HUDSON BAY PROJECT - 1997 PROGRESS REPORT

HUDSON BAY PROJECT - 1997 PROGRESS REPORT

Robert F. Rockwell, American Museum of Natural History
Robert L. Jefferies, University of Toronto
Kenneth F. Abraham, Ontario Ministry of Natural Resources
Andrew Jano, Ontario Ministry of Natural Resources
Walter Skinner, Environment Canada
James O. Leafloor, Ontario Ministry of Natural Resources

Overview

The 1997 field season was the second year of support for the Hudson Bay Project under our current funding arrangements. Intensive studies were undertaken at our 2 primary research sites, La Pérouse Bay and Akimiski Island. In addition, we conducted detailed aerial or ground surveys of nesting colonies from Akimiski Island to the Knife and Seal River deltas north of Churchill. These were planned to coincide with the fixed wing aerial inventories coordinated by Dick Kerbes of the Canadian Wildlife Service. We also initiated vegetation surveys (including erecting and sampling exclosures) on the Pen Islands. These are located near the Ontario and Manitoba border and until recently did not have a large number of nesting snow geese. As part of our attempt to understand recovery potential of degraded habitat, we initiated detailed investigations of seed beds in the La Pérouse Bay region. These would be a primary source of raw material for vegetation recovery. We continued and expanded assisted revegetation trials aimed at determining limiting factors for establishment of dominant graminoids. We also continued examination of changes to aquatic and terrestrial invertebrate populations in areas impacted by habitat degradation. We completed analyses of the long-term bird list data from La Pérouse Bay to ascertain whether there have been declines in any of the other bird species using the region. Since that analysis indicated a significant decline in several species of shorebirds, we initiated a detailed investigation of habitat use and foraging by staging and nesting shorebirds. Finally, we are pleased to report that Jim Leafloor has joined us as a full member of the Hudson Bay Project research team which significantly enhances our research potential.

The entire research team and our graduate students are heavily involved in preparing abstracts, posters, oral presentations and workshops for the 1998 North American Arctic Goose meeting. We felt it most appropriate to focus our detailed quantitative and analytical energies on those and will provide those details to you as additions to the following season narratives as they become available. We will also be sending you copies of technical reports and published papers throughout the year.

As a final note, the Hudson Bay Project web site is up and available. Like all active research sites, it is ever-changing with reports and announcements of new developments. It can be accessed as:

We invite you to visit often and would appreciate any links to the site you can provide.

The La Pérouse Bay field station was opened on May 30th, 1997 and closing took place on August 25th, 1997 after 87 days. The season was marked by a late melt and very little precipitation until the first part of August. Even at that stage, there was only one major storm. As a result conditions were dry to very dry throughout much of the season.

1. Measurements of above-ground biomass in grazed areas of intertidal salt marsh - Measurements of standing crop were made weekly on Randy's Flats and the East Bay Flats. This was a continuation of measurements started in 1979. At that time the above-grou

nd biomass was in excess of 40 g m-2 dry weight for most of the growing season. However, the effects of grubbing over much of these Flats have led to a decline in biomass of remaining patches of vegetation, as a result of heavy grazing by increased numbers of geese. By late July the above-ground biomass was between 15 and 5 g m-2 dry weight. These values were similar to those of 1996 and represent the continuing decline of available forage.

2. Faecal densities - As in previous years, faecal densities were counted weekly between early June and mid-August on 12 plots (each 16 m2) on the intertidal flats where patches of salt-marsh graminoids remained. The highest counts recorded were 4 faecal droppings m-2 per week. This is considerably lower that the high values of 10-16 droppings per week counted in the late 1980's and represents the declining use of the intertidal flats by large numbers of geese.

3. Loss of vegetation as a result of grubbing, hypersalinity and heavy grazing along 803 m of permanent transects on the intertidal flats - The loss of vegetation has been recorded since 1986. Further losses occurred this year along the 24 transects. Since the start on the annual monitoring in 1986, about 92% of the vegetation has either been destroyed, or else vegetation cover values are less than 15%.

Permanent transects and long term exclosures are used at La Pérouse Bay to measure specific changes in plant community characteristics over time. In 1997, we re-examined a set of transects established in 1976 and 1977 which have not been re-surveyed since then, using the original techniques and the original surveyor. These data will be analyzed over the winter of 1997-98. Initial observations include the virtual disappearance of one grass dominated association, expansion of shrub dominated associations in freshwater areas, diminishiment of all sedge associations in both area and "condition" and loss of some uncommon elements of local plant diversity which were present in the mid 1970s.

4. Exclosures in fresh-water sedge meadows - The geese continue to forage in fresh-water sedge meadows. Loss of sedges is marked at the seaward end of transects along which exclosures (1 m2) have been established. At more inland sites destruction is less marked. The exclosures were repaired and the density of sedges inside and outside the exclosures (paired plots) recorded. These data, which will be collected over a number of years, will be used to record the rate of removal of sedges overtime along the transect (open plots) from the coast to inland sites, and the rate of recovery of sedge populations in exclosed plots, once the geese can no longer forage in these plots.

