The percentage of recaptures depends on species. The percentage of recaps is higher for birds that live here year-round since they frequent our feeders and have more chances to be netted at one of our sessions. The percentage of recaps goes up for these birds the longer we band here.
For migrants, the percentage of recaps is much smaller.
As an example: today we banded 25 Black-capped chickadees (BCCH) and netted another 22 of them that already had a band--so today, for BCCH, almost 47% of the birds netted had already been banded, not unexpected in a year-round resident. Our last session was on Halloween of this year and we had a 48% recap rate then, so it's leveled off to just below 50%.
The figures are different for migrants like Rose-breasted grosbeaks (RBGR). 2011 was the first summer we banded and that year we banded 78 of them. This summer we banded another 45 of them but only recaptured 2 banded the year before--the others either didn't make it through winter or they didn't stop at our yard on their way to their nesting grounds. It will be interesting to see if the percentage of recaps goes up for RBGR in the next few years. I'm still hoping that at some point, some of the migrants we band might be captured at a different site and we'll learn something about their travels.
Not all migrants have such a low percentage, though. We banded 2 Gray catbirds (GRCA) in 2011 and of the two birds that returned to nest in 2012, one was banded. We were unable to recapture it, but chances are very high that it was the one banded here the year before. That would make the return rate 50%, which is right on par with the BCCH, but for different reasons. In this case, we don't get as many of the species but the one bird, at least, exhibited strong site fidelity and returned.