Family protection occurs in some interesting ways in the bird world.
This is the time of year when bird nests are being built and filled with eggs throughout
the Ozarks. All of us have seen many bird nests in our lives, but most of us have never stopped to
marvel at what amazing architectural feats these little bundles of grass or daubs of mud are.
Using primarily their beaks and feet, birds build structures strong enough in their initial stages to
hold several eggs and a parent bird and, later, sturdy enough to withstand the wear and tear of
feeding and fledging activities.
Along with roominess and stability, protection is another important component of nest-
building. Predators are a numerous and an ever-present threat in the bird world so taking steps to
make sure its offspring reach adulthood is an important instinctual consideration of every bird’s
nest-building project.
One of the more unique protective strategies some birds employ is to use shed snake skin
as a nest-building material. On occasion, you will see a bird’s nest that includes pieces of snake
skin and, very likely, the skin will be in a part of the nest where it’s easily seen. A study several
years ago by Arkansas State University ornithologists determined this isn’t just an instance of
birds using a material that’s handy – it’s an intentional effort to try to ward off predators. The
study showed some birds include pieces of snake skin in their nests while others place a skin
next to the nest in the hopes of making potential predators think the snake that crawled out of this
skin might still be nearby.
For many birds, nest defense comes down to location, location, location. The harder and
more uncomfortable it is for a predator to reach the nest, the safer it is. For instance, an
abundance of large thorns make honey locust trees prime nesting sites each year. Thorny shrubs
and brushy plants such as hawthorns or wild raspberries also provide protective nesting sites.
One of the more extreme examples of nest protection by location is the pied-billed grebe.
This secretive resident of Missouri wetland areas constructs a nest that floats on water and is
anchored to marsh vegetation.
On the simplistic side of nest-building is the killdeer. It wouldn’t be correct to say
killdeer do not make a nest because they do – it’s just not much of one. Eggs are laid in what’s
little more than a scraped-out spot in gravel or rocks. The tan-and-brown speckled eggs blend in
well with the speckled coloring of their surroundings. So do the chicks when they’re born and,
frequently the parent birds are hard to spot, too.
When something (animal or human) that is perceived as a nest threat gets too close to a
nest, the parent birds will distract the potential predator by acting injured, often flopping its wing out in an awkward position as if it were hurt. The adult bird will continue this fake injury routine to lead threats away from the nest.
It’s theorized there may be another factor that plays a role in predators not finding a killdeer nest – the location is simply too obvious. The predator’s instinctual mindset is that there’s no point in spending much time looking for a nest or eggs in a wide-open location because who would nest in plain sight? Also, many predators prefer seclusion to open areas because their minds are wired to operate from concealment. Staying concealed also protects them from predators further up the food chain (hawks, coyotes, etc.) so this is yet another reason to avoid open areas. Thus, the strategy of hiding in plain sight has several advantages for a nesting killdeer.
It should be remembered that it’s a violation of state and federal wildlife laws to disturb or destroy the nest of any native bird. Disturbing nests is a bad idea for several reasons besides the legal ones. Any intrusion, however brief, may keep birds from their nests. Handling bird nests that are currently in use is a bad idea because of the mites, bacteria and other potentially harmful organisms that may be found in them. Bird information can be found at mdc.mo.gov.
Francis Skalicky is the media specialist for the Missouri Department of Conservation’s
Southwest Region. For more information about conservation issues, call 417-895-6880.
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