Mostly Yellow-rumped Warblers and the first Wilson's Warbler for the year. When the tank first fills up the water is rather muddy, but once it settles down it looks better.
I'm sure this is the first time it has been full in April, although some years ago it filled in January, so that April it must have looked similar to this. The oasis is quite birdy. Since no where else around has much water, it really is an oasis. A visitor today said seeing the Lucifer Hummingbirds and their courtship displays, etc. was worth the whole trip (from Houston). She saw a female gathering nesting material from the cotton basket I have hanging for them. So breeding is in full swing. Well, maybe another wave of migrant Lucifers will arrive in May. Kelly Bryan has suspected as much but it's not provable at this time.