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BRIAR ISLAND HOTEL, BRIAR ISLAND NS (ACADIA) 1999 An assessment
of the influence of avian predators on egg and duckling survival at a
common eider (Somateria mollissima) colony at east
bay, Southampton Island, Nunavut, Canada. Avian predation can have important influences on the reproductive success of colonial birds. High predation rates have been estimated previously on common eiders (Somateria mollissima) nesting in temperate regions. Research at certain colonies in eastern Canada revealed Great black-backed gull (Larus marinus) predation can result in virtually complete reproductive failure. Despite this, little information exists on the factors influencing avian predation rates, and sources of temporal and spatial variation. This study will examine the effects of herring gull (Larus argentatus) and parasitic jaeger (Stercorariusparasiticus) predation on common eiders nesting at a colony in the eastern Canadian Arctic. This colony is located on a small treeless island, where observation blinds equipped with access tunnels allow detailed observations, keeping disturbance to incubating eiders and their predators to a minimum. Specifically, I will examine how predation varies in relation to time scale (i.e. time of day, during the course of the eider breeding season, annually). I will also examine how predation varies in relation to eider colony attendance patterns, eider nesting density, foraging behavior of individually marked gulls and weather conditions. Hypotheses, as well as methods used for this research will be discussed. Examining the effects of bloom
harvesting on Limonium carolinianum using stage
structured matrix population model analysis Limonium calolinianum (sea lavender) is a long-lived salt marsh perennial whose blooms are harvested commercially for dried floral arrangements. There is anecdotal evidence that the current harvesting practices are causing a decline in various populations of these plants. To determine harvesting effects and establish sustainable harvesting regulations we have been collecting demographic data on L. calolinianum on the Wolfville salt marsh since 1996. We have also experimentally manipulated harvest times to examine the effect of harvest on survivorship. From this data we have been constructing a stage structured matrix population model to project long-term harvesting effects. The life-cycle of L. carolinianum
includes seeds, seedlings, juveniles and mature adults. For the model
the adult category was broken into size classes based on the number of
ramets (1, 2-4, 5-7 and 8+). As the plants have a fairly long life
span, the effects of extensive harvesting would not be immediately
apparent. Sensitivity and elasticity analyses were conducted and an
examination of the long-term effects of bloom harvesting carried out
using the current model. Habitat Selection and Breeding
Success of Black Terns (Chlidonias niger) in
Impounded Wetlands in New Brunswick There are a third as many Black Terns nesting in North America today as there were 30 years ago, most likely due to the loss of wetlands suitable for nesting. The Black Terns along the Saint John River floodplain in New Brunswick prefer to nest in impounded wetlands; however only a few of the impoundments are used even though they all appear to provide suitable nesting habitat. My objectives were to determine the environmental cues Black Terns (Chlidonias niger) use for habitat selection by relating physical and biological characteristics of impounded wetlands with use by this species. I also determined the quality of the habitat by relating reproductive success to impoundment characteristics. I examined habitat use and quality at two scales: the impoundment level and the nest site level. I also examined habitat selection using social attraction, tested by using decoys and calls, and I measured the degree of site fidelity. Size of impoundment, vegetation density considered concurrently with water depth, and abundance of odonate prey determined use at the impoundment level. Features important at the nest site level included density of vegetation, amount of open water, and amount of cover. Black Terns have weak social attraction and low site tenacity. One impoundment had higher breeding success, and hence higher quality habitat, than the others but there were no discernable differences in habitat variables at the impoundment level. Successful nests were initiated earlier, were on higher nesting substrate, and had more cover to protect against predators and the elements. Methods of counting and archiving