5. Nitrogen cycling in fresh water vegetation and the role of mosses - In moderately-grazed salt-marsh systems, the deposition of faeces by foraging Snow Geese accelerates nutrient (N) cycling, helping plants to replace lost tissue, and leading to sustained or increased primary production relative to ungrazed sites. In contrast, research in both the High and Low Arctic suggests that freshwater vegetation is much less able to compensate for tissue loss. In these communities, the effects of geese on primary production are weak or negative and even experimental nutrient additions may fail to increase production by graminoids. The poor ability of freshwater communities to respond to nutrient additions is not well understood, but deserves attention for two reasons. First, most arctic grazers (caribou, lemmings, hares, muskoxen, and many goose colonies) rely primarily on freshwater systems. Second, as a consequence of increasing goose populations, many salt-marshes now have been degraded by overgrazing, forcing geese increasingly to depend upon freshwater systems as sources of forage.

Freshwater systems may be less able to respond to goose grazing because nutrients released from goose faeces are absorbed rapidly by mosses, and therefore are unavailable to graminoids. In saltwater or brackish areas, mosses are scarce, but they often are the dominant groundcover in freshwater areas. Mosses play an important role in controlling nutrient cycling in other northern systems, such as boreal forests, and tend to increase in areas heavily used by geese, suggesting they may benefit from goose faeces even when forage species do not. This study will determine whether mosses play a key role in limiting the ability of graminoids to respond to grazing by Snow Geese and other arctic herbivores. (Collaborative work with Peter Kotanen)

6. Recovery potential of the forage following destructive foraging - We initiated four new experimental revegetation projects in which the progress of 1380 plants were monitored every 12 days for the duration of the full growing season. The ideas blossomed from the 1996 results and led to experiments that (1) addressed the role of water stress on the recovery of the dominant graminoids, (2) explored the effect of differing albedos on the recovery of these graminoids, (3) monitored the root development of Puccinellia phryganodes in response to a mulch treatment and (4) attempted to see if Festuca rubra and Calamagrostis deschampsioides (two later successional species of the salt-marsh) could establish directly in the hypersaline mudflats without the previous establishment of Puccinellia phryganodes and Carex subspathacea (two of the earlier successional species). We also continued to sustain the three assisted revegetation projects that were initiated in the spring of 1996 on the three dominant graminoids of the salt-marsh and adjacent freshwater marsh: Puccinellia phryganodes, Carex subspathacea, and Carex aquatilis. These experiments involved monitoring the response of 3150 plants and their edaphic environments every 12 days for the duration of the growing season. As well, P. phryganodes colonies that had established in 8 of the naturally revegetating ( 4 year-old exclosures) were mapped in 1997 using identical methods to the 1996 mapping surveys thus enabling the calculation of a yearly growth rate for P. phryganodes under natural conditions. Finally, some descriptive community ecology was conducted in which 188 quadrats were sampled across a range of different exclosed and unexclosed habitats. These data are particularly useful as they are currently being compared to surveys done in these identical 188 quadrats 15 years ago.

Results from the assisted revegetation trials, conducted over the 1996 and 1997 growing seasons, indicate that the three dominant graminoids are capable of successfully establishing in the absence of foraging by geese. In the fresh-water areas, C. aquatilis tillers have established in the moss carpets and produced new vegetative shoots. In the salt-marsh, plugs of P. phryganodes and C. subspathacea have established and, in some cases, coalesced into a continuous mat of vegetation. The strongest treatment response on plant growth observed in 1996 was the initial application of a peat-mulch treatment. The 1997 experiments show that, depending on the stage of the snow-free season, two properties of the mulch act to enhance growth: (1) its insulation properties and low albedo alter soil temperatures in a favorable way for establishment and (2) it retains soil moisture in a habitat where lack of water is evident during the growing season. The Festuca-Calamagrostis experimental results indicate that these later successional species clearly cannot establish directly in the hypersaline mudflats. Thus, it is of high value to understand the factors that limit the recovery of P. phryganodes and C. subspathacea, the earlier successional species. Now that a vascular template has been established in these exclosures, subsequent changes in the plant assemblages will be recorded over time as the recovery progresses. (Graduate work of Tanya Handa)

7. Seed bank dynamics in degraded and undamaged coastal habitats of the Hudson Bay lowlands - The exponential increase of the mid-continent population of the lesser snow goose (Anser caerulescens caerulescens) during the past two decades, in conjunction with the foraging behavior of the geese, has been instrumental in converting large tracts of coastal salt marsh into bare mudflats. In these degraded areas largely devoid of vegetation, a potential source to fuel revegetation is the soil seed bank. In order to assess this potential, the objectives of this study were 1) to determine the size and composition of the seed bank in undamaged and degraded soils and 2) to deduce the relationship between the existing species present in the vegetation and the seed bank.

