5th October 2018 Daniel Roca

Avoidable impact

Earlier this year –it was late winter–, I happened to be birding in a pre-Pyrenean valley. Hawfinches, Redwings… It was very birdy indeed. I saw a newly built Padel court in the outskirts of a small town. Padel is a racquet sport similar to tennis that is trending in the country and rapidly expanding town to town. Anyway, I approached the court, oblivious of what I was about to find.

It was built in a natural area, an open field near a stream, and the surroundings were composed by olive groves, riverside woodland, orchards and some oaks. And this is what I saw:

Glass collision blue tits
First, a pair of Blue Tits. I kept walking along the glass walls.

Then I found this Blackbird. A few meters more, and a Robin. Around the corner, a Cirl Bunting…

Glass collision hawfinch
And then, a hawfinch. I was shocked.

In all, I found six birds, all dead on that same morning. How terrible. Glass collision has been a serious threat to birds for a long time. Windows and glass buildings come to mind, but also noise cancellation barriers on road sides are known to cause high mortality.

But this was new. And in this case, clearly avoidable. A glass cube in the middle of a natural area, with nothing around it and clear blue skies on the other side.

According to Sibley (www.sibleyguides.com/conservation/causes-of-bird-mortality/), glass collision is the first human-related cause of mortality among birds. The chart on the link refers to direct death causes, and does not include other factors like habitat loss. Glass collision stands out above other threats like feral cats or electric wires.

I called the rangers and explained the situation. Something had to be done. They took note of the problem but no immediate solution was possible. So I left.

Later in the day, just after lunch, I went back and checked the court again. To my surprise, no dead birds. Even the birds that I had found earlier were gone. But where?

Glass collision birds, cat
Well, you can imagine. A deadly trap that kills birds regularly is a safe and easy source of food for predators and scavengers, particularly in a place like this. There was a feral cat around, looking very suspicious. I guessed that the birds that were not taken during the day by cats or crows, were taken during the night by beech martens or foxes.

Birds are most active early in the morning. Midday hours are more quiet. Then it turns a bit busy again in the afternoon or the evening. With this in mind, every time I was in the area I checked the Padel court. Indeed, I kept finding dead birds, especially if I checked a bit before noon. Right after the peak of bird activity had taken place.

Sadly, a bird crashing into a thick glass at a high speed leaves a mark.

For the next months, nothing happened, although I was told that the town mayor was aware of the problem and a solution was coming. And finally something was done.

Glass collision birds, padel court
Big raptor-shaped stickers were attached to the upper-parts of every glass panel.

Glass collision birds, raptor shaped sticker
It has been proved that bird-of-prey stickers reduce mortality, but they don’t provide a 100% safety. Some birds get used to the shapes, others are not as affected by the sight of a raptor. In a place like this, a vegetation hedge growing very close to the court and around it could be a good solution for the lower parts. And then of course, the glass should be much more visible. The entire surface should be covered with a very distinct pattern. It may even be good for the Padel players, who sometimes crash themselves into the invisible wall!

Anyway, the problem seems to have improved, but the impact on birds remains. And it’s not only because of the glass walls. I have found since then some House Sparrows trapped in the nets.

Birds trapped on a net
Humans cause countless environmental issues to nature and hazards to wildlife. Some of them are not easily fixed. But others… others are just plain unforgivable.


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