Friday, May 27, 2022

Welcome back!

 

Adult females and all juveniles return to the beach

More seals are on the beach in May at the Piedras Blancas elephant seal viewpoint than any other time of the year. Adult females, returned from their short migration, sleep. Juveniles, both male and female, have been out to sea all winter. They now fill out the beach crowd. Young males spar while their elders take advantage of the time to rest and all molt their skin.

Researchers marked M 92 and watched her give birth to her pup. They observed them until the pup was weaned. Then the pup got two white tags, so his appearance can be tracked. (Christine Heinrichs photo) 

Molting

The obvious change the seals undergo is molting their skin. The old brown skin and hair peels off in chunks, exposing new skin and hair underneath. Look for pearly gray seals next to brown and tan seals. Check out the ones with skin curling off around eyes and nose. Old scars also start peeling back the molted skin.

The process carries its own distinctive aroma, from all those mammals shedding skin on the beach. A few of the less thoughtful have orange feces smeared on their back ends.

Good thing the seals don’t defecate on the beach, or the smell would chase visitors off the boardwalk. It’s just a few outliers who add to the smell.

The seals stop foraging for food a day or two before they arrive, and don’t eat anything while they are on the beach. Their digestive and metabolic processes change. My observation is that arriving seals often defecate just before they arrive on the beach, leaving an orange bloom behind them.

Female migration

The females are undergoing changes as the egg that was fertilized back during the breeding season now implants in the uterine wall and begins to develop into an embryo. The process is called delayed implantation. After fertilization, the egg divides a few times and then pauses.

The process gives the mother time to restore her weight so that she is strong enough to carry the pregnancy to term.

Starting now, gestation takes about eight months. The females will leave the beach in a month or so. They will return in January, after their long migration, to have their pups.

Look for marks, other species

With research projects ramping up at Cal Poly and other locations adding marks, marked seals are more commonly seen on the beach. All marks are temporary, since they come off with the molted skin.

Other wildlife share the beach. A Guadalupe fur seal pup and a California sea lion pup hauled out on the beach recently. Every day brings different animals and birds to the viewpoint. The elephant seal viewpoint is easy to access but provides world-class wildlife viewing.

Monterey Bay National Marine Sanctuary is one of 15 that protect seascapes, wildlife and maritime heritage resources. Save Spectacular is the theme of the 50th anniversary.  (Douglas Croft photo NOAA)

The beach is within Monterey Bay National Marine Sanctuary. To celebrate 50 years of national marine sanctuaries, NOAA has compiled a series of Resource Collections. Peruse the many events, photos, lesson plans, maps, and other educational materials at https://sanctuaries.noaa.gov/50/?utm_medium=email&utm_source=GovDelivery. One covers Ocean Sound and Impact of Noise, https://sanctuaries.noaa.gov/education/teachers/ocean-sound/. The SanctSound Monitoring Project offers a portal that provides downloadable tools for comparing ocean sound, with six tutorials to help use the data.