About this time of year I start to receive phone calls of birds attacking windows. This is different than birds flying into windows. We see that all winter long. Birds are startled and don´t realize that the reflection of the outdoors in the window is not really a continuation of outdoors. They fly right into it. Sometimes they fly right away, sometimes they fall to the ground stunned and sometime they break their necks and never fly again. This is a big problem by the way. It´s estimated that 200 million birds die from window collisions in the USA and Canada annually. That´s a lot of birds but a drop in the bucket compared to the 2.6 billion that cats kill annually.
But the birds I receive calls about now just keep flying at the window. Or sometimes it may be a mirror on a vehicle parked at their house. I even had a new BBQ grill one time that a meadowlark just couldn´t stay away from. These crazy birds will obsessively fly at the window, flutter at it, peck at it and often leave a whole lot of what we birders call “whitewash” all over the window or the side of the house. It´s annoying, it´s messy and it can be down right unnerving!
Quite frankly what we have here are raging hormones. To be specific, most often it is male birds. They don´t realize that the other bird is their reflection. They view it as a rival male and he is invading MY territory. First thing in the morning he remembers that bird so goes to see if he is still there. Well yes he is so I must chase him away. And so it goes on and off all day long, for days on end sometimes for weeks on end.
The most common species that does this is Northern Cardinals but I”ve seen robins, wrens and meadowlarks do it too. I honestly think that male cardinals may be the most testosterone crazed birds out there! It starts happening this time of year because rapidly lengthening minutes of daylight trigger hormones in most bird species, which prepares the females for egg laying and the males for finding mates. I think it happens regularly with cardinals because they tend to nest in shrubs very close to houses so they are more likely to first encounter their image in the window reflection and once they do, it is all over.
First of all, no, they do not learn that it isn´t another bird so don´t even hope for that to occur. Secondly, cutouts of hawk silhouettes that you put on the inside of the windows won´t do any good. The reflection is seen in the outer portions of the window pane. The only way to stop the bird is to cover up the window with just about anything. I´ve seen newspapers, cardboard, and thin plywood used. You may be able to put up some screening or netting and block enough of the reflection so the bird wouldn´t be seeing himself. If you are going to do this, the sooner you start the less time the bird will have to get this habit ingrained. I will say that for two or three years we had cardinals nesting in the holly bush outside our kitchen window. The outside of those windows had screens on them and we never had problems with the cardinals attacking the windows.
The next question homeowners have is how long will this behavior last. Unfortunately, cardinals can have multiple broods through the summer and it could last well into August in many years. Once they get started they are liable to be at it all summer long. The activity may dwindle some when the parents are busy feeding the young but it´s liable to pick right back up when they start the second brood. Yes it is annoying. No you can´t shoot them as cardinals, like most all songbirds, are protected by federal law. The birds will stop eventually, but until then….
CHUCK OTTE is the agricultural and natural resources agent with the Geary County Extension Office.