Soil core samples were collected from intact and degraded sites and their seed content was determined using a two-fold method. Firstly, germinable seeds were identified and tallied after the seeds were concentrated by sieving and germinated on layers of sterile sand. Secondly, viable seeds that did not germinate were separated from the soil manually under a microscope. Preliminary results have indicated large differences in the seed bank composition of intact and degraded sites. The seed banks of degraded areas were dominated by weedy species while undamaged sites exhibited greater diversity of seeds and closer representation of species typical of salt-marsh vegetation.

Input into the seed bank by both seed rain from surrounding vegetation and seed dispersal from other areas was measured by setting seed traps and monitoring them weekly. These traps were then left in the ground over the winter to collect seed input from dispersal following snow melt in the spring. Results are currently being analyzed. (Graduate work of Esther Chang)

Akimiski Island, Pen Islands and the coasts of Hudson and James Bay

We have been monitoring above ground biomass at a variety of sites beyond La Pérouse Bay, Manitoba, since 1993. In 1997, we focused on Akimiski Island and the Pen Islands because they represent different stages in a trajectory of snow goose occupancy and use. Akimiski Island marshes along the north shore are heavily damaged by cumulative foraging of several populations of geese in addition to snow geese (the snow goose colony is 30+ years old). The Pen Islands are relatively undamaged in comparison with most sites in southern Hudson Bay that we have investigated and have a relatively young snow goose colony (approximately 10-12 years). Both areas serve(d) as spring staging areas; the Pens are frequented by geese from colonies of the western part of the Mid-continent Population and Akimiski historically supported birds from the eastern part of the Mid-continent Population.

1. Productivity estimates - New Exclosures were erected at Akimiski Island at hatch in 4 areas and older exclosures (1-2 years old) were repaired. Each was sampled in June, July and August for a measurement of grazing pressure and productivity. New Exclosures were erected at Pen Islands during early June and sampled then and again in August for a measurement of grazing pressure and productivity. Polar bears destroyed some of the Pen Island exclosures.

2. Plant community structure. On Akimiski Island, little is known about the historic vegetation community. Areas of severe degradation and loss of vegetation similar to La Pérouse Bay have been documented with remote sensing and with ad hoc ground transects since 1994. In 1997, with the assistance of Jenny Bull and Carol Mountifield, we established new permanent transect similar to those that have been monitored at La Pérouse Bay since 1986. Species present, relative abundance, and proportion of bare ground (including that due to grubbing) were measured on 4 transects totaling over 5000 meters. These will be monitored for at least the next three years.

We have substantially more detailed data on the biology, reproductive success and survival of the lesser snow geese in the La Pérouse Bay region than in the other regions of Hudson and James Bays. To collect more comparative data in general and to test specific hypotheses based on the La Pérouse Bay data set, we focused many of our detailed efforts on Akimiski Island in 1997 and spent some time checking the feasibility of collecting basic data at the recently established colonies in the Seal and Knife River Deltas and on the Pen Islands. We are hoping to begin that work in 1999.

For similar reasons, we centered our banding efforts at Akimiski Island. However, we feel that it is critical to the monitoring aspects of proposed changes in regulations affecting the Mid-continent population of lesser snow geese that banding be reinitiated in the La Pérouse Bay and Cape Churchill regions. To that end, we are collaborating with Dale Caswell in seeking additional money to support that program. Since a large number of geese in that region are already banded, reinstituting the program there would allow us to estimate survival based on recapture rather than having to depend on recovery. This is particularly critical in light of the recent switch to bands that allow telephone reporting and for which reliable reporting rate estimates are not available.

Surveys of Lesser Snow Goose Nesting Colonies in the Hudson and James Bay Region

We conducted ground surveys, photographic aerial surveys and visual aerial transect surveys of lesser snow goose nesting colonies in southern Hudson Bay in May-July 1997 to continue documenting the current distribution, to estimate population size and to develop efficient survey techniques for future monitoring.

1. Photographic inventories - The nesting colonies at Cape Henrietta Maria, Shell Brook, and Pen Islands, Ontario were all photographed during incubation following protocols developed by Richard Kerbes, Canadian Wildlife Service, Saskatoon. Our surveys were, in part, a contribution to an overall effort led by Kerbes to have all Mid-continent lesser snow goose colonies photographed in the same year. Analysis of these photographs is being conducted in Peterborough, Ontario over the 1997-1998 winter.

