Preparing for Migration

By Joe Duff

When you set out to make a list of all the things that must be done before the migration can begin, you first have to decide where to start. I have a bad habit of beginning every story with too much background information. One word answers are not my forte.

Only a very few have had the honor and privilege of leading a migration of endangered birds halfway across the country and we owe that front seat vantage point to a hundred others who have worked very hard to make it possible. Before you talk about migration preparation it seems only fair to credit all those who made it happen, yet are not able to come along.

There are nine founding agencies in the Whooping Crane Eastern Partnership and sixty-two people attended the fall meetings in Necedah in mid-September. Each of them plays a vital role and without their participation there wouldn’t be one whooping crane in the eastern flyway let alone 78.

It starts every year at the Patuxent Wildlife Research Center where the crane ecology team and OM conduct the imprinting and early conditioning. The WCEP health team (at this time of year from ICF) help with the arrival of the birds at the Necedah National Wildlife Refuge and again for the pre-migration health check in September.

We have 21 birds this year with an age range of 32 days from the youngest to the oldest; meaning that some learn to fly a month ahead of others. Because of that difference the younger birds are still running up and down the runway while the oldest are off flying with the aircraft.

To deal with that discrepancy we divide them into cohorts and house them at three separate facilities in closed areas of the refuge. These separate groups can have up to 9 birds in them but because they are all roughly the same age and therefore size, they are evenly matched and can form a dominance structure that is fairly balanced.Once they have all fledged and reach their sub-adult size it’s time to put them together into one flock.

Whooping cranes are not colonial like Sandhill cranes. They don’t gather in large flocks so building a social order that includes 21 normally independent individuals of varying ability and confining them in a portable pen for a 3 month migration takes patience and practise.

If we mixed the oldest birds first, the youngest cohort wouldn’t have a chance when their turn came. They would be smaller, less experienced and out numbered. And even if they survived the aggression that reinforces their social order, they would likely never fit in. So we mix the youngest birds with the middle group and let them work out a hierarchy. Once that is established we bring in the older birds. They are bigger and more experienced but they don’t have the home field advantage and they are out-numbered. That seems to balance the inevitable battles for top bird and although we have to intervene occasionally to stop the most aggressive donnybrooks they each eventually settle on a position in the pecking order with which they are all happy.

Based on the mixing of the flock and their endurance we set a target date for the migration to begin and this year it’s October 10th. At that point the team of staff and volunteers has assembled; the vehicles are serviced, packed and ready and all of the equipment has been repaired and tested.

What started in May with the first hatch all comes together on day one. A thousand little jobs and a hundred different people all prepared for this event. The actual departure is weather dependant so with luck we can be on our way. If not we get to practise the patience that got us this far.

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Last updated: October 6, 2009