Possible niche compression and individual specialization in Pacific Arctic beluga (Delphinapterus leucas) from the 19th to 20th century

• Published in: Ecology and Evolution
• Main Authors: Devin C. Fraleigh, Frederick I. Archer, Amanda S. Williard, Luis A. Hückstädt, Alyson H. Fleming
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2023
• Subjects: beluga; growth layer groups; isotope; niche; Pacific Arctic; specialization; Ecology; QH540-549.5; Arctic; Pacific; Beluga; Beluga*; Delphinapterus leucas
• Online Access: https://doi.org/10.1002/ece3.10230; https://doaj.org/article/a8e9d27bbf5e472ba0826cd77d717bbc

Abstract Cetaceans have shown a potential to be used as sentinel species for tracking environmental change in marine ecosystems, yet our assessment of change is typically limited to recent decades and lacks ecological baselines. Using historical museum specimens, we compared community niche metrics and degree of individual dietary specialization in groups of Pacific Arctic beluga (Delphinapterus leucas) from the 1800s (n = 5) to 1900s (n = 10) using stable carbon and nitrogen isotopes drilled from teeth. Beluga occupied a broader trophic niche and demonstrated a higher degree of individual specialization in the 1800s than in the 1900s. The cause of this shift is difficult to confirm given long timescales and constraints of specimen‐based research but could indicate changes in the prey base or competition. The scale and nature of this detected shift provide perspective for continued research on these climate‐vulnerable species.