Disturbing a bird’s nest can have serious consequences for both the birds and the person doing the disturbing. Birds are very protective of their nests and will aggressively defend them against intruders. However, there are also laws in place to protect migratory birds, their eggs, and their nests. So if you disturb a nest, you could face legal trouble in addition to attacks from angry parent birds. In this article, we’ll look at what exactly happens when a bird’s nest is disturbed, why birds are so protective, the legal implications, and how to avoid accidentally disturbing nests.
Why Are Birds So Protective of Their Nests?
Birds invest an incredible amount of time and energy into building their nests and raising their chicks. They carefully select nest sites, collect materials, and intricately weave everything together into a secure home. Birds will aggressively defend their nests against any perceived threat because their reproductive success depends on it. Here are some of the main reasons birds are so protective:
Instinct
Nest defense is deeply ingrained in birds’ instincts. Over countless generations, birds that vigilantly protected their nests were more successful at raising young than those who were more tolerant of nest intruders. This resulted in the aggressive territory defense behaviors we see today getting hardwired into birds’ genetics.
Energy Investment
Building a nest takes a lot of time and effort. Birds often make multiple trips to gather hundreds or even thousands of bits of grass, twigs, moss, feathers, and other materials. It can take days or even weeks to build a sturdy, weatherproof nest. If the nest is destroyed, they have to start over from scratch. Birds don’t want to see all that hard work go to waste.
Offspring Vulnerability
Baby birds are extremely vulnerable in the nest. They can’t fly or adequately defend themselves. Parent birds are very protective against anything they perceive as a threat to their helpless chicks. Their main priority is keeping predators away from the nest.
Survival Instincts
For most bird species, reproducing and raising chicks each breeding season is essential for the survival of that species. Birds only have a short window of time to successfully build a nest, lay and incubate eggs, raise the chicks to adulthood, and then repeat the process again the next year. Disruption of their nest can jeopardize the survival of that pair of birds’ offspring, which goes against all of their natural instincts to preserve their lineage.
What Happens When a Birds Nest is Disturbed?
Disturbing a nest essentially triggers a fight-or-flight response in parent birds. Here are some common reactions:
Alarm Calls
When a nest is approached or touched, parent birds will start making loud alarm or distress calls. These serve to alert the intruder to back off, as well as to attract other birds to mob the intruder.
Mobbing
Birds will often mob or attack intruders to drive them away from the nest. They may repeatedly dive bomb the intruder or even strike with their beaks, wings, or claws. Mobbing gets more intense the closer you get to the nest.
Injury or Death
In some cases, birds can inflict serious injuries while mobbing perceived threats near their nest. They may peck or scratch the intruder’s head and eyes. There are even reports of birds killing small mammals or knocking down children from nest attacks.
Nest Abandonment
If disturbance is severe or prolonged enough, parent birds may permanently abandon the nest and eggs. This leads to loss of all the eggs and baby birds. However, birds rarely abandon nests with babies old enough to thermoregulate on their own. At that point, the parents are too invested in the chicks to leave them.
Increased Predation
An adult bird flushed off the nest leaves the eggs and chicks unattended and vulnerable. This opens up the opportunity for egg-eating predators like snakes, raccoons, and crows to raid the nest and destroy everything. Nest abandonment also makes chicks easy prey.
Disrupted Incubation
Every time a brooding mother bird is scared off the nest, eggs are left unattended. This can lead to disrupted incubation, eggs getting cold, and even embryo death if the adult stays off the nest too long. Newly hatched chicks are also at risk of overexposure without an adult keeping them warm.
Why is Disturbing Nests Illegal?
Disturbing or destroying bird nests is illegal under the Migratory Bird Treaty Act of 1918. This law makes it unlawful to pursue, hunt, kill, capture, possess, sell, purchase, or barter any migratory bird, including the feathers or other parts, nests, eggs, or young. Here’s why this federal law is so strict:
Conservation of Species
Hundreds of native North American bird species are in decline. Protecting nests helps stabilize struggling populations. Even abundant species rely on high reproductive success each year.
Preventing Cruelty
The law aims to prevent cruelty and overexploitation of wild birds. In the past, nests were disturbed for egg and chick collection. Supply couldn’t meet demand for feathers used in hats.
Habitat Protection
Leaving nests undisturbed also protects surrounding bird habitat. Breeding sites remain suitable for reuse in future seasons.
Recreational Benefits
Birdwatching activities depend on birds being relatively tolerant of quiet, respectful observers. Widespread nest disturbances would make finding and viewing birds much harder.
Penalties for Disturbing Nests
There are legal consequences for disturbing or destroying a bird’s nest in the U.S. Here’s an overview of the penalties:
Fines
First-time offenders usually face fines starting around $500 up to $1000 per violation. Each nest illegally taken can be considered a separate violation.
Jail Time
Serious or repeat offenders may face up to 6 months jail time, in addition to steeper fines up to $5000 per violation.
Probation
Courts may issue probation periods of up to 5 years during which the offender cannot disturb more nests. Violating the probation leads to fines and potential imprisonment.
Loss of Lease/License Rights
Offenders violating nesting regulations on public lands can lose their rights to use those lands for grazing, logging, or other activities.
Federal Charges
Particularly damaging nest disturbances impacting threatened/endangered species may be elevated to federal charges. These are prosecuted very strictly.
How to Avoid Disturbing Nests
Here are some tips for avoiding accidentally disturbing bird nests:
Stay Alert
Watch for signs of nests like birds carrying material or food, territorial behavior, warning calls. Also check sites birds favor before pruning trees or doing yard work.
Avoid Nesting Sites
Give natural and man-made nesting areas like shrubs, cavities, and ledges a wide berth during breeding season. Respect exclusion zones around known nests.
Alter Work Timing
Schedule tree trimming and construction activities outside peak breeding season when possible. If not, have a qualified person inspect for active nests first.
Keep Cats Indoors
Cats are a major predator of baby birds. It’s best to keep them in during spring and early summer when fledglings are most vulnerable.
Monitor Bird Feeders
Check the vicinity of feeders for nests periodically. Discontinue feeding if birds seem agitated or territorial.
What to do if You Disturb a Nest
If you accidentally disturb an active nest:
Back Away
Immediately back at least 30 feet away from the area. Give the adult birds adequate space to re-settle on the nest.
Wait and Watch
Quietly observe from a distance. Monitor to see if the adults return and resume incubating eggs or feeding nestlings.
Avoid Further Disturbance
Mark the nest location and avoid the area for at least several days. Don’t trim nearby vegetation or make other habitat changes.
Call for Help
If adults don’t return to the nest or eggs/chicks are exposed, call a wildlife rehabilitator for rescue advice. Don’t attempt to return contents to the nest yourself.
Learn from Mistakes
Use the experience to become more aware of nests in the future. Educate others about the importance of leaving bird homes undisturbed.
Conclusion
Disturbing a bird’s nest often elicits aggressive defense behaviors from the parent birds. They see any intruders as threats to their vulnerable eggs and chicks. However, repeatedly disturbing a nest can cause the parents to abandon it altogether. This jeopardizes the survival of that pair’s offspring for the year. There are legal protections in place to prevent human activities from damaging nests. It’s important that everyone does their part to respect birds’ breeding territories during nesting season. Being mindful of your surroundings and altering your actions around known nest sites will help prevent unnecessary disturbances. If you accidentally interfere with a nest, back off right away and monitor the situation. With proper care and caution, we can coexist peacefully with our wild feathered neighbors.