The other day I found a large (American robin size) dead bird in my skimmer basket. There were no visible signs of trauma. I've only had a pool for 7 years, but I've never seen a dead bird in the pool before. It's unlikely to have happened during the day as I would have seen it. I look out the kitchen window at the pool several times a day as I'm grabbing food or gettling a glass of water. Has anyone else seen this? I'm wondering what might cause it.