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JOHNSON GEO-CENTRE, SIGNAL HILL, NL (MUN) 2006 Reorganization
and research in the Canadian Wildlife Service Environment Canada¹s Canadian Wildlife Service (CWS) continues its focus on the conservation of migratory birds, species and risk, and the habitats on which they depend, and ensuring that conservation and policy decisions are based on sound science. Environment Canada has recently been re-structured, with its research scientists now grouped together in a new Science and Technology Branch, separate from CWS, but working together on the same programs. The department has just completed the development of a Science Plan that sets out the direction for its scientific programs, in which it highlights the continued importance of research partnerships with universities, such as ACWERN. Against this background, CWS continues to lead, coordinate and provide scientific support to a range of applied research and monitoring initiatives in Atlantic Canada. CWS science includes monitoring bird populations to assess changes in their numbers and distribution (magnitude, cause and implications) and to support harvest management and regulations; modelling and research to understand causes of population declines; assessing risks and selecting conservation options to reduce human impacts; and supporting the science priorities of other government departments. We will discuss the changing context and the emerging scientific and conservation priorities that face the agency, and which ACWERN is helping to address, as we seek to extend Environment Canada¹s financial support for the next five years.
Comparing adult and chick diet in
two alcid species using stable isotopes Until recently, descriptions of seabird diet were limited to stomach content analysis, or direct observation, both of which have inherent problems. Chick provisioning studies are easily done for alcids, but it is not known of this is also representative of adult diet. Recently, the use of stable-carbon and stable-nitrogen isotopes has been used to infer diet, and depending on the tissue sampled, a different time frame is examined. We sampled and analyzed whole blood from adult and chick Atlantic Puffins (Fratercula arctica) and Razorbills (Alca torda) on Machias Seal Island, New Brunswick, during the 2005 breeding season. Whole blood is an indicator of diet during the two weeks prior to sampling, and is easily obtained. Puffin adults and chicks had similar diets, as did Razorbills. We also use isotope mixing models to show if our provisioning studies are representative of assimilated diet in both adults and chicks. Temporal trends in mercury
concentrations in seabird eggs from Atlantic Canada, 1972-2004 Seabird eggs are commonly used to monitor trends in contamination of marine ecosystems. Mercury concentrations were measured in eggs from three species of seabirds collected every four years in Atlantic Canada, 1972 - 2004. Atlantic puffin (Fratercula arctica) eggs were collected off Newfoundland, in the Bay of Fundy, and in the northern Gulf of St. Lawrence. Double-crested cormorant (Phalacrocorax auritus) eggs were collected from the St. Lawrence Estuary and the Bay of Fundy. Leach's storm-petrel (Oceanodroma leucorhoa) eggs were collected from the Bay of Fundy and Newfoundland. Robust regression was used to assess linear temporal trends in mercury levels. Mercury levels declined significantly in Atlantic puffins in Newfoundland but no trends were found in the Bay of Fundy or Gulf of St. Lawrence. In cormorants, mercury concentrations decreased from 1972 to 2004 in the St. Lawrence Estuary but no trend was found in the Bay of Fundy. Mercury levels in Bay of Fundy storm-petrel eggs declined while no trend was found in Newfoundland. In 2004, mercury concentrations were higher in eggs of storm-petrels than in puffins and cormorants. The apparently stable or decreasing mercury trends in Atlantic seabird eggs contrast with increasing mercury trends observed in many Arctic seabirds.
Assessing stopover behaviour from
migration monitoring data: the need for powerful models Migration monitoring data collected from mid-route stopover sites are valuable for inferring population trends and migratory timing, but realizing their potential for assessing changes in stopover behaviour requires powerful modeling tools. In particular, captured individuals often represent an unknown fraction of the migrant population, so traditional analyses may confound changes in stopover behaviour with changes in abundance. We applied a recent formulation of multi-state mark-recapture methods to annual fall migration data to reveal dramatic inter-annual variation in passerine stopover use and duration, and its links to both physiological and environmental variables. These analyses suggested that in some years as few as 10% of landing migrants may remain at a stopover for refueling, and uncovered the importance of climatic influences at both local and regional scales. A more statistically-robust evaluation of trends in stopover behaviour, however, demands a flexible method that can analyze data from multiple years, locations or species groups simultaneously. Consequently, we are developing a hierarchical Bayesian model that will be used to synthesize stopover data, and will provide an improved quantification of weather and climate effects on migratory stopover behaviour.
