Do Gray Whales Count Calories? Comparing Energetic Values of Gray Whale Prey Across Two Different Feeding Grounds in the Eastern North Pacific
نویسندگان
چکیده
Predators must consume enough prey to support costly events, such as reproduction. Meeting high energetic requirements is particularly challenging for migrating baleen whales their feeding seasons are typically restricted a limited temporal window and marine notoriously patchy. We assessed the value of six most common nearshore zooplankton species collected within Oregon, United States range Pacific Coast Feeding Group (PCFG) gray whale ( Eschrichtius robustus ) grounds, compared these results predominant amphipod fed on by Eastern North (ENP) in Arctic. Energetic values Oregon differed significantly between (Kruskal–Wallis ? 2 = 123.38, df 5, p < 0.0001), with Dungeness crab Cancer magister megalopae displaying highest mean caloric content all tested (4.21 ± 1.27 kJ g – 1 ). This value, well mysid Neomysis rayii (2.42 1.06 ), higher than Ampelisca macrocephala , Arctic amphipod. Extrapolations daily indicate that lactating pregnant PCFG would require 0.7–1.03 0.22–0.33 metric tons less per day if they or N. respectively, A. Yet, do not account differences availability foraging whales. therefore suggest other factors, density, costs feeding, natal philopatry site fidelity play role population sizes ENP Climate change implicated causing reduced body condition increased mortality both due decreased abundance. Therefore, improved understanding dynamics response environmental variability regions critical.
منابع مشابه
Assessment of genetic structure among eastern North Pacific gray whales on their feeding grounds
Although most eastern North Pacific (ENP) gray whales feed in the Bering, Beaufort, and Chukchi Seas during summer and fall, a small number of individuals, referred to as the Pacific Coast Feeding Group (PCFG), show intraand interseasonal fidelity to feeding areas from northern California through southeastern Alaska. We used both mitochondrial DNA (mtDNA) and 12 microsatellite markers to assess...
متن کاملGRAY WHALE (Eschrichtius robustus): Eastern North Pacific Stock
STOCK DEFINITION AND GEOGRAPHIC RANGE The gray whale formerly occurred in the North Atlantic Ocean (Fraser 1970), but is currently only found in the North Pacific (Rice et al. 1984). The following information was considered in classifying stock structure of gray whales based on the Dizon et al. (1992) phylogeographic approach: 1) Distributional data: isolated geographic distribution in the Nort...
متن کاملGRAY WHALE (Eschrichtius robustus): Eastern North Pacific Stock
STOCK DEFINITION AND GEOGRAPHIC RANGE The gray whale formerly occurred in the North Atlantic Ocean (Fraser 1970), but is currently only found in the North Pacific (Rice et al. 1984). The following information was cons idered in classifying stock structure of gray whales based on the Dizon et al. (1992) phylogeographic approach: 1) Distributional data: two isolated geographic distributions in th...
متن کاملMitochondrial and nuclear genetic variation across calving lagoons in Eastern North Pacific gray whales (Eschrichtius robustus).
Accurate knowledge of population structure in cetaceans is critical for preserving and managing breeding habitat, particularly when habitat is not uniformly protected. Most eastern gray whales return to their major breeding range each winter along the Pacific coast of Baja California, Mexico, concentrating in 3 major calving lagoons, but it is unknown whether genetic differences exist between l...
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ژورنال
عنوان ژورنال: Frontiers in Marine Science
سال: 2021
ISSN: ['2296-7745']
DOI: https://doi.org/10.3389/fmars.2021.683634