USFWS ‘Vision’ Recommends Ending Aircraft-Guided Migration

Table of Contents 

FWS Vision Document – Published October 15, 2015 

OM Response to the FWS Vision Document 

PETITION – Safeguard the Future of Whooping Cranes Using the BEST Method!

Milwaukee Journal Sentinel Article – published October 23, 2015

FWS FAQ Document – Published October 28, 2015

OM Response to the FWS FAQ Document

Milwaukee Journal Sentinel Article – Published October 29, 2015

OM Response to the FWS Vision Document

On October 15th the U.S. Fish and Wildlife Service (Service) posted a document outlining their vision for the next 5 year strategic plan for the Whooping Crane Eastern Partnership (WCEP) and the Eastern Migratory Population (EMP).

In their Vision Document, they proposed radical changes to the release methods used for the Eastern Migratory Population (EMP) including ending the use of the ultralight-guided migration technique (UL) an all costume rearing methods in favor of other, as yet, untested methods. According to the Service, the document carries no regulatory authority but is to be considered at an upcoming meeting of all WCEP partners scheduled for mid-January. However, it was posted publicly on the FWS Midwest Region website shortly after it was shared with the WCEP Guidance Team and well before any final decisions have been made.

In making public their Vision Document even before it was discussed by WCEP, FWS breached the WCEP protocol and gave no consideration to the effect it would have on Operation Migration and its dedicated supporters who may now question their future donations. That has forced OM into a very awkward position of having to publicly point out the shortcomings of these ill-conceived recommendations.

In making these proposals, the FWS used information presented at a WCEP Structured Decision Making (SDM) process that was conducted in 2013. At that time, only information from 2001 to 2010 was considered. 2010 was the same year that the Whooping Crane Recovery Team ended releases at Necedah because of low reproduction, which is generally accepted to be caused by a large population of parasitic black flies resulting in nest abandonment. It is important to note that the results of the 2013 SDM were to approve both DAR and UL releases within the Wisconsin Rectangle for the next five years.

Since the 2011 move to White River and Horicon Marsh, almost five years of work has been done by the Non-Government Organization (NGO) WCEP partners.

In using only data from the first ten years of this project to justify their Vision Document, FWS has painted the entire Eastern Migratory Population (EMP) with a Necedah brush. They have 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.

In order to evaluate the ability of a wildlife species to survive into the future, researchers use a method called Population Viability Analysis (PVA). It involves a complex set of algorithms that consider a variety of milestones along the path to self-sustainability. No published PVA has been conducted for either the UL or the DAR methods that have been used to release birds into the
Wisconsin Rectangle.

In their Vision Document, the FWS states “Ultralight-led rearing and release is more artificial and costly than any other currently used release method and does
not appear to yield substantially better results
There are three important points made in that single sentence that need to be addressed.


The term artificial is used several times in the Vision Document but is not supported with scientific data and appears to be opinion only. In fact, it could be argued that the UL method is less artificial than other methods. It more closely replicates the natural life history of Whooping cranes by releasing birds after they have been taught to migrate and protecting them until they would naturally separate from their parents as young adults.

Conversely, the DAR method releases immature birds prior to when they would naturally become independent. They must then quickly learn to survive on their own and to migrate just at a time when the conditions in Wisconsin are rapidly changing and food becomes more difficult to find.

Originally the DAR cranes were to be released in proximity to older, experienced Whooping cranes but unfortunately only two adults have returned to the Horicon Marsh and they reportedly show no interest in the DAR chicks. Instead, DAR birds have been released in the company of Sandhill cranes. This can result in cross-species imprinting as evidenced by the two adult DAR birds presently at
Horicon that are known to copulate with Sandhills and recently produced the first Whoophill hybrid in the EMP.

Further evidence of the risk of releasing immature birds is the plight of the 2013 DAR cohort when most failed to migrate appropriately and perished in the cold.


To date Operation Migration has invested more than ten million dollars to help establish the EMP and fulfill the mandate of the FWS. That is more than any other WCEP partner. These are privately sourced funds that are not transferable to other projects and do not impinge on the fundraising efforts of other partners. To complain about the cost of that gift is ungrateful. Not using it
to its fullest potential is short-sighted.

Does not appear to yield substantially better results

“Does not appear suggests speculation when, in fact, the numbers prove otherwise. Even in the black fly environment of Necedah, nine chicks have survived to fledge since 2006. All nine are the result of UL/UL pairs. After ten years of release, no DAR or even half-DAR pair has fledged a chick in the EMP with the exception of the recent Whoophill hybrid.

