What a nice memory you have visiting the island with your Dad. The event is all very romantic but care wise the practicalities need to be addressed and it seems to be handled on Chincoteague better than most. I did not know about the Assateague side of things .. sad; I think the Sable Island horses are similar. No human contact whatsoever so nature does the culling.. a hard life for them. I wonder how and why the little pony found its way to Skydog in Oregon.. she doesn’t say in the note with the video. But, since Skydog is mainly a Mustang Sanctuary, with donkeys and the occasional Zebra, the Chinciteague pony will eventually be released to run with Mustangs. Fingers crossed it goes well but it has a good chance.. anyway..The Chincoteague ponies are cared for far better than the wild mustangs, which I don't think receive much in the way of care. Actually there are two different herds, one on the Maryland side, which are also called Assateague horses, and one on the Virginia side, called Chincoteague ponies. The one on the Maryland side receives no care. I do not know how they keep the island from being overrun, unfortunately some probably die of illness due to lack of vet care, some drown in storms, some wander into the road and get killed (the Chincoteague ponies are fenced off from the road). I was reading that awhile back - the 90s? a bunch of previously purchased Chincoteague ponies were brought back and set loose on Assateague because the numbers had gotten so low over there.
The ponies on the Chincoteague side are rounded up twice a year for veterinary care and are monitored over the year to identify and treat any minor injuries. I remember at the auction a lady let me go up with her and look at a pony she was interested in buying and the pony allowed it's feet to be picked up and be examined. The proceeds go to the Fire Department because they are the ones who take care of the ponies. Also, some of them are "buybacks" - people buy them and send them back to the island to live for life. Which doesn't accomplish thinning of the herd, so I'm not sure what purpose that serves.
Anyway, that's what I know about it in a nutshell. The ponies have to go somewhere, they need to keep the size of the herd stable. Money is needed for their vet care and supplemental feeding in the winter. I'm not sure what else could be done with them other than auctioning them off.