Field Notes 2012 "We are monitoring the number of gray whale calves migrating north each year because we think that the number of calves born is related to weather conditions (ice cover) in the Arctic." —Wayne Perryman
FINAL, May 26: 2012 brought a record number of gray whale calves! This year’s final counts documented 330 newborns making their way with their mothers past the Piedras Blancas Light Station, near San Simeon, California. The ninth and final week of the census was May 22-26, when 4 cow/calf pairs were counted at the migration's end. See Histogram. NOAA's Southwest Fisheries Science Center says: "This [330 newborns] is nearly double the number born in previous years. According to Jorge Urban and his colleagues at Universidad Autónoma de Baja California Sur, a record 1,198 gray whale calves were born this season along the coast of Baja California, where the animals spend the winter breeding and calving. In comparison, 599 whales were born in 2011, and 183 in 2010. This year’s births contribute to a recovered gray whale population, thanks in large part to protections under the U.S. Marine Mammal Protection Act and Endangered Species Act." May 12: We got 39 cow/calf pairs last week, even though we lost more that two days of effort to fog and wind. That brings our total to an even 300 calves so far. It has been a good year already and we have another two weeks of effort planned. May 8: Total of 273 cow/calf pairs to date, and a total of 442 adults and juveniles all together since the counting began March 26. May 5: We saw 95 cow/calf pairs this week (April 30-May 4). On a couple of days we could see pairs in the distance—heading our way when we had to shut down effort [counting] due to weather conditions. Our May 5 season total is 261 (cow/calf pairs plus other adults/juveniles), which already exceeds last year's total count. We saw over 20 calves in each of the last three days of this week. Things don't appear to be slowing down yet. It's a good year for recruitment into this population already, and we have three more weeks to go in the survey. April 27: We had 93 c/c pairs last week, culminated by BIG FRIDAY when we had another 28-pair day. Total for season sits at 166, which isn't bad for this time of the year. Now we have to see how this all finishes up. April 23: We've seen 87 cow/calf pairs—and a total of 417 adults and juveniles—since we began counting our 19th annual census on March 26. April 21: We had a good week with a total of 68 c/c pairs sighted in the five days on duty, bringing our total to 73 for the season. Lost some effort to fog this week. Next week should be a good one. April 18: We saw 28 cow/calf pairs in the biggest single day count since 2004! April 16: The team is participating in a Virtual Research Mission with some San Diego area classrooms. They will receive daily web blogs from us as we are counting the gray whales at Piedras Blancas. April 11: A beautiful day! No wind, lots of animals around (Fraser's dolphins, humpbacks, Tursiops and grays). Had 4 cow/calf pairs but they were hard to see. Fraser's dolphins seem to like to harass gray whales and it scares the heck out of the grays. So the cows with calves we say were in total stealth mode, hiding along the beach and rocks and not making a sound. I don't know why Fraiser's dolphins do this to gray whales. Might just be fun to pick on someone bigger than you. April 9: Today we had our first sighting of a northbound gray whale cow/calf pair of the season. They passed within 100 meters of the sighting station and we got a great look at the head of the calf. With all the little indentations in the baby's head it looked much like a little grey pickle. March 28: The team drove up to the Central California coast to the research site at Pt. Piedras Blancas on March 24. By Monday afternoon, March 27, we should be counting whales. I heard some scattered reports of calf sightings already, but counts in the lagoons are still on the upswing..." Stay tuned! March 8: Nineteen gray whales were tagged with satellite transmitters iin Laguna San Ignacio. The tracking data should provide a great researching tool. There is a 24-hour delay in the data set, and we repopulate the information every morning at 0930 west coast time. See Tracking Map/Data. February 1, 2012: We plan to start the 19th annual calf survey on March 26 and continue until the party is over, generally the last week of May. We will work 5 days a week for 12 hrs a day when the weather allows. I expect a big year for calf production based on the early retreat of ice last year.
Counts of northbound cows and calves have revealed surprising variability in calf production for this population. It appears that the number of calves born each year is related to environmental conditions in the Arctic that limit prey populations and/or the availability of prey to reproductive females. We have hypothesized that the timing of the melt of sea ice in the Arctic may control access to primary feeding grounds for newly pregnant females and thus impact the probability that existing pregnancies will be carried to term. |
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