From Vagrant to Resident: occurrence, residency and births of leopard seals (<i>Hydrurga leptonyx</i>) in New Zealand waters

In contrast to previous reports that leopard seals (<i>Hydrurga leptonyx</i>) are rare vagrants to New Zealand, we show that this species is a regular member of the marine fauna of this region. We present a first analysis from the New Zealand Leopard Seal Database – an extensive collation of 2,711 records of leopard seals within New Zealand between 1200 and 2018. Of these records, 51.2% (<i>n</i> = 1,408) were photographic. Leopard seal sightings have increased over time and been reported in all seasons and regions of New Zealand. Sightings are predominantly of adult individuals of good or excellent body condition, which differs to previous hypotheses suggesting that leopard seals visiting New Zealand shores are primarily juvenile animals in poor health condition. A total of 176 unique individuals have been identified in the New Zealand Leopard Seal Catalogue between 2014 and 2018 and preliminary results indicate that numbers per annum have continued to increase over time. Three leopard seal births and a number of juvenile animals (34% of the NZ records) have been documented. Considering the information presented here and the current definitions in the New Zealand Threat Classification System, the threat status of leopard seals within New Zealand waters should be reclassified from Vagrant to Resident.与此前认为豹海豹（leopard seal，学名<i>Hydrurga leptonyx</i>）是新西兰罕见迷游物种的研究报道相悖，本研究证实该物种实为该区域海洋动物区系中的常客。本研究基于新西兰豹海豹数据库（New Zealand Leopard Seal Database）开展首次系统性分析，该数据库汇编了1200年至2018年间新西兰境内共计2711条豹海豹观测记录，其中51.2%（n=1408）为影像记录。豹海豹的目击记录随时间推移持续增加，且在新西兰全境的所有季节与区域均有观测报道。目击个体多为身体状况良好或极佳的成年个体，这与此前“到访新西兰海岸的豹海豹主要为健康状况不佳的幼体”的假说相悖。2014年至2018年间，新西兰豹海豹名录（New Zealand Leopard Seal Catalogue）中共识别出176个独特个体，初步结果显示其年度种群数量持续攀升。研究还记录到3次豹海豹产仔事件，以及占新西兰境内观测记录34%的幼体个体。结合本文呈现的研究数据与新西兰威胁分类系统（New Zealand Threat Classification System）的现行定义，新西兰海域内豹海豹的保护威胁等级应从“迷游种（Vagrant）”重新归类为“留居种（Resident）”。