Opportunities for research on
colonial birds at the edge of their breeding range in central Labrador Several species of colonial waterbirds occur at the edge of their nesting ranges in central Labrador, in the area of Lake Melville and adjacent Groswater Bay. Caspian Terns, Double-crested Cormorants and Common Terns occur here at the northern end of their North American breeding range. Common Eiders nest on Lake Melville at the western-most edge of their range in the province. Black-headed Gulls are apparently recent colonizers from Europe, and occur in small numbers in tern colonies on Lake Melville. The status of these species in Labrador, and the potential for research opportunities will be discussed.
Seasonal Movements of the Razorbill (Alca
torda) at Machias Seal Island as determined by Satellite
Telemetry Little is known about Razorbill movements away from the breeding colony. Direct observations are often not feasible due to the great distances and isolated locations involved. The purpose of this project is to study the spatial and temporal movements of Razorbills from Machias Seal Island, NB. We wish to explore whether Razorbills undergo a large migration, or remain within the outer Bay of Fundy. Fieldwork began during the 2006 breeding season when eight Razorbills were equipped with satellite transmitters. Early data place Razorbills along the northern Maine and southern New Brunswick coast. Four additional birds were equipped with geolocator tags. Attempts to retrieve these tags will occur in the 2007 field season.
Breeding success of migratory
songbirds in patchy boreal forests of western Newfoundland Both timber-harvest and weather influence avian productivity. We studied breeding success of passerines in boreal forests of Newfoundland, where forests are naturally heterogeneous and annual variation in weather can be extreme. During 2004 and 2005 we monitored 174 nests and banded 956 hatch-year (HY) migratory passerines in landscapes having either naturally or anthropogenically-created (clear-cut) forest openings. We tested for breeding responses to proportion clear-cut at three different scales and found that these measures significantly interacted with year when predicting nest initiation date, hatch success, fledging success, and proportion of hatch year bird captures. Daily Survival Rate (DSR) of nests were not significantly related to year or proportion cut. However, DSR for each of three common species were consistently higher in 2005 and direction of clear-cut influences differed by species. Our results demonstrate the importance of considering interactions between harvesting and temporal trends when monitoring avian productivity in variable environments.
Early warning of demographic shifts
seabirds of Machias Seal Island The abandonment in 2006 of the Gulf of Maine's largest tern colony, and North America's largest colony of Arctic Terns, raises the obvious question should we have seen this coming? I review the various parameters we have measured there since 1995 for prior signals of this major shift, and address the likely consequences for the other species of this seabird community that have not yet abandoned the island. Diet changes were identified several years before, but are important only in the birdss responses to them, which can be more subtle than crude measures of breeding success and may provide earlier warning of looming problems.
Influence of nesting habitat on
transmission of infectious diseases among Double-crested Cormorant (Phalacrocorax
auritus) chicks with emphasis on prevalence of Salmonella
organisms. My research is to be an epidemiological study that will look at the influence of nesting habitat on transmission of infectious agents among Double-crested cormorant (Phalacrocorax auritus) chicks. I believe the study of the ecology of infectious diseases of wildlife is a new direction for the ACWERN group and one that is largely under-represented in the literature. The role that pathogens can play in structuring ecological communities needs to be examined more closely in order to better understand how populations are affected.
