Gray Whale Photo-ID Catalogs for 2022 & 2023

Gray Whale Photo-ID Catalogs for 2022 and 2023

Our gray whale photographic identification catalogs for the 2022 and 2023 winters at Laguna San Ignacio and at Bahía Magdalena are now available on our website at:

http://sanignaciograywhales.org/research/photo-id-catalogs/

These catalogs contain images of gray whale females with calves and single adult whales collected in both winter aggregation areas for gray whales during the whales’ 2022 and 2023 winter breeding seasons. All our gray whale photo-identification files from 2006 to the present may be viewed and downloaded from our website for comparison with photographs from other portions of the gray whales’ range. Please let us know if you discover a “match” with any of our photos, and we will provide you with information on the where and when we also saw the same gray whale.

The naturally occurring pigmentation patterns, “white” scars, and other markings are characteristic for each individual gray whale and, because these are permanent features, they allow the identification of individual whales within a season, and across years.

Our digital gray whale photographs are sorted and catalogued by year, especially noting those whales that are encountered and photographed multiple times during a winter season. The time periods between the first and last time an individual whale was photographed provides an estimate of the minimum amount of time that individual remained in the area, or a minimum residence time during that winter. Minimum residence times are calculated for single adults (males and females without calves), and for females with calves. Each catalog is then compared with catalogs from previous winters to identify individual whales that have visited an area in multiple years. Interannual sightings of the same whales are used to evaluate site fidelity to a particular lagoon or winter aggregation area, and the calving interval for breeding females. Photographs from both Laguna San Ignacio and Bahía Magdalena are compared to evaluate the exchange and movements of whales between these winter aggregation areas, and others portions of the gray whales range.

A good example of the power of photographic identification comparisons comes from our collaborations with researchers studying highly endangered Western North Pacific (WNP) gray whale population and the Eastern North Pacific (ENP) population. Comparison of photographs from both populations over the years confirmed the eastward fall migration of WNP gray whales off Russia eastward includes individual whales that cross the North Pacific to join the spring and fall migrations of the ENP population along the west coast of North America to Baja California, Mexico, and then returning to the Western North Pacific in the spring. Photographic matches from both areas confirm these include adult male and female gray whales  as well as some females with calves of the year.

You can learn more about this research and how photographic identification provides information on gray whale behavior, migrations, reproduction, estimation of minimum age, and fidelity to specific wintering aggregation areas by reading our annual research reports posted on our website at:

http://sanignaciograywhales.org/research/research-blog/

Our gray whale research is made possible by donations of support from our family of supporters, and we invite and encourage you to become a member of this family. If you want to become a supporter, you can make a safe, and secure donation to our program by going to our website link:

http://sanignaciograywhales.org/donate/

Thank You for your Support!

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