ugh..sounds yucky Pam.
I live in a residential neighbourhood that is 29 years old. backyards meet backyards etc. and the lots are around 50 x 120..in may when i opened the pool i looked out one morning and a large black bird (probably a grackel i think) was floating around, quite dead. i have no idea how or why it ended up dead in the pool..i forgot about it until the next morning and when i looked there was no bird floating nor had it sunk..hmmm..i went downstairs to the sliding doors that are near the shallow end of the pool and the stairs. on the mat right outside the door was a part of a wing and a few 'leftovers' of the bird! ugh ugh ugh..my question is - what animal got that bird out of the pool and then ate it at my backdoor..?? i have racoons come into my yard and there have been foxes and coyote and even the odd bobcat in the neighbourhood as there is a ravine on both sides and creeks. the area north of us used to be open fields and is now housing so the animals are losing their homes and hunting grounds and making their way thru the ravines..But whatever animal it was had to fish that bird out of the pool..and if i recall it was not up to the level as i hadn't started the pump etc..so the water was a good 16 inches below the deck level..odd odd odd..and my yard is fenced..altho the neighbour has his deck under construction and one side of the area is open to my yard..
those animal parts you found are beyond creepy..can you call the fisheries/gaming people or some animal group to find out what's going on? i almost lost my brekkie reading about it..