Using the WCEP database and other records, OM has employed PVA techniques to evaluate the birds released in the Wisconsin Rectangle since 2011. We looked at standard milestones such as first year survivorship (UL 75% vs. DAR 59%) and annual adult survival (UL 92% vs. DAR 84%). Not a marked difference until projected over 10 years when 35% of the UL birds will survive and 12% of the DAR
birds will still be around (see graph below).

Additionally, as of spring 2015, 67% of the surviving UL birds are members of a pair, while only 44% of surviving DAR cranes are paired.

Philopatry is a term used to describe an animal’s propensity to return to its natal area. Currently there are two DAR cranes using the Horicon Marsh where they were released and ten UL cranes using the White River Marsh area where the UL cranes are reintroduced.

WCEP must take into consideration the real data and science to ensure it is using the best possible method. The Vision Document posted by Region 3 of the FWS is not such an evaluation. It only uses a portion of the available data (2001- 2010) and proposes drastic changes and untested methods based on what appears to be speculation.

FWS ultimately holds the keys to the kingdom of Whooping crane conservation: the Service controls both the allocation of captive eggs and the collection of wild eggs.

Recently the Recovery Team recommended that WCEP should be responsible for producing its own eggs. In other words, the Louisiana non-migratory reintroduction would receive all captive produced eggs and WCEP would collect abandoned and second eggs from all the wild nests. However, a large percentage of those eggs are produced at Necedah which is federal land.

Still, as they point out, the Necedah cranes could produce up to 37 eggs annually and still be able to reproduce if the blackfly issue can be resolved. A few of those eggs could be used to test the FWS-proposed ‘adoptive release’ idea, while the rest could be introduced into the Wisconsin Rectangle using the most appropriate method and allowing WCEP to finish what it started in that area
five years ago.

Figure 1: Survivorship to one year of age and annual adult survival thereafter for birds released via the UL program (blue bars with 95% CIs) and DAR program (orange bars with 95% CIs). Estimates were generated using a multi-state model with live and dead encounters. Note that breeding and non-breeding birds were combined for these analyses. Annual adult survival of UL birds from 2011 to 2015 is thus comparable to previously reported estimates for UL birds in the EMP (93% to 94% for unpaired adult birds; Servanty et al. 2014) and wild birds from Wood Buffalo National Park population (89% to 94%; Link et al. 2003), the latter of which has exhibited long-term growth of approximately 4% per year. Conversely, birds released into the EMP by the DAR project have exhibited 59% survivorship to one year of age (9% S.E.; n=23; Fig. 1) and 84% annual adult survival (5% S.E.; n=12; Fig. 1). Too little time has passed to qualify analyses or inferences on reproduction for either DAR or UL in the Wisconsin Rectangle. However, 28% of the cumulative UL and DAR cohort released in 2011 (18) were confirmed nesting as early as three years of age (3 nests) and 44% were found nesting the following year (5 nests).

Figure 1: Survivorship to one year of age and annual adult survival
thereafter for birds released via the UL program (blue bars with 95% CIs)
and DAR program (orange bars with 95% CIs). Estimates were generated
using a multi-state model with live and dead encounters. Note that
breeding and non-breeding birds were combined for these analyses.

Annual adult survival of UL birds from 2011 to 2015 is thus comparable to previously reported estimates for UL birds in the EMP (93% to 94% for unpaired adult birds; Servanty et al. 2014) and wild birds from Wood Buffalo National Park population (89% to 94%; Link et al. 2003), the latter of which has exhibited long-term growth of approximately 4% per year.

Conversely, birds released into the EMP by the DAR project have exhibited 59% survivorship to one year of age (9% S.E.; n=23; Fig. 1) and 84% annual adult survival (5% S.E.; n=12; Fig. 1). Too little time has passed to qualify analyses or inferences on reproduction for either DAR or UL in the Wisconsin Rectangle. However, 28% of the cumulative UL and DAR cohort released in 2011 (18) were
confirmed nesting as early as three years of age (3 nests) and 44% were found nesting the following year (5 nests).


Based on these data, the probability of birds released via the UL program surviving to the earliest confirmed breeding age (three years old) is 63%. In contrast, the probability of birds released via the DAR program surviving to earliest confirmed breeding age is 42%.

Why Would FWS Want to Kill the Goose that Lays Golden Eggs?

In the past 15 years Operation Migration has provided over $10 million in private funding to establish the EMP. We provided the manpower and the expertise and in doing so we developed the most effective method to date in terms of survivability, philopatry, pairing with conspecifics and reproduction.

