Early spring brought the usual numbers, but as summer edged in and then slipped by, populations at feeders grew. And grew. Now, during the first week of September--the area's usual hummer peak--folks have been stirring up sugar nectar by the gallon, one host reporting serving two gallons a day.
Indeed, the volume of disappearing syrup gives the best measure of how many hummers come sipping. After all, who could possibly count a swarm of tiny birds, none of which sit still for more than a few seconds while others zip past or hover or reverse directions mid-flight.
Given that, here's betting you're seeing some pudgy little hummers at your feeders right now, stored fat bulging along necks and bellies. Thin birds must strive to become tubbies themselves.
But hummer diets consist of only part nectar. Small arthropods provide needed protein and comprise--according to some experts--as much as 50 percent of hummers' diet. Wet conditions also typically translate into more bugs.
In short, readily available nectar and bug resources likely affect hummer populations two ways. First, when females can readily and reliably consume an ample bug-nectar combo, they more likely survive the physically draining challenge of reproduction. Second, when mom regurgitates a ample supply of nutritious mix into the mouths of babes, she likely produces more successful broods. Populations bump up. Multiply that scenario across multiple states to our north, and local migrant populations jump up.
What does the population bump mean to local hummer hosts?
While many authorities recommend a ratio of four parts water to one part refined white sugar, others recommend--especially during migration--boosting the ratio to three parts water to one part sugar. Sugar fuels the bug-eating machines we know as hummingbirds.
Over the next weeks, populations will begin an overall decline. Each time a weather front brings north winds, huge numbers will flood south overnight, using tailwinds to aid their journey to Costa Rica.
So keep feeders fresh. Since length of day triggers migration, don't be concerned about leaving feeders up too long. In fact, we do hummers a disservice by bringing in feeders just when they need the extra energy most. Indiana DNR biologists recommend we keep feeders out until Christmas--minding, of course, freezing temps.
To watch a video of hummingbird swarms at feeders, visit my Facebook page for Aug. 28, 2015.