Methods of monitoring the activity
of an invasive alien species at a seabird colony Sirius Point, Kiska
Island, Aleutian Islands Alaska With an abundance of resources and lack of pressure from natural enemies, invasive alien species in remote island ecosystems often present a threat to avifauna. The auklet colony at Sirius Point, Kiska Island, Aleutian Islands Alaska provides optimal food resources and habitat for Norway rats (Rattus norvegicus) to threaten the existence of Least (Aethia pusilla) and Crested Auklets (A. cristatella). In 2006, nine rats were radio collared to investigate home range size, social organization and habitat use to provide information on the behavior and ecology of Norway rats in a major seabird colony. Preliminary analysis shows overlapping home ranges, territorial females, and preference for densely vegetated areas within the colony. Also, tracking tunnels, wax blocks and chew sticks were new methods tested to obtain an index of rat activity throughout the entire auklet colony. Rat activity increased and rat presence expanded throughout the auklet breeding season.
Seasonal interactions in short and
long-distance obligate migrants In migratory Neotropical songbirds, individuals who obtain good quality non-breeding habitat arrive earlier to the breeding ground, lay earlier and breed more successfully, highlighting the need to consider events over the annual cycle if we are to understand factors driving population dynamics. Missing from these analyses is the effect of seasonal interactions between arrival condition (reflecting non-breeding habitat) and breeding site habitat quality. Using stable isotopes, corticosterone and food supplementation experiments, I will examine the potential compensatory effects of high quality breeding habitat on Bicknell's Thrush (Catharus bicknelli), a species that may be constrained at other points in the annual cycle. The Resplendent Quetzal (Pharomachrus mocinno) is a short-distance, obligate migrant that is thought to make three altitudinal migrations a year across four montane regions providing a rich opportunity to study seasonal interactions on a smaller spatial scale. Using various condition indicators and stable isotopes I will examine carry-over effects in a declining Resplendent Quetzal population in central Nicaragua.
Research and monitoring of moulting
Surf Scoters in eastern Canada Population status, ecology, biology and demography of Surf Scoters (Melanitta perspicillata) has been poorly documented. In 2004, the Canadian Wildlife Service, with funding from INCO and the Sea Duck Joint Venture, undertook a study of Surf Scoters moulting on the north coast of Labrador. Our program touches on demography (estimates of survival and recruitment), behaviour (activity budgets), nutrient dynamics, diet, and local and long range movements of moulting surf scoters. I will give a brief overview of the project highlighting potential opportunities for collaborative research.
Population trends of shorebirds
during fall migration in insular Newfoundland 1980-2005 Overall negative trends have been documented in shorebird populations throughout north eastern North America over the past 3 decades. An analysis of shorebird data collected from 12 sites in insular Newfoundland between 1980 and 2005, including 6 years of data collected by the Newfoundland and Labrador Shorebird Survey (NLSS) volunteers, was carried out. The analysis showed an overall population increase for most shorebird species using stopover sites in Newfoundland between 1980 and 2005. However, when broken into discrete intervals, between decades, significant increases demonstrated during the 1980¹s, masked less significant declines demonstrated from 1990 to 2005. This provides further evidence that the overall shorebird population declines documented in the Atlantic Provinces and north eastern United States are continuing into the first decade of the 21st century. Long term volunteer monitoring programs, such as the NLSS, provide valuable contributions to long term monitoring programs at minimal cost and help spread awareness and involvement in both regional and national conservation.
Prevalence and Diversity of Avian
Influenza Viruses in Environmental Reservoirs in Alaska A proportion of Alaskan birds, especially waterfowl, carry influenza viruses. Viruses have also been found in Alaskan environmental sources such as water bodies and waterfowl feces. There is potential for such environmental reservoirs to act as sources of infectious viruses that can initiate new infections of birds. Influenza viruses are shed in the feces of infected birds and given that many birds forage in lake and pond sediments, there is potential for transmission from these sources. I will talk about work underway to characterize the Avian Influenza virus communities present in the sediments from several ponds that are heavily used by birds, especially waterfowl, at Creamer¹s Field Migratory Waterfowl Refuge in Fairbanks, Alaska. A reverse transcriptase polymerase chain reaction (RT-PCR) approach was used to screen RNA extracted from sediments for avian influenza viruses. Samples were collected from these ponds over a 1-year period and the results show that influenza viruses are readily detectable in the majority of the samples. Sequencing of RT-PCR products shows that a diverse population of influenza viruses is present in these samples.
