Pam Loring NRS 509 Fall 2010

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1 Pam Loring NRS 509 Fall 2010 GIS and the Spatial Ecology of Seaducks Many species of seabirds come ashore only to breed. Investigating the spatial ecology of these winged creatures on the open ocean can be a challenging endeavor. However, understanding the at-sea distribution, movement patterns, and habitat use of birds at sea is becoming increasingly important given the widespread alteration of marine ecosystems by anthropogenic and natural forces. Seaducks (species of the subfamily Mergini) may be especially sensitive to changes in marine environments, as over half the populations in North America are declining (SDJV 2008). Since many of these species are at home in the turbulent waters of the far north, the details of their life histories have remained largely a mystery that relatively recent geospatial technology has begun to reveal. Spatial data related to seaducks is commonly collected through surveying or telemetry techniques and analyzed using Geographic Information System (GIS) software. The program ArcGIS offers a suite of mapping and analysis functions that provide users seemingly limitless options for displaying and interpreting spatial data. For example, McKinney et al. (2006) paired waterfowl survey data with GIS land cover data to investigate the influence of landscape characteristics on the distribution of waterfowl in adjacent estuarine habitats in Rhode Island. In British Columbia, Zydelis et al. (2006) used GIS to link survey data of scoters in georeferenced polygons to examine the influence of environmental factors and shellfish aquaculture on their densities. Surveybased studies provide a static snapshot of the distribution and abundance of birds throughout a geographic area, which may used in GIS overlay analyses with spatial data layers of interest. Telemetry studies investigate movement patterns of individual birds throughout space and time. The development of satellite-based telemetry has enabled researchers to follow the movements of seabirds remotely throughout their vast oceanic realms. The first successful attempt to satellite track birds occurred the Indian Ocean in Six male wandering albatross (Diomedea exulans), were instrumented with transmitters on island nesting sites and, upon switching incubation duties with their mates, tracked on foraging trips of up to 15,200 km, flying at speeds of 80 km/hr (Jouventin and Weimerskirch 1990) In the early 1990s, satellite transmitters were modified to track seaducks. Previous research utilizing radio telemetry identified negative effects of using externally mounted transmitters on diving ducks (Perry 1981). Korschgen et al. (1996) developed a surgical technique to implant transmitters inside abdominal cavity of waterfowl. Specially designed coelemic implant transmitters weigh between g, depending on the target species, and communicate with satellites via an external antenna. USGS scientist Margaret Petersen and colleagues were the first use coelemic implant transmitters to track seaducks for their pioneering study of the federallythreatened Spectacled Eider (Somateria fischeri). Population estimates of Spectacled Eiders were declining precipitously at major Alaskan breeding sites, but their distribution outside of the breeding season was virtually unknown. In 1993, pilot study Petersen et

2 al. tracked 12 spectacled eiders captured on breeding grounds on Alaska s Yukon- Kuskokwim Delta (Y-K Delta) to post breeding areas in the Bering Sea. Between 1993 and 1996, Petersen and colleagues deployed 88 transmitters on Spectacled Eiders from the three identified breeding populations (Y-K Delta, Alaska s North Slope, and Arctic Russia). The GIS software Arc Info was used to plot telemetry data and conduct distance-to-shore calculations on a 1:1,000,000 scale digital chart of the world. Researchers surveyed telemetry locations of instrumented birds by plane to estimate flock size and collect aerial photos used for determining over-all sex-ratios. Through combining telemetry, surveying, and remote sensing techniques, this famous study revealed the previously unknown information on wintering areas of Spectacled Eiders vital to managing their imperiled populations (Petersen et al. 1999). A number of studies utilizing satellite telemetry to track seaducks followed Petersen s early success. Specific methodologies vary depending on the objectives of the researcher and are limited by the transmitter battery (approximately hours total transmission time), which is programmable on an on-off cycle to conserve power. Studies that collect many location fixes over a short amount of time are often used to examine circadian and seasonal movement patterns. For example, Merkel et al. (2006) tracked movement patterns of Common Eiders on wintering in southwest Greenland and estimated kernel-based probabilistic home ranges with the ArcView GIS Extension Animal Movements. Another study of winter movements mapped diurnal and nocturnal distributions of Long-Tailed Ducks (Clangula hyemalis) in relation to boundaries of a proposed wind farm development site (Allison et al. 2009). Phillips et al. (2006) paired remote sensing data with satellite telemetry data to examine habitat use by King Eiders in remote areas of the Bering Sea. The research potential of pairing telemetry and remote sensing data is ever increasing with the quality and availability of satellitederived environmental data. Studies with longer on-off cycles are used to examine broad scale movement patterns over the course of a year or beyond. A number of satellite telemetry studies on seaducks focus on linking tagged individuals to wintering, staging, breeding, and molting sites to better understand connectivity of populations. ArcGIS is used to display locations individual birds use during different parts of their annual cycle, while extensions such as Animal Movements or other data-filtering tests for plausibility and direction estimate general migration paths from individual location points. These routes are typically displayed in GIS as a poly-line of interconnected location fixes. Published work related to seaduck population connectivity include studies on: Surf Scoters (Melanitta perspicillata) along Pacific Flyway (De La Cruz et al. 2009), Harlequin Ducks (Histrionicus histrionicus) breeding in Central Labrador (Chubbs et al. 2008), and Barrow s Goldeneye (Bucephala islandica) in Eastern North America (Robert et al. 2002). A number of these studies utilize web-based data sharing (eg. to allow other scientists or the interested public to follow satellite-tagged birds around the world. As geospatial technology advances, studies utilizing satellite telemetry have increased in sample size and scientific rigor. Large scale, collaborative studies using satellite telemetry to monitor seaducks are underway throughout coastal North America with the objectives of drawing population-level inferences that may contribute to national sea duck management plans (Sea Duck Joint Venture Management Board 2008).

