Several folks have contacted me recently with questions regarding the relative scarcity of hummingbirds at their feeders now.
It’s not unusual for hummers to become scarce at feeders during the first couple of weeks of June, and there are a few contributing factors. One is trumpet vine (Campsis radicans), a native plant that has begins its bloom period in late-May/early-June. Hummingbirds often forsake feeders when this native vine is in bloom.
Throughout the recorded history of our tiniest feathered friends, it has been well-documented that Ruby-throated hummers have an intimate relationship with this plant. If you will take the time to find one of these vines in bloom, observe the large blossoms for 10 minutes or so, and odds are you’ll see a hummingbird visit to take advantage of this natural nectar source.
In addition to trumpet vine, a number of other native flower species are currently blooming, such as coral honeysuckle (Lonicera sempervirens) and cardinal flower (Lobelia cardinalis), both of which are hummingbird-favored plants. Some authorities state that cardinal flower can only be pollinated by hummingbirds, which gives a clue as to the importance of this plant to the miniature marvels. Once a fairly common plant frequently found in drainage ditches and along wetland edges, cardinal flower is rapidly disappearing from our area as ditches are filled and landscapes are cleared up to the edge of wetland boundaries.
Coral honeysuckle is disappearing as well, as it’s a vine that grows along the edges of forests and woodlots. I try to have both of these plants in the yard where I live for the hummingbirds (and a few butterfly and moth species.) Our native cardinal flower can be grown in large pots as long as the soil is kept moist. (Note: there are varieties of cardinal flower available thru commercial growers/nurseries, etc., and most of these are not the same species as the plant native to our area, therefore not as attractive to hummingbirds.)
There are also a few other native Lobelia species that hummingbirds favor, and all of these are wetland-associated plants.
Another factor in the tiny birds’ presence/absence is certainly the availability of tiny insect prey. Most folks tend to ignore the fact that at least 50 percent of a Ruby-throated hummer’s diet is comprised of tiny bugs. Hummingbirds cannot survive on sugar water or nectar alone for any extended period. Forty-eight hours without insects to meet protein and fat needs, and their bodies start to deteriorate.