Tracking Scaup by Satellite

Investigators:

Dr. Scott Petrie, Long Point Waterfowl Executive Director
Dr. Shannon Badzinski, former Long Point Waterfowl Scientist
Dr. Michael Schummer, Long Point Waterfowl Scientist
Dr. Glen Olsen, Patuxent Wildlife Research Centre
Kevin Jacobs, Pennsylvania Game Commission

Satellite transmitters have been used to determine the migration chronology and pathways for several large waterfowl species (Blouin et al. 1999, Petrie and Wilcox 2003, Clausen et al. 2003), and recently have been successfully used in similar studies of diving ducks (Petersen et al. 1995, Petersen et al. 1999, Rosenburg and Petrula 2000). This technology is very effective for obtaining large-scale movements and broad-scale and local habitat use data for birds, such as Lesser Scaup, that inhabit remote or inaccessible areas throughout the annual cycle.

Long Point Waterfowl implanted satellite transmitters in Lesser and Greater Scaup on southern spring staging areas in the Atlantic Flyways. Satellite telemetry can be used for many purposes; however, in this study we were looking to increase understanding of spring migration chronology of these birds and evaluate effectiveness of the Waterfowl Breeding Population and Habitat Survey for counting Scaup. Satellite tracking Lesser Scaup was also important to determine if there were previously unknown migration pathways, patterns, and chronologies, spring/fall stopover sites, breeding areas, and/or wintering areas of birds using the lower Great Lakes. A second objective of the project was to evaluate the migration strategies of Lesser and Greater Scaup and determine the amount of variation in strategies among Scaup. The third objective was to determine the local movements and broad-scale habitat use of scaup on Lake Erie during the migratory period. By having satellite transmitters (PTTs) transmit for 24 hours a day for the first two weeks we were able to get numerous locations on each bird per day. These data provided insight into energetic demands of Scaup during spring and enable precise determination of diurnal and nocturnal habitats. These data will be combined with additional satellite telemetry locations collected by Long Point Waterfowl and other scientists to document seasonal differences in habitat use of scaup on the Lower Great Lakes and in North America.

Waterfowl Breeding Population and Habitat Survey

To determine abundance and trends in populations of waterfowl in North America, as well as availability of habitat for these birds, the U.S. Fish and Wildlife Service, Canadian Wildlife Service, and cooperators conduct the Waterfowl Breeding Population and Habitat Survey annually during May and June. The Waterfowl Breeding Population and Habitat Survey is conducted using airplanes and helicopters and includes the traditional and eastern survey areas (USFWS 2010).  Estimates of duck abundance have been produced annual since 1955 and 1990 for the traditional and eastern survey areas, respectively.


Lower Great Lakes and Lesser Scaup: Investigating Selenium as a Cause for Population Decline

The combined North American lesser and greater scaup population has declined by about 3.5 million birds since the mid-1980s. Recent population estimates of about 3.7 million birds in 2005 are among the lowest ever recorded for scaup since the Waterfowl Breeding Population and Habitat Survey began in 1955. Lesser scaup comprise about 89% of the North American scaup population, so it is thought that factors affecting this species may be very important in explaining why scaup numbers have declined and remain below North American Waterfowl Management Plan population goals. It has been suggested that reduced annual recruitment or female survival are the main demographic factors that ultimately have affected, and continue to contribute to, the scaup population decline.

The lower Great Lakes provide continentally important staging habitats for Lesser Scaup during both spring and fall. Typically, tens of thousands of Lesser Scaup feed and rest at several major stopover sites on the lower Great Lakes en route to breeding or wintering areas.
Lesser Scaup use of the lower Great Lakes increased dramatically after zebra mussel invasion, which also coincidently occurred during the mid-1980s.  After zebra mussels invaded the lower Great Lakes, they rapidly increased in abundance and distribution and likely caused Lesser Scaup to reduce their reliance on traditional foods, including native gastropods (snails) and possibly aquatic plants. In support of this, Long Point Waterfowl diet studies conducted in the early 2000s showed that Lesser Scaup now eat large quantities of zebra mussels during spring on the lower Great Lakes. This dietary shift is concerning because zebra mussels are efficient at filtering food from the water column and at accumulating some contaminants, such as selenium, which can increase their availability to predators at higher trophic levels, including Lesser and Greater Scaup. Thus, it is notable that Long Point Waterfowl recently determined that female Lesser Scaup acquire high burdens of selenium at several major spring stopover sites on the lower Great Lakes.

Selenium is a semi-metallic element that is nutritionally required by birds in trace amounts, but can cause physiological problems or death at very high levels in the body. This is important, especially because a large percentage of the female Lesser Scaup staging on the lower Great Lakes during spring had selenium burdens at or above levels known to cause reproductive impairment in Mallards  Effects of selenium burdens on birds can vary from species to species and presently there are no data regarding what selenium levels are necessary to cause behavioural, reproductive, or survival problems in Lesser Scaup. Physiological processes within most birds can cause selenium to decline over time, especially after they stop eating selenium-enriched foods (e.g., zebra mussels), and may eventually return to natural levels; this process is called depuration. At the time of this study, no data existed regarding selenium depuration rates in Lesser Scaup, therefore Long Point Waterfowl initiated a study to determine these rates in 2006.

