Banding Nestling Tree Swallows

What’s different about banding nestlings?

Banding nestling Tree Swallows is much simpler than banding adults.  All the bird bander does is affix the band and record the bird’s species, age, and band number, plus the date and location.  However, there are some very important timing and handling rules. See the warnings, below.

banding a nestling tree swallow

For your own records you can use our simple Nestling Banding Record.

You record each nestling’s:

  • Box number.
  • Date of banding.
  • Age in days after hatching.
  • Band number.

Why don’t you record as much banding data when banding nestling Tree Swallows as you do for adults?

It’s impossible to determine nestling sex by plumage or other external appearance, and their physical characters are still growing and developing.

At what age are nestling Tree Swallows banded?

The following three species-specific warnings are from the North American Bander’s Manual for Banding at Nest Boxes. Your bander must observe them!

Warning! There is a very short window of time for banding Tree Swallow nestlings, either day 11 or day 12 after hatching.  (This is one more reason for keeping a Control Sheet that tracks nestling age at each box).  Your bander must resist the temptation to band nestlings outside this window.

Warning!  Before day 11 nestling legs are usually too swelled with fatty tissue.  Applying a band too soon could constrict and damage the leg.

 Warning!  Nestlings older than day 12 should not be handled for any reason, including banding!  Doing so could cause them to jump from their nest before they can fly strongly. Young Tree Swallows that fledge prematurely usually aren’t fed by their parents and die!

Take a close look at the 12-day-old nestling’s wing, below.  Notice how the flight feathers have partly erupted from their sheaths, so they look like little paintbrushes. If you find nestlings in a box with flight feathers more erupted than those in this example, leave them alone!  Handling them for any reason, even banding, risks premature fledging and the death of the birds!

12 day old tree swallow nestling wing.  There should be no banding of nestlings older than this.

Warning! Don’t ever let adult Tree Swallows to see their nest emptied of young or they may desert!  Band nestlings next to the box, which prevents adults from entering. Or if you must move nestlings away from the box, take half the brood at a time, so the parents never see an empty nest.  

Will your young swallows return to your project as adults to nest?

  • Banding nestlings will give the answer for your site!
  • However, don’t expect many nestlings to return.  
  • While 30-60% of adult nesters come back, banding studies show nestlings returns average less than 10%, often much less.

Why is there such a difference in return rates of adults and nestling Tree Swallows?

  • Mortality of young, inexperienced swallows is high during their first autumn and winter of life.  
  • One study of Tree Swallow demographics estimated only 20% of young swallows survive through the migration south, wintering and migration north to their first nesting season.
  • Young Tree Swallows entering their first nesting season also tend to migrate north later than older adults.  If they do return to where they were raised they are apt to find nest sites already claimed by older swallows.
  • The options for the younger birds aren’t great. They can risk trying to take a nest site away from more experienced swallows. They can “float” in the area and wait for a vacancy that may never occur. Or they can move on and prospect for nest sites elsewhere.

The combination of high first-year death rates and shortage of nest sites means you won’t find many of your nestlings back at your projects as adults.  However, have them banded anyway, if you can.  Maybe they will be reported nesting elsewhere, and this can help scientists studying Tree Swallow dispersal.

———————————————————————————————-

Home: Tree Swallow Nest Box Projects

Creating Tree Swallow Nest Box Projects

Tree Swallow Life

Diary of One Season at Salmon Creek

Monitoring Nest Boxes and Keeping Records
Making Box Checks Keeping Box Records Control Sheets Season Summaries Print Sheets

Banding Your Tree Swallows Banding Adults Banding Nestlings

Tree Swallows in Research Research Bibliography Glossary of Terms

Contact Us