As if life wasn’t already hard enough for birds – food isn’t always easy to come by, cuckoos come and expect you to raise their babies, other creatures are keen to eat you and then humans come along and build their houses right in your flight paths! What a literal pain in the neck!
Bird strike is a common occurrence throughout the world and of course, more prevalent where bird populations are high and windows are plentiful. In North America, windows claim an estimated 1 billion birds per year, largely due to high rise buildings that have been built in migratory pathways.
Bird strikes occur where windows reflect the sky and surrounding vegetation, and also where it is possible to see straight through to vegetation on the other side. Birds do not understand glass, plus they fly fast and are very fragile. This can only lead to unfortunate outcomes unless you can help them avoid a collision.
Assess the Risk
You may already be aware of problematic windows but if not, take a walk around your house, both inside and outside, and look at your windows (or other glass/reflective structures such as pool fences) with a bird’s eye view in mind.
Assess the size of your windows and their reflective potential for both summer and winter months. Can you see straight through the house to the sky or vegetation on the other side? Consider likely flight paths and whether there are attractive items that will encourage birds to come near the house such as baths, feeders, fruiting trees or roosting sites.
Once you have determined which windows pose the greatest threat, you need to make your windows visible to birds. You do this by breaking up the reflection so birds can be more aware of the presence of the solid wall of glass. It may be necessary to use a combination of modifications. Here are a few suggestions.
Non-Permanent Solutions
Mark the glass. You can add your own marks to the inside or outside of your windows using various products and techniques. The main rules to follow are:
- White gives the highest contrast and is therefore the easiest colour for birds to see.
- Apply marks across the entire surface of the window with the spaces between the marks too narrow for birds to fly through, i.e. 10cm gaps or less.
- Birds don’t like to fly between vertical spaces narrower than their wingspan, for this reason, vertical lines are more effective than horizontal lines.
Here are a few DIY ideas:
- Use an oil-based white paint pen that is designed to be used on glass (see your local art and craft store or Officeworks). Use a ruler to draw vertical lines 5-10cm apart. Oil based paint is long lasting and can be scraped off when necessary.
- Apply stickers / decals or film directly to the windows (there are plenty of options available online). White automotive tape is a cheap, long-lasting option that can be scraped off when necessary.
- Regularly add your own patterns with yellow highlighter pen, or paint the entire pane with tempura paint or whitewash (a good solution for garages or sheds that don’t really need windows for views). These will need to be reapplied as they will fade and may wash off with rain.
Semi-permanent Fixtures
Create a curtain of dangling things such as ropes, wind chimes, CDs or hanging baskets. Soft materials such as rope or cord can be hung at 10cm intervals and attached to the top edge of the window frame to dangle immediately in front of the glass. Hard objects should be hung away from windows to prevent them from tapping on the glass when it is windy.
Permanent Fixtures
- Awnings, shutters, shade sails, external blinds, mosquito mesh against the glass or taut, fine mesh netting at least 10cm away from the window that birds can bounce off without harm.
- Replace regular glass with decorative glass with permanent patterns etched, sandblasted or fused onto the glass. Windows broken into smaller panels such as French-windows or leadlight windows also offer a safer solution.
- If you are building a new home, consider reducing the amount of glass used in the house and avoid unnecessary use of glass for things like pool fences or balconies. Also avoid horizontal cables on fences and balistrades, vertical cables are the safer option.
- Consider angling windows downward by 20 degrees to prevent reflection from occurring at all.
Inside Tips
Prevent visual pathways. In areas of your house where you can see straight through multiple windows to the sky and/or greenery on the other side, create some sort of barrier between. Close internal doors or use curtains or blinds and be conscious of keeping some of them closed or partially closed on at least one side of your house during the day.
Prevent night-time collisions. Turn lights off at night when you’re not using them or close the blinds or curtains, as some nocturnal birds can get confused by or attracted to the light.
How to Assist an Injured Bird
- Gently examine the bird. If there are obvious injuries such as a broken wing, unusual movement, discharge from beak or eyes – immediately take it to your local vet or call Wildcare on 5527 2444 (available 24/7) to find a local wildlife carer.
- If the bird looks physically intact, see if it is able to perch on a branch, and watch it to see if it recovers enough to fly away. If it is too dazed or has been knocked unconscious, carefully place it in a well-ventilated box with a lid and place it in a warm quiet place that is safe from pets or other predators.
- Check on it regularly but don’t touch it or try to feed it.
- If the bird seems to recover, take the box back outside near where you found the bird and open the box, hopefully it will fly away. If not, continue to try every 30 minutes. If after a couple of hours the bird has not recovered, seek vet/carer assistance.
Land for Wildlife member, Pippa Welden (aged 10), has come up with a creative way to use window crayons to prevent bird strike.
The northern and southern windows don’t seem to be a problem, and we have only had two incidents on the eastern windows, both Channel-billed Cuckoos. One flew straight through a glass window and landed on the floor in our bedroom. The window was on the second floor and directly opposite a very large fig tree about 30 metres away where we often get a flock of these cuckoos in the summer when the fig tree is in fruit. After giving us the fright of our lives, it eventually dusted itself off and flew back out the large hole it had created (and left for us to repair!). The second one was about a year later and flew into a window on the ground floor. Unfortunately, it died on impact. I happened to be gardening about a metre from where it hit, poor thing, it gave me a big surprise.
We applied the stripes with a grout pen. I have a nice long piece of light stainless steel which I used as a ruler. It’s actually quite a quick process. As a housekeeping tip I would wash the windows first because you don’t want to do a repeat job with the stripes – or delay it as long as possible! The grout will come off when you wash the window. You can of course wash the outside of the window with impunity. You can buy grout pens in any paint or hardware store, and there are a variety of brands, all of which will do the job.
Prior to painting on the stripes, we we would average about five bird strikes a year with 3-4 fatalities. In the time since we applied the stripes (about a year ago), we have only lost one Rose-crowned Fruit-dove. However, this may have come to grief on a nearby window that we hadn’t painted with stripes because (a) it usually has a blind down behind it and (b) there are some bushes/golden canes quite close which I thought would be enough protection. So, it looks like the striped windows have actually been 100% successful.
Article and photos by Colleen Watts
Land for Wildlife member
Upper Brookfield, Brisbane
Article by Sue Nolan
Land for Wildlife Officer
Brisbane City Council