Gray Whale Migration Update: March 22, 2000

Today's Report Includes:

 Gray Whale Migration Route (Click on face of map)
Keeping Track and Counting
Whale-watch guide Kristin "Ellie" Kusic greets us from the nurseries in Laguna San Ignacio, where it's not easy to keep track of whale counts! Kristin says: "Whale numbers within the lagoon change with each new census. No one knows how long individual whales stay in the lagoon, or even how many different whales visit the lagoon each year. Here's an example of our lagoon counts from this year:"
• Census Feb 11: single adults 184; mother/calf pairs 45
• Census Feb 15: single adults 196; mother/calf pairs 20
• Census Feb 24: single adults 132; mother/calf pairs 62
• Census March 1: single adults 145; mother/calf pairs 35

Challenge Question #10:
"Using the census data above, how many adults would you estimate for the time period shown? How many mother/calf pairs? How many calves? Give a range and the average number in your answer."

Spring Training Underway!
Tom Lewis, wearing his Journey North T-shirt, sends us the latest news from Laguna San Ignacio. What are all those mothers and babies doing, and why? Tom writes:

"When we see a brand new baby gray whale, its flukes and flippers are very floppy, and have not yet become rigid. It is very difficult for these newborns to swim fast enough to keep up with an adult, so the mothers move very slowly, and are very protective of their young. Once the calves' flukes and flippers have gained strength, they begin to explore the lagoon. Mothers carefully swim with their babies around the lagoon, gradually teaching them how to swim. However, they do this in a very specific manner. The majority of the whales, and particularly the mothers with calves, swim in a predictable pattern while inside the lagoon. The tidal current inside San Ignacio can be very strong, as much as 2 or 3 knots. The mothers and calves swim against the tidal current. If there is an incoming tide, they will swim toward the mouth of the lagoon. If there is an outgoing tide, they swim toward the upper end of the lagoon. This pattern helps to protect the young calves from an accident, and prepares the calves for their life in the open ocean."

Challenge Question #11:
"Why would mothers teach their calves to swim against the tidal current?"

Swimming isn't the only thing the babies learn in the lagoons. Do you remember from past reports the comical stories of babies learning to breach and spyhop? Tom tells more about these important whale behaviors in his full report. And aren't the whales getting hungry by now? Read what they're doing about it:

Latest Highlights from the Gray Whale Observation Posts
The big news this week is that the migration is plowing northward in full swing. Gray whales have already reached Seward and Kodiak, Alaska! No cow/calf pairs have been spotted swimming north yet, and only one southbound whale has been seen since Susan's last report. According to Alisa of the ACS Census, the total number of northbound whales as of Friday, March 17 was 585 compared to an average total of 628 grays over the past 10 years. The average peak day over all years has been on March 18. Has the migration peaked yet? How do the numbers look for the past two weeks? Is it unusual for the census spotters to see no cow/calf pairs by this date? What surprise do students at Nelson Lagoon School on the Alaskan Peninsula hope to show you when the whales arrive? For these and other highlights, see Susan's full report:

Going, Going. . .But Not Gone Yet
From the Laguna Guerrero Negro, Keith Jones sends this news: "If you plan on seeing gray whales this year, I suggest you go this week or next week at the latest. There are far fewer whales in the lagoon than two weeks ago. Still plenty of action, but it will be tapering off fast. The northern migration is now beginning in full force." Here's another of Keith's latest photos of a baby gray breaching.

Try This! Whale Journey Literature Link
In her 50 years, Old Gray has swum a distance equal to traveling to the moon and home again. What's in store for her baby, about to make his first migration? Whale Journey by Vivian French (1998, Zero to Ten Limited) is a richly detailed picture book that all ages will enjoy. Join three generations of whales on their travels. Then try a point-of-view writing experience along with other fun extensions built on this literature link to the study of gray whales. See:

First Whale Reaches Kodiak! Answer to Challenge Question #3
In our first report this year we asked: "When do you predict the first gray whale will be sighted in the Gulf of Alaska, near Kodiak?"

Susan Payne announced the news in today's report. No one predicted the March 16 date, but Susan Allen came closest. "We predict the first gray whale will be sighted in the Gulf of Alaska, near Kodiak on March 2, 2000." Thanks, Susan, for sending us your prediction! (susanjallen@mailcity.com)

Millennium Baby's Life Span: Discussion of Challenge Questions #7
"How long might the millennium baby whale live if she has a normal life span? How do scientists determine the age of a whale?"

Grays can expect to live about 30 to 50 years, or even 60 years. Scientists determine a gray whale's age by counting the annual layers in the whale's waxy ear plug. If you think this sounds something like counting the rings in a tree stump to tell the age of the tree, you're right!

Up-and-Down Numbers: Discussion of Challenge Question #8:
"What might be some reasons why numbers of northbound whales on a given date changes from year to year?" Many of Susan Payne's reports include references to weather or rough seas. That seems to be one reasonable guess. Keep thinking about this question, and send us your ideas!

Just Hangin' Out: Discussion of Challenge Question #9
Last time we asked: "Why do some gray whales hang out all winter in the open ocean off Washington, Oregon, and British Columbia, with no apparent desire to migrate north or south?"

No one knows what a whale thinks, but in Susan Payne's March 8 report, a newsletter from Strawberry Isle Research Society explained it this way: "We see Grays who hang out all winter in the open ocean with no apparent desire to migrate one way or the other. On our January continental shelf survey we recorded nine Grays in two groups who were just lazing about on the surface seventeen miles offshore. We believe they are too young, too old, or simply barren so they have no need to make the long swim to the breeding grounds."

How to Respond to Today's Challenge Questions: