Twenty years ago colleagues and I published a paper showing that artificial nesting platforms increase loon’s hatching success by 70%. Others have reported similar patterns. So there is no doubt that, on average, loons that incubate their eggs on artificial nesting platforms (“ANPs”) put more chicks in the lake than do pairs using natural sites. Moreover, our paper showed that greater hatching success produced by ANPs also leads to more fledged loons.

In the last two decades, ANPs have become an enticing tool used by loon conservationists to boost loon populations. This is not surprising. ANPs have proven to be effective, and they are rather easy to make and place in the water. So conservationists can plop a mess of ANPs in the water and feel pretty confident that they have added young loons to the population. And they can make a strong case to funding agencies that their actions might help loons avoid population decline. Indeed, many millions have been/are being spent in the U.S. to float ANPs as a means to mitigate the negative effects that oil spills in the Gulf of Mexico have had on the species.

Are ANPs really just as good as natural sites at producing young loons that reach adulthood? Or are platform-raised chicks not as likely to survive to fledging age as chicks hatched as natural sites? We must remember that loons pick the location of a natural nest, whereas humans choose the site where platforms go. So it seems quite plausible that platform-raised young face hazards that natural-raised young do not.

It is only now that I have large enough samples of nests from platforms and natural sites that I can run a head-to-head comparison. Despite my 32 years of Wisconsin data, only a small proportion of loons in the Wisconsin Study Area (e.g. 15 of 90 focal pairs in 2024; 17%) nested on platforms. In Minnesota, however, almost half of all of our focal pairs use ANPs (38 of 84 territorial pairs in 2024; 45%), so our sample of platform-hatched chicks has swollen markedly since 2021.

As the graph above shows, hatchlings from platforms are lost slightly more often than are natural-hatched chicks in both states. While the pattern shows up in both Minnesota and Wisconsin, the difference is quite small and does not reach statistical significance. In other words, we have no scientific evidence that chicks hatched on platforms suffer lower survival than those hatched at natural sites. The same can be said for chick loss in Wisconsin versus Minnesota, despite what appears to be a slightly higher rate of chick loss in the North Star State.

Frankly, I am relieved! It has become almost de rigueur to place an ANP in your lake to support the loons. If, for some reason, ANPs had been producing chicks likely to perish before reaching adulthood, it would have sent shockwaves through the world of loon conservation.

I am still not a great fan of nesting platforms. Why not? Because we have learned in recent years that nest predation is not the main problem loons are facing in the Upper Midwest. Remember, nesting platforms are a one-trick pony. They increase hatching success enormously and put more chicks in the water. But if chicks cannot get enough food to survive to adulthood or reach prime condition, then all of the platforms in the world will not help them.