Recently, Eric, a second-year team member who is experienced at reading colored leg bands, ran across our oldest loon. This male, evicted in 2007 from Little Bearskin Lake, has been cooling his heels in Bearskin Lake since his displacement and shows no indication of regaining a territory. “Blue over Silver, Yellow only” produced 14 fledglings during his breeding career, 7 of which also bred in the study area. That level of chick production places him among an elite few in our study population.
Blue over Silver, Yellow only’s age sets him apart from all others. He is at least 28 years old, because he was banded as an adult breeder, which means he was at least 4 in 1991. He may be in his 30s. But a number of other loons that we have marked during the study approach this male in age — and three exceed him in productivity. The female on Upper Kaubashine (“Silver over Yellow, Red over Green”), for example, is 27 years old at a minimum. (Females first breed at no younger than 5 years of age, so her estimated minimum age is one year older than if she were a male.) She can boast having bred with four different partners on four different lakes, spanning two counties. The 25+ year-old Townline male, “Silver over Red, Orange over Green”, is unrivaled in terms of stick-to-itiveness, as he has held the Townline territory since at least 1994 — and still owns it. He has reared 16 chicks to fledging during his tenure, if we throw in the two from this year. Only two loons have raised more young: the current Oneida-West female (19 fledglings and counting on Oneida-East and Oneida-West) and the former Hancock male (17 fledglings from 1993 to 2009).
Although it is fun to gawk at the age and breeding success of certain star individuals, my quick analysis of the study’s oldest loons reinforces another point that I have made before — and one with substantial scientific importance: females are the ones that generally live to a ripe old age in loons. The reason(s) for this gender disparity are becoming clear. Males seem doomed to die young because of their participation in dangerous battles, and perhaps also their unfortunate proclivity for attacking fishing lures and baits. Inspection of the table above certainly makes one wonder whether males should rethink their high-risk approach to both territory acquisition and foraging. Then again, maybe there are compensating benefits that offset the costs.