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Gray Whale Migration Update: March
21, 2001
Today's Report Includes:
- Latest Highlights From Gray Whale Observation Posts
- A Bratty Baby?
- Teacher Tip: Heavy!Challenge Question #8
- Cows and Calves Really Count
- Challenge Question #9
- Celebrating the Gray Whale Migration
- Update on Challenge Question #5
Latest Highlights From Gray Whale Observation Posts
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Gray Whale Migration Route |
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Since our last Update, these are the daily Gray Whale counts from the ACS/LA Gray Whale census, located on Palos Verde Peninsula (33.44N,-118.24W):
| Date |
Southbound |
Northbound |
Total Whales |
Calves South |
Calves North |
| 08-Mar |
3 |
20 |
23 |
0 |
0 |
| 09-Mar |
2 |
14 |
16 |
0 |
0 |
| 10-Mar |
1 |
19 |
20 |
0 |
0 |
| 11-Mar |
2 |
4 |
6 |
0 |
0 |
| 12-Mar |
0 |
19 |
19 |
0 |
0 |
| 13-Mar |
2 |
31 |
33 |
0 |
0 |
| 14-Mar |
1 |
10 |
11 |
0 |
0 |
| 15-Mar |
0 |
15 |
15 |
0 |
0 |
| 16-Mar |
0 |
29 |
29 |
0 |
0 |
| 17-Mar |
0 |
8 |
8 |
0 |
0 |
| 18-Mar |
0 |
23 |
23 |
0 |
0 |
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Season to Date* |
424 |
270 |
694 |
11 |
0 |
As we've mentioned before, most of the world's estimated 26,000 gray whales migrate past California, but census
observers spot only a small portion of them because at this location, whales travel farther offshore. Also, bad
weather can prevent observers from seeing the whales. Based on the numbers in the table above, how would you sum
up the 2001 migration so far?
Meanwhile, not all the whales are traveling. Whale-watch guide Keith Jones writes
from the calving and breeding waters of Laguna Ojo de Liebre, where he no longer sees signs of the mating activity
that was so evident two weeks ago. Keith reports approximately 1000 mothers and babies still inside the lagoon.
Read on for Keith's newest whale tales and photos!
A Bratty Baby?
"We observed an interesting display of impertinent baby behavior last weekend," writes Keith Jones.
"Our panga (motor boat) was slowly moving through the lagoon from one group of whales toward another group. Suddenly I heard a whale blow behind and turned around in time to see the head of a baby popping out of the water. He did a head lift and looked right at us as he began to swim quickly toward us. His mother was directly beneath him. As he got within about 100 meters of the panga, she surfaced between him and our boat. He tried to zoom ahead and circle around her nose to get to us. This attempt to approach us continued until the mother and baby had circled our panga at least two times.
Photo courtesy Keith Jones
"Mother finally got tired of his display of disobedience. As the baby made the 15th or 20th effort to get to us, she poked her head beneath his stomach and sort of lifted and threw him gently about 2 meters back away from us. We were all awestruck by how effortless this head lift of the two-ton baby appeared to us. Being somewhat of a brat whale, this guy didn't stop. He finally got around his mother and quickly swam directly to the port (left) side of our boat. Everyone on that side ended up with wet sleeves as they all tried to touch him. He continued playing the bad boy and stayed 100 millimeters beyond anyone's reach.
Photo courtesy Keith Jones
"Meanwhile a solitary, very large, 40-foot whale drifted beneath our boat. It stayed there for quite a long time, possibly 10 or 15 minutes. This whale lay with its tail sticking out on one side of our panga and its head sticking out past the other side. It is so amazing that an animal this size can float within inches of the boat, but never even bump against it! The babies don't have quite this control, and they may bang the side or bottom of the boat when they swim near."
Photo courtesy Keith Jones
Teacher Tip: Heavy!
What makes it possible for animals as huge and heavy as gray whales to easily float and move in water? Try our lesson investigating density and the properties of salt water to shed light on that question.
Then come back and send us your answer to:
Challenge Question #8:
"What makes it possible for animals as heavy as gray whales to easily float and move in water?"
