As our breeding ruby-throated hummingbirds continue to arrive, a few more facts on these amazing jewels of the avian world.
Hummingbirds are ecological marvels; they are predators, prey, and perhaps most notably, they are highly efficient pollinators. As predators, hummingbirds feed on a wide variety of insects, including tiny flies, gnats, aphids, tiny spiders, and even mosquitoes, in short, most anything they can handle with their long slender bills. They primarily capture prey by flycatching, i.e. grabbing items while in flight. They will also pluck tiny spiders (and spider’s prey) from webs as well as pluck insects from plant leaves, stems and blooms.
Hummingbirds are prey for a number of other creatures. Several species of birds have been documented to take hummingbirds, although hawks rarely cause them any problems.
Omnivorous songbirds such as mockingbirds, thrashers, grackles, jays, etc., have been documented to take hummingbirds. Many snakes are documented to depredate hummingbirds. The eyelash viper of Central America is well-known for capturing hummingbirds that are feeding at flower blooms. Here in our area, rat snakes have been observed staking out hummingbird feeders, laying in wait for the birds to appear. Squirrels will depredate hummingbird nests, and the foremost predator of ruby-throated hummingbirds is deemed to be the domesticated cat. I was somewhat skeptical of the latter’s ability to capture hummingbirds until I first observed it happen while on a hummer banding trip to Louisiana.
Sadly, I’ve observed it numerous times since then in our local area. Even some insects will take hummingbirds, most notably the non-native Chinese mantis. Native mantids are not as large as the introduced species and don’t appear to have any interest in hummingbirds. Some spiders capture and kill hummingbirds that become entangled in their webs.
It is as pollinators that hummingbirds have the most impact. There is a plethora of flowering plants that evolved over millenia to favor hummingbirds as their primary or even sole pollinators. Hummingbirds are highly efficient pollinators with some advantages over insect pollinator species. Rainy or cool weather doesn’t affect hummingbirds to the degree it does most insects, so the birds are able to do their job under conditions that may preclude much insect activity.
Many plants have a limited flowering period and in order to reproduce must be pollinated during that time. Hummingbirds are not able to pierce the base of flower blooms like a number of insects do, so their feeding activities are more likely to ensure the effective transfer of pollen. When you see a plant with elongate, tubular-shaped flowers (especially in the Western Hemisphere,) odds are good that hummingbirds helped drive the evolution of that plant’s bloom shape.