2. Helicopter transect inventories - The development of a visual aerial transect method of estimating colony pairs and geographic size during incubation began in 1996 with a helicopter survey of Cape Henrietta Maria. In 1997, we used the technique at Cape Henrietta Maria, Shellbrook, Pen Islands (all Ontario) and at La Pérouse Bay and the Knife-Seal River complex in Manitoba. In addition to an independent measure of size, the technique can be compared to the simultaneous nesting photographic technique this year. Analysis of these data are underway and will be presented at the 9^th North American Arctic Goose Conference in Victoria, B.C., in January 1998. Preliminary estimates of the numbers of nesting pairs at those colonies are:

Colony	Estimated number of nesting pairs
Cape Henrietta Maria	180,000
Shellbrook	2500
Pen Islands	7000
Broad River	1500
La Pérouse Bay	45,000
Knife-Seal River	9000

1. Nesting Density Surveys - We continued our standard ground transect estimates of nesting density in the original core areas of this region. We used sets of 5 circular plots (~1 hectare each) in each of 3 areas, a set of 10 linear transects along the east coast of La Pérouse Bay and 5 sets of linear transects at each of 2 sites near Cape Churchill. In all cases, nesting density was lower than in 1996, with reductions ranging from 10% to 15%. These are all areas that were once much more heavily used and now suffer from habitat degradation. The reduction likely reflects the continued dispersal of birds to adjacent areas that are less degraded. Analyses of long-term changes in nesting density are in progress.

2. Egg size and clutch size - We collected egg and clutch size data from each of the 6 nesting density survey areas and 4 other areas we have traditionally monitored. There are no significant differences in clutch or egg size among the areas and there was no significant reduction in clutch or egg size from last year.

3. Abandoned embryos and goslings - As part of our long-term efforts to monitor the frequency of abnormal embryos and goslings, we collected 157 eggs abandoned at nests by families moving to brood rearing habitat with hatchlings. Of these, 2 displayed obvious abnormalities affecting the beak.

4. Brood flock surveys - As part of our continued monitoring of reproductive success in the region, we photographed brood flocks on July 30-31. Surveys began at the Caribou River (north of Churchill) and extended south to Churchill, east to La Pérouse Bay and then Cape Churchill and then south to a point 10 km south of the Broad River. We selected 5 flocks at random in areas spaced at intervals of approximately 5 km along the coast. At La Pérouse Bay, we included additional inland areas since many families make use of fresh water marshes up to 10 km inland from the coast.

Akimiski Island, Northwest Territories has the southernmost persistent nesting colony of lesser snow geese in the world, continuously occupied since 1968. It has been a focus of attention for the Hudson Bay Project since 1992, with detailed studies of the snow goose nesting ecology beginning in 1995. Akimiski Island is of importance for several reasons, but two of the most important are the interactions between an expanding snow goose population and the declining Southern James Bay Population of Canada geese (30% of which nest on Akimiski) and the fact that poor habitat conditions and the relatively small size of the snow goose nesting colony combine to provide a unique research opportunity. Here we are able to study the reproductive performance of both snow geese and Canada geese in a degraded environment while tracking a high proportion of the population through individual marking techniques.

1. Population size - Intensive ground searches were conducted in early June, during incubation, to document the colony growth. Number of nesting pairs was 1725 pairs (v. 1917 pairs in 1996). The area occupied was much the same as the last 3 years, with a slight eastward extension at the "Stitt River".

2. Reproduction and survival - This was the third year of a basic study of reproductive performance, including measures of clutch size, predation, nesting habitat use and post-hatch survival. Data on these topics were collected from most of the 1725 nests. For these studies, nearly 5000 goslings were web-tagged at hatch and at banding (see below) over 500 web-tagged goslings were captured.

3. Nesting density and post-hatch dispersal - For the first time, nesting density was quantified and "mapped" by sub-colony areas. These data will be linked to quantified vegetation and ground cover data within each sub-colony to examine impact of density on plant communities and other species. During late July, we captured and banded 457 adults and 1277 goslings, including over 500 web-tagged goslings which can be tracked to nesting area within the colony for a measurement of dispersal distances. Observations of flightless families of snow geese were made farther east along the north coast in 1997 than ever before, including east of Houston Point. They were also recorded near the southwest tip of the island in mid August (near the end of brood rearing) the farthest west they’ve ever been recorded.

4. Size and condition of snow geese - Adult and gosling snow geese were measured during banding to compare condition and structural size at Akimiski with other years and other locations, especially La Pérouse Bay. Testing of the use of 9^th primary as an aging criteria continued.

5. The relationship of egg size to survival and growth. Most of the snow goose eggs laid in 1997 were measured. From the nearly 5000 goslings which were web-tagged at hatch, over 500 web-tagged goslings were captured at banding and measured to compare growth rates of birds from different egg sizes. Analysis of these data is underway for a preliminary report at the 9^th North American Arctic Goose Conference in January 1998. (Graduate work of Steve Timmermans)

1. Changes in aquatic and terrestrial invertebrate populations - Foraging (grubbing and grazing) by lesser snow geese (Anser caerulescens caerulescens) has led to the destruction of inter-tidal salt-marsh swards and the death of willow bushes in the supra-tidal marsh at La Pérouse Bay (near Churchill, Manitoba). A decline in the abundance of breeding populations of some bird species (stilt sandpiper, semi-palmated sandpiper, northern shoveller, American wigeon) may be linked to low availability of invertebrates in areas devoid or nearly devoid of vegetation. Collections of aquatic invertebrates were made from 70 ponds from degraded and intact areas in the supra-tidal marsh on different occasions between June and early August, 1996, and 15 of those ponds were resampled intensively between June and early July, 1997. The benthic macroinvertebrate assemblages showed shifts in group representation. Snails (Gastropoda) and worms (Oligochaeta) were the dominant benthos in densely vegetated intact ponds. Snails were completely absent from ponds in degraded areas. Midge larvae (Diptera: Chironimidae) preferred more open vegetated ponds, and small copepods (Copepoda) dominated degraded ponds. Both snails and chironomids are major food sources for duck species such as the northern shoveller and American wigeon.

