It's May and the saguaro cacti are in full bloom.
Although the flowers are open at night, they remain open long enough in the morning for bees and birds to gather their nectar and pollen.
Both honey bees and carpenter bees are visiting these flowers.
The birds that pollinate the saguaros are white-winged doves. They show up as the cacti begin to flower and stay through the summer fruiting season.
Why didn't I get any closer photographs?
That might have been a bit difficult, as saguaros can be roughly 50 feet tall when mature. The flowers form at the top.
Have you ever seen a saguaro cactus in bloom?