Patricia M Rivera
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Research Interests
Patricia M Rivera has a total of 8 co-authors. Here are the top co-authors by number of shared publications:
- Brian S. Fadely
Affiliation Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, Washington, United States of America
1 shared publication - Greg A. Breed
Department of Biology and Wildlife, University of Alaska Fairbanks 1 , Fairbanks, AK, USA
1 shared publication - Lorrie D. Rea
University of Alaska Fairbanks Institute of Northern Engineering 1764 Tanana Loop, Fairbanks, Alaska 99775, USA
1 shared publication - Robert H. Coker
Montana Center for Work Physiology and Exercise Metabolism, University of Montana , Missoula, MT
1 shared publication - Stephanie G. Crawford
University of Alaska Fairbanks Department of Biology and Wildlife and Institute of Northern Engineering 1764 Tanana Loop, Fairbanks, Alaska 99775, USA
1 shared publication - Todd M. O'HAra
Department of Veterinary Medicine, University of Alaska Fairbanks, P.O. Box 757750, Fairbanks, Alaska, 99775-7750, USA
1 shared publication
Latest Publications
- Open Access
- 1 January 2023
- Published by Oxford University Press (OUP) in Conservation Physiology
- Vol. 11 (1) , coad084
Fasting durations of Steller sea lion pups vary among subpopulations—evidence from two plasma metabolites
Geographic differences in population growth trends are well-documented in Steller sea lions (Eumetopias jubatus), a species of North Pacific pinniped listed under the U.S. Endangered Species Act in 1990 following a marked decline in population abundance that began during the 1970s. As population growth is intrinsically linked to pup production and survival, examining factors related to pup physiological condition provides useful information to management authorities regarding potential drivers of regional differences. During dam foraging trips, pups predictably transition among three fasting phases, distinguished by the changes in the predominant metabolic byproduct. We used standardized ranges of two plasma metabolites (blood urea nitrogen and β–hydroxybutyrate) to assign pups to fasting categories (n = 1528, 1990–2016, 12 subpopulations): Recently Fed–Phase I (digestion/assimilation–expected hepatic/muscle glycogen usage), Phase II (expected lipid utilization), transitioning between Phases II–III (expected lipid utilization with increased protein reliance), or Phase III (expected protein catabolism). As anticipated, the majority of pups were classified as Recently Fed–Phase I (overall mean proportion = 0.72) and few pups as Phase III (overall mean proportion = 0.04). By further comparing pups in Short (Recently Fed–Phase II) and Long (all other pups) duration fasts, we identified three subpopulations with significantly (P < 0.03) greater proportions of pups dependent upon endogenous sources of energy for extended periods, during a life stage of somatic growth and development: the 1) central (0.27 ± 0.09) and 2) western (0.36 ± 0.13) Aleutian Island (declining population trend) and 3) southern Southeast Alaska (0.32 ± 0.06; increasing population trend) subpopulations had greater Long fast proportions than the eastern Aleutian Islands (0.10 ± 0.05; stabilized population). Due to contrasting population growth trends among these highlighted subpopulations over the past 50+ years, both density-independent and density-dependent factors likely influence the dam foraging trip duration, contributing to longer fasting durations for pups at some rookeries.
- 1 January 2023
- Published by Oxford University Press (OUP) in Conservation Physiology
- Vol. 11 (1) , coad084
Open AccessFasting durations of Steller sea lion pups vary among subpopulations—evidence from two plasma metabolites
Geographic differences in population growth trends are well-documented in Steller sea lions (Eumetopias jubatus), a species of North Pacific pinniped listed under the U.S. Endangered Species Act in 1990 following a marked decline in population abundance that began during the 1970s. As population growth is intrinsically linked to pup production and survival, examining factors related to pup physiological condition provides useful information to management authorities regarding potential drivers of regional differences. During dam foraging trips, pups predictably transition among three fasting phases, distinguished by the changes in the predominant metabolic byproduct. We used standardized ranges of two plasma metabolites (blood urea nitrogen and β–hydroxybutyrate) to assign pups to fasting categories (n = 1528, 1990–2016, 12 subpopulations): Recently Fed–Phase I (digestion/assimilation–expected hepatic/muscle glycogen usage), Phase II (expected lipid utilization), transitioning between Phases II–III (expected lipid utilization with increased protein reliance), or Phase III (expected protein catabolism). As anticipated, the majority of pups were classified as Recently Fed–Phase I (overall mean proportion = 0.72) and few pups as Phase III (overall mean proportion = 0.04). By further comparing pups in Short (Recently Fed–Phase II) and Long (all other pups) duration fasts, we identified three subpopulations with significantly (P < 0.03) greater proportions of pups dependent upon endogenous sources of energy for extended periods, during a life stage of somatic growth and development: the 1) central (0.27 ± 0.09) and 2) western (0.36 ± 0.13) Aleutian Island (declining population trend) and 3) southern Southeast Alaska (0.32 ± 0.06; increasing population trend) subpopulations had greater Long fast proportions than the eastern Aleutian Islands (0.10 ± 0.05; stabilized population). Due to contrasting population growth trends among these highlighted subpopulations over the past 50+ years, both density-independent and density-dependent factors likely influence the dam foraging trip duration, contributing to longer fasting durations for pups at some rookeries.