Osprey Recovery in South Dakota

The Osprey is a fish-eating bird of prey that is listed as a state threatened species in South Dakota. A small population nests in the Black Hills, but Ospreys are very rare elsewhere in the state. Ospreys range throughout much of the world and are common in many parts of North America. This species responded well to the ban on DDT, which had caused eggshell thinning and led to population declines.

Ospreys tend to be poor nesting pioneers, meaning they don’t typically nest in new areas far from an existing population. In contrast, Bald Eagles may nest in a completely new area where they find favorable nesting and foraging sites, helping them to expand more quickly than Ospreys.

To help recover the Osprey in South Dakota, South Dakota Game, Fish and Parks (GFP) has spearheaded a reintroduction effort. New funding sources allowed the agency to focus on fulfilling its legal responsibility to recover species that are threatened or endangered in the state.

Ospreys live in both freshwater and saltwater areas, including coastlines, inland lakes, and rivers. They prey on fish that they capture in shallow water or near the surface. Ospreys select nest sites that are safe from predators and in areas open enough to allow this large raptor (wingspan is more than 60”) to maneuver.

Ospreys traditionally used large trees on or near water bodies as nest sites. As these sites declined and potential predators increased, many birds adapted to artificial sites, such as powerlines, channel markers, and nesting platforms erected specifically for them. Ospreys favor nest sites that are higher than surrounding vegetation and relatively free of threats from predators. Platforms are often fitted with predator guards to discourage mammalian predators from reaching the nest.

A male selects a nesting area, usually near the area from which he fledged. Birds are 2-3 years old when they begin nesting. The nest tree or artificial structure must be strong enough to support a large stick nest. After attracting a mate, the male brings sticks to the nest for the female to arrange. The pair may build a new nest or spruce up a used nest. The male feeds his mate at the nest from the time of courtship through the time the young fledge. The female usually lays 3 eggs, which she incubates for 5-7 weeks. Eggs hatch in the order they were laid, 4-5 days apart, giving the oldest chicks a survival advantage if times are tough. The female also broods the chicks, keeping them warm or shaded as needed, for the next several weeks.

Young birds try their first flight at 7-8 weeks of age. Even after learning to fly, parents continue to feed them for several weeks as they learn to fish for themselves. The adult female may begin her fall migration sooner than the male, which may stay behind to continue caring for the young birds.

Ospreys eat fish almost exclusively, with more than 80 fish species documented. They hunt by flapping or gliding 50-100 feet above the water’s surface looking downward in search of prey and dive feet-first to snatch a fish. Strong wings help the bird gain altitude as it adjusts the fish to face head forward on the way to a feeding perch. Ospreys are well adapted for capturing fish, with relatively long legs, a reversible outer toe to better grasp prey, raspy structures called spicules on the bottom of the foot to help grasp slippery fish, long curved claws, and valves that keep water out of the nostrils.

Osprey presence indicates that a wetland ecosystem is healthy and able to support this unique bird of prey. They’re also beautiful and interesting birds to see.

Preparation for this project began in the early 1990s, with a study by Robert Usgaard of South Dakota State University. Usgaard evaluated the feasibility of reintroducing both Bald Eagles and Ospreys to South Dakota. Bald Eagles expanded into South Dakota on their own, and nesting pairs presently number more than 50 in the state. The Osprey was slower to recover. Although historically documented in southeastern South Dakota, the first known successful nest in recent times wasn’t documented until 1991 at Pactola Reservoir in the Black Hills.

By 2001, new funding allowed GFP to plan an Osprey release along the Missouri River in southeastern South Dakota. Wildlife Experiences (WEI), a raptor education, rehabilitation, and conservation association, was contracted to evaluate sites and formulate a plan. State and federal permits allowed GFP, through WEI, to take up to a dozen Osprey chicks from Minnesota in 2003, the beginning of a long and interesting experiment.

