I have a whole new definition for streaming TV. A couple years ago, I installed a tiny color camera complete with audio inside one of my purple martin houses. This allows me to observe and study the nesting behavior of our largest swallow species. The camera also has infrared-emitting diodes that enable me to watch the birds even at night. And the best part is the birds don’t even know it.
I wired up the TV in my office to stream the live video of the interior of the nesting guard where the martins are nesting. And there you have it: better than watching Animal Planet or even the BBC because what I am watching is live, unedited and real life.
Observing bird behavior is one of the best ways to study and learn more about a species. The only trick is you must leave your human emotions behind and observe with an open and objective mind. You can’t just look at some behavior and interpret it according to what you would do or try to apply human logic to it. No, you need to approach it with more of a scientific mind or attitude. Only then will the doors of understanding open.
Purple martins (Progne subis) is the largest species of swallow in North America. They occur throughout the eastern half of America and have a few isolated populations in parts of Arizona, Oregon and Washington. They are highly migratory; all martins in the U.S. migrate all the way to Brazil for the winter. Even to this day, we still don’t know exactly where in Brazil they spend the winter.
But one of the unique behaviors of this bird is that nearly all purple martins nest exclusively in human-made nest cavities. Historically, these insect-eating swallows nested in natural cavities in trees. Early on it was reported Native Americans put up hollowed out gourds atop poles. Most agree this wasn’t when the birds switched over from natural to human-made nest cavities. But there are many reports coming from the late 1700s and early 1800s that early settlers had put up martin house in both rural farms and cities along the east coast.
At some point it became very fashionable to construct and install martin houses. There were huge advertisement campaigns extolling the virtues of having martins around your home. These ads said martins would eat thousands of mosquitoes each day. Who wouldn’t like to have a mosquito-eating machine flying around their home? (By the way, it turns out that only 10% of their diet consists of mosquitoes.)
By the mid-1800s, people put up thousands of martin houses. Companies started to manufacture martin houses. Attracting and watching martins became a national obsession. It was so successful that all these new homes changed the behavior of the entire species. By the mid-1900s, it was estimated that the entire purple martin population in the eastern half of the country, which for thousands of years had nested in natural tree cavities, switched.
I am sure many of the readers of this column can remember parents or grandparents who had martin houses and can attest to how common it was. Then something happened. I am not sure if it was World War II or the economy or just what changed, but the fashion winds started to blow from a different direction, and putting up martin houses suddenly stopped.
Neglected martin houses were taken over by house sparrows, which at the time were expanding their range across America. Wooden martin houses started to rot and fall apart, and people lost interest in the natural insect controller. The overall population of martins dropped dramatically due to a national housing shortage.
Fast forward to present day, and not much has changed. Martin numbers are still low, and they are still nesting in man-made nesting cavities. By studying these birds and their behaviors, we gain valuable knowledge that will hopefully help us keep this species healthy and strong.
Until next time…