High mortality rates for young elephant seals means long-lived females dominate the reproductive output of the population.
(From UC Santa Cruz/ By Tim Stephens) — Most of the pups born in an elephant seal colony in California over a span of five decades were produced by a relatively small number of long-lived “supermoms”, according to a new study by researchers at the University of California, Santa Cruz.
The long-term study, published September 17 in the Canadian Journal of Zoology, documented the lifetime reproductive success of 7,735 female northern elephant seals at the Año Nuevo rookery north of Santa Cruz. Only 6 percent of the females gave birth to 10 or more pups during their lifetimes, and those “supermoms” accounted for more than half (55%) of the total pup production.
“It’s surprising because there are so many more young females than older females, and you expect them to contribute more to the population. But it doesn’t work out that way, because most of them don’t live very long,” said Burney Le Boeuf, professor emeritus of ecology and evolutionary biology at UC Santa Cruz and lead author of the paper.
In fact, the researchers found…
Read the full article here: https://news.ucsc.edu/2019/09/supermoms.html