The Tricks Birds Use to Safeguard Their Nests

Zebra Finch

Story at-a-glance -

  • A new study proves that given the opportunity, birds intentionally decorate their nests to insure they blend into the surroundings. This camouflage helps keep eggs, nestlings, and brooding hens safe from predators
  • In an experiment, researchers gave zebra finches a selection of colored paper strips -- some that matched their enclosures, and some that didn’t. The birds largely chose to build their nests with paper strips the same color as their enclosures
  • Also of interest was that many of the birds selected small amounts of mismatched color strips to add to their nests in a strategy known as “disruptive camouflage”
  • These study findings are the first to prove that birds intentionally camouflage their nests to protect them from predators

By Dr. Becker

Did you know that when birds build nests, they intentionally choose a color palette that complements their surroundings? It’s not about interior design for the birds, though. They do it for a very practical reason – to camouflage their nests to protect their eggs, nestlings and themselves from predators.

Study Is First to Show That Birds Intentionally Camouflage Their Nests

Scientists at the University of St. Andrews in Scotland decided to study zebra finches to learn their nest material choices. The zebra finch, which is a small, friendly songbird, is native to Australia, and it’s the male of the species who builds the nest.

The researchers used blue, pink, or yellow pastel colors to wallpaper the enclosures of 21 male zebra finches. Then they gave the birds a choice of two colors of paper strips to build their nests. One of the colors matched the wallpaper; the other did not.

The zebra finches largely chose to decorate their nests with paper strips that matched the wallpaper in their enclosures. The researchers concluded that birds intentionally match their nest’s colors with its surroundings, making the camouflage affect deliberate rather than a coincidence.

Scientists were aware that birds often move their nests to avoid predators, but this study is the first to show that they also camouflage their nests for the same reason.

Birds Also Employ Disruptive Camouflage to Confuse Predators

Another intriguing finding from the study was that many of the zebra finches also added a few paper strips to their nests that were not the same color as their wallpaper. This suggests that birds use a method of concealment called “disruptive camouflage.” Adding a small bit of contrasting color breaks up the outline of the nest so that predators may not realize it’s a nest at all.

These findings add to previous research that shows nest building is not just an inborn skill in birds, but also a skill-building exercise as birds discover what works best to protect nest inhabitants.

The study was published in the January 2015 edition of the ornithological journal The Auk.1 Lead author Dr. Ida Bailey observes:

“Like us, they don’t choose just any colored material to build their homes, they avoid colors that would clash with their surroundings. Knowing this gives us a better idea of how birds may actively reduce the chances of predators finding their nests. It also opens up the possibility that this is yet another aspect of nest building that inexperienced nest builders may get wrong and need to learn about during their lives.”2