(Reposting: Originally published: January 9, 2013)
Over the years, many people have asked us if we have considered teaching the birds to avoid predators and it’s a question we have discussed many times ourselves.
One of the problems is which predator to simulate. In most cases it is hard to determine exactly what killed a bird. The leg mounted transmitter will lead the Tracking Team to the scene of the mortality, but often there isn’t much left. Whatever killed the bird could have consumed it, or scavengers may have found it dead. If there is enough left to be necropsied, medical tests can provide some evidence, but there is not much to be learned if all that is left are feathers and bones.
Bobcats are known predators, as are coyotes and feral dogs. Power line impact is listed as the primary cause of death, but unless the bird is found near wires and reasonably intact, it is hard to know if that was the cause. It could be that the impact injured or stunned the bird and left it vulnerable to predation. Aside from marking all the power lines that dissect wetland habitat and the surrounding fields, there is very little we can do about birds flying into wires they can’t see.
Still we could do some general predator avoidance conditioning. The problem is how?
Teaching animals to avoid certain things is not easy. As an example, the best dog to have if you live near a highway is one that has suffered a near miss with traffic. That lesson will never be forgotten. I have a friend whose golden retriever will run along the ditch for a quarter mile to use a culvert to cross the road, but it took a broken leg to learn that behavior. That’s not a risk we want to take with a predator encounter, either staged or real.
That is not to say that it cannot be taught. There are experts who can teach amazing things to animals and maybe they can offer advice, however there are some complications in our case.
In the wild, a chick would learn avoidance behavior from the parents. Adult Whooping cranes have a range of calls that indicate concern, alarm and fear in escalating volumes. Those calls could be recorded and used judiciously, but we are not sure of the exact message we would be conveying, or what actions need to accompany them. We could be crying wolf and teaching complacency rather than evasion. In the presence of real danger, the adults would take flight and lead the chicks away. Using an aircraft to stage an escape is more complex than simply flying to a safe distance.
When birds from previous generations return to the summering grounds they will occasionally take up residence near our training areas. They can be aggressive in their territorial claims and cause problems with the chicks in training, so we attempt to act like wild parents and chase them off.
Their reaction to our antagonism is surprisingly minimal. Rather than fly away in alarm, they will retreat just far enough. No amount of running or arm waving will scare them off. Many times we have exhausted ourselves running the full length of the runway with the birds trotting ahead just and out of reach. I have personally been lured out into the marsh in pursuit of adult birds only to have to have them fly back to the runway and mock my gullibility with a unison call to mark their victory.
Maybe the fact that we are dressed in a familiar costume is the reason they don’t react as we expect, but it adds to the worry of staging a simulated predator situation. What if we brought in a well trained dog to chase the birds and they didn’t run? What if they simply stood their ground and we ended up trying to explain to the owner why his dog was suddenly afraid to come out of his travel crate?
The lesson we would then be teaching is that taking a stand is better than running away. Taking the first option in the “fight or flight” scenario might lead to problems if a real predator didn’t cease the attack when its trainer called him off.
Predator avoidance conditioning is not simple, and it is made more complex with a creature that we are trying to keep wild. We are open to ideas but it will require serious preparation with lots of options for plan B. So far, teaching them to migrate has proven simpler than teaching them to be wary of furry things with teeth.