Is a Bird That Hit a Window Dead? The Unseen Aftermath of Collisions
Unfortunately, a bird hitting a window is often fatal, even if it appears to fly away; internal injuries are common. This article explores the factors determining a bird’s survival after a window strike, and what you can do to help.
The Silent Killer: Understanding Bird-Window Collisions
Bird-window collisions are a major cause of avian mortality, second only to habitat loss. Millions of birds die each year in North America alone after striking glass. The problem stems from birds’ inability to perceive glass as a solid object. They see reflections of trees, sky, or other habitat and fly towards them, resulting in a devastating impact.
Why Birds Don’t See Glass
Birds evolved in a world without transparent barriers. They rely on visual cues like branching patterns of trees or the horizon line to navigate. Glass completely disrupts these cues, tricking birds into thinking they can fly through what appears to be open space. Reflections only exacerbate the problem.
Factors Affecting Survival
The likelihood of a bird surviving a window strike depends on several factors:
- Speed of impact: Higher speeds usually mean more severe injuries. Birds migrating at night, or those being chased by predators, are more likely to be flying at higher speeds.
- Size and weight of the bird: Smaller, lighter birds are more vulnerable.
- Angle of impact: A glancing blow is less likely to be fatal than a direct head-on collision.
- Type of glass: Some types of glass, like reflective glass, are more dangerous than others.
- Availability of immediate care: Prompt intervention can sometimes save a bird’s life.
Common Injuries Sustained in Window Strikes
Even if a bird flies away after hitting a window, it may have suffered internal injuries that will eventually prove fatal. Common injuries include:
- Head trauma: Concussions and brain hemorrhages are frequent and often lead to death.
- Internal bleeding: Birds can suffer ruptured organs and internal bleeding from the force of the impact.
- Broken bones: Fractured wings, legs, or ribs are common.
- Eye damage: Birds can suffer corneal abrasions or even blindness.
What to Do If You Find a Bird That Has Hit a Window
If you find a bird that has hit a window, take immediate action:
- Approach cautiously: Avoid startling the bird further.
- Gently pick it up: Use gloves if possible, or carefully scoop the bird up with a towel.
- Place it in a dark, quiet box: A cardboard box with a lid is ideal. Provide a soft towel or paper towels for bedding. Do not offer food or water. The stress can be harmful.
- Keep it in a safe place: A warm, quiet room away from pets and children.
- Monitor the bird: Check on it every 30-60 minutes.
- Contact a wildlife rehabilitator: Search online for licensed wildlife rehabilitators in your area. They have the expertise and resources to provide the bird with the best chance of survival.
Preventing Bird-Window Collisions
The best approach is to prevent collisions from happening in the first place. Here are some effective strategies:
- External screens: Installing screens on your windows can break up reflections and provide a physical barrier.
- Netting: Hang netting in front of your windows to create a safe buffer zone.
- Window film: Apply films that are visible to birds but nearly invisible to humans.
- Decals: Apply decals to the outside of your windows. Ensure the decals are closely spaced, no more than 2 inches apart horizontally or 4 inches apart vertically. Silhouettes of raptors are not effective on their own.
- Movable shutters or awnings: Use shutters or awnings to cover windows, especially during peak migration periods.
- Indoor plants: Move indoor plants away from windows to reduce the attractiveness of reflections.
Comparing Different Bird Deterrents
| Deterrent | Effectiveness | Cost | Installation | Aesthetics |
|---|---|---|---|---|
| ——————- | ————- | ———- | ———— | ———- |
| External Screens | High | Moderate | Moderate | Moderate |
| Netting | High | Low | Easy | Low |
| Window Film | Moderate | Moderate | Easy | High |
| Decals | Moderate | Low | Easy | Moderate |
| Movable Shutters | High | High | Moderate | High |
| Indoor Plant Relocation | Low | Low | Easy | High |
Frequently Asked Questions
Is it always necessary to take a bird to a wildlife rehabilitator after it hits a window?
Not always, but it’s highly recommended. Even if a bird seems fine, it may have internal injuries that require specialized care. A rehabilitator can assess the bird’s condition and provide appropriate treatment. Leaving a potentially injured bird to fend for itself significantly reduces its chances of survival.
Can I tell if a bird has a concussion after hitting a window?
Signs of a concussion in a bird can include disorientation, difficulty balancing, an inability to fly straight, drooping wings, and a vacant stare. If you observe any of these symptoms, it’s crucial to seek professional help.
How long should I keep a bird in a box before releasing it?
If the bird appears uninjured, keep it in the box for at least one to two hours to allow it to recover from the initial shock. Check on it frequently. If it’s still showing signs of distress after several hours, contact a wildlife rehabilitator. Never release a bird at night.
What kind of decals are most effective at preventing bird-window collisions?
The most effective decals are those that are closely spaced and cover a significant portion of the window. Avoid using just a few widely spaced stickers. The “2×4 rule” is a good guide: No gap should be larger than 2 inches vertically or 4 inches horizontally.
Is it true that some types of glass are more dangerous to birds than others?
Yes, it is. Reflective glass, particularly used in modern office buildings, is a major hazard because it creates convincing illusions of habitat. Transparent glass without any markings is also problematic. Fritted glass (glass with etched patterns) and UV-reflective glass (which birds can see but humans can’t) are safer alternatives, but more expensive.
What role does outdoor lighting play in bird-window collisions?
Outdoor lighting, especially during migration periods, can disorient birds and attract them to urban areas where they are more likely to encounter windows. Turning off unnecessary outdoor lights at night can significantly reduce this risk. This is the principal behind many “Lights Out” initiatives.
Are bird feeders a cause of bird-window collisions?
Bird feeders can increase the risk of collisions if they are placed too close to windows. Birds startled at a feeder may fly directly into the glass. Position feeders either very close (within 3 feet) or far away (more than 30 feet) from windows to minimize this risk. Closer is sometimes better, as it reduces the momentum a bird can build up before impact.
What is the best time of year to take precautions against bird-window collisions?
While bird-window collisions can happen year-round, they are most common during spring and fall migration periods. These are the times when large numbers of birds are on the move, and are more likely to encounter unfamiliar environments and urban structures.
What are “Lights Out” initiatives and how do they help birds?
“Lights Out” initiatives are programs that encourage building owners to turn off unnecessary lights at night during bird migration seasons. This reduces the attractiveness of urban areas to migrating birds, minimizing disorientation and the risk of collisions. Many cities now participate.
Is it possible to train birds to avoid windows?
Unfortunately, it is not possible to train wild birds to avoid windows. Birds operate on instinct, and their inability to perceive glass as a solid object is a fundamental limitation. Preventing collisions requires modifying the environment, not changing the birds’ behavior.
What is the legal status of birds injured in window collisions?
In many countries, including the United States, most native bird species are protected by laws such as the Migratory Bird Treaty Act. It is illegal to harm or kill these birds, even unintentionally. Therefore, taking steps to prevent bird-window collisions is not only ethically responsible but also legally prudent.
If a bird hits my window and dies, what should I do?
If a bird dies after hitting your window, you can document the event with organizations like iNaturalist and report it to databases tracking bird mortality. You can then dispose of the body respectfully, such as by burying it. If you are in the US, consult the US Fish and Wildlife Service guidelines on what to do with deceased migratory birds. However, the most important step is to take action to prevent future collisions.