Reintroduction may be needed to restore or enhance wildlife or plant populations. With birds of prey, reintroduction is often called hacking, a technique that benefited greatly from the expertise of falconers. Along with the ban on DDT, reintroduction of Peregrine Falcons and Bald Eagles contributed to recovery of these species to allow their removal from the protection of the federal Endangered Species Act. These two species, along with the Osprey, are listed as state threatened species in South Dakota.

Osprey reintroduction makes use of some kind of elevated platform (hack tower) situated in areas that seem suitable for Osprey nesting. Prior to reaching fledging age, chicks are taken from a nest in an area with a stable or increasing Osprey population. At least one chick is always left in the nest. Chicks are placed at the hack site, fed, and monitored for health or safety problems. They are banded with metal U.S. Geological Survey bands and possibly another identifying marker or band. Chicks may be vaccinated against preventable diseases. Chicks are fed fish while in the hacking tower until they start showing signs that they are ready to test their wings and take flight. Even after they take some test flights, food is provided until they can reliably catch their own fish.

Three facets of Osprey biology make reintroduction feasible. Ospreys can learn to fish without their parents. They can migrate on their own without parents. And once mature, males, in particular, tend to select a nesting area near the area from which they fledged. Unfortunately, only a small percentage survives to reach even one year of age, making it critical that enough birds are reintroduced to result in enough survivors that live long enough to nest.

All reintroduced birds are banded with a uniquely-numbered metal identification band. In addition, birds released since 2005 have a color leg band on one leg, with the “silver” metal band on the other. We have had two band recoveries since the project began. A reintroduced bird was shot in Nebraska in 2004 and euthanized because of its extensive injury. A band was found in Iowa in 2009 from a bird reintroduced in 2004. We don’t know when that bird died, because no remains were found.

We recently received information about two surviving reintroduced birds. Nebraska biologists with the Tern and Plover Conservation Partnership twice observed a banded Osprey feeding near the Platte River in Nebraska in July 2009. They were able to read its band and followed up to learn of its origin as part of South Dakota’s reintroduction program. The bird was reintroduced in 2006. They did not report any evidence of nesting.

Birds are also fitted with small radio transmitters to track them near the hack site. These help in finding and retrieving birds that might get in trouble during some of their first flights. The transmitter is attached to a tail feather. When the tail feathers are molted, the transmitter drops off as well.

A more ambitious tracking system makes use of satellite technology. Platform telemetry transmitters, PTTs, are being used on a wide variety of wildlife species to track long-distance movements. We added this feature to our project to learn more about migration movements and wintering habits of reintroduced birds. Ospreys are 2-3 years old before their first nesting attempt. Young birds remain in the wintering area until they are approximately 22 months old before returning to a potential nesting area.

The released Ospreys initiate migration from the hack site during September, with departure ranging from early to late September. The young Ospreys tend to follow the Missouri and Mississippi River drainages during migration. Migration to the Gulf of Mexico is typically rapid with the birds often reaching the coast within a week. Early departing youngsters have reached the Gulf before others have left the hack site.

The birds appear to go east or west once they reach the Gulf, although some may fly directly across the Gulf to the Yucatan in Mexico and continue on to Central America. Birds turning east have the option of flying down the coast through Florida and on to Cuba and the chain of islands to South America. Those that turn west or cross the Gulf could end up in Mexico and Central America. Satellite telemetry has revealed considerable variation in where the young Ospreys released in South Dakota winter. Our birds have ended up wintering in Costa Rica, Cuba, and several locations along the Gulf of Mexico. One bird wintered along the Gulf in Mexico, south of the Texas border. Another bird wintered in the Louisiana delta. Yet another followed the Gulf to the end of the Florida Keys, but returned to the Everglades area, where it wintered.

Reintroduction projects are logistically complicated and expensive. It’s best to monitor species and habitats to detect declining populations and try to turn things around rather than relying on reintroduction as the best solution. But sometimes reintroduction is necessary.

