In the wild, the average age at first observed birth is around 12-14 years (Ford 2009), with a mean of 13 years using this average. Although it’s possible for females to give birth prior to this age, with two captive females giving birth at 7 years old, wild females factor in both sexual and social maturity before bearing a calf. Within wild pods, there are ‘social mechanisms’ which prevent young females from mating before they are mature enough to raise offspring appropriately. By ensuring a female is both sexually and socially mature enough to raise a calf, physiological damage and calf rejection is reduced. These social mechanisms often do not exist in the fractured artificial pods which exist in captivity. As a result, the average age at first observed birth in captivity is merely 11 years old. This is two years younger than the wild average and is actually closer to the average age a wild orca would be first impregnated, according to the same study.
Photo credit to NOAA.
Across 9 facilities, 29 females (excluding those previously mentioned) have been impregnated as part of captive breeding programmes and produced either live or stillborn calves during their first observed birth. 24/29 (~83%) of these captive mothers gave birth when they were younger than the wild average of 13 years old, with 17/29 (~59%) doing so when under the age of 11 (the captive average).
In terms of average age at first observed birth by facility, Marineland Antibes has the lowest average at 8 years and 10 months whereas Nanki Shriahama Adventure World (since defunct) has the highest average at 16 years and 10 months. Here’s how the other facilities compare:
Averages by Facility: (Lowest to highest)
Marineland Antibes: 8 years and 10 months
Marineland of the Pacific: 10 years, 2 months
Kamogawa Sea World: 10 years and 9 months
SeaWorld: 10 years and 10 months
Vancouver Aquarium: 10 years, 11 months
Mundo Marino: 11 years
Loro Parque: 11 years, 2 months
Sealand of the Pacific: 11 years, 3 months
Marineland Canada: 12 years and 10 months
Nanki Shriahama Adventure World: 16 years, 10 months
Photo sourced from Orca Pod Wikia.
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With the largest breeding programme, SeaWorld’s average is the fourth lowest at 10 years and 10 months (below both the captive and wild average). Additionally, of SeaWorld’s 14 mothers, 8 gave birth for the first time when they were younger than 11 years old. Overall, of the top five youngest mothers in captivity, four (Kalina, Kohana, Taima and Katina) were part of SeaWorld’s breeding programme – all of who gave birth for the first time under the age of 9.
Disclaimer: As this post compares a mother’s age at her first observed birth, both Kahana and Neocia have been excluded from the data as their pregnancies led to miscarriages, not births. Additionally, Kohana (who resides at Loro Parque) gave birth to both of her calves while under SeaWorld’s ownership so has been included in SeaWorld’s average. Likewise, Morgan gave birth to her calf after her ownership was transferred from SeaWorld to Loro Parque so she has been included in Loro Parque’s average.