Thank you so much for the interest everyone. I stopped production of the Halo device just for the Summer as we recollect parts and build inventory again. We tend to discourage Summer (July & Aug) mix-seed feeding in any case, since juvenile House Sparrows are generally immune to the wires and carry this into adulthood. This is where halo efficacy is somewhat lower in the Summer as seen in the U of Neb paper. Everything about this device is contained in my blog. Start home and scroll down, or at least check out these two:<p><a href="https://www.magichalo.org/2022/01/magic-halo-3-years-in-review.html" rel="nofollow">https://www.magichalo.org/2022/01/magic-halo-3-years-in-revi...</a>
<a href="https://www.magichalo.org/2022/01/as-we-enter-our-4th-year.html" rel="nofollow">https://www.magichalo.org/2022/01/as-we-enter-our-4th-year.h...</a><p>We find that, overall, the Halo is about 85% effective according to those surveyed. Cheers, -Francis
I made one of these halos 2 years ago, and my anecdotal experience is that the older (fully grown) sparrows can't figure it out, but the smaller, younger ones get through. Then, weeks later, I see fully grown sparrows at the feeder, ignoring the halo. Did the little ones "fit" and then grew too used to it to be spooked? Did the big ones learn from the little ones? I don't know.<p>Another observation: Because of the number of sparrows, I did pull the whole feeder down and kept it down for months. Then, when winter approached, I put the feeder and the halo back up, and no house sparrows made it through again. Did the adults who were defeating it before forget? Move on? Die? Who knows!
I thought it was interesting that it’s apparently a mystery <i>why</i> hanging lines deters sparrows (see the papers linked at the end of the first paragraph).
I wonder if avoiding the wires has anything to do with magnetic field lines? I know some birds can see the earth's magnetic field, maybe the wires appear larger to their magnetic senses compared to other bird species?
This surprised me, House Sparrows here in the UK seem to get along with other small birds just fine, I never see any aggression at feeders or in the hedgerows.
As far as this actually does anything, the birds will surely learn to ignore it / navigate around it. That is why house sparrows are so widespread in the first place, they have adapted to all the stupid things we humans do.