According to the origami node, the pajarita (little female bird) was invented in Spain. I always thought that it wasn't so. There goes my credibility. Anyway, it is really simple to fold one.
Let's make one!
Start out by folding an 'X' in a square piece of paper:
+----+
|\ /|
| \/ |
| /\ |
|/ \|
+----+
Hold the paper so the folds look like depressions to you. Then take a corner of the paper and fold it the opposite way till it touchs the center of the paper:
/--+
/ /|
/ \/ |
| /\ | (the X looks depressed still...)
|/ \|
+----+
Unfold this and now fold each of the edges of the paper 'till they touch the center of the paper, a fold in the same direction as the X. You shouldn't leave the folds made, unfold after each side so you see a little square centered on the paper.
Ok, now my ascii art is not enough to show what you should have. You should have the paper unfolded, with the X, the corner fold and the square. If 'A' is the corner with the corner fold, 'D' the opposite corner and 'B' and 'C' the other two, hold the paper, picking the 'B' and 'C' corners between your index and thumb, one corner in each hand, with the 'X' looking like an elevation now. You should be able to be able to bend slightly the part of the 'X' touching your fingers. Well, press a little on the center of the paper while joining your hands together and, with a little practise, you should have your pajarita:
/----- the head
/\
/-----/ ----- the tail
||-/
\| ----------- feet
\
(ermm... this last step requires some practise, and the best way to explain it is to see it... I'm afraid those instructions might not be enough to make a good pajarita, but I'll do my best to clarify anything... as always, msg yer favourite marsupial for anything...)