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Answers from the Gray Whale Expert 2003
Included in this Message:
Answers from the Gray Whale Expert
Special thanks to Dave Rugh for providing his time and expertise in responding to your questions below.
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| Dave Rugh in the Arctic |
Sappington School, LEAP program
Q: How would drought
affect the Gray Whale? What would the Gray Whale do in a drought?
A: If drought is defined as the lack of rain,
it would have no obvious affect on gray whales because they live in the
ocean. Whales get water from the food they eat, so they do not need to
find sources of fresh water. Lower levels of water runoff from land during
a drought might reduce the flow of nutrients to the animals (marine crustaceans,
such as amphipods and mysids) that these whales eat, but that would occur
only in the local areas affected by the drought.
Q: Do Gray Whales' eyes come in different colors like humans?
A: Interesting question! However I'm sorry that there isn't enough information available to give you a complete answer. People rarely get very close to wild whales, and when they do, it's hard to distinguish eye colors, so I can't tell you how much variety there is. Gray whale eyes appear dark and murky (most of what you see is pupil), and their iris color does not show well.
Q: How do you tell a male Gray Whale from a female?
A: Although female gray whales may be larger than males, the two genders are hard to tell apart until you look at their undersides. Males and females have urogenital slits (urinary/reproductive tract openings) in different locations on their bodies, and a male's penis may be visible if it is extruded (sticking out).
Q: How do they select a mate?
A: That is a very good question, and it is highly relevant to the evolutionary process; however, we do not have enough information on gray whales to provide any conclusive answers. We can speculate that mate selection is partly a function of size and behavior: big whales that breach high (leap out of the water) and come down hard with a big splash, for instance, may provide impressive displays that intimidate others. Gray whales seem to be relatively passive with each other, that is, they don't seem to fight over who gets to mate, but the competition may be expressed in how much sperm is delivered into the female.
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| Baby
Gray |
Groveland Elementary
Q: When does the baby leave the mother for good? How does she make the baby leave, or does it want to go?
A: Baby whales (called calves) leave their mothers in a process called weaning. This may occur gradually over several months, and it is usually complete by nine months, even though the mother stops providing milk (lactating) when the calf is about half a year old. Because we can't see what whales are doing underwater, we must try to make sense of what we see when they come to the surface to breathe. I once saw a very young whale, about one year old, approach three large whales. One of the large whales (perhaps its mother) turned around and chased the young one away. This appeared to be the process of weaning.
Q: Why do a few whales still head south in March and April, as shown by the ACS/LA census?
A: Although most gray whales in a migration are headed in the same direction, some turn around and go the opposite way for a while. For most gray whales, the urge to migrate south fades in mid-February. Whales going south in March and April are probably just departing temporarily from the northbound migration. It's possible they are turning back to look for other whales they had been traveling with earlier.
Q: Whales are mammals, so where is their hair?
A: You are right that hair is one characteristic that distinguishes mammals from other animals; however, whales have evolved away from needing a fur coat. They have a thick layer of blubber instead. Whales have only a few hairs around their mouths before they are born. Most of these hairs are shed at birth, although adults may have some bristles on their chins.
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| Killer
Whale |
Deephaven Elementary
Q: If a killer whale attacks a mother or baby, do other whales come to its defense?
A: A mother may struggle vigorously to protect its young, but other gray whales would probably not come near to help defend it. When killer whales attack, gray whales sometimes get very close together, perhaps more to protect themselves than to protect each other.
Q: Do you think they mourn, like elephants?
A: It's hard to say. Because we can't watch what whales do underwater, and we don't understand their expressions, we don't know how much they might mourn. Gray whales are gregarious (that is, they like to be together), so it is safe to assume that they are quite aware of losses in their group. But, we don't know how long groups stay together or how long the absence of one would be felt by the others.
Q: Why do some whales stop and become "residents," and not complete the migration?
A: Gray whales are opportunists in that they can take advantage of a variety of feeding opportunities. If they come across an area with plenty of food, they might stay there instead of migrating all the way to feeding areas in the Arctic, the way most of the population does each year. When gray whales find food in places like Washington State or British Columbia, they are more likely to return there in following years, becoming "resident whales," at least for awhile. Or, if a whale is quite sick, it might stop migrating and stay in one area, appearing to be a "resident" whale.
Dave Rugh
Wildlife Biologist
National Marine Mammal Laboratory
Since 1995, experts have contributed answers to students' questions about each Journey North species. These questions and answers are archived in our FAQ's (Frequently Asked Questions) section. You can use today's Answers from the Expert above, along with those from previous years, in the activities suggested in the lesson, "FAQ's About Journey North Species"
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