Mr. Day raises a good question about ospreys (“Question about thriving ospreys,” page A6, Aug. 30 Herald).
I’m not an ornithologist or a fisheries expert, but I know that eagle and osprey populations are both increasing, while we keep reading that wild salmon populations are in trouble. Environmental toxins and overfishing seem to have affected other fish populations as well. Overfishing lowers the average size of fish available, which is unfortunate because the older, larger fish are the champs when it comes to producing young.
Eagles and ospreys both prefer to eat fish, but ospreys may be better at catching them. These agile birds can hover directly overhead and time their swoop with precision. Eagles are bigger and less agile and, because of their size, require more food. On the other hand, they seem to be successful at cooperative hunting or surprise attacks on marine birds.
The article’s headline announcing that the ospreys are back may be misleading. They recently left for the winter. But they and their surviving offspring will be back in the spring, and their young will be looking for new nest sites and new territories.