Before I started working with birds some twenty odd years ago, I spent much of my life as a commercial photographer with studios in downtown Toronto. That was back in the days of film and retouchers and before images could be manipulated with simple keystrokes. Back then, you took the picture after all the manual adjustments and then waited a day with fingers crossed until you could see the results. Now we get to select the keepers before we even put the camera down. The point is, our modern world of instant results does not apply to Whooping crane conservation.
The milestones of a wildlife reintroduction like this one are measured in days, months, years and even decades. Thirty days of incubation are needed before vulnerable eggs can hatch and it takes three months before the chicks fledge and can safely fly away from danger. A population viability analysis uses data; such as how many individuals survive their first year of freedom when they have presumably learned the ways of the wild. Data collected thereafter include annual survival rates until they reach breeding age, which for Whooping cranes is generally around five years.
Since the beginning, our primary target has been survival to breeding age, which is a lot like waiting five years to see how your pictures turned out. Reaching the goal of a self-sustaining population for such a long-lived and slow-to-reproduce species can take 30 years if it all goes according to plan. It is no job for the impatient.
The other problem we have in trying to predict the outcome is sample size. Just as you can’t ask one person about their political opinions and consider it a representative poll, you can’t observe the behavior of a few birds and expect them all to behave in the same manner.
Our ambition now is to improve the breeding capabilities of these birds and we are hoping that can be accomplished with parent-rearing. Maybe there is some maternal lesson learned during the early stages that will help them be better parents when it’s their turn to protect offspring. But releasing parent-reared juveniles is a learning curve for us too. The Rearing and Release Team within WCEP is made up of impressive experts in avian ecology. It is co-chaired by Kim Boardman of ICF who also leads the Whooping Crane Species Survival Plan (SSP) group and Scott Tidmus who just celebrated 20 years as Zoological Manager at Disney’s Animal Kingdom. There are staff from other partners with expertise from captive breeding of Whooping cranes to tracking their movements after they are released.
With small sample sizes and a few years to wait for results, much of what we are doing now is the best guess of our collective knowledge. Last year was the first full-sized parent-reared release with more than just a few birds. After much discussion, it was agreed that the best place to promote an association between the chicks and the adults that we hoped would lead them south was in the open fields where the adults forage. We were worried that if we hard released the chicks, they might just fly away and the chance of making an introduction would be lost. You have to remember that parent-reared chicks are not familiar with people. You can’t just put on a costume and walk out there to lead them back and try again. So we tried putting the chicks in temporary pens before the adults got there, hoping they would interact even if it was through the wire mesh.
Except for a few cases. It didn’t work as planned, so the chicks were let out. They would spend a good part of the day in the company of the adults but when it was time to head off to proper roosting sites, the chicks didn’t follow. In fact, we lost one on its first night of freedom as it stood alone on dry land. In total, three were lost before they migrated, mind you; one was sick and compromised before it was predated. Still that attack took place in a field, not a marsh.
This year we decided to hard release the chicks where the adults spend the night. That would afford the same opportunity to interact but if that all-important connection didn’t happen right away, at least the chicks were in good roosting habitat; which is a much safer place to spend their first night of freedom. It may have been better for the birds but access to the wetlands is not always easy for the team – especially when you are carrying a crate full of delicate cargo. Most of the wetlands in central Wisconsin are surrounded by a wall of cattails. Access to the inner marsh that the cranes prefer is not easy.
Not all of the eleven PR birds have completed a southward migration this year, but so far, we have only lost one chick and that is being attributed to a power line collision, which is unrelated to the foraging/ roosting site release strategy. In another comparison, in 2016 only one chick, number 30-16, was adopted by adults. This year, two chicks followed adults south on migration and they are still together.
That’s a solid improvement but we still have to wait five years to see how this picture turns out.