Editing Ruby-throated hummingbird (section)

=== Breeding ===
[[File:Ruby-throated hummingbird on nest 01.jpg|thumb|Female ruby-throated hummingbird on nest]]
As typical for their family, ruby-throated hummingbirds are thought to be [[Polygyny in animals|polygynous]]. [[Polyandry in animals|Polyandry]] and [[polygynandry]] may also occur. They do not form breeding pairs, with males departing immediately after the reproductive act and females providing all parental care.<ref>{{cite web|author=Lanny Chambers |url=http://www.hummingbirds.net/rubythroated.html |title=Ruby-throated Hummingbird |publisher=Hummingbirds.net |access-date=13 June 2011}}</ref>

Males arrive at the breeding area in the spring and establish a [[Territory (animal)|territory]] before the females arrive. When the females return, males court females that enter their territory by performing courtship displays. They perform a "dive display" rising {{Convert|2.45|-|3.1|m|ft|abbr = on}} above and {{Convert|1.52|-|1.82|m|ft|abbr = on}} to each side of the female. If the female perches, the male begins flying in very rapid horizontal [[Arc (geometry)|arc]]s less than {{Convert|0.5|m|ft|abbr = on}} in front of her. If the female is receptive to the male, she may give a call and assume a solicitous posture with her tail feathers cocked and her wings drooped.<ref>{{Cite journal |last1=Hogan |first1=Benedict G. |last2=Stoddard |first2=Mary Caswell |date=2018-12-18 |title=Synchronization of speed, sound and iridescent color in a hummingbird aerial courtship dive |journal=Nature Communications |language=en |volume=9 |issue=1 |page=5260 |doi=10.1038/s41467-018-07562-7 |issn=2041-1723 |pmc=6299134 |pmid=30563977|bibcode=2018NatCo...9.5260H }}</ref>

The nest is usually constructed on a small, downward-sloping tree limb {{convert|3.1|to|12.2|m|ft|abbr=on}} feet above the ground. Favored trees are usually [[deciduous]], such as [[oak]], [[hornbeam]], [[birch]], [[Populus|poplar]] or [[Celtis|hackberry]], although [[pine]]s have also been used. Nests have even been found on loops of chain, wire, and extension cords.<ref name= Cornell/> The nest is composed of [[bud]] scales, with [[lichen]] on the exterior, bound with spider's silk, and lined with fibers such as plant down (often [[dandelion]] or [[thistle]] down) and animal hair. Most nests are well camouflaged. Old nests may be occupied for several seasons, but are repaired annually.<ref name="robinsonetal1996"/> As in all known hummingbird species, the female alone constructs the nest and cares for the eggs and young.

Females lay two (with a range of 1 to 3) white eggs about {{convert|12.9|x|8.5|mm|in|abbr=on}} in size and produce one to two broods each summer.<ref name= Cornell/> They [[avian incubation|brood]] the chicks over a period of 12 to 14 days, by which point they are feathered and [[Homeothermy|homeothermic]]. The female feeds the chicks from 1 to 3 times every hour by regurgitation, usually while the female continues hovering. When they are 18 to 22 days old, the young leave the nest and make their first flight.<ref name="robinsonetal1996"/>