This project benefitted from a Master of Science study by Robert Usgaard at South Dakota State University. Usgaard evaluated the feasibility of reintroducing Bald Eagles and Ospreys in South Dakota. His project was supported with Pittman-Robertson (P-R) funds, a source established to restore wild birds and mammals. P-R funds derive from a federal excise tax on sporting arms, ammunition, archery equipment, and handguns. Funds are apportioned to state wildlife agencies by the U.S. Department of Interior based on a formula that considers the state’s total area and licensed hunter numbers.

A new funding source allowed GFP to follow though on Usgaard’s feasibility study. The Wildlife Conservation and Restoration Program (WCRP) was a one-year funding source provided to state wildlife agencies to conduct nongame or rare species conservation projects, environmental education, and wildlife-associated recreation. WCRP funded a pilot project that included site selection and other preparation and the first year of reintroduction in 2003.

A new federal funding source emphasized conservation projects rather than education or recreation activities. State Wildlife Grants are federal dollars provided to all states and territories, with a priority placed on proactive conservation to prevent fish and wildlife species from becoming endangered. State Wildlife Grants funding is matched with a nonfederal source. GFP provides the majority of the nonfederal match for Osprey reintroduction in South Dakota, although volunteer time will also help defray some of the cost of the nonfederal match.

State Wildlife Grants funding has been extremely important in helping GFP and other state and tribal wildlife agencies fulfill their legal responsibilities to manage and restore nongame and endangered species. However, it is an unstable, annual appropriation that only scratches the surface of fish and wildlife funding needs.

The Teaming with Wildlife coalition is a broad and diverse group of government agencies, biologists, hunters, anglers, birdwatchers, hikers, nature-based businesses and other conservationists who support the goal of restoring and conserving our nation's wildlife. The Teaming coalition was instrumental in securing State Wildlife Grants funding and has been working hard to secure stable, long-term funding to meet the needs of fish and wildlife and native habitats. Visit http://teaming.com/ to learn more about the national effort to help wildlife.

South Dakota has a large and diverse state Teaming coalition that has helped deliver this message to our senators and representative in DC. For more information, including how to join the state coalition, visit this website: http://www.sdgfp.info/Wildlife/Diversity/teaming.htm

Idaho biologists Wayne Melquist and Janie Fink collected 21 young ospreys from the Coeur d’Alene Lake Basin the week of July 20^th for the 2009 South Dakota Game Fish & Parks sponsored reintroduction project on Lake Yankton. Assistance from cooperators included the U.S. Army Corps of Engineers at Gavins Point Project, Birds of Prey Northwest, Idaho Department of Fish & Game and the University of Idaho. After collection, the youngsters were banded, given medical exams, weighed and held in the north Idaho raptor facility. The young were collected from bridge structures, utility poles, and platforms over water. If a nest had only one young, one chick is left to maintain the family structure of the nesting pair.

In addition, two one-year olds were prepared for transport to South Dakota for the 2009 Release. One well-known osprey is “Gabby”( A-03), a returning bird from the 2008 release at Lake Yankton, where after successful medical intervention she overcame a serious lung condition , was twice recovered from the water and later line flown for exercise to build her flight muscles. Her third time out she ended up in the reeds along shore with minor wing damage. It was late in the season, so it was decided to overwinter her in Idaho for release again this year. The other one-year old was admitted to the north Idaho raptor facility last fall for a shoulder injury; now recovered she (A-41) is also scheduled for the 2009 Yankton Release.

A total of 23 ospreys were flown from Coeur d’Alene, Idaho to Yankton South Dakota, where they were placed atop the reintroduction tower the same day. To date the young osprey continue to imprint upon their physical environment, eat lots of fish daily, and are given periodic health checks. They are monitored by staff who observe them through a camera to record natural behaviors and developmental stages. The young are released from the reintroduction tower in staggered releases according to their developmental readiness, at which time staff and volunteers track their movements daily and continue to supply small fish until the young birds learn to fish independently. By mid-September many of the young will migrate south towards the Gulf of Mexico, where they will stay until reaching 2 years of age. It is hoped that the ospreys will return, after reaching reproductive age, to southeastern South Dakota and the shores of the Missouri River, thereby reestablishing a viable osprey population in that area.