The UL method more closely replicates the natural process by teaching cranes to migrate and protecting them until they would normally become independent from their parents. Along the way our method focused worldwide attention on Whooping crane conservation and helped to elevate awareness of the species and the wetlands they require.

FWS has authority over all endangered species so they effectively hold the purse strings, which may be their motivation for publishing their Vision Document. We are confident that the real numbers paint an accurate picture and time will tell the story.

We are fully aware of the challenges these cranes face, and we are ready, willing and quite able to continue working resolutely to help Whooping cranes thrive in Wisconsin.

Want to help? Please read the online petition and if you agree sign and share: 


Link, W.A., Royle, J.A., Hatfield, J.S. 2003. Demographic Analysis from
Summaries of an Age-Structured Population. Biometrics 59:  778-785.

Servanty, S., Converse, S.J., Bailey, L.L 2014. Demography of a reintroduced
population:  moving toward management models for an endangered species, the
Whooping Crane. Ecological Applications 24(5):  927-937.

U.S. Fish and Wildlife Service Statement on Vision for Eastern Migratory Population of Whooping Cranes

Questions and Answers
*OM Responses to Q&A document are below (italicized)

What is the Service recommending?

The Service is recommending implementation of rearing and release techniques of whooping cranes in the eastern United States that reduce artificiality and better mimic the natural conditions experienced by wild-hatched whooping cranes as closely as possible. This means moving away from methods that require greater exposure of cranes to humans and artificial conditions during rearing.

OM: The Ultralight method most closely replicates the natural process in that it does not release immature cranes before they would naturally separate from their parents. Other methods release them in the fall at a critical time when they must quickly learn to survive on their own and also learn to migrate before conditions rapidly change in Wisconsin and food becomes increasingly more difficult to find. This longer period of protection, until they have learned to migrate, accounts for a higher survival rate and better prepares the birds for life in the wild. It is known as a soft release and more closely replicates the natural process that wild hatched chick would experience with their parents.

Why is the Service recommending a shift to less artificiality?

The Service believes that the main obstacle to establishing a self-sustaining population of whooping cranes in the eastern U.S. is lack of reproductive success. There are many factors that may contribute to the lack of success, and it is believed that the high degree of artificiality and/or human interaction in some methods may be a primary cause. The Service sees a benefit in exploring other types of rearing and release methods that are less artificial and provide more natural conditions for the cranes.

OM: Reproduction has been low but the only birds in this population that have reached breeding age were released from 2001 to 2010 at the Necedah NWR. Those birds continue to use that area and continue to abandon their nests as a direct result of an abundance of parasitic black flies that are known to exist there. Post hatch and pre-fledge survival is also low at Necedah but it is interesting to note that all of the wild hatched chicks that have survived to fledge in that harsh environment are the result of Ultralight birds that have paired with other Ultralight birds to produce young. No other method has yet to result in a fledged chick or even provided one member of a successful pair. This demonstrates that even with that disadvantage, the Ultralight method performed better that other methods in terms or reproduction.

What evidence is there that reproductive success is low?

Since 2001, nearly 250 whooping cranes have been released into the Eastern Migratory Population. Of those, 93 survive today, including 27 reproductive pairs. This population has had 197 nests and hatched at least 63 colts, of which 10 survived to fledge.

Today, there are only four wild-fledged cranes; two have had successful nests, and the other two are less than a year old.

OM: This low reproduction rate at Necedah was the reason the Whooping Crane Recovery Team recommended in 2010 that no more releases should take place there until a solution could be found. In 2011, the Whooping Crane Eastern Partnership began releasing birds in the black fly free area known at the Wisconsin Rectangle, which includes White River Marsh and the Horicon Marsh. None of the data from the 5 years since the move to the Wisconsin Rectangle has been considered in the Service’s Vision Document.

Many of the birds released within the Wisconsin Rectangle since 2011 are now approaching maturity and may breed appropriately in this black fly free habitat. Ending the Ultralight method now when we are on the cusp of finding the answer negates all the work done by the partnership in the last five years and ignores those data.

What are some potential problems with artificial rearing and release methods?

We do not know how or when wild whooping cranes learn important behaviors or skills for migration and reproduction. Therefore it is difficult to know how to “teach” these behaviors and skills to whooping cranes in captivity. The rearing and release methods currently in use may have unforeseen negative impacts preventing whooping cranes in the Eastern Migratory Population from successfully reproducing in the wild. Similar concerns have been raised in response to poor reproduction in the non-migratory Florida flock of whooping cranes and with Mississippi sandhill cranes. To minimize the potential negative impacts, the Service feels it is prudent to minimize artificiality of the rearing methods. Unless we can ensure that released birds possess the learned behaviors to successfully reproduce, this population will never become self-sustaining.

