Slow Reproduction Rates

Sei whales don’t have a rapid reproduction rate like some other creatures do. Cockroaches, for example, have about 200 offspring in their lifetime. The sei whale is negatively impacted because of their slow reproduction rate, as they aren’t able to grow their population back quickly, especially once they are on the endangered species list.

Sei whales are considered K-Strategists, which are species that have organisms that tend to reproduce later in life, have a small number of offspring, live longer, and raise their young (Miller, 2015).

Sei whales don’t reach full maturity until they are about six to eight years old. They have an average life span of 50 to 70 years, although calving occurs every 2 to 3 years during the winter breeding season and then the calves nurse for six months. Gestation lasts for almost a year (11-12 months), between eleven and twelve months.  then the calves nurse for six months. Normally, the sei whale only gives birth to a single calve per birth, rarely two. Due to these slow statistics, it is difficult for the sei whale to increase its population quickly (WWF, 2020).