seabird survey photographs using a desktop computer. A simple way of counting and archiving seabird survey photographs is described. Medium format negatives shot at Northern Gannet colonies in 1999 were scanned onto Kodak Pro Photo CD, at various resolutions up to a maximum of about 100 pixels/mm. Scans at each resolution were viewed and a minimum resolution chosen so as not to compromise the ability to count targets. Each scan was read by Adobe Photoshop version 4, and adjusted to optimise brightness, contrast, and other image attributes. In preparation for counting, a new, transparent layer was created above the scan, through which the image could be viewed on the computer monitor. Onto this new layer, dots, each made up of a square array of pixels (normally 3 x 3) were placed above each target (in this case a gannet nest) using one of the drawing tools available in Photoshop. Dot size was chosen from one of the square brush palettes so as to be clearly visible on the monitor but not so large that targets were obscured. Once all targets were "dotted", the Histogram command in Photoshop was used to count the number of pixels on the new layer. The pixel count was divided by the number of pixels per dot to obtain a count of the total number of dots on the image. This method provides several advantages over the traditional method of counting photo enlargements or using computer software to determine targets and perform the counting. These advantages are discussed. Arctic Tern Metapopulations: Phase 2 Metapopulation biology has become a popular buzz-word in discussions of species dynamics. The development of this field has been based on theoretical models, and there is a need for the examination of real populations to test these models. Populations of seabirds often illustrate a natural metapopulation structure due to the distribution of suitable and available nesting habitat. Colonies are frequently scattered throughout a region on different islands. However, it remains to be seen if this arrangement of colonies actually display the dynamics of a metapopulation model. Arctic Terns (Sterna paradisaea) breed on several small islands in the Bay of Fundy and Gulf of Maine. In combining a traditional banding study with a genetic analysis I am examining the extent of movement among colonies. The goal of this project is to determine if terns nesting in this region are part of a metapopulation or if each island acts as an individual population. Management strategies will be planned depending on the type and amount of movement shown. Little movement will indicate the importance of any decline on any island. If there is much movement of terns among colonies, then management strategies on one island could impact the terns nesting on other islands. Razorbill population trends in the Gannet Islands, Labrador, and effects of Arctic Fox presence on breeding numbers. Elliot, Richard D., Canadian Wildlife Service, Environment Canada, Box 6227, Sackville, NB E4L 1G6 and Gregory J. Robertson Atlantic Cooperative Wildlife Ecology Research Network, University of New Brunswick, Fredericton, NB, and Canadian Wildlife Service, Environment Canada, 5 Bruce Street, Mount Pearl, NF A1N 4T3 The Gannet Islands seabird colony, located on six small islands off the coast of central Labrador, supports the largest breeding concentration of Razorbills (Alca torda) in Canada. Complete Canadian Wildlife Service surveys of the islands in 1978, 1983 and 1998-99 indicate that overall numbers of breeding pairs of Razorbills have apparently increased slightly over this period, with about 10,000 pairs present. However, the relative numbers nesting on each island have changed, apparently in response to the presence of Arctic foxes (Alopex lagopus) noted on different islands in different intervening years. Although actual predation of eggs, chicks or adults may have had some impact, it appears that Razorbills may have switched nest sites away from those islands on which foxes were present. Elsewhere in eastern Canada, Razorbill breeding numbers have increased at most Québec colonies in the Gulf of St. Lawrence since the mid-1980s, following earlier declines, and there have been recent increases in Witless Bay, Newfoundland, and the Bay of Fundy, New Brunswick, where appreciably smaller numbers nest. Navigation and orientation of
vagrant land birds occurring in Nova Scotia Avian migratory mechanisms (e.g. navigation and orientation) have been extensively researched. Abnormal migratory movements, such as reverse migration has been suggested to be linked with magnetic anomalies and weather disturbances. Bon Portage and Seal Islands in southern Nova Scotia are important migratory stopover habitats along the Atlantic flyway- a major migration route. These islands offer a great opportunity to research vagrant migration due to the high occurrence of vagrant birds noted during migration. I propose to conduct such a study, during the spring and fall migration, which will broaden the understanding of vagrant migration. Vagrant bird species will be captured and experimentally manipulated to quantify their navigation and orientation skills. This study has profound management implications. Reverse migratory species may indicate important stopover locations during migration that are otherwise unknown. Vagrant migration could also indicate a previously unrevealed increase in a species range of distribution. All of these principles are extremely important to avian conservation. Behavioral ecology of Harlequin
