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Many of the world’s rivers are dammed, altering the physiology, behaviour, ecology and survival of fish. Integrative research has the potential to improve our understanding of these impacts and could enable environmental managers to develop effective solutions for population conservation. Such approaches, however, are not yet prevalent. We use a case study on Pacific salmon (Oncorhynchus spp.) in British Columbia, Canada, to demonstrate how regulated rivers may be used as experimental systems, allowing for applied research that can advance our understanding of the biology of migratory fish as well as our ability to manage them. Through the integration of multiple research approaches (i.e. biotelemetry, behavioural tests, physiological and molecular analyses, and hydraulic monitoring), we characterized the effects of natal water dilution and dam flow releases on upstream navigation, passage success and post-passage survival of returning adult salmon. Our findings confirmed previously established operational guidelines for natal water dilution and informed the adoption of new operational conditions for dam flow releases, providing an example of the successful application of integrative research to the management of a fisheries resource in a regulated river. We encourage researchers to consider using an experimental approach that integrates multiple research disciplines to inform science-based management action.

Accurate knowledge of geographic ranges and genetic relationships among populations is important when managing a species or population of conservation concern. Along the western coast of Canada, a subspecies of the northern goshawk (Accipiter gentilis laingi) is legally designated as Threatened. The range and distinctness of this form, in comparison with the broadly distributed North American subspecies (Accipiter gentilis atricapillus), is unclear. Given this morphological uncertainty, we analyzed genomic relationships in thousands of single nucleotide polymorphisms identified using genotyping‐by‐sequencing of high‐quality genetic samples. Results revealed a genetically distinct population of northern goshawks on the archipelago of Haida Gwaii and subtle structuring among other North American sampling regions. We then developed genotyping assays for ten loci that are highly differentiated between the two main genetic clusters, allowing inclusion of hundreds of low‐quality samples and confirming that the distinct genetic cluster is restricted to Haida Gwaii. As the laingi form was originally described as being based on Haida Gwaii (where the type specimen is from), further morphological analysis may result in this name being restricted to the Haida Gwaii genetic cluster. Regardless of taxonomic treatment, the distinct Haida Gwaii genetic cluster along with the small and declining population size of the Haida Gwaii population suggests a high risk of extinction of an ecologically and genetically distinct form of northern goshawk. Outside of Haida Gwaii, sampling regions along the coast of BC and southeast Alaska (often considered regions inhabited by laingi) show some subtle differentiation from other North American regions. These results will increase the effectiveness of conservation management of northern goshawks in northwestern North America. More broadly, other conservation‐related studies of genetic variation may benefit from the two‐step approach we employed that first surveys genomic variation using high‐quality samples and then genotypes low‐quality samples at particularly informative loci.

Accurate knowledge of geographic ranges and genetic relationships among populations is important when managing a species or population of conservation concern. Along the western coast of Canada, a subspecies of the northern goshawk (Accipiter gentilis laingi) is legally designated as Threatened. The range and distinctness of this form, in comparison with the broadly distributed North American subspecies (Accipiter gentilis atricapillus), is unclear. Given this morphological uncertainty, we analyzed genomic relationships in thousands of single nucleotide polymorphisms identified using genotyping‐by‐sequencing of high‐quality genetic samples. Results revealed a genetically distinct population of northern goshawks on the archipelago of Haida Gwaii and subtle structuring among other North American sampling regions. We then developed genotyping assays for ten loci that are highly differentiated between the two main genetic clusters, allowing inclusion of hundreds of low‐quality samples and confirming that the distinct genetic cluster is restricted to Haida Gwaii. As the laingi form was originally described as being based on Haida Gwaii (where the type specimen is from), further morphological analysis may result in this name being restricted to the Haida Gwaii genetic cluster. Regardless of taxonomic treatment, the distinct Haida Gwaii genetic cluster along with the small and declining population size of the Haida Gwaii population suggests a high risk of extinction of an ecologically and genetically distinct form of northern goshawk. Outside of Haida Gwaii, sampling regions along the coast of BC and southeast Alaska (often considered regions inhabited by laingi) show some subtle differentiation from other North American regions. These results will increase the effectiveness of conservation management of northern goshawks in northwestern North America. More broadly, other conservation‐related studies of genetic variation may benefit from the two‐step approach we employed that first surveys genomic variation using high‐quality samples and then genotypes low‐quality samples at particularly informative loci.

