Dear Colleagues, On behalf of my coauthors, I’m pleased to share our new publication on the movements and dive behavior of Eastern Tropical Pacific killer whales in Pacific Mexico: https://onlinelibrary.wiley.com/doi/10.1111/mms.70133 Stewart, J. D., R. L. Pitman, P. Martinez-Loustalot, N. Ransome, T.R. Azizeh, H. Rosales-Nanduca, I.A. Fonseca-Ponce, A.A. Zavala-Jimenez, J. Urban R., 2026. “Shelf Life: Nearshore Movements, Dive Behavior, and Ecotype Status of Satellite-Tagged Killer Whales in Pacific Mexico.” Marine Mammal Science https://doi.org/10.1111/mms.70133. Abstract: Relatively little is known about the ranging patterns, diving behavior, or prey preferences of killer whales (Orcinus orca) in tropical latitudes. However, they are suspected to be prey-generalists rather than the prey-specialists that are typically found in high latitudes. In February 2025, we satellite-tagged three killer whales from a pod of seven in Bahía de Banderas, Mexico. The tags transmitted for 8–41 days. The tagged whales traveled a total of 4002 km along a narrow, 1000 km stretch of coastline. While tagged, they remained within 50 km of shore 92.5% of the time and in water < 500 m deep 69% of the time, but ranged up to 87 km offshore, to water deeper than 1000 m. Dives were slightly deeper during the day (mean dive depth 44 m) than at night (34.5 m), and they dived deeper (max 528 m) in deeper water. The group was observed attacking/consuming marine mammals, including a humpback whale (Megaptera novaeangliae) calf, a dwarf sperm whale (Kogia sima), common bottlenose (Tursiops truncatus) and spinner (Stenella longirostris) dolphins, and attacking/harassing two species of sea turtles. These data provide the first high-resolution records of movements and dive behavior of killer whales in the Eastern Tropical Pacific and support the existence of a unique ecotype in the region. Joshua Stewart, Ph.D. Pronouns: He/Him Assistant Professor, Marine Mammal Institute Oregon State University, Hatfield Marine Science Center