News This Week
Possible peak of the season hits, and expected decline of females expected next week.
Mating activity has been observed.
Drakes Beach closure continues.
High numbers of elephant seals at the park were recorded this week, with 2,441 total seals Tuesday, January 30. While pups are still being born, we are seeing an increased number of weaned pups. As the pups get close to weaning, the females will come into estrus and mate with the males. Mating and the departure of female post weaning, may be observed from the elephant seal overlook.
Researchers at Point Reyes conduct weekly surveys to document tagged animals, allowing for data collection on the movement of individual animals.This week, we had two exciting tag re-sights! A pregnant cow was spotted on Drakes Beach, with a massive healed shark bite on her back. She has a bright green tag in both rear flippers, which means she was tagged at Año Nuevo, but she has been consistently seen in Point Reyes since 2013. Also on Drakes Beach, a nursing cow was spotted with a pink Point Reyes flipper tag. She was tagged as a weaned pup in 2000 at the Headlands colony, and this is the first time she has been spotted since! It is possible this 18 year old cow has recently decided to relocate to the more protected Drakes colony for the breeding season. Elephant seals often return to breed at the beach where they were born, but these two females demonstrate that this is not always the case.
Pinnipeds (seals and sea lions) employ a reproductive strategy called delayed implantation. This delay allows for the timing of the birth to correlate with favorable environmental conditions, regardless if mating occurs early or late in the breeding season. The total gestation period for northern elephant seals is approximately 11 months. After successful mating, female seals will delay implantation for about 3 ½ months, after which the fertilized egg will implant in the uterus and continue to develop for the next 7 ½ months until birth. Examples of other animals that delay implantation are Ursids (bears) and Mustelids (weasels and otters).