Open AccessGlobal long-term stability of individual dietary specialization in herbivorous mammals
Author(s) -
Larisa R.G. DeSantis,
Melissa I. Pardi,
Andrew Du,
Michael A. Greshko,
Lindsey T. Yann,
Richard C. Hulbert,
Julien Louys
Publication year - 2022
Publication title -
proceedings - royal society. biological sciences/proceedings - royal society. biological sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.342
H-Index - 253
eISSN - 1471-2954
pISSN - 0962-8452
DOI - 10.1098/rspb.2021.1839
Subject(s) - intraspecific competition , herbivore , biology , ecology , ungulate , trait , range (aeronautics) , competition (biology) , mammal , variation (astronomy) , habitat , materials science , computer science , composite material , programming language , physics , astrophysics
Dietary variation within species has important ecological and evolutionary implications. While theoreticians have debated the consequences of trait variance (including dietary specialization), empirical studies have yet to examine intraspecific dietary variability across the globe and through time. Here, we use new and published serial sampled δ13 Cenamel values of herbivorous mammals from the Miocene to the present (318 individuals summarized, 4134 samples) to examine how dietary strategy (i.e. browser, mixed-feeder, grazer) affects individual isotopic variation. We find that almost all herbivores, regardless of dietary strategy, are composed of individual specialists. For example,Cormohipparion emsliei (Equidae) from the Pliocene of Florida (approx. 5 Ma) exhibits a δ13 Cenamel range of 13.4‰, but all individuals sampled have δ13 Cenamel ranges of less than or equal to 2‰ (mean = 1.1‰). Most notably, this pattern holds globally and through time, with almost all herbivorous mammal individuals exhibiting narrow δ13 Cenamel ranges (less than or equal to 3‰), demonstrating that individuals are specialized and less representative of their overall species' dietary breadth. Individual specialization probably reduces intraspecific competition, increases carrying capacities, and may have stabilizing effects on species and communities over time. Individual specialization among species with both narrow and broad dietary niches is common over space and time—a phenomenon not previously well recognized or documented empirically.