Population projection for Razorbills
(Alca torda) in Atlantic Canada: impacts of the murre hunt Canadian Razorbill (Alca torda) populations have experienced significant historical population declines due to human activities and have been slow to recover. Hunting of Razorbills is illegal, but due to their close physical resemblance to murres (Uria spp.), they are often accidentally shot during the annual Newfoundland and Labrador murre hunt. It is estimated that 1% (3000) or more of the Turrs shot in Atlantic Canada during this hunt are likely Razorbills. The impact of the hunt on Razorbill breeding populations has not yet been quantified and was therefore the goal of this study. Razorbill populations on the Gannet Islands, NL (affected population) and Machias Seal Island, NB (MSI, unaffected population) were projected using Population Viability Analysis for a 20 year interval and the mean intrinsic rate of increase for each population was compared. Estimates of juvenile survival for Razorbills at the Gannet Islands were 10% lower than for MSI, likely a result of hunting by-catch. Predicted lambda (intrinsic rate of population increase) values for the Gannet Islands and MSI were 0.9451 and 0.9859 respectively, indicating that in the absence of immigration, the Gannet Islands population would likely be declining.
Impacts of intraspecific
kleptoparasitism and diet shifts on Razorbill productivity at the
Gannet Islands, Labrador Intraspecific kleptoparasitism, the stealing of food from members of the same species, has received little attention in the scientific literature on Razorbills (Alca torda). However, the effects of such behavior can be significant. Here we report on high rates of intraspecific kleptoparasitism in the Razorbill at the Gannet Islands, a behavior that appears to be colony specific. Razorbills carry their prey conspicuously in their bill making them vulnerable to kleptoparasitic attacks from neighboring birds. We examined the relationship between the frequency of kleptoparasitic attacks and the prey species carried by breeding adults. Sixty nine percent of all Razorbills carrying food to their nest were attacked (n = 182) and of these attacks, 18% (n = 22) were successful. Group attacks (two or more kleptoparasites) were more successful numerically (27%, n = 71), however only one member of the group ever received the reward. The frequency of kleptoparasitism observed by Razorbills at the Gannet Islands is one of the highest reported for any seabird including many specialist kleptoparasites such as frigatebirds. This combined with the lowest observed Razorbill productivity (overall success = 0.40, n = 222) for the Gannet Islands and drastic shifts in diet may indicate decreased food availability.
Landscape connectivity and movement
behaviour of boreal-breeding passerines in response to forest harvesting Assessing functional landscape connectivity (FLC) requires information on spatial movement in response to landscape structure and how spatial scale influences those responses. We explored effects of landscape structure at multiple spatial scales on movement behavior of neotropical migrants on breeding grounds. To best illustrate potential differences we studied a habitat specialist and generalist species: the Northern Waterthrush (Seiurus noveboracensis) and Blackpoll Warbler (Dendroica striata), respectively. Individuals were captured and radiotracked (waterthrush n = 28; blackpoll, n = 33) in 2004 and 2005 in a naturally-patchy harvested boreal forest in Newfoundland, Canada. We used generalized linear mixed-effects models to assess the influence of times of day and season, year, local patch characteristics, and amount and type of gap (natural / clearcut) on movement rates at scales of 100 m (territory) and 1250 m (home range) from territory center. Movement rates of blackpolls were not influenced by structure of the landscape structure, but of the local patch. Waterthrushes showed sensitivity to clearcutting at the home range scale; this effect varied with time of day. Our results suggest that clearcuts may not jeopardize FLC for some species during breeding.
Individual quality and nest-site
selection in common eiders (Somateria mollissima dresseri) Patterns of avian nest-site selection likely reflect the influence of various biotic and abiotic factors on reproduction and survival. It is expected that nest-site selection should reflect habitat use that maximizes the potential for survival and successful reproduction. However, habitat-specific estimates of reproductive success can be confounded by the disproportionate use of favourable nesting sites by individuals of higher breeding quality. Therefore, I am currently investigating the relationship between individual quality and nest-site characteristics of female common eiders (Somateria mollissima dresseri) breeding in northern Newfoundland and southern Labrador. Nesting success in different habitats will be examined in relation to indices of female quality. The potential for nest-sites to influence the rates of conspecific nest parasitism and the rates of weight loss from incubating eggs will also be investigated. This research will contribute to our knowledge of patterns of nest-site selection by common eiders, and will help direct to management actions and conservation initiatives.
