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In the 1980’s, Canadian naturalist Bill Carrick learned that he could imprint Canada geese (Branta canadensis) to follow him while he motored around Lake Scugog in his boat. Once the goslings fledged, they flew beside him, creating a unique filming opportunity.

Bill Lishman is a Canadian artist, sculptor and inventor who was among the first Canadians to fly ultralight aircraft. He realized that the speed of Mr. Carrick’s boat matched the speed of his aircraft and he thought that maybe he could take the concept one step further by actually flying with the geese.

After several attempts and a difficult learning curve, he was finally successful in 1988. He spent the fall of that year documenting his daily flights around the countryside with his gaggle of imprinted geese. He produced a heart-warming video called C’mon Geese, which won several international awards.

Eventually that video was seen by Terry Kohler of Windway Capital, based in Sheboygan, Wisconsin. Mr Kohler is an avid pilot, an environmentalist and a long-time supporter of the International Crane Foundation. He showed Bill Lishman’s video to Dr. George Archibald, co-founder of ICF and the world’s leading crane expert. The idea of using ultralight-aircraft to teach birds to migrate was hatched.

Precocial birds like cranes, swans and geese learn to migrate by following their parents. The route they use to reach their wintering grounds may have evolved over millions of years but it is passed from one generation to the next. There are no maps or sign posts and when the last bird to use the route dies, so too does that knowledge. Before Mr. Lishman’s successful flights with geese and Dr. Archibald’s suggestion to use it to teach migration, there was no method of reintroducing Whooping cranes into a migratory situation.

In 1993 Bill Lishman asked Joe Duff to join him in an attempt to conduct the first ever human-led migration of birds. At the time, Duff was a fellow ultralight pilot and a successful commercial photographer. The two artists-turned-biologists imprinted 18 Canada geese and, in the fall, they used two ultralights to lead them from Purple Hill in Ontario, across Lake Ontario, to the Environment Studies Division of Airlie Center in Warrenton, Virginia. Sixteen of those birds survived the winter and thirteen returned on their own the following spring. That record setting trip was documented by ABC’s 20/20.

Operation Migration was founded as a Canadian Registered Charity in 1994. (In 1999 it was granted 501-c3 status in the United States.) In 1995 Lishman and Duff formed a limited company called In The Sky Productions and contracted with Columbia Pictures to produce Fly Away Home, starring Jeff Daniels and Anna Paquin. In The Sky Productions provided the story rights, the wildlife permits, the geese, the flying and even some of the cinematography for the popular film.

In the years that followed, Operation Migration conducted several migration experiments with Canada geese, Trumpeter swans (Cygnus buccinators), Sandhill cranes (Grus canadensis) and Whooping cranes

(Grus americana). The results of the early studies with non-endangered Sandhill cranes were presented each year to the International Whooping Crane Recovery Team. By 1998, Joe Duff was able to demonstrate that he and his team could imprint a crane species and lead those birds along a pre-selected migration route to a safe wintering area. In the spring, the birds would initiate their own return migration back to the introduction area where they first learned to fly, while avoiding humans and using appropriate habitat.

Up to that point the Recovery Team had been struggling to augment the only naturally-occurring population of Whooping cranes. Down to only 15 individuals in the 1940’s, their numbers had slowly increased but they were still threatened by avian disease, storm events such as hurricanes, chemical spills, and human encroachments. Operation Migration was asked to spearhead an attempt to reintroduce a second migratory population in Eastern North America.

In 1999, the Whooping Crane Eastern Partnership was formed as a consortium of nine federal, state and private agencies each contributing their resources to achieve a common goal. Operation Migration was responsible for care and training of the Whooping cranes from hatch until they were released at the wintering grounds in Florida.

Founding members of WCEP (pronounced “WeeSep”) include:

International Crane Foundation
National Fish and Wildlife Foundation
Operation Migration
US Fish and Wildlife Service
USGS Patuxent Wildlife Research Center
USGS Wildlife Health Center
Whooping Crane Recovery Team
Wisconsin Department of Natural Resources
Wisconsin Natural Resources Foundation

Necedah National Wildlife Refuge in Wisconsin was selected as the reintroduction site and Chassahowitzka NWR in Florida as the wintering grounds. Between them was 1250 miles and seven states. In 2000, Operation Migration and its new partners conducted a migration with non-endangered Sandhill cranes to determine if cranes could be led that far and to establish a list of stopover locations.