Collections of terrestrial invertebrates were made on a weekly basis from an intact willow sward, a semi-degraded area composed of live and dead (or dying) willow bushes with patches of bare ground and grazed grassland, and a fully degraded site (all bare ground and dead willows) between June and late August, 1997 in the supra-tidal marsh. At each site, 100 pitfall traps (to sample the ground fauna) and 3 malaise traps (to capture flying insects) were used to collect invertebrates. There were differences in both species assemblages and biomass between degraded and intact areas. Spiders (Aranaea), beetles (Coleoptera), and bees and wasps (Hymenoptera) dominated intact swards whereas springtails (Collembola), ground mites (Acari), and flies (Diptera) dominated degraded areas. The taxonomy of these collections is still in progress.

Overall, we are seeing a decline in invertebrate diversity in degraded supra-tidal marsh areas at La Pérouse Bay, as well as potentially detrimental shifts in the abundance of certain organisms in both aquatic and terrestrial systems. These changes are an indirect consequence of the foraging activities of the lesser snow goose and may be linked to declines in breeding populations of other bird species. (Graduate work of Brian Milakovic)

2. Declines in other bird species at La Pérouse Bay - We evaluated a portion of the extensive bird list data from the long-term study at La Pérouse Bay. To minimize potential biases associated with this type of data, we restricted ourselves to only reliably identifiable species from an annual time period that maximized daily effort and involved coverage of similar geographic areas. We found an overall decline in the population sizes of bird species from a range of habitats in the La Pérouse Bay region. We found specific decreases for American wigeon, northern shoveller, oldsquaw, red-breasted merganser, dowitchers, Hudsonian godwits, stilt sandpipers and parasitic jaegers. All but the last of these species depend on shallow, freshwater ponds and streams and their adjacent vegetation - habitats that have been particularly degraded at La Pérouse Bay. We have found no compelling evidence that these impacted species are declining at a more global level.

Based on these analyses, we have expanded and intensified our efforts to survey the frequency of other bird species in the area. Part of that effort involves the use of daily, area specific inventories with check lists. The other part is the initiation of detailed studies of habitat use and foraging by shorebirds (see below). (Collaborative work with Diana Pollak)

3. Shorebird Surveys at Akimiski Island - Daily bird observations and in particular an assessment of the status of Marbled Godwits on Akimiski Island were conducted in June for the third consecutive year. Aerial and ground surveys of shorebirds on Akimiski Island were conducted during the brood rearing period in late July. (Collaborative work with Ken Ross).

4. Habitat use and foraging by shorebirds - We began research at La Pérouse Bay to determine the relationships between habitat degradation, invertebrate populations and shorebird ecology. Initial collections included data on shorebird diets, richness, relative abundance, prey availability, foraging area selection and foraging area characteristics. For temporal comparisons, these data were collected throughout the summer. Special comparisons were made between areas of moderate, severe and total habitat degradation. Diet samples were collected from 17 species of shorebirds. Relative abundance, richness and foraging area selection were gathered using a grid count observation method. Core samples and pitfall traps were used to collect invertebrates for prey availability data. Vegetational assemblages, soil and water chemistry variables and landscape features will be used in establishing foraging area characteristics. Preliminary analyses indicate spatial and temporal variation in the data. (Graduate work of Curt Vacek)

1. Decadal vegetation changes in the Seal River - Knife River area - Continuing in 1997 with the vegetation change detection work reported earlier, the remote sensing investigations were extended to the snow goose colony around the mouths of the Seal and Knife rivers, west of Churchill, Manitoba. Three Landsat MSS (Multispectral Scanner) mini-scenes were purchased. The images were recorded on July 27, 1973, August 2, 1984 and July 18, 1996. A matching 1984 Landsat TM (Thematic Mapper) image was registered to the UTM (Universal Transverse Mercator) projection, using 1:50,000 scale NTS (National Topographic System) maps. All three Landsat MSS images were registered to the geocoded 1984 TM image.

Three subareas covering the study area proper, measuring 45 km by 32.5 km were created for further processing. To eliminate the effects of different water levels due to tidal action, a land mask was generated from the 1984 image showing the highest water level. All further processing has been limited to areas under the mask. Using channels 5 (red) and 6 (near-infrared), normalized difference vegetation index (NDVI) images were calculated for all three dates. The three NDVI channels (1973, 1984 and 1996) were transferred to a secondary file.

