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) in favor of the Direct Autumn Release (DAR) and 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 publically 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 blackflies 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 blackfly 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 black fly 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).
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.