We had a technical problem and sadly the February talk was not recorded so here are highlights from the speech.
February’s fascinating talk was attended by well over one hundred ACS chapter community members to hear from Dr. Roxanne Beltran and researcher Conner Hale relate their research "Unraveling individual and environmental drivers of variation among elephant seals". Due to a technical failure we are unable to provide a recording but are sharing these video links for further interest: 1) 2025 PBS feature, 2) 2024 Science Magazine feature, or 3) Roxanne's Kraw Lectures of 2022 and Slug and Stein Lecture of 2023.
We encourage those interested in keeping up with the cutting edge research underway at the Beltran Lab to subscribe to their newsletter here. And a snippet of the lively Q&A that ensued follows.
· How do researchers identify ES that arrive in various haul-outs?
Researchers at various California Elephant seal rookeries have agreed to use color tags to mark their locations. For instance, Pt. Reyes uses only pink tags; Ano Nuevo only uses green tags; the Marine Mammal Center uses orange tags for its rescued elephant seals. That is how researchers know that juvenile ES from Ano Nuevo have been seen at the Channel Islands, San Simeon, and Pt. Reyes haul-outs.
· Can elephant seals differentiate between fish-eating orcas versus mammal-eating orcas?
Answer: Unknown
Biggs orcas, which hunt marine mammals, go completely silent during hunts to avoid detection by their prey. Resident orcas, which primarily eat fish, use echolocation clicks to locate their prey. Elephant seals eavesdrop on deep echolocating cetaceans (i.e. orca, dolphins, beaked whales) and may follow these cetaceans to find prey in the deep Mesopelagic Zone of the oceans.
· How do elephant seals avoid predation by Orcas when they are swimming back from Alaska to California?
Answer: One behavior observed and recorded on the tags is that elephant seals do respond to Orca sounds by diving deeper away from the surface.
· Regarding an elephant seal’s weight gain in a foraging trip, Conner offered this:
“I calculated the BMI of a seal that wore a tag during the post-molt foraging trip, and at deployment her BMI was 41, and at recovery her BMI was ~75! She went from 290 to 524 kilograms.” Some female elephant seals consistently gain up to 100kg of weight when pregnant. Beltram Labs’ research showed that increased weight gain correlated with lifetime reproductive success. Females that gain weight consistently have heavier weanlings, which have a better chance of surviving.”
If people are interested in donating to the Beltram Lab in Santa Cruz, here is a direct link:
https://give.ucsc.edu/campaigns/38026/donations/new?designation=a1K8c00000i24K3EAI