From the three NDVI channels normalized pairwise difference (NPDI) images were created by dividing the difference between the later image and the earlier image with their sum. These images show the change of the vegetation index between the two dates. Low values correspond to a decline of the index, indicating loss of vegetation. Three such images were created corresponding to the time intervals of 1973-1984, 1984-1996 and 1973-1996.

Aside from small areas scattered throughout the study area, resulting from slight misregistration of the images, heavy concentrations of vegetation decline were evident in the coastal saltmarsh zone. Areas of vegetation loss are recognizable not only on the histogram, but also by their concentration in specific areas of the image. Digital values of 0-135 were considered as heavy loss, 136-140 as moderate loss, and 140-255 as no loss. Density slicing and a histogram count gave the following results:

Vegetation loss figures in hectares for the entire study area of 146250 hectares:

Period	Heavy Loss	Moderate Loss	Total
1973-84	198	321	519
1984-96	525	296	821
1973-96	907	358	1365

Period	Heavy Loss	Moderate Loss	Total
1973-84	176	260	436
1984-96	506	175	681
1973-96	862	256	1118

2. Ground truthing in the Seal River - Knife River area - The geocoded 1984 Thematic Mapper image was used to produce hardcopy maps for fieldwork, and to create a thematic land cover type map of the surrounding area. On July 30, 1997, a team of observers visited the Seal River - Knife River area by helicopter to obtain field information about the principal land cover types of the region. Twenty-eight locations were visited within a 40 km by 55 km area. A detailed description of the vegetation types and landform was recorded for each site. In addition, georeferencing information was collected for fourteen points, using the helicopters GPS unit. This information is useful to augment the coordinates of points derived from NTS maps based on aerial photograph as old as 1946 at some parts of the study area.

Research this year has focused on the interactions between indicators of gosling survival, climate variability, and vegetation degradation in the La Pérouse Bay area during the summer (June, July, August) season. Previously, a high degree of predictability of goose reproductive variables from selected early spring season climatic variables had been identified, demonstrating both the direct and indirect effects of climate on the reproductive biology of geese. This years work first examines the spatial and temporal nature of moisture availability and variability during summer in the Hudson Bay region through the annual progression of water surplus and deficit based on the Thornthwaite water balance model. Secondly, the multivariate relationships between goose variables (egg survival, hatching success, gosling survival, goslings leaving the nest, and brood size at banding), climatic conditions (air temperature and rainfall, drought severity (Palmer Drought Index)), and vegetation changes (standard crop data) during summer in the La Pérouse Bay area are being examined.

Our modeling efforts have been enhanced owing to a collaboration begun by RF Rockwell and the Alaska Science Center with additional funding from USFWS Region 7. Under that collaboration, which in part targets construction of a model for the spectacled eider, we are developing a generalized model that allows exploration of the dynamics of species complexes undergoing dispersal and competition. The model allows for density-dependence at all levels and incorporates environmental stochasticity. It is also being developed to allow for 2-way feedback between the birds and their environment. (Collaborative work with Paul Flint and Barry Grand)

The Hudson Bay Project, in collaboration with Ducks Unlimited and the Ontario Ministry of Natural Resources (OMNR), sponsored a series of three tours for representatives of various federal, state and provincial agencies, non-governmental organizations and the media. Each of the tours involved 10 individuals and began with first evening orientation lectures given by KF Abraham, RL Jefferies, RF Rockwell and Andy Didiuk (a Hudson Bay Project collaborator). The following morning, the guests were flown by an OMNR twin otter to Knights Hill Esker on the western edge of the La Pérouse Bay snow goose colony. From there, they were ferried by OMNR helicopter to a series of demonstration sites that depicted various problems associated with habitat degradation in the La Pérouse Bay / Cape Churchill region. Students of the Hudson Bay Project gave presentations at each site and Abraham, Jefferies and Rockwell were present at each to provide background and answer additional questions. The sites and student giving presentations were:

1. Randy’s Flats - This area is the longest studied salt marsh in the region and is "home" to the graphic exclosures depicted in numerous publications. In addition to Jefferies’ presentation on grazing and grubbing in the area (using the exclosures as a backdrop), Brian Milakovic discussed his work on the impact of habitat degradation on the local invertebrate flora, Curt Vacek presented his work on habitat use and foraging by shorebirds on habitat suffering various levels of habitat degradation and Diana Pollak discussed the recent analyses she and RF Rockwell have completed on impacts of habitat degradation on the La Pérouse Bay avifauna using our long-term birdlist data.

2. East Bay - This area was virtually destroyed in the mid 1980’s by huge numbers of snow geese that were delayed at La Pérouse Bay on their way to more northern breeding areas. Jefferies discussed the extreme changes in the vegetation and Abraham and Rockwell discussed the change in nesting habitat use. This area is the site of detailed work in restoration ecology and Tanya Handa, the student in charge of that program, discussed her work. Esther Chang presented her restoration work which focuses on the seed beds in the region and seeks to find just what plants could begin recovery if grazing and grubbing were reduced and soil chemistry could return to less stressful levels.

