漂泊信天翁(Diomedea exulans)是一种大型的信天翁,生活在南冰洋附近。漂泊信天翁是体型最大的一种信天翁,也是众多鸟类中,翼展最长的一种鸟,平均达3.1m,最长可达3.7m。漂泊信天翁以乌贼,小鱼,和船只丢弃的废物为食,有的时候会吃得太饱而飞不起来,只好很无助地在水面上休息。
漂泊信天翁一次繁殖只生一个蛋,蛋是白色,上面有斑点,大约10厘米长。在繁殖季节,它们会在南冰洋的岛上(如奥克兰、纽西兰、爱德华王子群岛等)占领一些松散的领地来筑巢并且繁育后代。它们的巢呈火山状,用植物建造,在底部宽约一米,顶部宽约半米。
漂泊信天翁平均寿命22.8年,一生有十分之九的时间生活在海上平均寿命22.8年,一生有十分之九的时间生活在海上。最新的研究发现,衰老对漂泊信天翁这种特别长寿的鸟类的觅食模式和繁殖等活动具有直接的影响,但是不会影响这种动物的天然生理。该研究发表于最新一期的PNAS上。
原文出处:
PNAS doi: 10.1073/pnas.0911181107
Patterns of aging in the long-lived wandering albatross
Vincent Julien Lecomtea,1, Gabriele Sorcib, Stéphane Cornetb, Audrey Jaegera, Bruno Faivreb, Emilie Arnouxb, Maria Gaillardb, Colette Trouvéa, Dominique Bessona, Olivier Chastela, and Henri Weimerskircha
How does an animal age in natural conditions? Given the multifaceted nature of senescence, identifying the effects of age on physiology and behavior remains challenging. We investigated the effects of age on a broad array of phenotypic traits in a wild, long-lived animal, the wandering albatross. We studied foraging behavior using satellite tracking and activity loggers in males and females (age 6–48+ years), and monitored reproductive performance and nine markers of baseline physiology known to reflect senescence in vertebrates (humoral immunity, oxidative stress, antioxidant defenses, and hormone levels). Age strongly affected foraging behavior and reproductive performance, but not baseline physiology. Consistent with results of mammal and human studies, age affected males and females differently. Overall, our findings demonstrate that age, sex, and foraging ability interact in shaping aging patterns in natural conditions. Specifically, we found an unexpected pattern of spatial segregation by age; old males foraged in remote Antarctica waters, whereas young and middle-aged males never foraged south of the Polar Front. Old males traveled a greater distance but were less active at the sea surface, and returned from sea with elevated levels of stress hormone (corticosterone), mirroring a low foraging efficiency. In contrast to findings in captive animals and short-lived birds, and consistent with disposable soma theory, we found no detectable age-related deterioration of baseline physiology in albatrosses. We propose that foraging efficiency (i.e., the ability of individuals to extract energy from their environment) might play a central role in shaping aging patterns in natural conditions.