I am "cow-sitting" 5 calves, 4 cows and 1 bull in addition to my own steer and heifer. The cow pasture (about 30 acres) has no water, so I have two 100gal water troughs at their gate and a bazillion linked hoses running down the length of the smaller pasture to fill them. I generally fill them 1-2x per day depending on how hot it is.
Yesterday about mid-day both were about half-full and I found 2 dead birds in one. Dumped, cleaned and filled that one, topped off the other. Went out this morning and one tank was empty except for a tiny amount and the other was 1/3 full and had FIVE dead birds in it!
I have various water troughs for our goats, pigs, chickens, turkeys and in the isolation cow pen, I've never had a dead bird before. A dead mouse once and handfuls of grasshoppers but that's it. This is really ridiculous..... why on earth is the entire bird population committing suicide in my troughs!? They're clean... well at least they start out clean each morning but these are cow tanks, so somewhat gross after the first one dunks it's head in.