Knowledge of population biological parameters can contribute to assessing the resilience of a population in the face of increasing anthropogenic pressures. Southern Hemisphere long-finned pilot whales (Globicephala melas edwardii) are susceptible to high rates of live stranding-related mortality. However, the biological parameters of this population largely are unknown. In this study, age, growth, allometry, and sexual dimorphism are described using teeth and external body measurements obtained from 515 male, 776 female, and 229 individuals of unknown sex, stranded on the New Zealand coastline between 1948 and 2017. Maximum ages of 31 and 38 years were estimated for males (n = 163) and females (n = 239), respectively. Females ranged in length from 160 to 500 cm (modal size class 400–449 cm) and males from 165 to 622 cm (modal size class 500–549 cm). Length-at-birth for both sexes was estimated at 170 cm using a logistic regression model. Growth models for both sexes indicated a preliminary rapid growth phase followed by a second phase of slower growth. For males, a two-phase growth model also indicated a moderate growth spurt around the average age at attainment of sexual maturity (ca.12–13 years). Asymptotic lengths were estimated at 570 and 438 cm for males and females, respectively. We found strong evidence of sexual size dimorphism, with males significantly larger than females for 13 of 14 external measurements. We also found sexual dimorphism with respect to shape, with males having proportionally longer pectoral fins, wider tail flukes, and taller dorsal fins, than females. Estimates of length-at-birth, maximum ages, and sexual shape dimorphism for G. m. edwardii differed from those previously reported for the North Atlantic subspecies (G. m. melas), which may indicate subspecies or population-level differences in morphology, longevity, and sociality.

中文翻译：

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南半球长鳍领航鲸 (Globicephala melas edwardii) 的年龄、生长和性别二态性

人口生物学参数的知识有助于评估人口面对日益增加的人为压力的复原力。南半球长鳍领航鲸（Globicephala melas edwardii）容易受到与活体搁浅相关的高死亡率的影响。然而，这个群体的生物学参数在很大程度上是未知的。在这项研究中，使用从 1948 年至 2017 年间滞留在新西兰海岸线上的 515 名男性、776 名女性和 229 名未知性别的个体获得的牙齿和外部身体测量值来描述年龄、生长、异速生长和性别二态性。男性（n = 163）和女性（n = 239）分别估计为 31 和 38 岁。女性的长度范围从 160 到 500 厘米（模态尺寸等级 400–449 厘米），男性的长度范围从 165 到 622 厘米（模态尺寸等级 500–549 厘米）。使用逻辑回归模型估计两性的出生时身长为 170 厘米。两性的生长模型都显示了一个初步的快速生长阶段，然后是缓慢生长的第二阶段。对于男性，两阶段生长模型还表明在达到性成熟的平均年龄（约 12-13 岁）附近有适度的生长突增。男性和女性的渐近长度估计分别为 570 和 438 厘米。我们发现了两性大小二态性的有力证据，在 14 次外部测量中，有 13 次男性明显大于女性。我们还发现了关于形状的性别二态性，雄性的胸鳍成比例地更长，尾鳍更宽，和比雌性更高的背鳍。G. m. 出生时身长、最大年龄和性别形态二态性的估计。edwardii 与先前报道的北大西洋亚种（G. m. melas）不同，这可能表明亚种或种群水平在形态、寿命和社会性方面的差异。