Ducks and low level flight training in southern Labrador; Pilot Study
1999 In May to August 1999, Harlequin Ducks were studied at a high-density site near Fig Lake outlet, a tributary to the Lower Churchill River in southern Labrador. Approximately 10 pairs of Harlequin Ducks attempted breeding in the area, and there was a strong bias to females. Adults and broods were captured and marked used colour alphanumeric bands that could be deciphered through spotting scopes. Behavioural watches (n=- 560), consisting of 30 minute watches, were undertaken and linked to known individuals. There was considerable variation among individuals in response distance to observer disturbances. There were very few military over-flights of the study area due to oversea activities in Kosovo and a subsequent labour strike on Goose Bay base, however behavioral response to jets and Transall aircraft were recorded, and of short duration, i.e., generally under 200 sec. per event). Data on sound levels were collected during brood rearing (mean 60.5 dBA + 8.87 sd), and brooding females may have responded to increasing (ambient) noise on the study area by increasing vigilant behaviour (P = 0.10). Feeding by paired females and by juveniles was dependent on vigilant levels in the males and brooding females, respectively, (P < 0.0001); vigilance varied considerably among individuals. Increased reaction to aircraft (sound) levels on the study area are hypothesized to result in tradeoffs to time being budgeted for feeding and vigilant behaviors which would be expected to affect survival and fitness of these Harlequin Ducks. Anthomyia Pluvialis
– What Is This Fly and Where Did They Come From I will be discussing the first reported occurrence
of Anthomyia pluvialis in Nova Scotia discovered in the Grand
Pre’ Dyke Lands of Annapolis Valley this summer. I will talk
about the capture technique, the method by which these flies were sexed
and the sex ratio of the captured flies. I will further discuss the
temporal and spatial distribution of the captures and what this may
mean with regard to the natural population. I will conclude with what
further research needs to be done in order to find out what, if any,
impact these flies may have on the agricultural sector of the Grand
Pre’ Dyke Lands. Do young conifer plantations
influence forest bird reproductive activity in adjacent stands? Young conifer plantations in the forest landscape not only reduce the amount of available habitat for certain species of forest birds within plantation stands, but may also reduce the suitability of the adjacent stands for breeding. We studied the reproductive activity of eight forest bird species in two landscapes representing different intensities of plantation silviculture use in northwestern New Brunswick. We performed logistic regressions to examine the relative effects of landscape structure and local habitat variables on the reproductive activity of forest songbirds. We used the distance from each sampling station to the nearest plantation edge and the area of plantation within a 100m, 250m, 500m, and 1000m radius as measures of landscape structure. We developed an index of avian reproductive activity using direct observations of reproductive-related behaviours (pairs together, adults carrying food, etc.) at each sampling station. Plantation landscape variables contributed significantly to lower observed reproductive activity for five species on the intensively-managed landscape (Black-throated Green Warbler, Red-eyed Vireo, Black-capped Chickadee, Northern Parula, and Black-throated Blue Warbler) and only one species on the moderately-managed landscape (Black-throated Blue Warbler). These results suggest that converting large proportions of landscapes to plantations over a short period of time may reduce suitable habitat for some forest birds beyond a critical threshold. Effects of predation, herbivory, and
nutrient enhancement on the structure and composition of an intertidal
mudflat community Semi-palmated sandpipers (Calidris
pusilla) migrating through the upper Bay of Fundy feed
heavily on the amphipod Corophium volutator, a
dominant invertebrate in the intertidal mudflat community. This
predation may represent a strong top-down force controlling intertidal
community structure. Alternatively, the system may be controlled
primarily by bottom-up forces such as nutrient availability. Using
predator exclosures to prevent shorebirds from feeding, and fertilizer
to enhance nutrient availability, we tested between these two
hypotheses during summer 1999 on a mudflat at Avonport, N. S. Corophium
and several species of polychaetes were the most abundant invertebrates
in the area. A herbivorous whelk, Ilyanassa obsoleta, which competes
with Corophium for diatoms, was also common. Preliminary field
observations suggest that shorebird predation reduced Corophium
abundance. Fertilization enhanced algal abundance within 3 weeks, but
the enhancement did not persist through the end of the experiment.