The potential impacts of selenium acquired on the lower Great Lakes are linked with Lesser Scaup migration ecology. It was unknown, for example, how much time females spend outside of the lower Great Lakes. Presumably, after birds leave the lower Great Lakes they no longer consume selenium-enriched foods, such as zebra mussels, and may depurate selenium. Because females staging on the lower Great Lakes are a long distance from the core Lesser Scaup nesting area, mainly the boreal forests of Manitoba, Saskatchewan, Alberta, Northwest Territories, and Alaska, there may be enough time for selenium to drop below levels that adversely affect reproduction before they reach the breeding grounds. Therefore, Long Point Waterfowl provided critical estimates for the time females spend at migration areas outside of the lower Great Lakes region on their way to the breeding grounds by implanting satellite transmitters on Scaup. This research, combined with future studies of selenium depuration rates and behavioural and physiological responses to various levels of selenium, greatly advanced understanding the role of contaminants in Lesser Scaup population limitation and their long-term decline in North America.

Research Objectives:

The specific objectives of this research are as follows:

1. Determine time spent during spring and fall on lower Great Lakes stopover sites

2. Determine how long it takes females to reach breeding grounds after they depart the Great Lakes and presumably selenium-laden foods.

3. Identify subsequent spring stopover sites or staging areas of Lesser Scaup using the lower Great Lakes.

4. Identify where females staging at Long Point Bay eventually breed.

5. Assess how females move across the spring landscape in relation to different potential migration strategies.

6. Identify major fall stopover sites or staging areas and assess migration corridors used relative to ones identified during spring; also assess seasonal differences in migration strategies.

7. Identify wintering areas of Lesser Scaup that use the lower Great Lakes during migration.

Using Satellite Telemetry to Evaluate the Effectiveness of the Waterfowl Breeding Population and Habitat Survey for Counting Lesser and Greater Scaup in North America

Annual variation in scaup migration chronology, potential for differential migration between sexes, and the tendency of scaup to pair late during migration (April – May) may introduce bias into breeding population estimates for scaup. Because the last comprehensive review of estimation procedures was completed in 1995 (Smith 1995), the U.S. Fish and Wildlife Service recently initiated another review of operational and analytical procedures in 2010 (UWFWS 2010).  Thus, additional evaluations of the effectiveness of the Waterfowl Breeding Population and Habitat Survey are timely and information that would help refine breeding population estimates may be useful to managers.

Our objectives were to track migrations of scaup into and through the Waterfowl Breeding Population and Habitat Survey traditional and eastern survey areas to:
1) Determine proportions of satellite marked scaup located within Waterfowl Breeding Population and Habitat Survey strata when aerial surveys were conducted
2) Determine proportions of satellite marked scaup located within multiple Waterfowl Breeding Population and Habitat Survey strata and available to be sampled on > 1 aerial survey (i.e. potential for double-counting)
3) Determine proportions of satellite marked scaup settling in inferred breeding sites within Waterfowl Breeding Population and Habitat Survey strata when surveys were conducted there
4) Determine proportions of scaup settling in inferred breeding sites outside Waterfowl Breeding Population and Habitat Survey strata

Trapping Lesser Scaup:

During spring 2005, several hundred Lesser Scaup were first observed in Inner Long Point Bay soon after an ice-free area opened just off the mouth of Big Creek on 13 March; about 1800 Lesser Scaup, and hundreds of other diving ducks, were counted in that open water lead 3 days later. At that time, two traps were placed just off the mouth of Big Creek and the area and traps were baited with a mixture of wheat and corn. After birds began using the trap locations, traps were set and Lesser Scaup began to be trapped from 25 March to 5 April 2005. From these birds, we selected 6 females for inclusion in the study.

Another successful day trapping ducks on the Inner Bay. Dive-in (on left) and cloverleaf style traps both were used to capture scaup and diving duck species during spring 2005 in Inner Long Point Bay, Lake Erie, Ontario.

 

Waterfowl bander, Martin Wernaart (on right), removes a male Lesser Scaup from the trap while Sarah Flemming and Dave Okines observe from the boat. Martin banded and released all male Lesser Scaup and other waterfowl species caught in traps, including Greater Scaup, Ring-necked Ducks, Redheads, Canvasback, Bufflehead, and Mallard.

 

Transmitter Implantation

Birds were transported to the Avian Energetics Laboratory in Port Rowan, Ontario. Researchers made several body measurements on the birds and then Dr. Glenn Olsen (wildlife veterinarian with USGS in Patuxent, Maryland) anesthetized the birds and prepared them for surgery. Glenn surgically implanted either a 22-gram or 38-gram PTT satellite transmitter into the abdominal cavity of each female. After birds came out of surgery, they were retained and observed over-night to ensure they were recovering well from surgery.

