Evidence map›Paper›PMID 39834348›Full record

ArticleConservation physiology2025

Variation in faecal testosterone levels in male gray whales on a foraging ground relative to maturity and timing.

A Fernandez Ajó, C L Buck, K E Hunt, E Pirotta, L New, D Dillon, K C Bierlich, L Hildebrand, C N Bird, L G Torres

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Conservation physiology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing 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

1 citing paper in PubMed.

  1. 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

10 authors.

A Fernandez AjóGeospatial Ecology of Marine Megafauna Lab, Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, 2030 SE Marine Science Dr, Newport, OR 97365, USA.
C L BuckDepartment of Biological Sciences, Northern Arizona University, 617 S. Beaver St., Flagstaff, AZ 86011, USA.
K E HuntSmithsonian-Mason School of Conservation & Department of Biology, George Mason University, 1500 Remount Rd, Front Royal, VA 22630, USA.
E PirottaCentre for Research into Ecological and Environmental Modelling, University of St Andrews, Buchanan Gardens, St Andrews, KY16 9LZ, UK.ORCID https://orcid.org/0000-0003-3541-3676
L NewDepartment of Mathematics, Computer Science and Statistics, Ursinus College, 601 E Main St, Collegeville, PA 19426, USA.
D DillonDepartment of Biological Sciences, Northern Arizona University, 617 S. Beaver St., Flagstaff, AZ 86011, USA.
K C BierlichGeospatial Ecology of Marine Megafauna Lab, Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, 2030 SE Marine Science Dr, Newport, OR 97365, USA.
L HildebrandGeospatial Ecology of Marine Megafauna Lab, Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, 2030 SE Marine Science Dr, Newport, OR 97365, USA.
C N BirdGeospatial Ecology of Marine Megafauna Lab, Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, 2030 SE Marine Science Dr, Newport, OR 97365, USA.
L G TorresGeospatial Ecology of Marine Megafauna Lab, Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, 2030 SE Marine Science Dr, Newport, OR 97365, USA.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Understanding wildlife reproductive seasonality is crucial for effective management and long-term monitoring of species. This study investigates the seasonal variability of testosterone in male Pacific Coast Feeding Group (PCFG) gray whales, using an eight-year dataset (2016-2023) of individual sightings, drone-based photogrammetry and endocrine analysis of faecal samples. We analyzed the relationship between faecal testosterone levels and total body length (TL), body condition (body area index, BAI), sexual maturity and day of the year using generalized additive mixed models. Our findings reveal a significant increase in faecal testosterone levels in mature males (MM) towards the end of the foraging season. This increase was not observed in JM, highlighting age-dependent development of sexual characteristics. No significant relationship was found between testosterone levels and TL. Additionally, BAI was not significantly associated with testosterone levels. Our results suggest that the increasing testosterone levels in MM gray whales may indicate preparation for mating before the southbound migration. These findings provide valuable insights into the reproductive biology of PCFG gray whales and underscore the importance of non-invasive faecal sampling for studying reproductive seasonality in large whales. Our approach not only provides further insights into the seasonality of male reproduction for the PCFG gray whales but also offers tools to enhance the understanding of male reproduction in baleen whales broadly with non-invasive approaches.

Indexed as

Enzyme immunoassayGray whaleMale reproductionPcfgTestosterone

Identifiers

PMID39834348
PMCPMC11744369

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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.