However, by the end of the experiment, there was more algae in
exclosures than in controls, suggesting that effects of predation by
sandpipers filtered down to the algal level. This result, and the
apparent loss of a fertilization effect late in the experiment, may be
explained by the presence of whelks, which were most common in
fertilized sites and in controls. They grazed algae and compensated for
both fertilization and bird exclusion. These results suggest that there
are elements of both top-down and bottom-up control in this system. The
compensatory effect of whelks may help to stabilize the community in
the face of variation in either bird abundance or nutrient availability. The Canadian Wildlife Service annually collects data on the number of breeding pairs of Black Ducks (Anas rubripes) in 100 km2 survey plots. Although much is known about habitat use by breeding Black Ducks at a local level, the reason for variation in Black Duck numbers among survey plots is unknown. This study is investigating the ability of landscape level habitat data such as the Maritime Wetland Inventory, topographical data, ecological land classifications, soil chemistry, and water chemistry, to explain differences in number of Black Duck pairs among survey plots. The Maritime Wetland Inventory describes wetland biophysical form, hydrologic connectivity, vegetative interspersion and other characteristics of over 67,000 wetlands in New Brunswick and Nova Scotia. The relationships between habitat and number of Black Duck pairs within survey plots will be used to create statistical models that estimate Black Duck populations in larger geographic regions. This study is also investigating the relationships between wetland biophysical form, water and soil chemistry, and ecological land classification for wetlands throughout the Maritime Provinces. Preliminary results from this study will be
presented. The peatlands of Newfoundland in which 26 species of dragonflies and damselflies (odonates) live are surrounded by forest and scrub. Examining how peatland odonate populations are distributed in natural landscapes with varying habitat structure at a spatial scale which encompasses their movements is integral to understanding the effects of landscape change on these insects. Surveys of odonate larvae were performed in five different landscape types. Comparisons of larval populations were made between three landscape types where the amount of suitable habitat (peatland) was held constant while the surrounding matrix (clearcut, forest, scrub) was varied. A second comparison was made between landscapes where the matrix was held constant (scrub) while amount of peatland was varied. Preliminary results indicate that forested landscapes had far fewer odonates. Landscapes with smaller peatlands showed higher density of larvae than landscapes with larger peatlands. Examining one species in particular (Leucorrhinia hudsonica), density increased from forested landscapes to clearcut landscapes to scrub. L. hudsonica were less abundant but larger in size in landscapes with large peatlands than those with smaller peatlands. The implications of these findings on forest management will be discussed. Sooty Shearwaters off Eastern
Canada: Spatial and Temporal Patterns of Abundance, 1966-1992, for a
long-distance migrant from unknown origin. Sooty Shearwaters (Puffinus griseus) have received little attention as species of interest or concern for the Northern Atlantic. The breeding status and the origin of Sooty Shearwaters in Eastern North America are poorly known. Based on the literature we provide a thorough overview about this species for the Northern Hemisphere (Northern Pacific and Northern Atlantic). Using the PIROP (Programme Intégré des Recherches sur les Oiseaux Pélagiques) Database, owned by the Canadian Wildlife Service and covering at-sea observations from 1966 -1992, we investigate the spatial and temporal patterns of abundance for pelagic Sooty Shearwater observations off Eastern Canada. The first and the last observations per year, yearly and monthly means (corrected for effort) are shown. Distribution patterns and flock sizes of all Sooty Shearwater sightings, and birds reported in moult are discussed. We describe how Sooty Shearwaters are distributed in relation to Greater Shearwaters (P. gravis), another long-distance migrant occurring in Canadian waters during the summer and fall season for moult. Our findings are interpreted and discussed considering El Nino and other events relevant to the southern hemisphere, where these birds breed. Information about foraging activity at sea is crucial to understanding the