Only the birds with the black beaks. I'm not sure the one with the orange beak is a swan goose, but I couldn't snap a photo without it. After I caught sight them on land (none of the shots came out, unfortunately), it looks like a male and two females, judging by their respective sizes.
Not native to Houston. These likely ended up here because swan geese have been domesticated in the United States. Swan geese originally come from Asia, especially China and Mongolia.
Like pretty much every goose I've encountered, these are EXTREMELY aggressive. Best to just stay out of their way and feed the more docile ducks, especially if you've got small children.
Lat: 29.72, Long: -95.39
Spotted on Nov 3, 2012
Submitted on Nov 18, 2012