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Answers from the Gray Whale Expert 2006
Included in this Message:
Answers
from the Gray Whale Expert
Special
thanks to expert Kim
Shelden for providing her time and expertise in
responding to your questions below.
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From: Oswego, Illinois
Forest Glen School
Q: How old can gray whales be?
A: The maximum lifespan of a gray whale is not known but there was a report of a large female that was estimated to be about 75-80 years old when she was killed.
Q: What is the biggest gray whale you have seen?
A: I would say that the largest gray whale I’ve seen is one measured from a photograph taken during our aircraft surveys and that whale was about 14m (45 ft) long.
Q: How much does a baby whale weigh when it’s born?
A: Like human babies, gray whales can range from very small to very large when they are born but on average a newborn gray whale weighs about 920 kg.
From: Arlington Heights, Illinois
Q: Do gray whales ever change color with age?
A: The skin of gray whales when they are born is fairly clean and dark. Gray whales are host to more external parasites than any other cetacean. These include barnacles that settle onto the whale’s skin soon after birth and become deeply embedded. These barnacles eventually form large colonies and this can change the mottled appearance of a gray whale over time.
Q: Like humans and many other animals, do gray whales have various eye colors?
A: There are few accounts of eye color in cetaceans. One exception is Dall's porpoise which have been described as having a black or dark blue iris and a deep, iridescent blue-green pupil. However, I could not find out if these porpoise only have blue-green eyes and not brown or black or other colors. This is a very good question and while we know a little bit about how these whales see the world no one has really described the color of their eyes.
From: Rolling Meadows, Illinois
Q: How many times per minute does a Gray Whale breathe?
A: That would depend on the size of the whale and how it is behaving.
When whales are migrating they may stay submerged for 3 to 5 minutes
then surface and take about 3 to 5 breaths before diving again.
These breaths are taken about 15 to 30 seconds apart. So a migrating
whale might take a breath 1 to 3 times per minute.
Q: How high is a Gray Whale's blow?
A: A gray whale can spout about 3 to
4 m (10-13 ft) into the air.
The spout will be taller and higher if weather conditions are calm.
Q:
Some observers say the gray whales blow and play and are very
visible. Other times they have no blows and seem to be in stealth mode.
Can you think of why they might do this? Is it because they
know
orcas are near?
A: This behavior is called “snorkeling” when
the whale only surfaces enough to reveal its blowhole to breathe.
When killer whales are in the area we do see this behavior.
Sometimes a mom with calf will migrate this way and stay very
close to shore.
It may be one way to protect her calf from detection. Also
by gliding slowly just below the surface, the mom is able to
pull her calf
along in her wake and the calf is better able to keep up with
mom.
Q: How does a mother defend her calf if orcas attack?
A: Some mothers try to protect their calves by lifting
them up out of the water using their head or back to support them.
Others
try to get their calves into shallow water where the killer
whales may not follow. Gray whales also roll belly up and slash
back and
forth with their tails when they feel threatened.
From Minneapolis, Minnesota
Q: Our book Whale Journey talks about the auntie, or another adult
whale that stays with a mom and calf to help them. Is this for
real?
A: We see evidence of this behavior, called alloparental
care, in some of the toothed whales like killer whales, pilot whales
and sperm whales. Humpback males will also escort a mom with
calf.
It is possible, but for the most part when we see gray whale
moms with calves during the migration they are not traveling with
other
gray whales.
Q: When orcas attack and kill a calf on the migration north, is
there any research about how a whale mother reacts or feels? Does
she grieve, like elephants do?
A: No, we do not have any research on this. It is very
hard to know how any animal feels especially one that spends so
much time
under water where we cannot observe it. We may not recognize
behaviors that indicate grief. Sometimes when a calf dies, the
mother will
stay with the body for a while, nudging it, and trying to keep
it at the surface.
Q: Do calves
make noises?
A: Yes, they make sounds similar to other gray whales such
as rasps, croaks, snorts, moans, groans, grunts, pops, and clicks.
Q:
What
do you think is the biggest threat to gray whales?
A: Gray whales have made an amazing recovery from the time
of commercial whaling. We still have so much to learn about
them but unfortunately
funding is hard to come by. The greatest threats still continue
to be anthropogenic, that is human caused, and these are
of concern for all whales and dolphins. It is very important
to
study the
effects of pollution, ship traffic, fishing, and oil and
gas development, just to name a few. However, without funding
the
biggest threats
may go undetected until it is too late.
How to Use FAQ's About Journey North Species
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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