[MARMAM] New publication: Assessment of a non-invasive approach to pregnancy diagnosis in gray whales through drone-based photogrammetry and faecal hormone analysis

Alejandro Apolo Fernández Ajó afernandezajo at gmail.com
Wed Jul 26 10:03:13 PDT 2023


Hello, marmam community,
I am pleased to share our new contribution, titled "Assessment of a
non-invasive approach to pregnancy diagnosis in gray whales through
drone-based photogrammetry and faecal hormone analysis."

In this study, using data from the Pacific Coast Feeding Group gray whales,
we assess the efficacy of a fecal progesterone immunoassay and drone-based
photogrammetry for pregnancy diagnosis. We estimate the probability of
pregnancy by analyzing fecal progesterone metabolites and body morphology
through normal mixture models. Progesterone levels exhibited high
variability, hindering accurate diagnosis. However, body width standardized
by the total length at 50% of the total body successfully distinguished
pregnant from nonpregnant females with high accuracy. Applying this method
to whales of unknown pregnancy status revealed eight additional
pregnancies, highlighting the potential of drone-based photogrammetry for
reproductive rate assessments.

*You can access this contribution here:*
https://royalsocietypublishing.org/doi/10.1098/rsos.230452.
*Cite this article:* Fernandez Ajó A., Pirotta E., Bierlich K. C.,
Hildebrand L., Bird C. N., Hunt K. E., Buck C. L., New L., Dillon D. and
Torres L. G. 2023 Assessment of a non-invasive approach to pregnancy
diagnosis in gray whales through drone-based photogrammetry and faecal
hormone analysis R. Soc. open sci.10230452230452.
http://doi.org/10.1098/rsos.230452
*Abstract*: Knowledge of baleen whales' reproductive physiology is limited
and requires long-term individual-based studies and innovative tools. We
used 6 years of individual-level data on the Pacific Coast Feeding Group
gray whales to evaluate the utility of faecal progesterone immunoassays and
drone-based photogrammetry for pregnancy diagnosis. We explored the
variability in faecal progesterone metabolites and body morphology relative
to observed reproductive status and estimated the pregnancy probability for
mature females of unknown reproductive status using normal mixture models.
Individual females had higher faecal progesterone concentrations when
pregnant than when presumed non-pregnant. Yet, at the population level,
high overlap and variability in progesterone metabolite concentrations
occurred between pregnant and non-pregnant groups, limiting this metric for
accurate pregnancy diagnosis in gray whales. Alternatively, body width at
50% of the total body length (W50) correctly discriminated pregnant from
non-pregnant females at individual and population levels, with high
accuracy. Application of the model using W50 metric to mature females of
unknown pregnancy status identified eight additional pregnancies with high
confidence. Our findings highlight the utility of drone-based
photogrammetry to non-invasively diagnose pregnancy in this group of gray
whales, and the potential for improved data on reproductive rates for
population management of baleen whales generally.

Thanks for sharing,

*Alejandro Fernandez Ajó**,** PhD *
*Postdoctoral Scholar*
*Geospatial Ecology of Marine Megafauna (GEMM
<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fmmi.oregonstate.edu%2Fgemm-lab&data=05%7C01%7Calejandro.fernandezajo%40oregonstate.edu%7C9bc3cca8fd3d42b260aa08da809a489c%7Cce6d05e13c5e4d6287a84c4a2713c113%7C0%7C0%7C637963697376854523%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=UBQEQV7v6pyq%2FopIxpVKZmnxPnVrZev9uB6cfyiL72I%3D&reserved=0>)
Lab *
Marine Mammal Institute | *Dept. of Fisheries, Wildlife, & **Conservation
Sciences*
*Oregon State University*
*Pronouns: he, him, his*
*fernaale**@**oregonstate.edu* <kevin.bierlich at oregonstate.edu>
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