3 Satellite transmitters of the future will likely be lighter weight, with longer battery life and higher-accuracy location calculations. Increasing tracking duration will allow researchers to study inter-annual movement patterns and site fidelity to key areas used throughout the annual cycle. Monitoring of these key areas will be greatly enhanced by advances in remote sensing technology. For seaducks, futuristic satellite tags with the capability of recording 3-D dive profiles over a remotely sensed benthos would be particularly intriguing. Advances in survey-based technology include the use of unmanned aerial vehicles that collect imagery along prescribed transects. Technological advances in GIS software used to analyze these spatial data will likely involve increased resolution, use of animation or video imagery, and a more powerful analysis toolkit. In the not- toodistant-future, it may be possible for scientists and the web-surfing public alike to roam and plunge dive on the back of a satellite-tagged Wandering Albatross throughout a 3- dimensional Southern Ocean from the comfort of their desks. References Cited Allison, T. D., S. Perkins, and M. Perry Determining night-time distribution of long-tailed ducks using satellite telemetry. U.S. Dept. of the Interior, Minerals Management Service, Herndon, VA. OCS Study MMS pp. Chubbs, T., P. Trimper, G. Humphries, P. Thomas, L. Elson, and D. Laing Tracking seasonal movements of adult male Harlequin Ducks from central Labrador using satellite telemetry. Waterbirds 31: De La Cruz, S., J. Takekawa, M. Wilson, D. Nysewander, J. Evenson, D. Esler, W. Boyd, and D. Ward Spring migration routes and chronology of surf scoters (Melanitta perspicillata): a synthesis of Pacific coast studies. Canadian Journal of Zoology 87: Jouventin, P., and H. Weimerskirch Satellite tracking of wandering albatrosses. Nature 343: McKinney, R., S. McWilliams, and M. Charpentier Waterfowl-habitat associations during winter in an urban North Atlantic estuary. Biological Conservation 132: Merkel, F., A. Mosbech, C. Sonne, A. Flagstad, K. Falk, and S. Jamieson Local movements, home ranges and body condition of common eiders Somateria mollissima wintering in Southwest. Ardea 94: Perry, M Abnormal behavior of canvasbacks equipped with radio transmitters. The Journal of Wildlife Management: Petersen, M., W. Larned, and D. Douglas At-sea distribution of spectacled eiders: a 120-year-old mystery resolved. The Auk 116: Phillips, L., A. Powell, and E. Rexstad Large-scale movements and habitat characteristics of king eiders throughout the nonbreeding period. The Condor 108: Robert, M., R. Benoit, and J. Savard Relationship among breeding, molting, and wintering areas of male Barrow's Goldeneyes (Bucephala islandica) in eastern North America. The Auk 119: Sea Duck Joint Venture Management Board Sea Duck Joint Venture Strategic Plan USFWS, Anchorage, Alaska; CWS, Sackville, New Brunswick.

