Keeping Track (of Whooping cranes)

With a hundred or so birds now using the eastern flyway, it’s difficult keeping tabs on them all. It is expensive to have people follow them north and south and listen for beeps from the leg mounted transmitters when the range of those devices is only a few miles.

The WCEP Monitoring and Management team is responsible for monitoring the birds and has been relying more heavily on satellite tracking devices or platform terminal transmitters (PTT). The problem, of course, is the cost of those units. They have to be small, light-weight and powerful enough to send a signal all the way to a satellite a few hundred miles above the earth. That means the initial unit cost is around $3000 each and the fee for acquiring the data is about $1000 per year. With a service life of 2 to 3 years that gets expensive fast.

There are new units available now that use cellular technology and with the proliferation of towers and the expanded service, these units are becoming more reliable, although, based on the service we get here at White River, that is hard to believe. Using that technology to track wildlife is relatively new so the unit cost is still high, but the annual service fee is only around $400. Adding solar cells to augment their battery life means they also last longer.

Ten of these cellular transmitters (CTT’s) were donated to WCEP, but they are fitted to the birds using backpacks. A signal Teflon ribbon wraps around the wings, holding the unit centered on their backs where they are exposed to the sun and can get a better signal than if they were leg mounted and spent most of their time submerged in water. Using one ribbon means that if one side (of the harness) is damaged, the entire unit falls off instead of dangling from the other wing.

Backpacks have been used on many avian species including a recent study of snowy owls. At ICF they have been tested on released Sandhill cranes and captive Whooping cranes with no adverse effects. Operation Migration has agreed to test three of these units on our birds this year. We will be able to evaluate their affects on endurance, social disruption and discomfort. We will be able to get images of them in flight and compare the birds with and without that extra baggage. They, and the other 4 birds will wear leg mounted VHF transmitters as usual.

Anne Lacy and Eva Szyszkoski from ICF are experienced bird-banders and will attach the units. Davin Lopez from the Wisconsin DNR will assist. Naturally the birds will not like being handled or having something strapped to their backs so it will take some time for them to forgive us and to get accustomed to flying again. That’s unfortunate because they have been following so well lately. It may even affect the first leg or two of the migration but it’s not as if our departure ever goes smoothly anyway. We have dealt with errant birds and delays before, yet we always manage to get the job done. And if we find that it is too invasive, we will simply cut the transmitters off.

There are negatives to attaching anything to a free flying bird, but the risk of injury is low, we have dealt with uncooperative birds before and there is a lot to be learned. And who knows, we might even find out that backpacks are not an issue and can increase the transmitter life and provide more detailed location data. Or we may find that they encumber the birds and reduce their endurance and should not be used. In the end, if we don’t try, we won’t learn anything.


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  1. Ruth Mitchell September 17, 2014 9:50 am

    Shepherd is right, Decorah uses transmitters ( back pack type) on their bald eagles, they transmitted two this year but one was, unfortunately electrocuted before he was able to disperse. WE all love following D1 the first Bald Eagle with a transmitter as she makes her annual migration to Polar Bear Park and then surprisingly ( Just like our WB’s!!!) comes back with half a mile of the natal nest!!!!!

  2. Christy September 16, 2014 9:05 am

    Didn’t we try this last year?

  3. Shepherd September 16, 2014 7:15 am

    WCV – Wildlife Center of Va – put a solar powered transmitter on a bald eagle – NX (who I call Nixy) – and tracked her travels. She was 1 of the 3 young they raised when NBG female was killed by a plane. The humor is – a couple times they tracked her in Alaska or somewhere, do not know what the glitch was. I think Decorah eagle did this this year. (RRP)