All About Flycatchers in Nature

 Here is a recent post from the Union Bay Watch Blog published by Larry Hubbell, long-time local photographer and birder.

Active Waiting

Typically, this species is often seen on a perch. One might assume they are the "couch potatoes" of the avian world and therefore "sitting ducks" for small falcons and accipiters. 

The truth is they are surprisingly active. Even when stationary, their heads are constantly twisting and turning. Imagine being very hungry and standing in a three-dimensional computer room where the walls, floor, and ceiling are screens that intermittently flash snippets of pertinent information about how to secure your next meal.

Their abrupt staccato-like movements bring to mind the robot, C3PO, in the Star Wars movies. 

It is not surprising that creatures who catch flies are called Flycatchers. However, you may be surprised that they can catch enough to replenish their energy expenditures. How can they possibly move so quickly, fly frequently, and eat so little? Insects must be extremely nourishing. I suspect the Flycatcher's mid-air, last-moment adjustments may also help to make their efforts more economical - from a nutritional perspective.

It would be interesting to know how far flying insects can see. Presumably, their fatal flaw is to venture into the flycatcher's strike radius before they notice the bird. Do insects that avoid flycatchers have better eyesight? Are they faster than average? or Is it just a matter of luck?

Since Dragonflies also catch flying insects I wondered if they might be best equipped to escape the Flycatchers? In Dennis Paulson's book, "Dragonflies and Damselflies of the West", he says, "Dragonflies have the finest vision in the insect world." Later, "Dragonflies have their good vision and swift and agile flight to protect them from predators." However, he does list large Flycatchers as an important Dragonfly predator.

Dennis also mentions three different foraging methods used by Dragonflies. They are hawking, sallying, and gleaning. As you read this post you might consider which one of these methods best describes the behavior of the two Flycatcher species we consider? 

The Flycatcher's quick-twitch, insect-inspection is not just a surprisingly active form of hunting, it is also an effective method to monitor for airborne predators. 

We are blessed with multiple species of flycatchers and many have surprisingly similar characteristics. Luckily, this species, the Olive-sided Flycatcher, is an easily identified exception. Their distinctly white bellies contrast quite nicely with their olive-green sides. Their wonderfully descriptive name includes both an easily identifiable attribute and an easily observed behavior. 

Plus, their song is distinctive. "Quick, three beers!" is the mnemonic to help file it in your memory. Click Here and play the very first recording to hear it.

At some angles, the head and the bill look like they belong on a much larger bird.

When they snag an insect out of the air. If it is relatively large, they will often return to their starting point to finish the snack.

This Flycatcher killed and possibly tenderized this bee before eating it. I did not notice the stinger being removed. They are super quick and it could have happened when I blinked. However, if it did swallow the bee whole, I wonder why the poison does not cause problems?

A few days earlier, I saw one of our other species of flycatchers. It was sitting a bit lower but otherwise, its behavior was similar.

It also caught what looked like a bee and appeared to eat it without removing the stinger.

One method for distinguishing this Flycatcher from the Olive-sided species is its lack of a clean white belly.

In fact, there is no clear distinction between the belly and the sides. It's almost like it is wearing a vest that is buttoned up tight, while the more "casual" Olive-sided has an unbuttoned vest.

The Western Wood-Pewee also has a naming advantage. It says its own name, at least the final portion. Click Here and play the very first recording to hear it.

Returning to our Olive-sided Flycatcher it was bumped off of its perch by the approach of a male Northern Flicker. The Flycatcher did not seem particularly scared. It flew off to catch an insect and quickly returned to a nearby location.

The Flycatcher appeared confident it could outmaneuver the Woodpecker. 

Although, perhaps the calls of the Flicker got on its nerves.

The Flycatcher finally left. However, it was not long before a Bald Eagle passed overhead and the Northern Flicker also abandoned the conspicuous post. Every creature in the web of life has weaknesses and strengths. The key to survival may be having a clear understanding of both.

Both species of Flycatchers that we reviewed today were hunting by perching and flying out to grab airborne insects. The two other hunting styles that they did not use were hawking and gleaning.

A Red-tailed Hawk circling on thermals overhead, and watching for a rodent to reveal itself, before diving, would be appropriately described as hawking. 

A Golden-crown Kinglet closely inspecting vegetation for insects could be described as gleaning.