What happened to the hummingbirds at the feeders in my backyard?
The hummingbirds that had been at your backyard feeders until a week or two ago could be missing for a range of reasons, but theres one possibility more likely than all the rest. Hummingbirds are in the height of their breeding, nesting and fledging season across Pennsylvania. Female hummingbirds, which build the nests, lay the eggs and tend the hatchlings/nestlings without help from their mates, more than likely are at those nests just now. They will stick close to the nest until their babies fledge and leave that nest. They will confine their foraging to a small area around the nest and might not visit feeders beyond that radius during the entire nesting period. They will sit on their eggs for 15 to 18 days until those eggs hatch and tend to the hatchlings in the nests for another 15 to 28 days. Also, at this time of year the males are in mating mode, which has them defending their territories aggressively even after breeding with every female with their territories. The males territory is larger than the females nesting territory and he will battle fiercely against any other males that blunder into it. A particularly aggressive male could be driving all others from an entire backyard. The combined impact of the current behaviors by both females and males could be just one male hummingbird visiting all the feeders in a backyard. Placing hummingbird feeders at the opposite sides of a backyard can lessen the nesting-season impact by offering distanced options to competing males, but only slightly in an average-sized backyard. The situation also will likely resolve itself later this month or early in July, as the new generation of hummers leave the nest and begin visiting the feeders on their own, which also will free up the females to return to the feeders. That will be the time to bring the feeders back into a group. The male may continue his defensive behavior, but probably will be overwhelmed by the juveniles and females jostling for their chances at the feeders. Another possible reason for a drop in the number of hummers at backyard feeders could be a shift in diet by the little birds. While hummingbirds eat about half their weight in nectar every day, they also eat large number of small insects to acquire the protein and vitamins and minerals not available in that nectar. Insects, as well as flower variety, are at their peak just now, giving the hummers more options for feeding locations than they had just a few weeks ago. One study did find that hummingbirds visited flowers more frequently than feeders when they had a choice. Something larger may have changed in a backyard or neighborhood to move the hummingbird activity. Trees or shrubs that provided shelter and protection previously may have been removed. Human and mechanical activity levels may have changed. A predator may have moved into the area. A neighbor may have added feeders or flowers preferred by the local hummers. Many environmental factors can cause hummingbirds to move or change their behaviors. Dirty feeders with nectar that is not changed frequently enough also can cause hummers to change their habits. The high sugar content of nectar can be a prime breeding medium for mold, fungus and bacteria, leading the birds to avoid the contaminated nectar. Nectar should be changed at least once a week in cooler weather and as often as daily during the heat of summer. Feeder cleaning frequency also should increase in hot weather. For more outdoor coverage, subscribe to Marcus Schnecks free, weekly Outdoor Pennsylvania newsletter right here:  Enter email:    You also can contact Schneck at mschneck@pennlive.com.