biology of diving seabirds such as auks, but is mostly lacking due totechnical limitations on measuring behaviour at sea. We quantified foraging activity and colony attendance of 17 breeding Thick-billed Murres during the chick-rearing period using temperature loggers and radiotelemetry. Each individual's activity was monitored for approximately four days. Arrival times and presence at the breeding site (i.e., feeding and brooding chicks) were quantified by using 3 g radio transmitters attached to leg bands and an SRX-400 telemetry receiver-logger. Frequency, duration and timing of 2,000 dives were determined from temperature logged every 10s by dorsally mounted temperature loggers. We evaluated whether selfmaintenance dives differed in timing or duration from chick provisioning dives. The latter exclusively involved the pursuit of Daubed Shannies (Lumpenus maculatus), a benthic fish. We also quantified the timing and distance from the colony of foraging by males and females. Movement and distribution of pitcher
plant insect communities in relation to habitat configuration in a
heterogeneous landscape Commercial forest cutting is proceeding around the border of Gros Morne National Park (GMNP) in western Newfoundland. A long-term study looking at the effects of timber harvesting on animal movement was initiated in 1998as a co-operative effort between GMNP, Acadia University, Western Newfoundland Model Forest, and Corner Brook Pulp and Paper with the goal of maximizing the ecological potential of remaining boreal habitat for animal communities. In association with this project, I am studying the movement and distribution of insects which inhabit non-merchantable patches of bog-land within this heterogeneous landscape. My aim is to increase our understanding of the influence of landscape structure on species living in a naturally patchy (boreal) environment. Three species of flies obligately oviposit/larviposit within the leaves of the pitcher-plant Saracen pursuer. This summer I looked at the relationship between habitat configuration (variable habitat patch density, isolation, and size) and larval distribution at four spatial scales. I am particularly interested in how/if the predictive power of structural variables changes when comparing areas with different amounts of suitable habitat, and at what spatial scale habitat structure most influences the study organisms. As well, experimental work was undertaken to determine basic movement patterns by adults of two species of fly; I will present these preliminary results. The influence of capelin
availability on Large gull predation on kittiwakes and its impact on
kittiwake breeding performance. We studied factors influencing predatory behaviour of Herring (Larus argentatus) and Great Black-backed (Larus marinus) gulls on Black-legged Kittiwakes (Rissa tridactyla) on Gull Island, Newfoundland. Generalist foragers, such as Herring and Great Black-backed gulls, are known to change diet in response to prey availability. Spawning capelin (Mallotus villosus) are an essential food resource for gulls during chick rearing. However, since 1990 capelin spawning has been delayed by 4-6 weeks. At Gull Island, the eggs and chicks of Black-legged Kittiwakes are an important alternative to capelin for large gulls. In 1999, capelin spawning occurred 9 d earlier than in 1998. In both years, predation rates of large gulls on kittiwakes were significantly higher after mean gull hatching but before capelin arrival compared to predation rates before gull hatching and after capelin arrival. However, mean predation rates were higher in 1998 throughout the season than in 1999. In 1998, 59.1% of all kittiwake eggs and chicks, which disappeared, were lost during the relatively short period of two weeks before capelin arrival. However in 1999, only 37.3% of all disappeared kittiwake offspring, were lost during that same period. I estimated that 42.8% (1998) and 30.3% (1999) of all kittiwake offspring were lost due to gull predation. From these results, we conclude, that delayed capelin arrival might not only cause a prolonged period of high gull predation on kittiwakes, but also might indicate a season of overall low food availability for gulls, causing higher predation of kittiwakes throughout the breeding season. Post-fledging movements and
