Last spring I was amazed at how many birds fed at saguaros as they bloomed and fruited, such as this white-winged dove sticking its face into fruit at the end of an arm along the Latigo Trail. It’s a good thing saguaros aren’t carnivorous or a lot of birds would lose their heads!
Cactus wrens are smaller than the doves but still large for wrens, this one stuck its head deep into a blossom on the saguaro where it was building its nest and raising its young. When it emerges its head will be covered in pollen, some of which will be deposited at the next blossom it visits.
The tiny verdin had to stick most of its body into the fruit to feed at the back, in this picture it is feeding closer to the front and only its head is hidden. When the fruit ripens it is the white-winged doves that eat the most, but other birds enjoy the short-lived bounty as well.
Boolie 
Nature at its best.