"Hummingbirders" wait for months for their little jewels to arrive, and once they do there's jubilation across the continent. There's a week or two of pure joy, and then things go silent in the garden. Worry and panic strikes every "hummingbirder" out there as it appears their hummingbirds are gone and won't return. Understanding their habits and cycles should give you reason not to be concerned.
Let's compare Robins to Hummingbirds for a minute. When Robins appear in your garden and start to build a nest, they don't travel far from their nesting site to get their materials or to find food. Those traveling distances decrease even more once the young hatch and require food. Even though hummingbirds are much smaller and quite a bit angrier than Robins, they still are birds with the same habits. There is one major difference between them though. Male Robins are always very near their mate. Even when she's gathering materials for her nest, the male is somewhere very close watching out for predators. He has a strong protective instinct. With hummingbirds, it's much different. After the initial mating act, the female remains on her own in building the nest and later gathering food for her young. She is the protector, the food gatherer, and the sole caretaker of the nest. The male will protect his territory with the sole purpose of finding as many mates as possible, to increase the population as much as possible. There's no harness on the males. They live the fast and loose lifestyle. The female hummingbird stays relatively close to her nest, just like the Robin. Eggs need to maintain a proper temperature, and if there's danger nearby, she's there to protect. This is the main reason we don't see many female Rubies after that first week or two of the season. They don't travel far when they have vulnerable little ones in the nest. As for the males, you may get a dominant one sticking around, but he also has the freedom to go away for the weekend without any responsibilities to tend to. Sightings can be very sporadic through this time. The females can sit on the nest for about 55 minutes out of every hour, which tells you why they're not in your garden.
The consistency starts to form when it's feeding time for the newly hatched young, and as the young get older the frequency of hummingbird visits will increase.
Don't lose hope that the hummingbirds are gone from your garden, or that the sightings have decreased. That is very normal, and it's only a matter of time before all the males, females and young will return to your garden to cause a whole lot of chaos.
Ziggy, the Ruby-throat hummingbird, hasn't given up on mating opportunities, nor has he given up his throne. He will continue to hang around, and believe that more females will arrive. There are also circumstances where a female loses her nest to a predator and has to start over. The males will remain around for those opportunities as well.
May 28, 2018. N.E. of Edmonton, Alberta, Canada.