On Left: Dr. Glenn Olsen (back left) inspects a female Lesser Scaup, Lady Long Point, that he has prepared for surgery, Dr. Kim Anderka (DVM) (left front) prepares to observe the procedure for the first time while Shannon Badzinski (front right) and Sarah Fleming (back right) help monitor the bird’s vital signs and keep a surgical record of the operation. Transmitters either weighed 22 grams (pictured) or 38 grams.

On Right: Dr. Glenn Olsen (back center) is placing a satellite transmitter into the female’s (Mussel-Muncher) abdominal cavity, Shannon Badzinski (right) is assisting by supporting the bird’s body from below (Note: Shannon’s hands are outside the sterile surgical field and under a plastic drape) so the antennae can easily pass through a hollow metal tube that Dr. Olsen surgically inserted to enable the antennae to protrude from the bird’s back. Dr. Jeff Buckland (DVM) (front right) assists above the plastic drape in the sterile zone with the transmitter implantation.

Minutes earlier Dr. Glenn Olsen finished suturing the skin and muscle layers of the abdomen and around the antennae, turned off the anesthetic, and has started administer oxygen to Henrietta. Shannon Badzinski (above) gently restrains the Henrietta to keep her calm after she wakes up.

Here is a picture of Little Sid minutes after awakening from surgery. She is still a little sleepy from the anesthesia, so she will be monitored for several hours overnight and released once Dr. Olsen gives her a final check-up and deems her fit for release.

Releasing Lesser Scaup:

Early the in the morning on the day after their surgery, females were transported the short distance from Long Point Waterfowl’s Port Rowan office back to Inner Long Point Bay where they were released. Females either swam off a short distance and then flew or immediately flew off to join the large rafts of scaup out in the bay.

On Right: Shannon Badzinski (left), Glenn Olsen (center), and Scott Petrie (right) prepare to release the first two female Lesser Scaup implanted with satellite transmitters, Lady Long Point (left) and Mussel-Muncher (right), back to Inner Long Point Bay.

 

On Left: Shannon Badzinski (right) and Scott Petrie (left) take CB and Mussel-Muncher to the edge of Inner Long Point Bay and set them into the water so they can join the thousands of other Lesser Scaup feeding on the Inner Bay and continue to build up their fat reserves for their long migration to the breeding grounds.

 

 

Spring Scaup Migration

Fall Scaup Migration

Project sponsors:

Satellite transmitters were purchased from funds provided by the following groups:

2005

  • Waterfowl Research Foundation – Buck-Danny
  • Sydenham Conservation Foundation – Little Syd
  • Aylmer Order of Good Cheer – Henrietta
  • Long Point Waterfowler’s Association – CB
  • Ontario Ministry of Natural Resources – Mussel-Muncher
  • To be determined – Lady Long Point

2006

  • Chip Pitfield – Dyda and Mich
  • Tod Wright – Blue Bill
  • Rondeau Bay Waterfowlers Association – Rondeau Bill
  • Doug Shade – Hope
  • Northwest Pennsylvania Duck Hunters Association – Lady Presque Isle
  • Aylmer Order of Good Cheer – Pot and Roast
  • Fred Mannix – Alta I
  • Bill Turnbull – Alta II
  • Long Point Waterfowlers’ Association – CBII
  • Delta Waterfowl – Kingsville Chapter – Kingsville Jack
  • Ontario Federation of Anglers & Hunters – Thumper

2007

  • Doc Guiser – Thelma & Louise
  • Chip Pitfield – Amy
  • Waterfowl Works UFO – Miss UFO
  • GreatLakesWaterfowler.com – Lil’ Miss GLW
  • Michigan Duck Hunters Association – Freda
  • Ontario Federation of Anglers & Hunters – OFAH OFAH / Zone J – Yolanda J
  • Rondeau Bay Waterfowlers Association – Rondeau Bill II
  • Delta Waterfowl Foundation – DWF
  • Mighty Layout Boys – Lady Huffnickle
  • Southwest Outdoors Club / Holland Testers LTD – Ruby Rose
  • Aylmer Order of Good Cheer – Order of Good Cheer
  • Long Point Waterfowlers’ Association – CB III
  • Central New York Waterfowlers – CNY-DNR
  • Long Point Waterfowl & Wetlands Research Fund - Noah
  • Long Point Waterfowl & Wetlands Research Fund – Bean

Project Partners

Long Point Waterfowl, Pennsylvania Game Commission, PAWHS, Susquehanna River Waterfowlers, U.S. Fish and Wildlife Service, Wildlife For Everyone Endowment Foundation, and N.W. Penny Duck Hunters Association

Additional in-kind support were provided by

United States Geological Survey – Patuxent Wildlife Research Center / Dr. Glenn Olsen
PA Department of Conservation and Natural Resources – Presque Isle State Park
Regional Science Consortium at TREC; United States Coast Guard – Erie Station
Glennwood Veterinary Hospital, Dr. Ken Felix
Bluff’s Hunting Club
Environment Canada’s Environmental Conservation Branch, Ontario Region

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