Dataset Information

Epidemiology of skin changes in endangered Southern Resident killer whales (Orcinus orca).

ABSTRACT: Photographic identification catalogs of individual killer whales (Orcinus orca) over time provide a tool for remote health assessment. We retrospectively examined digital photographs of Southern Resident killer whales in the Salish Sea to characterize skin changes and to determine if they could be an indicator of individual, pod, or population health. Using photographs collected from 2004 through 2016 from 18,697 individual whale sightings, we identified six lesions (cephalopod, erosions, gray patches, gray targets, orange on gray, and pinpoint black discoloration). Of 141 whales that were alive at some point during the study, 99% had photographic evidence of skin lesions. Using a multivariate model including age, sex, pod, and matriline across time, the point prevalence of the two most prevalent lesions, gray patches and gray targets, varied between pods and between years and showed small differences between stage classes. Despite minor differences, we document a strong increase in point prevalence of both lesion types in all three pods from 2004 through 2016. The health significance of this is not clear, but the possible relationship between these lesions and decreasing body condition and immunocompetence in an endangered, non-recovering population is a concern. Understanding the etiology and pathogenesis of these lesions is important to better understand the health significance of these skin changes that are increasing in prevalence.

SUBMITTER: Gaydos JK

PROVIDER: S-EPMC10306181 | biostudies-literature | 2023

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Epidemiology of skin changes in endangered Southern Resident killer whales (Orcinus orca).

Gaydos Joseph K JK St Leger Judy J Raverty Stephen S Nollens Hendrik H Haulena Martin M Ward Eric J EJ Emmons Candice K CK Hanson M Bradley MB Balcomb Ken K Ellifrit Dave D Weiss Michael N MN Giles Deborah D

PloS one 20230628 6

Photographic identification catalogs of individual killer whales (Orcinus orca) over time provide a tool for remote health assessment. We retrospectively examined digital photographs of Southern Resident killer whales in the Salish Sea to characterize skin changes and to determine if they could be an indicator of individual, pod, or population health. Using photographs collected from 2004 through 2016 from 18,697 individual whale sightings, we identified six lesions (cephalopod, erosions, gray p ...[more]

PMID: 37379317

Similar Datasets

Project description:Long-term field studies have been invaluable in the study of ecology and evolution; however, for particularly long-lived species, even long-term studies often rely on estimated ages, for example when investigating demographic processes. One approach is to estimate unknown birth dates from the known timing of other life-history events. Building on previous methods, we update estimation techniques for Northern Resident killer whales (NRKW; Orcinus orca) as part of an ongoing long-term study that began in 1973. Despite almost 50 years of observation, many individuals were born before records began, and detailed understanding of NRKW life history relies on estimated ages. Our age estimation approach incorporates new data from photo-identification surveys into a framework that relies on accrued knowledge of demographic rates from known-age individuals. We use Bayes' law to determine conditional probability distributions from age-at-event data, incorporating mathematical descriptions of demographic patterns parameterised from the data. Key to our approach is the discounting of higher age estimates due to the increasing likelihood of mortality with age, a pattern not previously taken into account for NRKWs. We estimate ages for multiple age and sex classes of individuals, using related but tailored approaches, and we incorporate uncertainty into our estimates. Our revised age estimates suggest that individuals are often younger than previously thought (3.5 years on average across 73 individuals; range: 0-15 years). Moreover, the largest discrepancies appear for mothers with offspring at the onset of the study, a class of individuals instrumental for investigating menopause in killer whales-one of the few species other than humans known to exhibit this life-history feature. Our results will ultimately enable a refined understanding of the evolutionary forces that produce such patterns. We discuss the implications of our findings for the study of resident killer whales and for age estimation in other long-lived animals.

Dataset Information

Epidemiology of skin changes in endangered Southern Resident killer whales (Orcinus orca).

Publications

Epidemiology of skin changes in endangered Southern Resident killer whales (Orcinus orca).

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets