An extreme wandering leopard seal, Hydrurga leptonyx, at Pitcairn Island, central South Pacific

Leopard seals are distributed around the Antarctic continent principally between 50°S and 80°S though they are known to wander even farther north, particularly to Australia, New Zealand, South America, and South Africa, and several sub-Antarctic Islands. Seasonal movements of leopard seals have been correlated with seasonal changes in the distribution of sea ice with seals moving north as sea ice develops in spring and winter and southward toward the Antarctic continent as it melts in late autumn and winter. On August 9, 2013, an emaciated juvenile male leopard seal was observed swimming in Bounty Bay at Pitcairn Island (25°4′S, 130°6′W). It was found ashore at a boat ramp in the bay the next day. Because of the seal’s apparent distress, it was promptly shot and killed humanely by an island police officer and then dumped at sea before any measurements or additional observations could be made. We estimated the seal to be a 10-month-old pup, about 1.8–2 m long. The appearance of this leopard seal at Pitcairn Island is only slightly farther south than the most northern record (the Cook Islands, 21°25′S, 159°8′W) for the species, but it is the most remote occurrence yet documented worldwide and correlates with the all-time record for sea ice coverage in the Antarctic in winter 2013.

豹海豹主要分布于南极洲周边，主要介于南纬50°至80°之间，尽管已知它们甚至可以向北更远的地方迁徙，尤其是澳大利亚、新西兰、南美洲和南非，以及数个亚南极岛屿。豹海豹的季节性迁徙与海冰分布的季节性变化密切相关，随着春季和冬季海冰的形成，海豹会向北迁徙，而在秋季和冬季海冰融化时，它们则会向南移动至南极洲大陆。2013年8月9日，在皮特凯恩岛的邦蒂湾（南纬25°4′，西经130°6′）观察到一只消瘦的幼年雄性豹海豹正在游泳。第二天，它在湾内的码头附近被发现。由于海豹的明显不适，岛上的警察官员迅速以人道的方式将其射杀，并在进行任何测量或进一步观察之前将其抛入海中。我们估计这只海豹大约10个月大，体长约1.8至2米。这只豹海豹出现在皮特凯恩岛的位置仅略南于该物种最北的记录（库克群岛，南纬21°25′，西经159°8′），但这是迄今为止全球最遥远的记录，且与2013年冬季南极洲海冰覆盖面积的历史最高记录相吻合。