3. Peter’s Rock - This inland area has been the site of detailed studies on the impact of geese on freshwater vegetation and the development of moss carpets. Hudson Bay Project collaborator Peter Kotanen was present and discussed the historic and on-going research in the area. Abraham again discussed the dynamics of goose nesting behavior in this area - one that began being heavily used in the mid 1980’s.

4. Blue Poles - This area is perhaps the most extreme example of the impact of hypersalinization on nesting habitat. It is home to the photographs of salicornia fields, dead willow forests, and ever-expanding goose ponds seen in numerous publications and videos. Jefferies discussed the processes leading to the degradation and Rockwell spoke about the impact of hypersaline conditions on goslings. The extent of the impact increases as the birds become less well nourished and more exposed to renal coccidiosis - a disease agent that increases as a function of snow goose density. This area is also home to several exclosures, one of which depicts the minimal recovery of extremely degraded habitat in nearly 15 years.

The guests were then returned to the twin otter by OMNR helicopter and flown to the Nestor 1 Canada Goose research station for a lunch, hosted by Murray Gillespie and the Manitoba Department of Natural Resources. Don Rusch reviewed the long-term research on the EPP population of Canada Geese in that area and highlighted the decline in nesting density and use of coastal marsh by those birds. Jim Leafloor gave a slide presentation on his extensive work showing the impact of snow geese on the SJBP of Canada geese nesting on Akimiski Island. His talk highlighted the fact that snow goose induced trophic cascades are not simply limited to the La Pérouse Bay region.

Following a question and answer period involving scientists from Nestor 1 and the Hudson Bay Project, the guests joined Ken Abraham for a twin otter tour of the coastal regions both south and north of the La Pérouse Bay and Cape Churchill regions. They saw the extent of snow goose brood rearing in the area and also the spread of habitat degradation south of Cape Churchill. They also saw the beginnings of degradation at the rapidly growing and recently established snow goose colony in the deltas of the Knife and Seal Rivers, north of Churchill.

The Hudson Bay Project participated in the filming of the documentary movie Snow Warning being produced by Ducks Unlimited and the Ontario Ministry of Natural Resources. Footage of early season staging and arrival was obtained at Akimiski Island as were sequences of nesting and hatching. Filming shifted to La Pérouse Bay later in the season and centered on habitat degradation, brood rearing, banding and gosling condition. Interviews were conducted with KF Abraham, RL Jefferies, JO Leafloor and RF Rockwell. All will appear as "talking heads" in the film which is to be initially shown at the 1998 North American Arctic Goose meeting in Victoria, BC.

Cooch, EG, DB Lank, RF Rockwell and F Cooke. 1998. Body size and recruitment in snow geese. Bird Study (in press).

Leafloor, J. O., C. D. Ankney, and D. H. Rusch. 1998. Environmental effects on body size of Canada geese. Auk 115:26-33 (in press).

Leafloor, J. O., and K. F. Abraham. 1998 Procedures for monitoring the Mississippi Valley population of Canada geese and suggestions for improvement. Canadian Wildlife Service Occasional Paper. (in press).

Lindberg, MS, JS Sedinger, DV Derksen and RF Rockwell. 1998. Natal and breeding philopatry in a black brant (Branta bernicla nigricans) metapopulation. Ecology (in press).

Skinner, WR, RL Jefferies, TJ Carleton, RF Rockwell and KF Abraham. 1998. Prediction of reproductive success and failure in lesser snow geese based on early season climatic variables. Global Change Biology 3 (in press).

Abraham, KF and RL Jefferies. 1997. High goose populations: Causes, impacts and implications. (pp. 7-72). In: B.Batt (ed.) Arctic Ecosystems in Peril: Report of the Arctic Goose Habitat Working Group. Arctic Goose Joint Venture, Canadian Wildlife Service, Ottawa and US Fish and Wildlife Service, Washington, D.C. (ISBN 0-9617279-3-4).

Hansell, RIC, JR Malcolm, H Welch, RL Jefferies and PA Scott. 1997. Atmospheric change and biodiversity in the Arctic. Environmental Monitoring and Assessment. 12 (in press).

Jano, AP, RL Jefferies and RF Rockwell. 1997. The detection of change by multitemporal analysis of LANDSAT data: the effects of goose foraging. Journal of Ecology 86 (in press).

Jefferies. RL. 1997. Long-term damage to sub-arctic ecosystems by geese: ecological indicators and measures of ecosystem dysfunction. (pp. 151-165). In: RMM Crawford (ed.) Disturbance and Recovery of Arctic Terrestrial Ecosystems. NATO, ASI Series, Volume 25, Kluwer Academic Publications, Dordrecht.

Jefferies, RL and JL Maron. 1997. An embarrassment of riches? Atmospheric deposition of nitrogen and community ecosystem processes. Trends in Ecology and Evolution 12:74-77.

Kotanen, P and RL Jefferies, 1997. Long-term destruction of sub-arctic wetland vegetation by lesser snow geese. Ecoscience 4:179-182.

