Bird Names

[OlderButNotWiser]

I have one answer left in local quiz to do with birds, all the other answers have been names of birds, but this one is eluding me, maybe its a birding term or something to do with bird watching!!

The letters given are S I T you then have to add another letter and from those four letters re-arrange for the answer.

Yes I know the obvious answer, but without too long an explanation I really need it to be either an H or F as they form part of another answer in the quiz.
If anybody has understood all this maybe you could help!!!

[mallyh]

otis

[Prudie]

Definitely not 5 letters - swift?

[dannyk13]

Otis looks good. The Bustard genus.

[aelmpvw]

not going to be an anagram of sit with h or f is it?

[Tilly2]

Not unless it's excrement, ael.

[mallyh]

whats the other answer?

[OlderButNotWiser]

I am liking the answer SWIFT, as with other local quizzes I have done, there is sometimes a typing error, as all the other answers are very well known names, I think I might go with that as it does give me the letter F that I needed.
Thanks for your help.