Savannah sparrow

Hi there. Quick question about savannah sparrow's. I went on a guided tour of Anahuac National Wildlife Refuge in April during spring migration, & the guide found a few of these birds there. I have looked them up in my Birds of Texas book (published in 2002) & this species is not listed. I thought maybe because it was not usually in this area & was just passing through/migrating.... But I found it online & apparently it's very common in the area. So I'm wondering is this a newly recognized species split from another species? Or do you think my book just accidentally omitted it?
Very strange!
Heidi

An omission in your book - it is a common and widespread winter visitor in Texas; no recent splits affecting it.

Maybe, does your book have separate sections for breeding and non-breeding species in Texas? If yes, look in the non-breeding section. Or maybe just an omission from the index? Check to see if its scientific name Passerculus sandwichensis is also indexed or not.

Resin

I checked the index & it's not there so they must have just accidentally left it out. I need a new book anyway! Thanks