Morphometrics of mammal‐eating killer whales from drone photogrammetry, with comparison to sympatric fish‐eating killer whales in the eastern North Pacific

Kotik, Chloe; Durban, John W.; Fearnbach, Holly; Barrett‐Lennard, Lance G.

doi:10.1111/mms.12965

Cited by 15 publications

(15 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our understanding of population structure and dynamics of cetacean species in Galaṕagos can be much improved by considering individual covariates, such as sex, age, and/or maturity classes, when estimating parameters with mark-recapture models. This information can be obtained using a variety of field and laboratory approaches: some species are sexually dimorphic (O. orca, P. macrocephalus) and others can be sexed genetically with remote biopsy sampling; hormonal analyses can indicate reproductive condition; epigenetic methods can be used for aging individuals (e.g., Polanowski et al, 2014); and boat-based photogrammetry and drone-based morphometry can generate body length estimates, especially of large Odontocetes (e.g., Kotik et al, 2022).…”

Section: Methodological Approachesmentioning

confidence: 99%

Priorities for ecological research on cetaceans in the Galápagos Islands

Palacios

Cantor²

2023

Front. Mar. Sci.

View full text Add to dashboard Cite

Located in the eastern tropical Pacific, the Galápagos Islands are an oceanic insular ecosystem subject to strong environmental variability driven by local and regional processes. Past research has shown that such conditions can attract and sustain at least 23 cetacean species, out of which 14 are common, including nine Delphinids, one Ziphiid, one Physeterid, and three Balaenopterids. These species occupy both coastal and oceanic habitats, most are present year-round, and a few are migratory. However, research on cetaceans in Galápagos has been sporadic and chronically underfunded and is not currently considered a priority in the research agenda for Galápagos. Based on a review of existing information and an assessment of knowledge gaps, here we identify priorities for ecological research on cetaceans in Galápagos along five topical areas: 1) spatiotemporal occurrence, 2) population assessment, 3) health assessment, 4) social ecology, and 5) trophic ecology. Addressing these knowledge gaps will also help inform actions to preserve cetacean biodiversity and to manage human activities involving or affecting cetaceans in Galápagos. Given the logistical and funding challenges of conducting cetacean research in Galápagos, we recommend optimizing data sampling and accessibility via integrated research protocols and open data repositories. We also recommend capitalizing on local citizen science activities, such as those conducted from cruise ships and whale-watching tours, which can serve as platforms of opportunity for obtaining basic data, thereby contributing to long-term data acquisition. Our proposed priorities should be assessed by Ecuadorian and Galápagos governmental institutions in broad and inclusive consultation with stakeholders and the scientific community prior to development and implementation of a research agenda. Collectively, these efforts will advance our understanding of the ecological role that marine megafauna, such as cetaceans, play in Galápagos and other oceanic islands, including maintaining large-scale connectivity and mitigating climate change.

show abstract

Section: Methodological Approachesmentioning

confidence: 99%

Priorities for ecological research on cetaceans in the Galápagos Islands

Palacios

Cantor²

2023

Front. Mar. Sci.

View full text Add to dashboard Cite

show abstract

“…Regional variation in a number of characteristics has led to the recognition of several forms of killer whales, which are often referred to as 'ecotypes' [6,7,[11][12][13][14][15][16][17]. These ecotypes are known to vary in body size [16,[18][19][20], colour patterning [6,16,[21][22][23], social structure [24][25][26][27][28], vocalization pattern [28][29][30][31] and foraging strategies [6,11,[32][33][34][35][36][37][38][39].…”

Section: Introductionmentioning

confidence: 99%

Revised taxonomy of eastern North Pacific killer whales ( Orcinus orca ): Bigg’s and resident ecotypes deserve species status

Morin,

McCarthy,

Fung

et al. 2024

R. Soc. Open Sci.

Self Cite

View full text Add to dashboard Cite

Killer whales ( Orcinus orca ) are currently recognized as a single ecologically and morphologically diverse, globally distributed species. Multiple morphotypes or ecotypes have been described, often associated with feeding specialization, and several studies have suggested taxonomic revision to include multiple subspecies or species in the genus. We review the ecological, morphological and genetic data for the well-studied ‘resident’ and Bigg’s (aka ‘transient’) ecotypes in the eastern North Pacific and use quantitative taxonomic guidelines and standards to determine whether the taxonomic status of these killer whale ecotypes should be revised. Our review and new analyses indicate that species-level status is justified in both cases, and we conclude that eastern North Pacific Bigg’s killer whales should be recognized as Orcinus rectipinnus (Cope in Scammon, 1869) and resident killer whales should be recognized as Orcinus ater (Cope in Scammon, 1869).

show abstract

“…Aerial, underwater and laser photogrammetry provide opportunities for non-invasive length measurements of live cetaceans [23][24][25][26][27][28]. In particular, the recent proliferation of drones (unoccupied aircraft systems, UAS) provides an accessible alternative for aerial photogrammetry compared to crewed aircraft [29][30][31]. Together, photo-identification history and photogrammetry-based length measurements of individuals enables a non-invasive approach for obtaining age and length measurements to generate growth models for cetacean populations [25,32,33].…”

Section: Introductionmentioning

confidence: 99%

Downsized: gray whales using an alternative foraging ground have smaller morphology

Bierlich,

Kane,

Hildebrand

et al. 2023

Biol. Lett.

View full text Add to dashboard Cite

Describing individual morphology and growth is key for identifying ecological niches and monitoring the health and fitness of populations. Eastern North Pacific ((ENP), approximately 16 650 individuals) gray whales primarily feed in the Arctic/sub-Arctic regions, while a small subgroup called the Pacific Coast Feeding Group (PCFG, approximately 212 individuals) instead feeds between northern California, USA and British Columbia, Canada. Evidence suggests PCFG whales have lower body condition than ENP whales. Here we investigate morphological differences (length, skull, and fluke span) and compare length-at-age growth curves between ENP and PCFG whales. We use ENP gray whale length-at-age data comprised of strandings, whaling, and aerial photogrammetry (1926–1997) for comparison to data from PCFG whales collected through non-invasive techniques (2016–2022) to estimate age (photo identification) and length (drone-based photogrammetry). We use Bayesian methods to incorporate uncertainty associated with morphological measurements (manual and photogrammetric) and age estimates. We find that while PCFG and ENP whales have similar growth rates, PCFG whales reach smaller asymptotic lengths. Additionally, PCFG whales have relatively smaller skulls and flukes than ENP whales. These findings represent a striking example of morphological adaptation that may facilitate PCFG whales accessing a foraging niche distinct from the Arctic foraging grounds of the broader ENP population.

show abstract

Morphometrics of mammal‐eating killer whales from drone photogrammetry, with comparison to sympatric fish‐eating killer whales in the eastern North Pacific

Abstract: Aerial photogrammetry has provided increased power for monitoring the health of individuals in the endangered population of Southern Resident killer whales (SRKW,

Cited by 15 publications

References 57 publications

Priorities for ecological research on cetaceans in the Galápagos Islands

Priorities for ecological research on cetaceans in the Galápagos Islands

Revised taxonomy of eastern North Pacific killer whales ( Orcinus orca ): Bigg’s and resident ecotypes deserve species status

Downsized: gray whales using an alternative foraging ground have smaller morphology

Contact Info

Product

Resources

About