On behalf of my co-authors, I am happy to announce the publication of our new article in Endangered Species Research entitled "Found: a missing breeding ground for endangered western North Pacific humpback whales in the Mariana Archipelago." It is open access and can be downloaded here: https://doi.org/10.3354/esr01010. We prepared a web story with the highlights of the study: https://www.fisheries.noaa.gov/feature-story/international-whales-mystery-un... . Reference:Marie C. Hill*, Amanda L. Bradford, Debbie Steel, C. Scott Baker, Allan D. Ligon, Adam C. Ü, Jo Marie V. Acebes, Olga A. Filatova, Siri Hakala, Nozomi Kobayashi, Yukari Morimoto, Haruna Okabe, Ryosuke Okamoto, Julie Rivers, Takayuki Sato, Olga V. Titova, Robert K. Uyeyama, Erin M. Oleson ABSTRACT: Humpback whales *Megaptera novaeangliae* that breed in the western North Pacific (WNP) are listed as endangered under the US Endangered Species Act. Previous research in the WNP concluded that the full extent of humpback whale breeding areas is unknown. Recovering this endangered population requires identifying all associated breeding grounds and potential threats in those locations. Prior to 2015, humpback whales were known to occur in the Mariana Archipelago (within the WNP), but their population identity and habitat use there were unknown. To determine the population identity of humpback whales in the Mariana Archipelago and whether the area serves as a breeding ground for these whales, small-boat photo-identification and biopsy sampling surveys were conducted in the southern portion of the archipelago during February and March 2015-2018. A total of 14 mother-calf pairs and 27 other non-calf whales were encountered. Seven non-calves were re-sighted in multiple years, including 4 females associated with calves in one or more years. Competitive behavior was observed in multiple years. Comparisons with other North Pacific humpback whale catalogs resulted in matches to breeding (Japan and Philippines) and feeding (Russia) grounds in the WNP. DNA profiling of 28 biopsy samples identified 24 individuals (14 females, 10 males) representing 7 mitochondrial DNA haplotypes. The haplotype frequencies from the Mariana Archipelago showed the greatest identity with the Ogasawara breeding ground and Commander Islands feeding ground in the WNP. This study establishes the Mariana Archipelago as a breeding area for endangered WNP humpback whales, which should be considered in ongoing research and conservation efforts. Please contact me with questions or help with the files. ________________ Marie C. Hill Joint Institute for Marine and Atmospheric Research Pacific Islands Fisheries Science Center Protected Species Division - Cetacean Research Program 1845 Wasp Blvd., Bldg. 176, Honolulu, HI 96818 marie.hill@noaa.gov 808-725-5710