Operation Migration warns: FWS ‘visions’ end to ultralight guided release of whooping cranes

Heather Ray | Operation Migration

On Oct. 15 the U.S. Fish and Wildlife Service posted a document outlining its vision for the next five-year strategic plan for the Whooping Crane Eastern Partnership and the Eastern Migratory Population.

In their vision document, FWS proposed radical changes to the release methods used for the Eastern Migratory Population including ending the use of the ultralight-guided migration technique in favor of the Direct Autumn Release and other, as yet, untested methods. 

The reason is that the FWS feels the ultralight release method is “artificial” yet they have provided no data to back their claim that this is detrimental to the Whooping cranes. Alternatively, if you read our response, you will see that using data derived from the WCEP database, the UL method is the most successful thus far in terms of survivability, migratory behavior, and breeding success. 

In fact, the UL method most closely replicates the natural life history of the species in that, just as their parents would, OM teaches the young Whooping cranes a suitable migration route and cares for them until the following spring — just as their parents would.  

It is important to point out that, while the FWS is but one member of the Whooping Crane Eastern Partnership, it has control over egg allocations each year. The FWS recommends prioritizing allocation of eggs for use in methods with shorter periods of captivity and more limited exposure to costumed humans.

A fact: Time spent in captivity and exposure to costumed humans is greater with other release methods.

Whooping cranes hatch at the captive breeding centers in May/June. The other methods involve holding cranes in captivity at the propagation centers until they are moved to the release sites in mid-September or later. The UL cranes are moved from the Patuxent Wildlife Research Center to the White River Marsh at an average age of 46 days. From this point on, they are being exercised and learning important flight skills, just as they would with their natural parents. Cranes raised under the other release methods are not allowed to fly until such time as they are moved to the reintroduction areas in September or later.

Cranes held in captivity throughout the normal fledging period are at a disadvantage to their wild counterparts in that their flight muscles are not as well developed and they lack flying skills normally learned earlier in their life history. These skills are important to avoid predators, power lines and other obstacles. UL birds learn those skills and develop that endurance well before they encounter such dangers in the wild.

A fact: The UL method has resulted in higher first year and annual survival thereafter.

A fact: The only wild-produced crane colts in the Eastern Population which have survived to fledge resulted from ultralight/ultralight pairs.

Since the 2011 move to White River and Horicon Marsh, almost five years of work has been done by the non-profit WCEP partners.

In using only data from the first 10 years of this project to justify their Vision Document, FWS has painted the entire Eastern Migratory Population with a Necedah brush. It has ignored almost one-third of the available data and discounted all that has been invested in the Wisconsin Rectangle so far. The timing of their recommendation to end UL releases is even more short-sighted when one considers that Whooping cranes don’t typically breed until five years of age and, even then, don’t generally produce more than one offspring per season.

We are now on the cusp of determining if these cranes can successfully breed in the blackfly-free habitat of the Wisconsin Rectangle. Ending the UL program now is premature.

Heather Ray is the director of development for Operation Migration.

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