(To respond to this question, please follow
the instructions below.)
Cows and Calves Really Count
Wayne Perryman works with NOAA's Southwest Science Center. His job is to count the mother/calf pairs when they start the journey north. He tells us why this is important, and one question he has about the count:
"The work that I am doing is directed at monitoring calf production for the eastern Pacific population of gray whales. This population was removed from the List of Endangered Species in 1994 and one of the agreements associated with that decision was to monitor reproduction in gray whales over a 5-year period. But because we have seen much wider fluctuations in the number of calves than we expected, we have extended the study. The last two years we have seen high stranding rates and low calf production. This year the number of strandings appears to be lower. What does that mean for calf production? We will know the answer in a couple of months."
The table below shows a summary of Cow/Calf surveys between 1994 and 2000 from Piedras Blancas, California.
Wayne Perryman's work is to gather the numbers for 2001.
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Year |
Total Calf Count |
Median Migration Date |
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1994 |
325 |
April 26 |
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1995 |
194 |
April 20 |
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1996 |
407 |
April 27 |
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1997 |
501 |
April 20 |
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1998 |
442 |
April 19 |
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1999 |
141 |
May 11 |
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2000 |
96 |
April 15 |
Look at the table and then answer:
Challenge Question #9:
"How would you describe the trend in numbers of cows and calves since gray whales were removed from the Endangered Species List in 1994? What reasons might account for the trends?"
(To respond to this question, please follow
the instructions below.)
Wayne Perryman's work began March 19 and will continue until June 1. You can imagine that it's not easy to count
whales migrating offshore, night and day, in all kinds of weather. How do they do it? During the gray whale winter
migration, nighttime surveys of cow-calf pairs are conducted using military thermal sensors. These sensors are
sensitive enough to detect the warm "blows" of the animals in the darkness. The information on nighttime
migration rates is used to calibrate daytime counts. The Center wants to detect trends in gray whale and other
marine mammal populations for several good reasons. Knowing the trends will help predict and prevent detrimental
effects of natural or human-caused environmental changes, such as fishing, habitat disturbance, and global warming,
on these populations. The scientists at the Center also develop and test mathematical models to determine how factors
such as growth, reproduction, and geographic distribution of marine mammal populations might influence changes
in population levels or their estimates of these levels.
Celebrating the Gray Whale Migration
The migration is marked by celebrations all along the whale trail. If you live near the Pacific coast or near Kodiak, enjoy these:
1. Santa Barbara Whale Festival
This two-day Festival is Saturday and Sunday, March 24-25, 2001.
2. BIRD BRAIN Navigational Dance Touring Project
This dance project follows the migratory pathways of gray whales and birds. In March, BIRD BRAIN will follow the female gray whales and their calves on their northward migration from Baja to Vancouver. Working with scientists throughout the tour, four performers will translate with dance the migratory and navigatory pathways of the tracked whales and their calves, performing in aquariums and national and state parks all along the coast. BIRD BRAIN is deeply inspired by the links migratory animals make between continents and ecosystems. See their Web site for further information, dates and locations.
3. Whale Fest Kodiak
Whale Fest Kodiak is a community celebration about whales and other marine mammals, timed to coincide with the annual northbound migration of the gray whales as they pass Kodiak Island: April 13-22 this year.
Update on Challenge Question #5
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Last year (2000) it was March 16. This year (2001) they are still waiting for their first returning grays. When do you think they'll arrive?
Susan Payne, biologist and JN reporter at Kodiak Island, AK says, "The southbound migration is much faster than the northbound. The migration lasts approximately 2 months going south and 4 months heading north." Why do you think this is true?
How to Respond to Today's Challenge Questions:
IMPORTANT: Answer only ONE question in each e-mail message.
1. Address an e-mail message to: jn-challenge-gwhale@learner.org
2. In the Subject Line of your message write: Challenge Question #8 (OR #9).
3. In the body of EACH message, give your answer to ONE of the questions above.
The Next Gray Whale Migration Update Will Be Posted on April 4, 2001.
Copyright 2001 Journey North. All Rights Reserved. Please send all questions, comments, and suggestions to our feedback form
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