Two of the young ospreys will be fitted with special tracking devices, about the size of a matchbox, to monitor their movements. These special radios track the birds using satellites that circle the earth and record their movements. Biologists receive the data by a computer and with a map overlay, track the young ospreys.

At this time, 3 of the young need medical issues resolved prior to release. A-22, A- 30, and A-41 will be examined by Dr. Ross Dirks on August 7^th for further evaluation. Prior to release all the ospreys receive health exams, feather replacements, wing paint for identification and tail mounts for tracking. After a door is gently lowered exposing them to freedom, each released group chooses when to leave the tower and take flight for the first time. Some birds fly quickly at first (males) while others are more cautious and linger for hours. While most young fly well, they may have trouble landing and calculating distance on their first flights. At that time water-stationed kayaks and boats are at the ready for those inevitable missed landings in the water.

Eight young ospreys will be the first group released on Saturday August 8^th, with subsequent releases on consecutive Saturdays. They can be identified by the green leg bands on their right leg. The birds are quite large, approaching the size of small eagles. They can be seen fishing over waters or perched in dead trees. South Dakota Game, Fish & Parks is requesting that the public report any sightings of ospreys sporting blue or green leg bands to (605) 773 3387. Grounded or injured ospreys should be reported to the Osprey Release Coordinator at (208) 582 0797 for assistance.

Update for Week of August 10, 2009

The first released group of reintroduced ospreys continue to fly and return to the Tower daily. They were wing marked with orange paint to differentiate them from the second group to be released. Only one water rescue occurred when A-26 ended up in the water and needed time out to dry. He was later released again and continues to do well. After nearly ten days of free flying, the first group can be observed soaring, dipping their feet in the water while flying, and beginning to hone their aerial skills for hunting. Several ospreys are beginning to make their first awkward attempts at hunting. Within the next week we fully expect them to crash into the water and come up with their first catch of the day!

On Saturday, the second group of ospreys were released, sporting lime green wing paint. Included in this group was “Gabby” a one –year old held from last year. She bears pink wing paint and is banded A-03. Prior to her release she had sixteen feathers implanted to replace damaged ones. Because of the feather replacement, it was decided that she would not be fitted with a radio transmitter. At this time fifteen young osprey have been successfully released, and have all made a return trip to the Tower to feed. Even in high gusty winds the first time fliers negotiated their important Tower returns. All birds were held for a minimum of ten days to allow for sufficient time to “imprint” on their new surroundings.

Tomorrow the two selected candidates will receive their special radios for tracking, and be released later this week. A-23 and A-38 will be monitored for movements and tracked as the young birds begin their expected southerly journey to their wintering grounds. It remains to be seen whether or not they will attempt an open water crossing over the Gulf of Mexico this fall. Last year’s birds played it safe and remained in protected coastal areas, decided not to cross the large body of water.

The volunteer support has been well-received as daily staff and bird observers track the birds daily. Individuals are identified by their numerical green bands and accounted for often. By week’s end, South Dakotans will be recipients of 20 free flying ospreys!

Educational programs occurred as well on the weekends with the use of trained educational birds at the Lewis and Clark Visitors Center and the South Dakota Game, Fish & Parks Welcome Center.

By Janie Fink, South Dakota Reintroduction Coordinator

Nineteen ospreys were reintroduced at the Lake Yankton site. Many are now moving away from the release site and embarking upon their migration as fewer ospreys are seen daily at the tower. Some return to the tower to feed. Fish continue to be provided at the tower daily, which will continue until no ospreys are seen returning.