4 Žydelis, R., D. Esler, W. Boyd, D. Lacroix, and M. Kirk Habitat use by wintering surf and white-winged scoters: effects of environmental attributes and shellfish aquaculture. The Journal of Wildlife Management 70: Annotated Bibliography De La Cruz, S., J. Takekawa, M. Wilson, D. Nysewander, J. Evenson, D. Esler, W. Boyd, and D. Ward Spring migration routes and chronology of surf scoters (Melanitta perspicillata): a synthesis of Pacific coast studies. Canadian Journal of Zoology 87: This large scale, collaborative study analyzed data from 85 Surf Scoters instrumented with satellite transmitters at four Pacific-flyway wintering sites (San Quintin Bay, Baja California; San Francisco Bay, CA; Puget Sound, WA; Strait of Georgia, BC) from Specific objectives were to: 1) compare spring migration chronology and routes among surf scoters wintering different latitudes; 2) evaluate the relationship between winter body mass and migration chronology; and 3) identify important stopover sites and staging areas along the Pacific flyway. The authors used ArcMap version 9.2 to plot locations and delineate migration routes. The majority (83%) of instrumented scoters followed two major spring migration routes to northern nesting areas: a southern inland route with a major staging area Puget Sound and the Strait of Georgia, and a northern coastal route along the coast of British Columbia and Southeast Alaska. Results showed no differences in departure dates and migratory routes of scoters captured at different wintering sites. However, migration routes were significantly associated with migration chronology, use of stopover sites, and nesting site latitude. Among females, departure date was related to body mass, with heavier females initiating migration earlier. Six females that continued to transmit location data for a second spring migration showed strong inter-annual route fidelity but differences in timing at stop-over sites. Overall, the satellite telemetry data in this study revealed important linkages between wintering sites, staging areas, and breeding grounds of surf scoters along the Pacific Flyway. Zipkin, E., B. Gardner, A. Gilbert, A. O Connell, J. Royle, and E. Silverman Distribution patterns of wintering sea ducks in relation to the North Atlantic Oscillation and local environmental characteristics. Oecologia:1-10. In this study, Zipkin et al. examined climatic and habitat influences on the spatial and temporal distribution of seaducks wintering along the Atlantic coast of North America. Counts of black scoters, surf scoters, white-winged scoters, common eiders, and longtailed ducks were analyzed from Atlantic Flyway Sea Duck Survey data.

5 During this annual survey, a single, north-south aerial transect is flown ¼ mile from shore from Nova Scotia, Canada to southern Georgia, USA. Hand drawn maps of survey route were digitized in ArcGIS 9.3, with a 250 m buffer added on each side of transect to delineate count area. Count data was modeled with monthly values for the North Atlantic Oscillation (NAO) and four local-scale habitat covariates (sea surface temperature, mean bottom depth, maximum bottom slope, and embayment versus open-water habitat). The NAO was the only covariate showing a significant effect on all five seaduck species, although responses to NAO conditions differed by species. In near-shore areas, higher numbers of scoters were observed during cold, snowy winters and higher numbers of common eiders and long-tailed ducks observed during wet, mild winters. All species excluding white-winged scoters showed greater abundance in shallower depths. Scoter numbers had a negative relationship with slope, while eiders and long-tailed ducks were associated with steeper bathymetry. This large-scale modeling is particularly relevant to monitoring the impacts of climate change to seaducks wintering along the Atlantic coast. Phillips, L., A. Powell, and E. Rexstad Large-scale movements and habitat characteristics of king eiders throughout the nonbreeding period. The Condor 108: The northern geographic range occupied by King Eiders (Somateria spectabilis) makes them a particularly difficult species to research in the field. Post-breeding King Eiders migrate to coastal sites, molting typically in large flocks before dispersing to wintering areas. The majority of Alaskan-breeding King Eiders are thought to spend the nonbreeding period in the Bering Sea, but little is known about their movements and habitat use. In this study, Phillips et al. combined data derived from satellite telemetry and remote-sensing to examine habitat characteristics of molting and wintering sites in the Bering Sea. Sixty King Eiders (27 females and 33 males) were captured on Alaska s North Slope and instrumented with satellite transmitters from Using ArcGIS, a subset (n=290) of telemetry locations obtained during wintering and molting periods were selected at random and analyzed with 6,500 randomly generated points along the Alaskan and Russian coasts. Habitat characteristics were modeled using remotesensing derived data related to food availability (phosphate, nitrate, chlorophyll levels) and oceanographic conditions (surface salinity, temperatures, and weekly percent ice cover data). In addition, bathymetric and coastline GIS data-layers were used in depth and distance to shore calculations for each random point or eider location. Results showed that males departed breeding areas and molted earlier than females, with the earliest molt initiation occurring at higher latitudes. Molting and wintering sites were located significantly closer to shore, at shallower depths, and at lower salinity than randomly generated points. As technology continues to advance, pairing satellite-