Tabanid (horsefly) diversity in the
Greater Kejimkujic Ecosystem and forestry-induced wetland change. Wetlands in Nova Scotia are offered varying protection from forestry activities. Most wetlands are protected by 20 m (or more) buffer zones, but treed peatlands are not. Forestry influences chemistry and hydrology of wetlands but our understanding of the further impacts on biodiversity, in particular within treed peatlands, is limited. Insect communities respond to changes in water quality and wetland health and to changes in the landscapes surrounding focal habitats. Peatlands are no exception, and comprise the focal resource for numerous species of insects including the horse and deer flies (Tabanidae). In Canada, an estimated 38 species of Tabanid are at least partially dependant on peatlands. The dependence of most larval states on aquatic habitats and of the adults on mammalian hosts (for blood-feeding), and the Tabanid¹s association with peatlands, make the group an excellent candidate for ecological studies of the impacts of human activity in forested peatlands. In conjunction with an existing project (MTRI) examining impacts of forestry on biodiversity in treed peatlands within the Greater Kejimikujik Ecosystem, we selected a series of treed peatlands that varied along independent gradients of intensity of nearby forestry activity and associated changes in water chemistry and hydrology. Over 4,400 individuals from 5 genera were collected this summer and identified to species; analysis is ongoing.
The effects of invasive ants on the
nesting success of Tristram's Storm-petrel in the Northwest Hawaiian
Islands The ability of invasive ants to negatively affect the breeding success of birds is a crucial issue in island conservation. Invasive ants are established on all Northwest Hawaiian Islands, yet no study has yet to investigate their effects on the native avifauna. Efforts were made to document the effects of 10 species of invasive ant on the nesting success of Tristram¹s Storm-petrel (Oceanodroma tristrami) over the coarse of 2 breeding seasons on Laysan and Tern Islands, Northwest Hawaiian Islands. Despite recording harassment events, ants did not appear to significantly affect Tristram's Storm-petrels during either the incubation or chick rearing stages in 288 monitored burrows. Ants were found to forage often in Tristram's Storm-petrel burrows but were not attracted to the birds themselves, possibly due to the presence of more attractive food sources including carrion and other arthropods. Despite these findings, more research is urgently required to examine the effects of weather and seasonality on these relationships and to investigate the effects of ant communities on other islands in the chain, most notably Midway Atoll.
The reproductive success of
Bicknell's Thrush (Catharus bicknelli) in managed forests of New
Brunswick Bicknell's Thrush (Catharus bicknelli) is a rare songbird sparsely distributed throughout the Maritimes and New England. Historically in New Brunswick, Bicknell's Thrush bred in forests regenerating after blow-downs or spruce budworm outbreaks. Today, extensive forest harvesting has altered Bicknell's Thrush habitat by clear cutting, thinning and planting of commercial tree species. Although Bicknell's Thrushes have been detected in this managed habitat, it is unknown whether they are breeding successfully. Survival of this species in Canada depends on its ability to reproduce in a managed forest landscape. This project will determine the reproductive success of Bicknell's Thrush in the Christmas Mountains region of New Brunswick. To quantify the breeding success, information on both nesting and fledgling success will be collected. Nests will be monitored with minimal disturbance by using video cameras and infrequent nest checks. Surveys for fledglings will take place later in the breeding season. Habitat will be quantified by assessing stem density, forest composition and management status (i.e. age of regeneration, thinned or not) within a set radius of the nest. Reproductive success in managed forests will be compared with that of birds nesting in the less disturbed habitat in Mount Carleton Provincial Park. The final product of this study will be a management plan that forestry companies can directly apply to ensure viable breeding habitat is in continuous supply for Bicknel's Thrush.