Accurate knowledge of geographic ranges and genetic relationships among populations is important when managing a species or population of conservation concern. In the western Canadian province of British Columbia, a subspecies of the northern goshawk (Accipiter gentilis laingi) is designated as Threatened under the Canadian Species at Risk Act. Historically, the range of this bird of prey has been ambiguous and its genetic distinctness from the other North American subspecies (Accipiter gentilis atricapillus) has not been well established. Given the uncertainty in using morphological traits to assign individual goshawks to these two subspecies, we analyzed genomic relationships in tens of thousands of single nucleotide polymorphisms identified using genotyping-bysequencing of high-quality genetic samples. This genome-wide analysis revealed a genetically distinct population of northern goshawks on the archipelago of Haida Gwaii and subtle genetic structuring among the remainder of our sampling sites within North America. Following from this analysis, we developed targeted genotyping assays for ten loci that are highly differentiated between the two main genetic clusters, allowing the addition of hundreds of low-quality samples to our analysis. This additional information confirmed that the distinct genetic cluster on Haida Gwaii is restricted to that archipelago. As the laingi form was originally described as being based in Haida Gwaii, where the type specimen of that form is from, further study (especially of morphological traits) may indicate a need to restrict this name to the Haida Gwaii genetic cluster. Regardless of taxonomic treatment, our finding of a distinct Haida Gwaii genetic cluster along with the small and historically declining population size of the Haida Gwaii population suggests a high risk of extinction of an ecologically and genetically distinct form of northern goshawk. Outside of Haida Gwaii, sampling regions along the coast of BC and southeast Alaska (often considered regions inhabited by laingi) show some subtle differentiation from other North American regions. We anticipate that these results will increase the effectiveness of conservation management of northern goshawks in northwestern North America. More broadly, other conservation-related studies of genetic variation may benefit from the two-step approach we employed that first surveys genomic variation using high-quality samples and then genotypes low-quality samples at particularly informative loci.

Ecological restoration projects have traditionally focused on vegetation as both a means (seeding, planting, and substrate amendments) and ends (success based upon primary productivity and vegetation diversity). This vegetation-centric approach to ecological restoration stems from an historic emphasis on esthetics and cost but provides a limited measure of total ecosystem functioning and overlooks alternative ways to achieve current and future restoration targets. We advocate a shift to planning beyond the plant community and toward the physical and biological components necessary to initiate autogenic recovery, then guiding this process through the timely introduction of top predators and environmental modifications such as soil amendments and physical structures for animal nesting and refugia.

In order to reverse the decline of imperilled species, we need to know what is threatening their survival. Canada’s Species at Risk Act (SARA) is intended to provide for the protection and recovery of species listed under the Act. Threats to SARA-listed species must be documented in recovery strategies, which also define recovery goals and critical habitat. We reviewed finalized recovery strategies for 146 species to determine the major threats to these species and whether designation of critical habitat or the relative ambition of recovery goals is associated with the nature of threats. We then compared our findings to the threats described in reports prepared by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), the independent body which prepares status reports for all imperilled species (including those not listed under SARA). Human disturbance, in particular due to recreation, was the most frequently listed threat in recovery strategies, followed by invasive species and residential and commercial development. Threats differed among taxonomic groups and broad habitat types, but there was no evidence that low ambition of recovery goals or failure to designate critical habitat were correlated with particular threats. However, species with certain threats, including biological resource use, were less likely either to be listed under SARA and/or to have a finalized recovery strategy once listed. Documenting threat-based differences in the recovery process is an important first step toward ensuring that SARA results in timely and effective measures to recover all listed species.