territoriality in forest songbirds Among passerines, studies stress the importance of territoriality in early breeding stages, however, an review of 40 recent species accounts indicates that little evidence exists to link post-fledging feeding and movements to territories. My study provides the link by measuring the distance between locations of fledglings in a deciduous forest and the nearest territorial singing point of the male parent, a point assumed to be within or at his territory boundary. Of 103 observations of 13 species collected in 1996-99 ( 4 years), 67% of fledglings were found within a previously plotted territory of that species, 31% were within 50 m. outside the boundary, and 3% were over 50 m. outside. Observations of banded birds with known territories (27) showed that all fledglings were fed on territories or near (50 m.) plotted boundaries for 3-4 weeks, after which both adults and young were not seen in the plots. Because this evidence strongly suggests territorial movements of the adults in the post-fledging period related to feeding young, I conclude that territoriality is important also in the latter part of the breeding cycle and that it directs the movements of juveniles until dispersal. Arthropod Density and Diversity, and
Tree Species Structure as Determinants of Avian Foraging Use Two forest songbirds, the Black-throated Blue Warbler (Dendroica caerulescens), and the Black-throated Green Warbler (Dendroica virens) have demonstrated significantly higher foraging use of two tree species, American Beech, (Fagus grandifolia) and Balsam Fir (Abies balsamifera) in relation to the abundance of these two tree species. Data collected on the arthropod community and avian stomach contents suggest that the observed use patterns may be driven by arthropod density and diversity in the high use tree species. While arthropod density and diversity seems to explain some of the use patterns, it is still likely an alternative dynamic operates as well. This alternative dynamic involves the efficency of a particular bird species' foraging strategy in relation to the geometry of a tree species. The two hypotheses explaining high foraging use in two tree species will be discussed. Pitcher plant surveys in Gros Morne
National Park, NF I surveyed the density of three species of insects that inhabit the leaves of the pitcher plant, Sarracenia purpurea, in Gros Morne National Park, Newfoundland to examine patterns of spatial structure at various scales. The primary inhabitants of these water-bearing leaves are larvae of the mosquito (Wyeatomyia smithii), midge (Metriocnemus knabi), and sarcophagid fly (Fletcherihmyia fletcheri). Densities of the larval communities were quantified by non-destructive sampling of 800 leaves over a 2 year period. Two leaves were sampled from each of five plants, at randomly chosen locations (points) within bogs, and across open and closed bogs of three different sizes. Species varied in abundance at different spatial scales. In the first year midge abundance varied most significantly at the level of the plant and leaf, while mosquito abundance varied most at the level of the leaf and the point. This variation at the level of the point suggests that spatial structure may exist in the mosquito population. The results indicate that populations of different species may be structured at different spatial scales. Analysis of the ectoparasite
community structure of four Auk species (Alcidae) at the Gannet
Islands, Labrador Ectoparasite community structure is an important aspect of seabird biology that is quite frequently overlooked due to lack of adequate data. This study documents the incidence of a diverse assemblage of arthropods living in association with four auk species (Alcidae ). The diversity and density of arthropod taxa are compared within and between auk species as well as in relation to the each other. Infestation levels of adults are compared to chicks to illustrate transmission in the different auk species. Lice and feather mite genera are given special consideration in relation to host coloniality. The significance of feather mite taxa as a commensal rather than a parasite is discussed. The role of phoretic species in this regard is also discussed. Non-lethal predator control: a
successful method for controlling gull predation on Country Island, NS Country Island is one of only four main nesting sites for Roseate Terns (Sterna dougallii) in Canada and also an important nesting colony for Arctic and Common Terns (Sterna paradisaea, S. hirundo). In 1996, predation by gulls and corvids seriously affected reproductive success, and in 1997, the colony was partially abandoned. In 1998, the Canadian Wildlife Service proposed a colony restoration plan using non-lethal control (human presence, pyrotechnics, and nest destruction) as a means to prevent predators from nesting and loafing on the island. Yearly gull counts, intrusion observations, tern nest censuses and productivity