Leafloor, JO, MRJ Hill, DH Rusch, KF Abraham and RK Ross. 1997. Nesting ecology and gosling survival of Canada geese on Akimiski Island, Northwest Territories. Canadian Wildlife Service Occasional Papers (in press).

Leafloor, JO and DH Rusch. 1997. Clinal size variation in Canada geese affects morphometric discrimination techniques. Journal of Wildlife Management 61:184-191.

Prewett, M, P Rockwell, RF Rockwell, NA Giorgio, J Mendelsohn, HI Scher and NI Goldstein. 1997. The biological effects of C225, a chimmeric monoclonal antibody to the EGFR, on human prostate carcinoma. Journal of Immunotherapy 19:419-427.

Rockwell, RF, EG Cooch and Solange Brault. 1997. Dynamics of the mid-continent population of lesser snow geese - Projected impacts of reductions in survival and fertility on population growth rates. (pp. 73-100). In: B. Batt (ed.) Arctic Ecosystems in Peril: Report of the Arctic Goose Habitat Working Group. Arctic Goose Joint Venture, Canadian Wildlife Service, Ottawa and US Fish and Wildlife Service, Washington, D.C. (ISBN 0-9617279-3-4).

Rockwell, RF, KF Abraham and RL Jefferies. 1997. The best laid plans: What happens when conservation efforts work too well? Living Bird 16:16-23.

Rusch, DH, MM Gillespie, HG Lumsden, KF Abraham and AB Didiuk. 1997. Distribution and derivation of the Canada goose harvest in the Mississippi Flyway. Proceedings of the International Canada Goose Symposium (in press).

Tacha, TC, JC Davies, D Thornburg and KF Abraham. 1997. Estimating production and fall flights of Mississippi Valley population Canada geese. Proceedings of the International Canada Goose Symposium (in press).

Trost, R, KF Abraham, JC Davies, KE Bednarik and HG Lumsden. 1997. The distribution of leg-band recoveries from Canada geese in the Southern James Bay region of Canada. Proceedings of the International Canada Goose Symposium (in press).

Abraham, KF, RL Jefferies, RF Rockwell and CD MacInnes. 1996. Why are there so many white geese in North America? Proceedings of the 7th International Waterfowl Symposium pp. 79-92, Ducks Unlimited, Memphis.

Bazely, DR and RL Jefferies. 1996. Trophic interactions in arctic ecosystems and the occurrence of a terrestrial trophic cascade. (pp. 183-207). In SJ Woodin and M Marquiss (eds.). The Ecology of Arctic Environments. Special Publication of the British Ecological Society. Blackwell Scientific Publications, Oxford.

Leafloor, JO, KF Abraham, DH Rusch, RK Ross and MRJ Hill. 1996. Status of the Southern James Bay Population of Canada geese. Proceedings of the 7th International Waterfowl Symposium pp. 103-108, Ducks Unlimited, Memphis.

Leaflor, JO, CD Ankney and KW Risi. 1996. Social enhancement of wing molt in female mallards. Canadian journal of Zoology 74:1376-1378.

Leafloor, JO, DH Rusch, AE Smith and JC Wood. 1996. Hunting vulnerability of local and migrant Canada geese: a comment. Journal of Wildlife Management 60:452-457.

Leaflor, JO, JE Thompson and CD Ankney. 1996. Body mass and carcass composition of fall migrant Oldsquaws. Wilson Bulletin 108:567-572.

Rockwell, RF, KF Abraham and RL Jefferies. 1996. Tundra under siege. Natural History 105:20-21.

Rusch, DH, FD Caswell, MM Gillespie and JO Leafloor. 1996. Research contributions to management of Canada geese in the Mississippi Flyway. Transactions of the North American Wildlife and Natural Resources Conference 61:437-449.

Schmutz, JA, RF Rockwell and MR Petersen. 1996. Relative effects of survival and reproduction on the population dynamics of emperor geese. Journal of Wildlife Management 61:191-201.

Srivastava, DS and RL Jefferies. 1996. A positive feedback: herbivory, plant growth, salinity and the desertification of an arctic salt marsh. Journal of Ecology 84:31-42

Wilson, DJ and RL Jefferies. 1996. Nitrogen mineralization, plant growth and goose herbivory in an arctic coastal ecosystem. Journal of Ecology 85:841-851.

Our research receives financial and equipment support from numerous sources including: the Arctic Goose Joint Venture, the Central Flyway, the City University of New York, Cultor Food Sciences, the Department of Northern and Indian Affairs (Canada), Ducks Unlimited, Inc., the Mississippi Flyway, the National Sciences and Engineering Research Council (Canada), the Olive Bridge Fund and the Ontario Ministry of Natural Resources.

Our work would not be possible without the dedicated work of our students, collaborators and volunteers. In addition to those mentioned in the text, we especially appreciated the help of Greg Dunn, Alex Dzubin, Don Fillman, Elizabeth Gold, Leslie Gold, Larry Hill, Paul Matulonis, Asha Mellor, Kevin Mulcair, Ted Senese, Chris Witte and Don Wolkoski.