During that time, the US Fish and Wildlife Service acquired the permits needed, including an exemption within the Endangered Species Act known as the Non-Essential, Experimental Population Designation (NEP). This exemption reduced the status of the birds OM introduced from endangered to threatened and encouraged the cooperation of seven direct line states and 13 neighboring states, plus two Canadian provinces into which the birds may disperse.

In 2001 WCEP began the reintroduction and 7 Whooping cranes were led to Florida and monitored over the winter. The following spring 6 of the 7 returned to Wisconsin (one had been predated over the winter by bobcat).

In 2005 WCEP began experimenting with a second reintroduction method. Known as the Direct Autumn Release (DAR), birds were raised at ICF, introduced into the Wisconsin wetlands and released in the fall near experienced Whooping cranes that OM had taught to migrate.

The first wild chick was hatched in 2006 and followed its parents along the route OM taught them. It was confirmed that December near the wintering grounds in Florida - proving that the concept was sound. It was the first wild-produced migratory Whooping crane to hatch in eastern U.S. since the last nest was reported in 1878.

Despite this milestone, the population was slow to reproduce and many of the nests initiated at Necedah were abandoned mid-incubation. Several years of observations indicate that the majority of nest abandonments occur in sync with the emergence of peak Black fly populations. Of the more than 200 species of black flies in North America, at least three are known to target birds. Unfortunately, all three are present in the wetlands in and around Necedah NWR. Additionally, post hatch/pre-fledge mortality at Necedah is high.

As of 2015, the population included approximately 27 reproductive pairs that have produced 197 nests and hatched 63 chicks. Of those, only 10 chicks have survived the 80 days until they are capable of flight. That pre-fledge mortality occurs after the black fly season and its cause has not yet been determined.

Although work continues to mitigate the black fly problem and increase reproduction at Necedah, WCEP moved the release sites to an area referred to as the “Wisconsin rectangle.” This is an area of fragmented wetland east of Necedah with very few of the black fly species that feed on birds. Ultralight releases began at White River Marsh State Wildlife Area and DAR releases began at the Horicon NWR in 2011.

In 2013, WCEP completed an 18 month long Structured Decision Making process that used Population Viability Analysis and algorithms to evaluate this reintroduction. It was determined that the best chance for the population to persist is to keep reintroducing birds into the Wisconsin rectangle for the next five years using both the Ultralight and the DAR methods and habitat at Horicon and White River.

Unfortunately the DAR method did not showed acceptable results. After eleven years, no offspring survived past fledging, plus pairing rates, philopatry and survivorship were all lower than other methods.


In early 2016, the US Fish and Wildlife Service determined that the UL method was too “artificial” and that cranes raised by hand/costume, missed early learning opportunities. As a result, it was speculated that they did not properly nurture or protect their chicks when they had their own offspring. It was suggested that this inattentiveness was the cause of high pre-fledge mortality at Necedah. In 2016, the U.S. Fish and Wildlife Service exercised its authority over the Endangered Species Act and ended the aircraft-guided reintroduction method.

Going Forward

Both WCEP and Operation Migration believe the Eastern Migratory Population will ultimately be successful. The habitat within the Wisconsin Rectangle is black fly free and it already supports large numbers of Sandhill cranes. Releases into Wisconsin will continue using a method known as parent rearing (PR). Instead of artificial incubation and hand rearing, the chicks are raised at the captive centers by adult Whooping cranes. They will be moved to the reintroduction sites in late August or early September and released in proximity to older, experienced Whooping crane pairs that have abandoned their own nest or lost their chick. It is hoped this Parent-Reared/Fall Adoption technique will provide a more natural experience for the chicks and possibly improve their parenting skills once they mature.

Operation Migration will assist with the release of these chicks and track their fall migration. OM will also monitor nesting birds in the spring, and document the movements and behavior of pairs with chicks. Data collection is the key to determining the cause of low fecundity and to assist in making informed management decisions for the future of the EMP.

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