The Ducks Unlimited Canada's Eider
Initiative Ducks Unlimited Canada's Eider Initiative is a 5-year research initiative. The goal of this research is to develop a population model to guide Common Eider (Somateria mollissima dresseri) harvest regulations and management decisions. To reach this goal, we are using capture-mark-recapture techniques to estimate survival parameters. During 2004-06 we captured 6,260 duckling (1 d old), 551 prefledged juvenile (>30 d old), and 1,837 adult Common Eiders. So far we have received a total of 164 hunter band recoveries, most (n = 153) of which were for eiders marked at < 30 days of age. Direct band recoveries (those shot during the same year as marking; n = 139) allowed us to calculate maximum duckling survival rate. Direct recovery rates varied by site and age category. Maximum duckling survival was estimated at 0.17. Preliminary results suggest that adult survival varied among years and study sites and averaged 0.87 (95% CI = 0.710.94). Common Eider adults and ducklings banded to date form a solid base for future mark-recapture survival analyses.
A hazy relationship? The effect of
fog on the feeding of four species of Atlantic seabirds Most seabirds rely on observing other birds in foraging flocks to identify appropriate locations where to forage. Fog is a common occurrence in the marine environment where seabirds feed, and could hinder a seabird¹s ability to locate these foraging birds. We used ten years of weather data and chick-feeding data from four species of seabirds on Machias Seal Island, New Brunswick, to test whether fog affects the feeding rates of seabirds and the types of prey that adults deliver to chicks. We conducted block ANOVAs with year as the blocking variable to test our prediction that fog would reduce feeding rates, and increase the species richness of prey delivered to chicks, as adults fed whatever prey they encountered. Block MANOVAs were performed to investigate whether birds fed fewer schooling fish on foggy days. We did not find fog to affect feeding rates or the types of prey delivered for three out of four species. We did not have sufficient power to test our hypotheses regarding feeding rates and suggest that fog be monitored on foraging grounds to concretely test these questions regarding the effect of fog on foraging.
Juvenile songbird movement in a
boreal forest The relationship between changing forest cover and movement for boreal songbirds remains largely unknown. To describe and explore the extent to which changing forest cover influences juvenile boreal songbird movement, we outfitted 49 yellow-rumped warblers (Dendroica coronata) and 51 blackpoll warblers (D. striata) with radio transmitters between 2005 and 2006. Data for both species were pooled, as no differences in movement metrics were found. Movements can be classified as residency, meso-scale, and migration types. Residency movements had a median movement rate of 305 m/day (scale = 10s to 100s of meters). Meso-scale movements had a median movement rate of 974 m/day (scale of 100s to 1000s of meters). Five migration movements were observed (total distance moved range = 13 49 km). Meso-scale movements were orientated to the south-east (119 deg, rho = 43), and were associated with decreases in elevation. LME models were used to model movement rate. Changing forest cover did not significantly influence movement rate (p >0.05), however there were significant species and time of season (p = 0.01), as well as change in elevation and time of season interactions (p = 0.01) requiring further investigation. In summary, meso-scale movements were orientated to the south-east and down-slope, suggesting directed movement to productive pre-migratory habitats.
Emerging infectious diseases and
wild bird conservation: West Nile Virus and Avian Influenza revisited. Emerging infectious diseases are increasingly recognized as important to wild animal-, domestic animal- and human-health. The spread of West Nile virus (WNV) across the Western hemisphere and the repeated outbreaks of the highly pathogenic avian influence (HPAI) viruses in Southeast Asia serve as examples of diseases that have caused mortality in wild birds. The role of wild birds and vectors in the spread and persistence of WNV is well recognized. Contrastingly, HPAI has largely been spread and disseminated through human activities such as poultry operations and the caged bird trade. In either disease, wild birds have experienced mortality although the impact of such diseases on wild bird populations is not documented or understood. Laboratory experiments and comparative studies of susceptible bird populations for both of these diseases indicate that such novel diseases can lead to morbidity and mortality capable of causing local population declines. There is therefore an urgent need to address the question of wild bird mortality as a result of such diseases particularly from the point of population ecology and conservation of endangered species.
