Did You Know?
We used to see Zorro regularly, but not lately…Why has he not been around?

About Zorro

Zorro is a 7-year-old male gray whale (as of 2021). We saw him many times throughout the 2017, 2018 and 2019 seasons, including filming him from a drone as he breached! However, we only saw him on three days in 2020 and not at all in 2021. Zorro is not the only whale we used to see regularly who we have not seen much or at all in recent years. This decline in the number of whales observed each summer in our Oregon study area is concerning and we are trying to figure out why. One theory we are investigating is decreased prey availability that may be related to a decline in kelp density. Nearshore reefs covered in kelp provide important habitat for gray whale zooplankton prey items like mysid shrimp, so a decline in kelp may be causing a decline in prey availability. In Port Orford, Oregon we collect data on kelp health, urchin density, zooplankton abundance, and gray whale foraging behavior, allowing us to document a coincident and dramatic increase in urchin density and decline in kelp health over the past six years. Alongside these changes, we have also documented decreased zooplankton prey and whale foraging. Many gray whales in Oregon, including Zorro, feed in kelp habitats using specialized feeding strategies like “headstands” where they beat their fins and fluke to keep their head down to gobble up a prey patch near the seafloor. We are investigating if individual whales prefer to feed using certain strategies and in certain habitats. Does Zorro like to feed in reef areas with kelp, and have we seen Zorro less in the past couple years because there is less kelp (and mysid prey) along the Oregon coast? We are trying to answer these questions by studying Oregon’s marine ecosystem from kelp to whales. Whales, kelp, and marine systems are dynamic and resilient, so we hope to see Zorro and his gray whale friends back in Oregon waters soon.

Learn more about how gray whale habitat in Oregon is changing and why kelp habitats are so important to gray whales.

Facts and Figures

How to Identify Zorro:

Zorros' pigmentation is pretty subtle but he has a distinctive white dot behind his first knuckle on his right side
Zorro has some small white dots and mottling on his left side
Zorro's Health History
Unlike reproductive female gray whales, males tend to have more stable BAIs across years as they experience less variation in body condition as a result of calf production and care. Instead, their body condition changes are mostly influenced by weight gain or loss related to nutrition. Zorro’s BAI has remained fairly stable across the years, typically in the high-30 to low-40 range.

We fly drones over whales and then measure how skinny or fat they are from the images we capture. We compare the body condition of whales using an index called the Body Area Index (BAI), which is like the Body Mass Index (BMI) used to compare the body condition of humans. Small BAI values mean the whale is skinnier and larger BAI values indicate the whale is fatter.