We investigated how pre-dispersal strategies may mitigate the effects of weevil infestation of acorns in a population of Quercus schottkyana, a dominant oak in Asian evergreen broad-leaved forests, and assess if weevil infestation contributes to low seedling recruitment. We counted the number of acorns produced, daily from the end of August to mid-late November for 9 years from 2006–2014. We also recorded the rate of acorn infestation by weevils and acorn germination rates of weekly collections. Annual acorn production was variable, but particularly low in 2011 and 2013. There was no trade-off between acorn production and acorn dry mass. However, acorns produced later in the season were significantly heavier. For most years: (i) the rate of weevil infestation was negatively density dependent (a greater proportion of acorns died with increased acorn density), (ii) the percentage germination of acorns was positively density dependent (proportionately more acorns germinated with increased density), and (iii) as the season progressed, the percentage of infested acorns declined while germination rates increased. Finally, (iv) maximum acorn production, percentage infestation and percentage germination were asynchronous. Although pre-dispersal mortality is important it is unlikely to be the primary factor leading to low recruitment of oak seedlings.

The addition or removal of predators from food webs by humans can have profound effects on the interactions between species. However, predators and primary producers are inextricably linked by the flow of energy through ecosystems. In temperate grasslands energy flow through ecosystems is often limited by water availability to plants. So, if the number and strength of interactions between species in grasslands depends on the amount of water available to plants, and we remove predators along a gradient in water availability, then we should see change in species interactions with predator removals along the gradient. After estimating trophic position and diet breadth of key predators, we excluded birds and small mammal predators from grasslands along a rainfall gradient in south central British Columbia for four years, and measured the response of plants and arthropods. Water availability significantly altered food web structure, and consequently the role of predators in structuring these ecosystems. When water was scarce, vertebrate predators impeded plant growth by feeding on spiders that would normally eat herbivorous insects. When water was more abundant, vertebrate predators facilitated plant growth by feeding on a broad range of arthropod prey. As water availability to plants increased they grew more. Herbivores were not able to consume all the new growth and thus dead plant material accumulated. Increasing detritus helped establish new links between predators and plants. Phenomena such as climate change can determine the availability of water entering ecosystems, which then alters trophic structure. If water availability can alter food webs there are no simple generalizations for community dynamics that are independent of climate.

The northern goshawk (Accipiter gentilis) has been the subject of considerable interest because of the impact of logging on this species' nesting habitat. However, few studies have examined movements of fledgling birds around the nest prior to independence, and even fewer have described resource requirements of young birds during their postfledging period. Over 3 years, we followed 31 radiotagged goshawk fledglings from 15 nests in southeastern British Columbia, Canada. Of these birds, 26 survived to disperse. Between fledging and dispersal 95% of fledgling relocations (n = 1,148) were within 450 m of the nest. Fledglings primarily remained within 298 m of the nest during the first 21 days postfledging and within 525 m of the nest between 21 days postfledging and dispersal. Fledglings' movements were highly directional, with individual and sibling movements away from any particular nest tending out in one direction. Postfledging areas averaged 36.7 ha in size (median = 23.1, inter-quartile ra...

We examined the seasonal food habits of wolverine Gulo gulo in subboreal and interior wet-belt montane environments in British Columbia by analyzing scats collected during the course of two concurrent wolverine studies. Understanding foraging ecology for a wide-ranging carnivore such as the wolverine is important, particularly because reproduction has been demonstrated to be closely linked to food abundance. Wolverine diet was shown to vary regionally and seasonally. Regional variation was related to differences in prey availability between study areas. Moose Alces alces, caribou Rangifer tarandus, and hoary marmots Marmota caligata were abundant and common prey items within both study areas. Mountain goats Oreamnos americanus and porcupine Erithizon dorsatum were more abundant and more frequent prey items in the Columbia Mountains, while snowshoe hare Lepus americanus and beaver Castor canadensis were more abundant and more frequent prey items in the Omineca Mountains. Within the winter season, ...