“The rearing and release methods currently used in the Eastern Migratory Population may have unforeseen negative impact”.

OM: Thus far this has not been substantiated and is not based on any available data. The only data used to arrive at these assumptions refers to the birds released at Necedah and does not include the birds released in the Wisconsin Rectangle over the last five years. It is too early to determine reproduction success there because these birds have not yet reached breeding age… but they are close.

What are some of the methods that require a higher degree of exposure to humans and/or artificial conditions?

All rearing and release methods have some degree of artificiality; however, ultralight-led rearing and release and directed migration is more artificial than other release methods such as direct autumn releases and parent rearing.

OM: Again, the Ultralight method more closely replicates the natural experience by protecting the birds until they would naturally separate from their parents. The birds released using the Ultralight method are better prepared for life in the wild and that is evidenced by the higher survival rate.

Does this mean there will no longer be ultralight-led flights of whooping cranes in the eastern U.S.?

The Service believes that ultralight-led flights should be phased out, based on the best science available, and that priority should be placed on release methods (direct autumn release, parent rearing) that more closely mimic natural conditions. Other methods can accomplish the same results with less exposure to humans.

OM: “the best science available” This vision document does not provide credible research to support its conclusions. It uses terms like “may” or “the Service believes” or “the Service feels.”

A PVA or Population Viability Analysis is a scientific method used to determining the ability of a species to survive into the future. No PVA has been published that evaluates the cranes that have been released since 2011 into the Wisconsin Rectangle. Only data available up until 2010 was used to make these determinations and only refers to the birds released at Necedah. Fully one third of the history of this project is not being considered in the Vision Document.

Don’t these other methods also involve some artificiality?

All captive rearing and release methods involve some degree of artificiality, but methods such as direct autumn release and parent rearing are considerably less dependent on human interaction with the cranes than ultralight-led rearing and release methods. The Service recommends prioritizing allocation of eggs for use in methods with shorter periods of captivity and more limited exposure to costumed humans.

OM: The Parent Reared release method was approved by WCEP and the Recovery Team to test the impact costume rearing may have on future reproduction. That study is still in the testing stages. No Parent Reared cranes have yet reached breeding age and the sample sizes are still too small to determine survival rates. This study should continue until it can highlight any ill effects of costume rearing but has not yet reached the stage when conclusions can be made.

One could argue that the time spent in captivity and exposure to costumed humans is greater with the 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.

Using this past summer as an example, the UL birds exercised with the aircraft during 44 days over the summer and fledged at an average age of 94 days, similar to wild Whooping cranes.

This period of learning flight skills is important to their survival. Although we do not teach actual flying skills, we have observed inexperienced juvenile cranes making critical mistakes such as landing downwind or colliding with obstacles. 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.

Why is the Service making these recommendations now?

The Whooping Crane Eastern Partnership, of which the Service is a member, is preparing to develop its next 5-year strategic plan. The Service believes that the effort to introduce whooping cranes onto the landscape in the eastern United States has been highly successful and is attributable in large part to directed migration. This method has also been instrumental in garnering public attention and support for whooping crane recovery. Using good science and an adaptive approach to management, the Service believes it is time to look ahead and address those issues that are affecting the success of the eastern migratory population to become self-sustaining.

Additionally, beginning in 2016, there will be no allocation of eggs from the captive centers; all eggs for the Eastern Migratory Population will come from nests within Wisconsin.

When will the Whooping Crane Eastern Partnership consider the Service’s recommendations?

The partnership will meet in early 2016 and consider these recommendations along with others from the partners as they develop the next 5-year strategic plan.

What happens if the Whooping Crane Eastern Partnership does not agree with the Service’s recommendations?

The Service’s vision document is a framework for WCEP’s next 5-year strategic plan. It was released to afford all partners the opportunity to offer additional perspectives. It is anticipated that partners will discuss these recommendations, along with others, during development of the strategic plan.

As with all efforts that rely on adaptive management as a project progresses, strategies may be added, deleted or modified as the partnership deems most beneficial to the program. All WCEP partners provide valuable contributions to the effort and will continue to fill important roles within this reintroduction project. Roles of partners may change as we explore alternatives and options.

OM: The face-to-face WCEP meeting scheduled for January is the correct venue to address these and other recommendations. Unfortunately the Service Vision Document was publicly posted even before it was distributed to WCEP. No consideration was given to the effect that would have on the non-profit partners particularly Operation Migration and its funding base. That premature posting has forced Operation Migration to address our concerns in a public forum.