated that ornamental traits and behaviours of females may function by attracting mates or signalling competitive ability when competing against conspecifics for access to mates and resources, less is known about how such traits influence the mating success of free-living female birds. For my research, I experimentally examined how variation in plumage brightness and behaviour of female tree swallows (Tachycineta bicolor) influenced their mating success. Plumage brightness of females had no influence on investment in parental care or mating strategies of males, or the quality of social mate paired to the female. These results suggest that bright plumage is not a signal of attractiveness preferred by male tree swallows. In contrast, I report evidence that plumage brightness of female tree swallows is involved in agonistic interactions with conspecifics. Females whose plumage brightness was enhanced to signal high quality were less able to retain their nest site than females whose plumage brightness was reduced to signal low quality. This suggests that females displaying bright plumage may be challenged by conspecifics of high quality to test the quality signalled by bright plumage, and is supported by the finding that females displaying enhanced plumage brightness suffered social costs, such as delaying breeding and producing low-quality nestlings. Despite these costs, females in the enhanced plumage brightness treatment mated with extra-pair males that were higher quality than their social mate. Behaviour of females, manipulated by elevating testosterone (T), lowered the proportion of extra-pair offspring in the broods of T-treated females. Females manipulated so that the androgenic and estrogenic actions of T were blocked also produced fewer extra-pair... .
Wilderness is an abstract concept containing both an ecological component more generally referred to as naturalness, and a social/human component attributed with recreation; it varies geographically, culturally and jurisdictionally. This thesis focuses on a case study of the Muskwa-Kechika Management Area (M-KMA) in northern British Columbia, Canada where maintaining wilderness is central to the vision. Previous mapping within the M-KMA has focused on wildlife and resource values, whereas this thesis aimed to define and map the wilderness character of the M-KMA. This thesis assesses the current state of wilderness to potentially examine changes over time and to spatially compare wilderness with other uses such as resource potential. When wilderness character data are separated into categories (lower, moderate, high and very-high), 55% is represented in the very-high quality category and only 9% by the lower category. In addition, there is 26% overlap between high resource potential values and very-high wilderness values.
Forest fire is the primary natural disturbance process influencing the distribution and abundance of terrestrial lichens across ranges of woodland caribou (Rangifer tarandus caribou), including the Klaza Caribou Herd in west-central Yukon. I used stand and understory data to understand variation in the abundance of lichens in burns of various ages. Focusing on the distribution of individual caribou, I used a dataset of GPS collar locations to examine resource selection on the winter range and within burns. Results suggested that burns provided suboptimal habitat for the KCH until 50 years post-fire; however, analyses focused on the use of burned habitat indicated that they regularly encountered burns and opportunistically used remnant lichen within the burn perimeter. The relationship between caribou and burned landscapes is complex and non-linear indicating that wildlife managers should look beyond burn age to account for the effects of fire on the availability and quality of caribou habitat.
Smolting is an important time in the life of anadromous salmon when juveniles undergo changes that prepare them for life in the ocean. Widely distributed salmon populations have evolved based on the selective pressures of their local environments. I examined population differences in the development, duration (smolt window) and loss of seawater tolerance, how temperature influenced development among populations, and temperature preference throughout smolting in coho salmon (Oncorhynchus kisutch). For my first objective, I compared smolt development among three populations in British Columbia, Canada that each had different migration distances to the ocean. In year one, fish appeared to undergo an incomplete smoltification based on the biochemical marker Na+/K+-ATPase (NKA). Additionally, molecular markers (mRNA expression of gill NKA α1a, NKA α1b, as well as growth hormone (GHR), prolactin (PrlR) and glucocorticoid (GR1) receptors) suggest that fish also did fully develop physiological changes associated with smolting. In year two, the smolt window (approximately 300 accumulated thermal units – ATU) did not differ by population as evident by elevated NKA activity. Molecular markers (gill NKA α1a, NKA α1b, GHR, and PrlR) for smolting also did not show a population difference – indicating that distinct populations do not differ in their development, duration, or loss of seawater tolerance. For my second objective, I examined temperature preference in short- and long-distance migrating populations of coho salmon juveniles. Mean temperature preference did not differ between the two populations (15.9 °C and 16.1 °C) and did not change throughout smolting. Based on the observed temperature preferences, smolts do not prefer temperatures that are advantageous for prolonging the smolt window. Additionally, the disparity between temperature preference and what is likely available in the environment at the time of smolting demonstrates that temperature is not a selective pressure for juveniles to behaviourally regulate the development of seawater tolerance.