measurements were used to determine the effectiveness of non-lethal control. No predators nested successfully on Country Island in 1998 and 1999, and since 1998, gull numbers have declined markedly. In 1999, Arctic and Common Tern populations had fully recovered, productivity was high, and predation levels were minimal. Roseate Terns increased to 16 pairs, and a productivity of 1 chick per nest was attained. These results suggest that non-lethal predator control has been an effective method to limit the impact of predators on the Country Island tern colony. Geographic information systems (GIS) are capable of cataloguing and sorting large amounts of data and information on habitat and physical landscape structure. As a planning tool foresters and urban planners often rely on them heavily. Can the same capacity for correlating data be applied to conservation planning? Current efforts to re-establish fisher (Marts pennant) over the former range in Nova Scotia provides an opportunity to test the efficacy of predictions made by GIS models with respect to habitat choice. Based on the idea that fishers are trapped in areas they prefer to inhabit, harvest location data can be used to isolate habitat characteristics from the GIS database common to all trap locations. When these characteristics are identified we can then choose areas of habitat in unoccupied areas which, theoretically, should hold fishers. Testing of the model constructed in the above manner will involve translocating individuals to areas of optimal and sub-optimal habitat as chosen by the GIS model. The animals’ response to the new habitat will be monitored via radio-telemetry. Estimates of egg and chick survival are needed in a large range of ecological and behavioural studies. There are several problems in many field studies: 1. data is often incomplete, i.e. key events such as egg laying or fledging were missed. 2. comparisons of survival using chi square tests have low statistical power. 3. siblings lack independence. 4. often only a particular cause of mortality, e.g. predation or starvation, is of interest rather than overall mortality. Survival analysis, in particular Kaplan-Meier estimates and Cox's regression provides powerful tools to address these problems. Required data are nest checks at regular intervals, preferably daily. Thus a more laborious sampling protocol is needed than for the Mayfield method, however, the assumption of a constant mortality rate can be avoided. Examples are drawn from a study of Little Penguins in New Zealand. We investigated the winter diet of murres (Uria
spp.) in coastal Newfoundland waters in relation to environmental and
ecological changes that have occurred in the Northwest Atlantic since
the 1980s. We analyzed the contents of 371 stomachs (311 Thick-billed
Murres Uria lomvia and 60 Common Murres Uria
aalge) collected from birds shot by hunters around the
Newfoundland coast during the winters of 1996-98. We observed that the
frequency of empty stomachs was greater in our sample than in a similar
study conducted during 1984-86. We found no difference in the
proportion of fish in the diet between the 1980s and 1990s. However,
Arctic cod (Boreogadus saida; 55% to 12%) and
capelin (Mallotus villosus; 28% to 6%) decreased
in frequency. The proportion of stomachs containing crustacea and squid
did not change between the 1980s and 1990s but hyperiid amphipods (Parathemisto
spp.) replaced euphausiids (Thysanoessa spp.) as
the predominant crustacea. Changes in murre winter diet off the coast
of Newfoundland corroborate other sources of information that major
changes in distribution and biology of marine organisms have occurred
in the Northwest Atlantic during the 1990s. The declining quality of Prince Edward Island wetlands has been attributed to both siltation and eutrophication. By excavating accumulated silt and debris, to fragment dense stands of vegetation, and to create open water, locally declining American black ducks (Anas rubripes) may benefit. Since 1991, under the Eastern Habitat Joint Venture, over 100 small wetlands have been excavated in PEI. In 1998, we began a 2-year study to examine waterfowl, songbird, rail and anuran use of small, excavated wetlands. The primary objectives of the study are to determine if and how the wildlife community changes. In 1998 and in 1999, the study included 18 excavated sites paired with 18 non-managed sites (i.e. controls). The selection of sites was based on a 1990 pre-management wetland inventory and a stratified random selection scheme. Thus, within each category there are three types of wetlands based on dominant vegetation class--shrub