Two birds were fitted with satellite transmitters. According to the most recent data available, both birds remained near the hack site after release. One of the birds moved downstream below Yankton by September 12-13.

After two months at the Lake Yankton site, 18 free-flying Ospreys fledged from the tower. Careful monitoring indicated that all birds were well-prepared for their migration south.

We know of one loss from this year’s cohort to date. A bird was found dead on September 10, 2009, in Houma, Louisiana. The person who reported the band found the bird beneath a powerline, with the remains of a fish nearby, indicating that the bird was foraging successfully prior to its death.

A view from the inside of a compartment, showing perches that allow the birds to
exercise their wings. This photo shows the temporary green paint and the green band
on the right leg and aluminum band on the left. This bird is one of two fitted with a
satellite transmitter in 2009.

Photo provided by Janie Fink.

The two birds fitted with satellite transmitters continue to broadcast interesting information. Here are some highlights, provided by Wayne Melquist:

Female osprey A-23 was observed at the hack site area on 1 October, but either later that day or early on the 2nd, she finally initiated migration. At 2202 hrs on 2 October, she was located about 8 mi ENE of Burlington Junction, Missouri (in NW Missouri near the Iowa border). By 1041 hrs on 4 October, she was located in central Missouri near Bagnell Dam, Lake of the Ozarks. Once she decided to move, she didn’t waste much time. On 15 October, she was still hanging around Lake of the Ozarks, where she’s been since October 4. On the 17th she was east of Pine Bluff, Arkansas, on the 18th, off the coast of northern Belize, and on the mainland of Honduras on the 20th. She likely crossed the Gulf rather than following land or island-hopping. Upon arrival on terra firma in Honduras, she continued along the Honduras coast (between 21 and 31 October), crossing just into Nicaragua on 26 October, then returned a short distance back north into Honduras, where she remains (28-31 October).

Male osprey A-38 was located near Garnett, KS, on 23 September. On 29 September, he was located at Point Coupee, LA, which is west of Baton Rouge and North of Henderson. On the 30th, he was located on the Gulf of Mexico coast, SW of Houma, straight south of Thibodaux, LA, in the China Island area. He remained in this area for another day and was located approximately 15 mi E of Galliano, LA (straight south of New Orleans), at 1057 hrs on 2 October. At 1515 hrs, he was in the Port Sulphur area along the Mississippi River, approximately 60 miles from the mouth. On 10/04/09 between 0058 hrs and 0449 hrs, the bird was located just north of Venice, AL, along the Mississippi River, approximately 30 mi from the mouth and 75 mi from New Orleans. Between 23 and 31 October, the male osprey remained in the Venice, LA, area along the Mississippi River, Louisiana Delta. A short distance downstream from Venice is "Head of Passes" where the main stem of the Mississippi River branches off into 3 distinct directions at its mouth in the Gulf of Mexico.

This reintroduction project will continue through 2010. Sites are being selected for placement of nesting platforms. Reintroduced birds aren’t expected to nest on the hack tower itself, but they may choose to return to the general area. Because Ospreys are well-adapted to nesting on artificial structures, they have shown acceptance of nesting platforms.

We hope to begin seeing reintroduced birds return as nesting birds. We will continue to publicize the project, particularly to bird-watchers and river recreationists in hopes that they will observe and report banded birds. We will continue to network with other states about our project to learn if birds reintroduced in South Dakota contribute to nesting populations elsewhere.

Year	# Reintroduced Chicks	Source	Markers
2003	9	Minnesota	Temporary color tape and paint; USGS metal band
2004	20	Idaho	Temporary color tape and paint; USGS metal band
2005	20	Idaho	Blue metal band on right leg; USGS metal band on left leg
2006	12	Idaho	Blue metal band on left leg; USGS metal band on right leg
2007	no releases
2008	20	Idaho	Green metal band on left leg; USGS metal band on right leg
2009	20	Idaho	Green metal band on right leg; USGS metal band on left leg
2010	20 (planned)	Idaho