First record of the Lyme Disease
spirochete (Borrelia garinii) at Gull Island,
Newfoundland: vector ecology, epidemiology and human health concerns Ixodes uriae is a ubiquitous tick occurring in seabird colonies in both hemispheres. It is a vector for the Lyme Disease agent Borrelia garinii, the genospecies present in seabird enzootic cycles. We examined the importance of adults and chicks of Atlantic Puffins (Fratercula arctica) as hosts for Ixodes uriae. We also examined ticks from various seabird colonies in eastern North America for B. garinii using PCR methods. The prevalence of nymphal and adult female ticks varied between years and during the seasons. Puffin chicks had the highest prevalence (above 70% in July) of nymphs. Female ticks rarely fed on puffin chicks and were more prevalent on adult puffins. 9 of 22 female ticks and 1 of 39 nymphs from adult puffins in Gull Island, Newfoundland tested positive for B. garinii. This is the first record of B. garinii from this region. Adult puffins seem to play a role in this Borrelia cycle. Female ticks seemingly were more important since they had a greater prevalence of Borrelia (40.9%) compared to nymphs which could reflect transtadial transmission of Borrelia and/or a higher infection prevalence in adult puffins. Nymphal ticks feed on puffin chicks during the peak questing period in Gull Island and the extent of their involvement in the cycle needs to be determined. The emergence of B. garinii in eastern North America warrants further detailed investigation, both from the wildlife epidemiology and the human health perspective.
Study of passerine migration in
southwestern Nova Scotia We used a modified marine radar to monitor the nocturnal migration of passerines at the Atlantic Bird Observatory (ABO). 45% of all migrants detected occurred on 6 nights (12% of all nights monitored). These high-volume nights were mainly during relatively light (10-28 km/h) winds originating from the N to NE and consisted of predominantly a SW migratory direction, which is consistent with the :Expected" migratory pattern in the region. Consistent with other studies, the numbers of migrants detected by radar were significantly positively correlated with numbers of birds detected by censuses and through constant effort mist-netting. Although these survey methods were correlated, nights of very high volumes of migrants my not be adequately represented by banding and censuses due to the asymptotic nature of the ground measures. Radar data also confirm that migrants typically employ an overall "constant-heading" migration strategy, orienting towards a fixed goal without compensating for wind-displacement during flight. However, during favourable migratory conditions migrants compensate for wind-displacement.
Mitochondrial variation and global
population structure of an endangered bird, the Ivory Gull (Pagophila
eburnea) The Ivory Gull (Pagophila eburnea) was recently re-classified as Endangered in Canada due to an 80% population decline since the 1980s. There are critical gaps of information available about the global population ecology of the Ivory Gull and this study aims to fill these for more accurate conservation management plans. To determine its global genetic population structure, several different mitochondrial markers were used in the analysis, including the control region, 12S, ND4 and ND4L, totalling approximately 2000 base pairs. Using Analysis of Molecular Variance (AMOVA), the vast majority of the genetic variation was seen within populations. This was as a result of genetically similar breeding colonies and indicates the presence of considerable gene flow between colonies. The lack of genetic structuring prevented the determination of the breeding origin of wintering birds seen in Newfoundland and elsewhere. The overall haplotype and nucleotide diversity observed was very low, which is often seen in endangered or arctic avifauna. This is the first conservation genetic study of this quickly declining species.
Contributions of the Pacific auklets
to the knowledge of seabird evolutionary ecology- an overview The tribe Aethinii of the widespread avian family Alcidae comprises five species of small North Pacific auklets. Studies on their breeding behavior and ecology over two decades have made a profound impact on our knowledge of seabird ecology. Here we review the present state of knowledge of auklet ecology with a viewpoint of their acoustics and ornamentation. These highly vocal auklets have 3 distinct vocal display patterns suggesting the possible role of ecological and phylogenetic relationships on their acoustics. Among the tribe the monophyletic genus Aethia are characterized by their elaborate ornamentation. Previous studies on the forehead crest of crested auklet have demonstrated its role in mutual mate choice as a sexually selected trait. The crestless least auklet expresses heterospecific preference for this same trait, which two of its closest relatives the crested and whiskered auklets uniquely share. Furthermore some of the least auklet facial plumage and bill color are weak indicators of quality. The recent findings of the lesser-known but more elaborate facial ornamentation of whiskered auklet emphasize an alternate explanation for their use: as a sensory device.
