A Beginners' Guide to Swallow ID.

[Joe Roller]

Birders,

There is often great info on CObirds about sorting out rare and tough, look-alike bird species.

But for many less-experienced members of our field class fraternity and the scope sorority,

this weekend is a great time to learn to identify Swallows in Flight. 

At almost any water body there should be swallows, put down by the nasty weather,

which keeps insect morsels "down on the deck." (see footnote).

This weekend, swallows in flight will be close and near eye level, thus easier on your neck 

than when you gaze at stratospheric dots on clear days.

Swallows on a wire are easier. Just like in the field guides.

Get your warm clothes, anorak, hot tea, big hat, gloves, and a buddy and get thee to a lake! 

Park close, using your car as a blind and look, look, look.

Here is how I sort out swallows on gray days, when colors are muted and visibility is iffy.

Look at the swallows closest to you first, especially ones that are moving toward you. They will be moving fast

and hard to keep in view, but be patient, trying to stay on ONE swallow until it gets way too far away. Take a stab at an ID,

then find ONE more.

Here are the six most common birds in the swallow tribe, in pairs of two, roughly in order of prevalence.

First, look for a swallow that seems all dark. That will be your Barn Swallow. In gray conditions don't bother looking for colors - the dark blue back

and orange breast - or for the forked tail, which can be hard to see, as those are only confirmatory field marks.

Cliff Swallows are easy, with the orange rump. But on dark overcast, the rumps may appear just pale & contrasty, not bright orange.

"Cliff's" confirmatory mark is the BROAD squared off tail. Other swallows have square tails, but appear much narrower.

Next, find one that seems dark above, white below.

These will be either Tree or Violent-green Swallows. 

To sort out those two can be tough, but the VG's will give a flash of its bright WHITE "Saddle-bags".

Trees lack that or may have just a hint of white on the sides of the rump. IF you see Violet on a Violet-green,

come back on a darker day!

The other good mark for those two is the large white cheek of the VG. Trees have a little white on the lower cheek, but not much.

If you are not sure whether it's a Tree or VG, it's probably a Tree, as VG's stand out and are hard to mistake for a tree.

Next are the brownish backed pair -  Rough-winged and Bank. Banks rare among the swallows you'll see, so don't expect too many. 

Maybe below 1%.

Rough-wings have pale bellies, but NOT bright white like Tree and VG.

If you have a candidate for Rough Winged or Bank, look at the throat. Rough wings have a dull brownish throat.

And don't look for the brown breast band on Banks. That's a good mark for a perched Bank, 

but in flight, look for the White CHIN. It stands out because it's bordered by the brownish head

 and the brown breast band, but the white chin stands out. You may not find any on a given lake.

And Bank Swallows could have been included in a trio of the other two WHITE-bellied swallows.

There are a ton of other field marks, size, tail shape, sluggish or sprightly flight, etc, but the field marks I mentioned are the place to start.

As for Cave Swallows and Purple Martin, you won't see any this weekend. 

If you get a chance to test these tips in the field, please let me know which ones are the most or the least 

helpful for you. Constructive comments are welcome.

My next topic will be a beginners' guide to distinguishing a hawk from a handsaw.

Joe Roller

Denver

footnote:

The classic question non-birders ask is, "What's up with all the swallows at intersections?"   The best theory I have heard is that cars idle there, 

so intersections are warmer than any one street. The warmth and carbon dioxide from car fumes attract bugs. Microclimate.

[Jennifer Hallam]

Thanks for this Joe! Great info! :-)

Jennifer Hallam
Ken Caryl/C470 and Kipling
Jeff CO

[Derek Hill]

The issue of swallow ID has been understated for decades as far as books and articles go. Sure, gulls, shorebirds, seabirds are traditionally among the tougher families for US birders. Well Empids, sparrows, fall warblers, etc etc as well.

USA swallows are highly mobile and visible species, more limited in diversity than the above listed groups, and limited enough that swallow ID should not be a huge issue. But it is.

As an "experienced" birder, until the day by a lakeside in north Texas, in peak swallow migration, that I realized that swallows were not as easy peasy as I always thought.  Peak swallow-migration time, standing at the shore of a large reservoir near Dallas, with hundreds of swallows of various species, and less than ideal lighting from the birder's vantage point.   Surely swallow ID is easy, but when you have hundreds/thousands of birds zipping and darting and swooping around in front of you, it is QUITE difficult to ID bird-by-bird what you're looking at. When you're in an area where every swallow (besides Violet-green, in this Texas example) is perfectly expected and usual, it is quite hard to gauge a ratio of which species to species mix you're looking at in a migratory flock over a lake in poor viewing conditions. And swallows love to congregate and feed over lakes.

Thank you Joe Roller for the swallow-ID post.  It is not an easy task to come across giant mixed migrating flocks of swallows and determine how many of each species you're looking at, or even rough ratios.  More work should be done on this front.

Good birding,

Derek Hill
Fort Collins