UPDATE: The hummingbird nest filmed for this post fell out of the tree in a wind storm on July 2. I will post more at a later date, but here's the short story: we rescued the immature female who had fallen out of the nest, tucked her back in (the nest was still adhered to the branch), and mounted the branch on a tripod. The young hummingbird was re-found by the mother and successfully fledged later in the week. I got some GREAT footage of some of this activity, and hope to get it online as soon as possible.
This year in the London Planetree next to our house we have
THREE (updated!) FOUR active nests all at the same time:
One huge tree -
three FOUR active nests. Pretty cool. I have captured pictures and video of some of these birds, and will post them as I have time.
First up is this short video of a female hummingbird nest building. Ruby-throats will use lichen, downy plant material, spiderwebs, and the outer casing of buds to construct their tiny nests which are reminiscent of Blue-gray Gnatcatcher nests. I believe the female is on her own for the whole job - she builds the nest, incubates the eggs, and feeds the young without help. When you consider the crazy ratio of energy to body mass these little birds require to live (Basal metabolic rate, or "BMR") even without raising the young, its hard to believe the male does not help out.
Hummingbirds are incredibly light, but for every gram of weight they need an insane amount of calories just to get through the day. Their diet is flower nectar with some insects mixed in (for protein). But its mostly nectar - and they actually can consume several times their body weight in nectar PER DAY. How do they make it through the night? Good question - they actually go into a "hibernation" like state at night called "torpor."