swamp, emergent marsh, and wet meadow. Other study objectives are to determine the relations of environmental variables with marsh bird and anuran species abundance, composition and distribution in small wetlands. Habitat characteristics under examination include variables at a wetland or local scale, such as wetland area, amount of open water, and type of perimeter, and variables at a landscape scale, such as degree of isolation, and type of surrounding habitat. Observations made in 1998 suggest that breeding waterfowl benefit by wetland excavation--30 broods used excavated sites and 6 broods used natural sites. Biological diversity and ecosystem health are increasing concerns in the forestry industry. This project investigates the value of Habitat Management Areas (HMAs) on Fraser Paper Freehold to the reproductive success of a guild of birds associated with mature-overmature forest. The preliminary field season focused on determining which species in a guild of cavity nesting birds are appropriate indicators of forest health in HMAs and on developing an effective design for monitoring relative reproductive success. Relative reproductive successes of the cavity nesting species were determined using a productivity index to rank activity according to their associated breeding stage. The productivity indices will be compared to detailed vegetation measures in order to determine which habitat features best support successful breeding pairs, and which species are appropriate indicators of forest health in an HMA. Several different types of monitoring protocols have been examined: 1) line transects versus circular plot monitoring, and 2) chickadee mobbing call playback versus systematic walks of transects and plots. Six transects and fourteen circular plots were placed in softwood dominated mixed forest, and included uncut and partially cut mature and overmature stands. The number of visual observations and the degree of sampling effort will be analyzed in order to develop an effective monitoring protocol for future work. In future work we hope to compare the habitat needs and productivity of the guild species in privately managed areas (i.e. HMA) to protected (e.g. Mount Carleton Provincial Park) or Crown managed areas (e.g. Mature Coniferous Forest Habitat). Increase in chronic oil pollution in
the waters around Southeastern Newfoundland The waters around Newfoundland are a cross-road between high activity shipping lanes and up to 30 million seabirds which reside and/or migrate through this area annually. Small and large oil spills are recorded in this region every year and countless seabirds die after coming in contact with the oil from hypothermia, starvation, and/or physiological damages. Analysis of systematic beached bird surveys conducted by the Canadian Wildlife Service around the Abalone Peninsula since 1984 showed an overall oiling rate of 71 % and a yearly increase in the proportion of oiled birds found of 3.2 %. It further revealed that winters (Oct. - Mar.) are by far more severe in oiling rates that summers (9.4% vs. 71.8%), and that alcids are the most affected by this anthropogenic pollution, making up 89% of all birds found since 1984. Reasons for this increase may include changing seabird distributions, increased shipping activities and/or larger proportions of vessels illegally discharging oil at sea. Future research to determine the causes, as well as to determine annual seabird mortalities due to oil are outlined. An investigation of the population
dynamics and dispersal patterns of Musca domestica The summer of 1999 marked the second year of an investigation into the decade-old Grand Pré housefly problem. Housefly populations were above outbreak levels causing an annoyance, health risk, and economic impact in the local community. The study examines the dispersal patterns and ranges of houseflies released on the marshbody around the Grand Pré National Historic Site. Flies were grown in chicken manure and mass-marked in a variety of striking colours using the ‘complete bucket’ method. Pheromone-based baited traps were located throughout the region and changed regularly during a series of releases involving over five million flies. Measurements looked at dispersal in the first few minutes after each release, the distribution of the flies over the first week after release, and at the ultimate distances traveled. This data will be used to model the dispersal patterns of houseflies in the local system and offer evidence for future policy decisions. The project includes extensive cooperation with area farmers, Parks Canada, and the NS Department of Agriculture and Marketing. |