6 derived telemetry and environmental data will become increasingly important to monitoring wildlife in remote areas inaccessible by direct observation. Schamber, J. L., P. L. Flint, and A. N. Powell Patterns of use and distribution of king eiders and black scoters during the annual cycle in northeastern Bristol Bay, Alaska. Marine Biology 157: Aerial surveys and recent satellite telemetry studies indicate that northeastern Bristol Bay, Alaska is an important area for migrating, molting, and wintering seaducks. However, information on spatial and temporal patterns of habitat use by seaducks in this region is limited. In this study, Schamber et al. investigated the mean monthly residence time, home ranges, and core use areas of King Eiders and Black Scoters in Bristol Bay. Satellite telemetry data from previous studies was compiled for King Eiders (n=157) and Black Scoters (n=77) captured on breeding or wintering grounds in Alaska from 2002 to Location coordinates were plotted in ArcMap v 9.2 and assigned depth and distance to shore values from NOAA Electronic Navigational Charts (2009). The Animal Movement extension for ArcView v 3.3 was used to calculate 95% (home range) and 50% (core use) home ranges using a fixed kernel analysis. For both species, number of telemetry locations in Bristol Bay peaked during spring migration (mean residence time 2 weeks) and a longer autumn molt period (mean residence time >3 weeks), with lowest numbers observed during summer. Distribution among the two species differed, with King Eiders occupying larger home ranges, located farther from shore and in deeper water than Black Scoters. Overlap of core areas used by King Eiders and Black Scoters was minimal, further suggesting habitat segregation. This study revealed species-specific differences in the chronology and habitat uses of seaducks in northeastern Bristol Bay, while underscoring the overall importance of the region to Pacific seaduck populations as a whole. Petersen, M., and P. Flint Population structure of Pacific common eiders breeding in Alaska. Condor 104: Since 1960, populations of Pacific Common Eiders (Somateria mollissima v-nigrum) have declined by over 50% from largely unknown factors. Understand linkages among breeding and wintering areas is important to improving management strategies. In this study, satellite telemetry was used to identify staging and wintering areas of Pacific Common Eiders from two geographically isolated breeding areas in Alaska. Female Common Eiders were instrumented with satellite transmitters at nesting sites in the Yukon-Kuskokwim Delta (n=20 eiders) and on the western Beaufort Sea coast (n=21 eiders) during the 2000 breeding season. Kernel analysis of location data was used to identify utilization distributions and core areas for each bird during the fall, winter, and

7 spring. Females marked from the two separate breeding areas showed geographic isolation throughout the entire non-breeding season and strong site fidelity to breeding areas the following spring. Since Common Eiders breeding on Yukon-Kuskokwim Delta and western Beaufort Sea appear to be allopatric, the authors recommend that these populations should be managed separately and identify the need for future research related to population genetics. Petersen, M. R., and D. C. Douglas Winter ecology of Spectacled Eiders: Environmental characteristics and population change. Condor 106: Spectacled Eiders (Somateria fischeri) are a federally-listed as threatened under the Endangered Species Act. Numbers of breeder pairs on Alaska s Yukon-Kuskokwim Delta have shown steep, long-term declines for largely unknown reasons. Spectacled Eiders winter exclusively in Bering Sea, although relationships between population trends and environmental variability on the wintering grounds are poorly understood. In this study, satellite telemetry data collected from were used in a GIS-based kernel analysis to estimate total distribution and core wintering areas for 13 adult Spectacled Eiders. Data on bathymetry, sea ice cover, and weather conditions were modeled with two separate population indices of Spectacled Eiders breeding on the Yukon-Kuskokwim Delta (Breeding Pair Survey: , Nest Plot Index: ). Population indices showed negative correlations with extreme concentrations of winter sea ice and cold temperatures in the winter and spring. However, a large amount of inter-annual variation in the overall population indices from remained unexplained by climate parameters. The authors conclude by citing additional factors that may contribute to the declining numbers of breeders on the Yukon-Kuskokwim Delta, including mortality of females during the breeding season, and speculate on the impacts of future environmental variability associated with climate change.