Evidence map›Paper›PMID 40170578›Full record

ArticleThe Journal of animal ecology2025

Resource partitioning among pelagic predators remains stable despite annual variability in diet composition.

Elan J Portner, Barbara A Muhling, Antonella Preti, Owyn E Snodgrass, Travis M Richards, Catherine F Nickels, Heidi Dewar, Elliott L Hazen, C Anela Choy

Abstract read
In one paragraph

Article in The Journal of animal ecology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Elan J PortnerIntegrative Oceanography Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA.ORCID 0000-0001-9112-863X
Barbara A MuhlingInstitute of Marine Sciences, Fisheries Collaborative Program, University of California, Santa Cruz, Santa Cruz, California, USA.ORCID 0000-0002-4555-6382
Antonella PretiInstitute of Marine Sciences, Fisheries Collaborative Program, University of California, Santa Cruz, Santa Cruz, California, USA.
Owyn E SnodgrassFisheries Resources Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, USA.
Travis M RichardsInstitute of Marine Sciences, Fisheries Collaborative Program, University of California, Santa Cruz, Santa Cruz, California, USA.
Catherine F NickelsInstitute of Marine Sciences, Fisheries Collaborative Program, University of California, Santa Cruz, Santa Cruz, California, USA.
Heidi DewarFisheries Resources Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, USA.
Elliott L HazenEcosystem Science Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Monterey, California, USA.
C Anela ChoyIntegrative Oceanography Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA.

Funding

NOAA California Current Integrated Ecosystem Assessment ProgramNOAA Climate Program Office: Climate and Fisheries Adaptation NA20OAR4310507US National Science Foundation, Division of Biological Infrastructure 2011031
6 · The paper itself

Abstract

Diet data are critical for describing predator resource use and partitioning among competitors. However, time series needed to properly assess variability in resource use and partitioning are limited, especially in pelagic (open ocean) ecosystems where predators and prey make broad use of horizontal and vertical habitats. We examined a diet time series spanning two decades (1998-2018) consisting of 2749 stomachs from 10 pelagic predators in the southern California Current Ecosystem (SCCE): albacore tuna (Thunnus alalunga), Pacific bluefin tuna (Thunnus orientalis), swordfish (Xiphias gladius), blue shark (Prionace glauca), shortfin mako (Isurus oxyrinchus), common thresher shark (Alopias vulpinus), bigeye thresher shark (Alopias superciliosus), short-beaked common dolphin (Delphinus delphis), long-beaked common dolphin (Delphinus capensis) and northern right whale dolphin (Lissodelphis borealis). We quantified feeding habits with respect to prey taxonomy, length, vertical habitat and horizontal habitat. From 1998 to 2015, each predator exhibited diet variability but maintained consistent resource partitioning with the other predators. Across years, the diets of predators feeding mostly on shallow-living prey (<200 m) were more variable than those feeding on deeper-dwelling prey (>200 m). Following an increase in the abundance of northern anchovy (Engraulis mordax) in the SCCE starting in 2015, the ecological niches of Pacific bluefin tuna and swordfish converged. During 2016-2018, both predators fed more heavily on northern anchovy and other prey that occupy shallow nearshore habitats. We show that pelagic predators can maintain resource partitioning under a wide range of conditions. However, we also observe that drastic changes in resource availability can alter the degree of niche partitioning among competitors, providing new perspectives on the flexibility of predator niches. As climate change continues to alter food webs, understanding how predators forage will be essential for anticipating changes to pelagic ecosystem structure and services.

Indexed as

DietFood ChainPredatory BehaviorSharksAnimalsCaliforniaEcosystemFeeding BehaviorTunacompetitiondiet analysisforaging ecologymarine food web structureniche partitioningrealized niche

Identifiers

PMID40170578
PMCPMC12056350

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.