Eastern North Pacific gray whale calf production estimates 1994-2018
David W. Weller and Wayne L. Perryman
Shore-based visual counts of eastern North Pacific gray whale calves during their northward migration were conducted between late March and early June each year from 1994-2018 off central California. Estimates of the number of northbound calves showed a high degree of inter-annual variability, ranging from a high of 1,528 in 2004 to a low of 254 in 2010. Calf production was consistently high (exceeding >1,000 calves annually) between 2012-2017, when more than 7,500 calves were estimated. The 2016 estimate of 1,351 calves was about 5% of the most recently reported total abundance of 26,960 (in 2016) for the eastern North Pacific population. In 2018, calf production declined to 867, a level similar to 2011 (858 calves).