Click here to download a PDF of the Acopian BirdSavers Fact Sheet.
We’ve been using this technique for many years to keep birds from hitting ‘problem’ windows. I thought that anyone else who has this same problem should know about this solution. It’s a very simple solution. I hope you try it on your own ‘problem’ windows to prevent birds from being killed.

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  1. Suzette says:

    Hi Jeff-

    The BirdSavers seem to be doing their job really well.

    Thanks for all you help,


  2. Jeff says:

    Hello Suzette,

    I’m glad that people are receiving the BirdSavers well.
    That’s pretty typical. Most people think they look cool!

    As far as the color, that is the color of the most readily available paracord. That is the color of all Acopian BirdSavers and it does seem to be the most pleasing to the eye. And it does work. But I suspect that any other dark color would work just as well. For that matter, any color may work, but I haven’t tested other colors.

    They work just as well if the bottoms are secured so that they don’t move at all. Again, it is just more pleasing to the eye, for most people, when the bottom of the cords are visible. It is also kind of nice to see the movement of the cords on the days when the wind does blow. People sometimes worry about the cords tangling, but I really haven’t seen that to be much of a problem. Occasionally it may happen, but is very easily ‘untangled’.

    If you order more BirdSavers and want to secure the bottoms, let me know and I will leave the bottom cords longer.


    Take care,

  3. Suzette says:

    Hi Jeff-

    We just got the BirdSavers up a couple of days ago. We’ve mounted them with the Velcro right now and we placed them a couple of ways – right next to the window, from overhead of the window casement, and from the wall just above the casement (farther from the window). We’ll see if there is any difference in bird strikes and how they hang. At least to people, they look fairly different depending on how they are hung, and they seem to move differently with a breeze. We’ll secure them better before the really hot temperatures melt the adhesive on the Velcro. So far the reaction from the people who work here is that they look cool, even if they don’t know why they were put up.

    We did have a couple of questions:

    Do you use olive green-colored cord for a specific reason? Does it work better, or is it just not so noticeable?

    Do they work best if the bottom is loose and they can move? Or do the birds perceive the cords just as well if they are still? We wondering about putting them over a couple of doors and securing the bottom of the cords as well.
    We also have some very tall windows (taller than what I ordered the BirdSavers for this time, even if we make 2 tiers of birdsavers) and thought if we make our own, we might secure the bottoms of the cords so they don’t tangle in strong wind.

    Thank you
    Suzette Maneely
    US Arid Land Agricultural Research Center US Department of Agriculture
    21881 N Cardon Ln
    Maricopa, AZ 85138

  4. dizzybird says:

    Hi Jennifer,

    Acopian BirdSavers cords are spaced at 4-1/4″ because we have found, over the years, that this spacing works very well to prevent the birds from flying into windows and at the same time is not obtrusive to someone looking out the window from the inside. Spacing them closer together certainly won’t hurt. I always keep in mind that birds will occasionally even fly into the sides of buildings where there are no windows!! Strange as that seems.

    Let me know how you make out and if you feel like it you can even send some photos of your final installation.


  5. Jennifer says:


    Is it possible to have the cords spaced 4 in. or less apart?
    I’ve read a distance less than 4 inches is most effective.


  6. Nancy Taras says:

    We live in a wooded area adjacent to State Game Land in Eastern Pennsylvania near the Appalachian Trail. Our bird feeders are usually filled three seasons of four which attract many songbirds. Unfortunately, a few hawks have found those passerines easy prey. Other birds have hit windows with no obvious predator in pursuit. Our daughter read some of Dr. Klem’s research and suggested Acopian BirdSavers on all the house windows. They really do work to deter bird collisions. This has been especially evident during the 2011 spring warbler migration when not one warbler has been killed as has happened in the past. What a relief!

  7. dizzybird says:

    Both the Acopian BirdSavers and the Bird Screen provide a “visible signal” not to fly into the window. The “visible signal” is the nylon cords on the Acopian BirdSavers or the screen on the Bird Screen. This is effective almost 100% of the time. The Bird Screen has another level of protection (what I call the “trampoline effect”) for those rare times when the bird sees the “visible signal” too late or doesn’t see it at all (believe it or not, as an extreme example, birds sometimes fly into the sides of buildings where there are no windows). Here is an excerpt from the Bird Screen Installation Instruction Sheet: “The Bird Screen works in two ways. First, the number of collisions is reduced by 98% simply by presenting a visual barrier. Most birds can see the Bird Screen and therefore do not strike it. Second, for the few birds that still strike the Bird Screen, the cushioning effect is usually sufficient to prevent injury. However, on longer Bird Screens, the tautness may not be enough to protect all birds (especially larger birds) that collide with it. If this is the case with one of your windows, you can purchase an additional frame to place in the middle of the screen to increase the tautness. This frame would be attached across the middle of the screen and attach to the window with suction cups just like the bottom frame does. Extra frames can be ordered online or by contacting the Bird Screen Company.”

    I have never seen a bird strike a window with such force to break the glass, but I have heard such stories. In Anne’s stories above, had the bird flown into a taunt Bird Screen it probably would have bounced off, with no glass broken and the bird would probably have ended up in better shape than having hit glass. On the other hand, if either Acopian BirdSavers or Bird Screen had been on the window in the first place, the birds would have gotten the “visible signal” and would have avoided the glass.

    Jeff Acopian

  8. Peter says:

    I’d say that a 100% covering of a window with screening works 100% to prevent bird-glass collision- a no brainer, but I personally do not like the way those screens look. Decals only work if you put enough of them on the glass to pretty much cover the entire surface, so no fun to look at or to look through.

    Acopian BirdSavers remain, in my opinion, the most effective solution while allowing people to enjoy the view out of their windows, easy cleaning behind them, and very inexpensive if you make your own.

    Dr Klem’s’s recent field trials on Acopian BirdSavers, which concluded last month, have shown that they are very effective. The official report will be published shortly.

    Peter G. Saenger

  9. Anne says:

    My husband and I live in the suburbs of New Jersey. Both our kitchen window and our patio door were broken by bird strikes. In the first case it was the result of a hawk chasing a robin; the robin broke its neck and died and the hawk sat on our back patio, dazed, for at least 30 minutes before it recovered enough to fly away. In the case of the patio door, we simply found it broken without witnessing the cause but I feel sure that it was, again, a hawk because of the damage done. One pane of the double-paned glass was completely destroyed. Oddly enough there was no sign of casualties.

    We have just paid lots of money to replace the door and have also replaced two windows. Already we have heard the thunk of collisions and have sighted a hawk who is keeping an eye on our three bird feeders, looking for another easy meal. I am worried about the birds and, I must admit, our new door and windows.

    I have looked at the three proposed solutions to this problems and would appreciate some feedback on which works the best: the strings (Acopian BirdSavers), the screen (Bird Screen) or the decal approach. Has any comparison been done of these three methods and/or other methods I don’t yet know about? I have downloaded Dr. Klem’s article “Preventing Bird-Window Collisions” as a starter.

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