I have seen- and you probably have, also- the photos of someone holding a quarter up to a hummingbird nest just to show you how small a hummingbird nest is. I know that makes the nests look small, but is hard to visualize a real nest without seeing the real thing right infront of you. However, it just so happens that I found a hummingbird nest and was able to see just how small they really are. For illustrative purposes, I will be the stereotypical humbug and insert a picture of the nest beside a quarter:
I found the nest in early June on the tip of a branch that had been cut out of a oak tree. Now it is important to note that this nest is either uncomplete or damaged, which is what gives the nest it's lopsided appearance. I am guessing that it is the former, due to the time of year and the overall appearance of the nest. The nest has no signs of having been used (being slightly smooshed down, looking worn, etc.) at all. I do not beleive the nest was damaged because it did not look as if it was torn when the branch came out of the tree, and it had no other signs of damage.
In appearance, it looked like any other hummingbird nest that I have ever reador heard about (or seen in pictures). It was extremely small, attached to the limb with small strands of spider web, camouflaged by lichens which covered the entire outside of the nest and with a very soft lining, to boot. Why so small? There are two explanations. The first one is simple, and the second somewhat surprising. I will give both. The first is that hummingbirds always lay two eggs. No less, no more. The pure white eggs are pea-sized, so they don't need a very big nest (they could easily fit into a two liter soda bottle cap). On top of that, the mother sits on the very top of the nest to incubate, not hunkered down within the nest as it is with most birds. Now for the second reason. A full-grown Ruby-Throated Hummingbird only weighs... are you ready for this? An 1/8 of an ounce. That is barely more than a penny. That's pretty tiny.