Photogrammetry of growth and body condition as sensitive indicators of reproductive potential in endangered whales
Abstract
Stressors can have immediate effects on vital rates of protected whales, but acute responses cannot often be diagnosed in advance and are therefore difficult to manage effectively. However, conceptual models (e.g. population consequences of multiple stressors, Tyack et al. 2022) and recent data suggest that stressors can also accumulate to cause more chronic changes in health and energy stores (Stewart et al. 2021a, 2021b) and affect vital rates, including the energy available for reproduction (Pirotta et al., 2023; Stewart et al. 2022). For endangered whales that reproduce slowly, long-term reproductive success is required to meet recovery goals, andaccumulating health impacts that will likely affect reproductive potential may be more tractable to manage after detection, before they result in realized demographic consequences.Here we propose to extend in time and scope two ongoing studies that have pioneereddrone photogrammetry to evaluate the health of two of the most endangered whale populations in U.S. waters: North Atlantic right whales (NARWs, Eubalaena glacialis) and Southern Resident killer whales (SRKWs, Orcinus orca), both of which have distributions overlapping Navy testing areas. We aim to increase the power of photogrammetry data to detect ongoing and predicted changes in growth and further elucidate the relationships between female size (which determines energy storage capacity) and reproductive success. Notably, additional data collection will allow repeated length measures of the same individuals to better inform estimation of asymptotic size by growth curve models. Data collected on the body condition of growing whales will also allow the relationship between body condition and growth to be evaluated, with the aim of using measures of condition as an early warning of impending health impacts, because changes in condition can be measured before they impact longer term growth or reproduction.Approved for Public Release.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 08, 2024
- Source ID
- N000142412451
Entities
People
- Michael J Moore
Organizations
- Office of Naval Research
- United States Navy
- Woods Hole Oceanographic Institution