ABJ

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LMG_3148 SOO ABJ It is easy for me to say, I suppose, because I am sitting here in southern California in my shorts and t-shirt, wondering only if we have enough lemonade to survive the day (and enough water to make lemonade)! Still, I think most of us can agree that the season is beginning to turn. This week’s highs in Oneida County will be in the 60s, which should take care of most or all of the remaining ice on the lakes, especially with the help of the wind. After a rather brutal winter, we have an ice-out that is about a week earlier than average. Early iceout created an odd spectacle on many lakes this week past: open water devoid of loons. To be sure, breeding pairs are trickling back. Joel Flory has confirmed that both members of the breeding pair on Manson Lake have returned. Lake residents have spotted a pair on Lake Mildred and one of two pair members on Sherry. Linda Grenzer reports that “Clune”, the male on Muskellunge Lake, returned on Friday for the first time, although his long-time mate, “Honey”, has not shown up, and he is currently frolicking with a new female (see Linda’s photo, above) that we banded as a chick in 2004 on Soo Lake, Linda reports. (We are not judging!) Why would territory owners leave their lakes undefended, especially at a time when many adult loons without territories are on the prowl, anxious to seize any vacant lake? The answer is simple. Weather changes rapidly. As migrants that must fly hundreds of miles between the wintering and breeding grounds, loons face a meteorological puzzle. If they molt their feathers and migrate too early to the breeding grounds, they will encounter wintry conditions and uninhabitable frozen lakes on arrival, struggle to find enough food on open water along rivers, and ultimately settle on their breeding lake in poor condition. They will then be at risk for losing their territory to a fitter, stronger usurper who times his or her arrival better and remains in better condition. If, on the other hand, they wait too long to migrate, they might return to find a squatter established on their territory. In such cases, a territory owner would have to battle the squatter to reassert itself as owner. In short, gauging when to return to the lake you own is an inexact business for a territorial loon. We can understand why they might often arrive a bit too early or too late. So we must be sympathetic about the pitfalls of long-term planning and content with a steady trickle of returning loons. Don’t worry. Territorial loons have evolved a sound set of strategies for coping with fluctuating weather conditions — and interlopers. We expect to see most of them re-established on territories within a week. I will keep you posted!

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After the black fly debacle in recent weeks, we were all ready for some good news. Indeed, most territorial pairs had shaken off the flies and gotten back to the business of reproduction. Good tidings seemed the order of the day. Yesterday, Al Schwoegler of West Horsehead Lake called with a thrilling and unexpected report: the eggs laid by the pair, which they had left unattended for many long hours on several days because of the torment of black flies, had begun to hatch! At first neither Al nor I could believe that the eggs were viable. As Al described the behavior of the female on the nest — who has reared a whopping 19 chicks to fledging since 1996, when she was first banded — we gradually let ourselves believe that the impossible had occurred.

But our positive feelings were dashed suddenly by the cruel realities of loon territorial behavior. You see, the last few weeks at West Horsehead have been marked by frequent territorial intrusion. At the very time that the pair was trying to recover from the onslaught of biting insects, the male owner was facing repeated challenges for his position. Finally, by yesterday, both Al and Sally Yannuzzi of my team confirmed that male ownership had passed from the 14 year-old male hatched on Alva Lake who had resided on the lake for most of the past decade to a 9 year-old upstart from Harrison Lake in Lincoln County. The new male, confident in his new position, spent much of the morning resting and foraging near the nest, while the female patiently sat on the eggs. Finally, the female slid off of the nest into the water, revealing a newly hatched chick and second egg, which was on the brink of hatching. Alas, the new male behaved as animals typically do when confronted with helpless young that are not their genetic offspring: he quickly pecked the chick to death as its mother looked on helplessly. The celebration of an unexpected hatch gave way to a wake for a young loon doomed by territorial usurpation. Al took this photo of the female, still mildly protective of her nest containing the dead and unhatched chicks. (Shortly after the photo was taken, the female left the nest to forage with her new mate, with whom she might still renest.) IMG_20140616_134217_724Sorry for the unpleasant photo and description. But there is a valuable lesson here. Loons, like lions and langurs and mice and water bugs, behave so as to promote their own reproduction. Despite the ugliness of this episode, we can hardly hold it against the 9 year-old that he is looking to produce his own biological offspring — before a new usurper comes along and shows him the exit.

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A lot can happen in a short time, it seems. I have spent only three days in the study area so far, but already we — Joel, Eric Andrews and I, and our incredible citizen scientists Linda Grenzer and Al Schwoegler — have found 8 active nests. Considering the territories we have visited recently and those we have not, I estimate that about 15-20% of all pairs in the study area are already incubating. Clearly the pairs have shortened the window between ice-out and egg-laying in order to compensate for the very late spring this year. I suspect this is possible, in part, because females were able to recoup much of the energy consumed during spring migration by foraging for weeks along rivers in the study area, before their breeding lakes opened up. That is, the extra foraging time near their territorial home apparently compensated for the foraging time that would normally occur on their territory.

Territorial turnovers have been common this spring; many marked pair members from 2013 either failed to return in the spring or did return but were evicted from their territories. The evicted birds include a young “ABJ” (“adult banded as a juvenile”; meaning a loon we banded as a chick) male from Schlect Lake. This ABJ male, hatched on Fox Lake in 2005, produced two chicks, of which one fledged, in 2012. But in early 2013, the Fox ABJ had been replaced by another ABJ male, this one also hatched in 2005, but on McNutt Lake. In late 2013, the Fox ABJ was able to retake his territory (possibly after the McNutt ABJ left it) and lived there the rest of the summer. However, two days ago, Eric and I witnessed a nasty battle between the Fox and McNutt ABJs (now both 9 years old) that culminated in the exhausted and defeated Fox male taking refuge on shore to avoid further attack from the McNutt male. Quite a grim spectacle! It remains to be seen whether the Fox ABJ can recover, drag himself off of this tiny 25-acre lake and get on with his life.

While our problems pale in comparison to the desperate life-and-death struggle that the Fox ABJ is facing, this latest contest is troubling to us as well. You see, we have hypothesized that dangerous contests of this kind likely occur when very old males (with very little reproductive fitness to lose) roll the dice by battling to win a few more years on their territory rather than accepting displacement by a younger, stronger male. (This is termed the “terminal investment hypothesis”.) Naturally, we must use statistical tests on a large body of data before drawing any conclusions. Still, it was unsettling to see a vigorous young male — and one that doubtless would have many potential future years of reproduction ahead of him — suffer a life-threatening encounter that flies in the face of our pet hypothesis.