USGS Science⌕ Search
Home/Archive/USGS

USGS · 1007656

An incidence of twinning in the sea otter (Enhydra lutris)

Ronald J. Jameson·James L. Bodkin
View original source ↗Export metadata ↓

Abstract

On 3 October 1984 at 0928 h (PST) near Pt. San Simeon, California (35°39’N, 121°11’W), we observed a female sea otter ( Enhydra lutris ) resting in a kelp bed ( Macrocystis pyrifera ) with a small pup on her chest; approximately 2 m away another small pup floated unattended in the kelp. The only other otters we saw in the area was a mated pair (adult male tending an adult female) resting about 20 m from the mother and pups. At 0929 h the mother swam to the unattended pup and placed it on her abdomen next to the other pup. We concluded that live birth of twin pups had occurred, an incident previously unrecorded for the species.

Explore related subjects

Marine Mammal ScienceArticle
90° N90° S · 180° W ← longitude → 180° E
Source-reported bounding extent: 35.49813313935565° to 35.632744348010625° latitude; -121.27601623535156° to -121.11946105957031° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Ronald J. Jameson, James L. Bodkin. 2006-08-26. An incidence of twinning in the sea otter (Enhydra lutris). https://doi.org/10.1111/j.1748-7692.1986.tb00138.x

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Quantifying southern sea otter (Enhydra lutris nereis) reactions to a quadcopter drone in central California

Drones are useful for wildlife research and management, but they can cause disturbance and harassment to wildlife. Sea otters ( Enhydra lutris ) are candidates for drone-based observation and monitoring but are vulnerable to disturbance. No studies have evaluated drone effects on sea otter behavior, but based on prior disturbance studies, we hypothesized: (1) sea otters would exhibit behaviors indicating higher reactivity in the presence of drones than when drones were absent and (2) drone disturbance to sea otters would be greater when drones were closer. At two sites in Monterey Bay, CA, we conducted 37 observational sessions, recording behavior codes for focal sea otters during a baseline (no drone) period and three consecutive drone flights. Data were analyzed using ANOVA and ordinal logistic regression models. At both locations, focal sea otters had higher behavior codes during drone trials compared to baseline, and behavior codes increased with descending drone altitude. Pup presence, group size, flight trial number, and gull presence were significant covariables. We calculated multipliers to predict drone-mediated behavioral responses at a range of drone altitudes. Our findings can inform best practices for a variety of uses of drones around sea otters, including population monitoring, oil spill response, and drone photography/videography.

California↗
USGS2023

Effects of feeding and habitat on resting metabolic rates of the Pacific walrus

Arctic marine mammals live in a rapidly changing environment due to the amplified effects of global warming. Pacific walruses ( Odobenus rosmarus divergens ) have responded to declines in Arctic sea-ice extent by increasingly hauling out on land farther from their benthic foraging habitat. Energy models can be useful for better understanding the potential implications of changes in behavior on body condition and reproduction but require behavior-specific metabolic rates. Here we measured the resting metabolic rates (RMR) of three captive, adult female Pacific walruses through breath-by-breath respirometry when fed and fasted resting out of water (sitting and lying down) and while fed resting in water. RMR in and out of water were positively related with pretrial energy intake when not fasted and 25% higher than RMR when walruses were fasted and out of water. Overall, RMR was higher than previously estimated for this species. Fasting RMR out of water was only 25% lower than subsurface swimming metabolic rates suggestive of relatively efficient swimming in adult females. Our results identify the importance of considering feeding status and species-specific differences in affecting metabolic costs. Further research is needed to better understand potential energetic costs of thermoregulation at temperatures experienced by wild walruses.

Valencia↗