Northern Goshawks (Accipiter gentilis laingi) have been recognized as a species of management concern in western North America for over 20 years. One of the most significant factors threatening Northern Goshawk populations in coastal British Columbia is the loss and fragmentation of structurally old and mature forests they use for breeding, foraging, and roosting. The goal of this report is to provide science-based guidelines for qualified environmental professonals to assist in their decision-making processes concerning Northern Goshawk habitat management in coastal British Columbia. These guidelines were previously unavailable or inconsistent and did not provide a thorough review of the scientific literature. The best management practices presented here are intended for use by qualified environmental professonals and managers when undertaking industrial activities, primarily forestry, around Northern Goshawk breeding areas within coastal British Columbia.

Restoration of degraded landscapes has become necessary to reverse the pervasive threats from human exploitation. Restoration requires first the monitoring of progress toward any chosen goals to determine their resilience and persistence, and second to conduct in a comparable adjacent area but with less human impact the restoration of trophic structures and ecosystem processes to act as reference systems (controls) with which we compare the viability of the chosen goal. We present here the rationale and a method for predicting the trajectory of restoration and assessing its progress toward a predetermined state, the endpoint, using a restoration index. This assessment of restoration requires that we know when a predetermined endpoint has been achieved and whether the envisioned community of species and their interactions can be restored. The restoration index can use species’ presence or density, and the rate of change of ecosystem processes. The index applies to trophic levels, functional groups, successional stages, alternative states, and novel ecosystems. Also, our method allows measurement of the resilience of ecosystems to disturbance, a desired property for conservation and management. We provide global examples to illustrate these points.

Salmon from a 3 male×3 female sockeye salmon cross were raised under three different light regimes (UV: 300–850 nm for 8 hours day-1, visible: 400–850 nm for 8 hours day-1, and a control in which eggs were kept in darkness until hatching, followed by increasing amounts of light as the embryos approached swim-up) up to the parr interval (105 days from fertilization). The dose rates (W m-2), and total intensities per day (J m-2), for each treatment were less than 0.46 and 0.28 times of those measured in the shaded part of a stream, respectively. Egg mortality was higher for the UV and visible treatments compared to the control, and the number of alevins alive after day 83 was significantly different between treatments: highest for the control and lowest for the UV treatment. Eggs and hatched fish from female F2 suffered higher mortality than those from the other two females raising the possibility that sensitivity to UV-B in sockeye salmon may be either a maternally inherited trait or due to physiological or physical differences between egg groups. Alevins and parr from the control treatment transferred to the UV treatment suffered little mortality compared to animals raised in the UV and visible treatments from fertilization. These results, in conjunction with light measurements from streams, suggest that light and UV-B radiation could be a source of young salmon mortality in perturbed environments such as those resulting after forestry intervention.

Grassland vegetation can provide visual cover for terrestrial vertebrates. The most commonly used method to assess visual cover is the Robel pole. We test the use of digital photography as a more accurate and repeatable method. We assessed the digital photography method on four forage grassland species (Pseudoroegneria spicata, Festuca campestris, Poa pratensis, Achnatherum richardsonii). Digital photos of 2-dimensional cutout silhouettes of three bird species sharp-tailed grouse, western meadowlark and savannah sparrow were used to model the impact of clipping (i.e., grazing) on visual cover. In addition, photos of artificial voles were used to model litter on cover available to small mammals. Nine sites were sampled and data were analyzed by the dominant grass species in each study plot. Regression analysis showed that digital photos (r2 = 0.62) were a better predictor than the Robel pole (r2 = 0.26) for assessment of cover. Clipping heights showed that clipping at less than 15 cm left the silhouettes 50% exposed. Digital photo analysis revealed that visual cover was affected by the type of grass species, with F. campestris > P. pratensis > A. richardsonii > P. spicata. Biomass and litter were both positively related to cover for small mammals.