


To understand how the eastern North Pacific gray whales population is thriving – having recovered from low numbers – and is responding to changes in the environment, we study the abundance of the over time.
Monitoring gray whale population abundance is one of two focus areas for gray whale research at NOAA Fisheries. We estimate the abundance (i.e. the number of whales) of the eastern North Pacific gray whale population by conducting shore-based surveys overlapping with the timing of the southward migration from the Arctic to Mexico. Surveys of this type began in 1967 and take place at our Granite Canyon field station south of Monterrey, California. Since the mid-2000s we have conducted surveys for two consecutive years in every five year period.
We combine new and established methods to count southbound gray whales passing Granite Canyon from December through February. Combining multiple observation methods increases the precision and accuracy of our estimates.
The eastern North Pacific gray whale population migrates south from summer feeding areas in high latitudes to protected lagoons on the coast of Northern Baja Mexico between November and February. The migration past the Granite Canyon field station generally peaks in mid-January. Some pregnant females give birth after arriving at their winter areas in Mexico, whereas others give birth during the migration south. The whales do most of their feeding for the year in the summer, and feed only opportunistically during the migration or while overwintering.
In 2016 we estimated the size of the eastern North Pacific gray whale population to be nearly 27,000. We conducted our most recent population abundance survey in winter 2019/2020, and we are currently analyzing the data.
The small drone, or unmanned aerial vehicle, is called the FireFly 6 Pro. It can sample large areas by flying up to 34 mph. NOAA’s Unmanned Aerial Systems Program office supports this research.
Potential applications for this new technology include:
This project is spearheaded by Dave Weller, a research wildlife biologist. He leads our studies on gray whales and also works with the International Whaling Commission and the International Union for Conservation of Nature (IUCN) on the conservation of whale populations world-wide.
Sullivan, K., Fennell, M., Perryman, W. and Weller, D. 2020. Automated detection, tracking, and counting of gray whales. Proc. SPIE 11409. Thermosense: Thermal Infrared Applications XLII, 1140906 (23 April 2020); doi: 10.1117/12.2567187
Guazzo, R.A., Weller, D.W., Europe, H.M. et al. 2019. Migrating eastern North Pacific gray whale call and blow rates estimated from acoustic recordings, infrared camera video, and visual sightings. Scientific Reports 9, 12617.
Durban, J.W., Weller, D.W. and Perryman, W.L. 2017. Gray whale abundance estimates from shore-based counts off California in 2014/2015 and 2015/2016. Paper SC/A17/GW06 presented to the Scientific Committee of the International Whaling Commission, May 2017
Durban, J.W., D.W. Weller, A.R. Lang, and W.L. Perryman. 2015. Estimating gray whale abundance from shore-based counts using a multilevel Bayesian model. Journal of Cetacean Research and Management 15:61-68.
Laake, J.L., Punt, A.E., Hobbs, R., Ferguson, M., Rugh, D. and Breiwick, J. 2012. Gray whale southbound migration surveys 1967-2006: An integrated re-analysis. J. Cetacean Res. Manage. 12:287-306.
Durban, J., D. Weller, A. Lang, and W. Perryman. 2011. Abundance indices of eastern North Pacific gray whales from southbound migration counts, 2007-2011. Paper SC/63/BRG7 presented to the International Whaling Commission, Scientific Committee (SC63 meeting, Tromso, Norway, 2011). 4 p.
Durban, J., A. Lang, D. Weller, D. Rugh, R. Hobbs, and W. Perryman. 2010. Comparing two methods of shore-based counts of eastern North Pacific gray whales. Paper SC/62/BRG8 presented to the International Whaling Commission, Scientific Committee (SC62 meeting, Agadir, Morocco, 2010). 6 p.
Gray Whale Research at NOAA Fisheries
Gray Whale Condition and Calf Production Project