A short history of blipmovies. The blipmovie made its debut in early September on Bon Portage Island. It was an immediate hit. Blipmovies are compressed archives of single nights of bird migration produced by the program Radr. I will demonstrate the program, and show some exciting scenes from some of the best blipmovies produced to date -- including massive movements of dragonflies, birds taking off at dusk, re-orientation at dawn, large flocks of waxwings and robins moving north, and huge nights of migration. Stay tuned.
Partnerships behind the science -
the Gros Morne Project A brief overview of the issues which led to the formation of the Greater Gros Morne Ecosystem Connectivity Working Group and the partners who become involved. A collaborative effort among government, industry and academia has enabled the development of a project which has provided information of interest and of value to each of the partners.
Predictive habitat models for
seasonal moose distribution in the Yukon Predictive habitat models are potentially useful tools for assisting wildlife managers in decision making in the face of habitat change, particularly over large regions. Often it is difficult to interpret whether large-ranging organisms, such as moose (Alces alces) are responding to environmental cues, or to habitat and resource variables. While predictive habitat models have been widely applied in conservation and ecology, the range of available models is varied. Few studies have constructed a suite of models to test model performance. Here, we used radio-collar moose data together with environment and habitat variables in a GIS analysis to build and test three types of predictive habitat models. We built and compared logistic regression, classification and regression tree (CART), and Mahalanobis distance-based models for moose habitat in the southeast Yukon. We validated our models using independent data, and found that, overall, the logistic regression model minimized error rates. We discuss how these models might perform in different applications. Our results also aid in identifying priority sites and habitat characteristics for moose management, and shed light on the relative importance of environmental (such as elevation and distance from roads) and habitat (such as stand characteristics) variables, as predictors for moose occurrence.
Natal and Breeding Dispersal by
Migratory Boreal Forest Songbirds Fidelity to breeding sites is often assumed to be high for songbirds, though few studies have measured breeding dispersal. From 2003-2006 we banded 5,526 songbirds at 18 sites in a 10×20 km study area in Newfoundland. Included in this were 2,469 individuals of 6 species that were colour banded. In 2006 we conducted a systematic resighting survey in which we sampled all points on a 500 m grid out to 4.1 km from all netting sites (n = 830 points). We used recapture data as well as resightings to measure interannual displacement of returning individuals. While dispersal by adult male white-throated sparrows was negligible, the remaining 5 focal species showed moderate interannual site fidelity, with median, mean, and maximum movements of 82 m, 115 m, and 447 m, respectively. Breeding dispersal by adult females was greater, with median, mean, and maximum movements of 473 m, 997 m, and 4,311 m, respectively. Only 2.3% of 1051 juvenile birds were observed in a subsequent year, and for these the median, mean, and maximum movements were 2,550 m, 2,898 m, and 6,102 m, respectively. Our observations are discussed in the context of incorporating emigration into estimation of annual survival rates.
Apparent survival and population
viability of a forest bird indicator species in relation to
landscape-scale forestry A central question of this research is: How does reduction of mature forest influence the survival of forest songbirds? Earlier related work identified Blackburnian Warbler as a species particularly sensitive to the amount of mature forest in landscapes in the Greater Fundy Ecosystem, New Brunswick, Canada. A congener, Black-throated Green Warbler, tolerates a wider range of habitats and so provides a useful comparison. Our overall strategy is to measure survival of the two focal species along the habitat reduction gradient within the 4000 km² study area: Fundy National Park, where contiguous mature forest covers approximately 80% of the landscape, and land adjacent to the Park where mature forest cover has been reduced by intensive forestry to about 12-50% of the landscape. We report the first apparent annual and within-season survival estimates for both focal species at such a large scale. We will use these data to develop population viability analysis (PVA) models that will assess the influence of a range of forest management scenarios on forest bird populations. This information should help managers decide how much mature forest is needed on a landscape to maintain populations of species requiring this habitat. |