Birds tend to grab the animals and leave, if the prey is too big to fly off with they will rip off some meat and eat it then leave, probably not a bird. If the scratch is on one wide and there is no damage on the other it must have been claws not teeth so a cat is most likely the culprit, also since they weren't all eaten or taken a domestic animal is likely. i.e. some jerk thinks its alright to let out his cat. sorry for your loss.

Feeder goldfish are not kept to any decent standard so it is not uncommon to loose some. One batch of 16 I got once I lost 1 the first night and 1-2 over the next month. I still have the rest of them. The fish in there are probably just pretty scared as you think. It is a new place for them and they don't know what the threats are. I give mine some hiding places under some big slate slabs I have. Once the water lettuce gets into gear and covers most of the surface the fish are happiest. They tend to stay under cover but will come out for food as "safety" is just a swish of the tail away. Do keep an eye on the water quality (ammonia, nitrite) as you still need to grow the bacteria that handles the fish waste. Water changes are the best way to handle that, as are squeezings from the filters of healthy established ponds or aquariums. That gets seed bacteria into your pond.

Glad to hear the bird was ok. There is a good bit of information on how to help an injured bird on the Bird Watching forum, it is at the top of the forum.

Hi Lisa, I really know nothing about bird illness. The only thing I could think of was the relatively sudden change of air temperature (it's been the same here in Massachusetts - unseasonably COLD - but I bet it's even colder where you are). I did read that sudden changes in air temperature can affect birds' energy levels (a study done in Scotland). But I don't know whether the way your bird looks could be explained by something like that. Our birds here are still pretty lively and doing the usual things. Is the bird eating or drinking? Is it losing feathers? I wish that I could be more helpful. Would the Cornell Lab of Ornithology site have information? They seem to be a good place to refer to. Best of luck, I know you care so much about the birds.