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Signs of Spring Update: March 29, 2002
Today's Report Includes:
Holy Cow! Counting Right Whale Calves
Courtesy of
East Coast Ecosystems.
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Right now, the great whales are taking care of their newest generations on calving
and birthing grounds in Earth's oceans. This week we'll share news about a species
that we have tracked for many years, but are giving just limited coverage this spring:
the Northern Right whale. The right whale is the most endangered of the great whales,
and scientists believe there are only 300 or so of these animals left in the North
Atlantic. After the end of commercial whaling, people thought the Northern right
whale population was recovering. But evidence since about 1990 shows a decline. Biologists
estimate that a population of 300 can hardly support the genetic diversity necessary
for a healthy and thriving population to continue, and many feel the species may
be functionally extinct.
But there are new calves to count this spring! Read on for background information
about this whales' whereabouts, the status of its numbers, news from the calving
grounds, and some very real dangers. With the troubles it faces, you will wonder
why this whale is called the RIGHT whale. (We'll tell you that answer at the end
of today's report!)
Oh Where Oh Where Can That Right Whale Be?
The migration route of the right whale is not as cut-and-dried as other animal species.
Because of their marine habitat and the difficulty of placing and keeping radio tags
on these animals, it is difficult to monitor their migration route. The map at the
right can help you understand what we do know. Can you find these areas?
- We know that the pregnant females seek the warmer
waters of more southern latitudes to birth and raise young calves. Many can be found
in the warm coastal waters off of Georgia and northern to central parts of the Florida
coast.
- Some non-pregnant females, males and juveniles have
been seen feeding during the winter months in Cape Cod Bay (and to a lesser extent
southern Stellwagen Bank).
- Feeding continues during April through June in the Great South Channel, an area
between Nantucket and Georges Bank, which is also the major north-south shipping
channel off the NY-MA coast. But this is only a fraction of the entire population.
We do not know where most of the animals are during this time period.
- In the late summer and early fall, right whales congregate in the Bay of Fundy
and off the coast of Nova Scotia in areas believed to be breeding and feeding grounds.
Scientists suspect there may be other calving, breeding and feeding grounds, perhaps
farther offshore, that we don't yet know about.
Population Trends and Concerns
Right whales probably never had a large population to begin with, and constant whaling
over centuries kept the numbers down. By the mid 1930s when the whales received international
protection, their numbers were pitifully low. Although hunting has stopped, other
factors may be keeping the population numbers down. Low birth ratesand entanglement
in fishing gear are major causes of right whale deaths.
Interactions with humans and changes to the right whale habitats may be affecting
the health of individual animals and the birth rate. But collisions with ships is
the number one known cause of right whale mortality. The migration route takes the
animals across the paths of major shipping channels into many ports along the eastern
seaboard (Portland, Boston, Newport, New York, Chesapeake Bay, Charleston, and Port
Canaveral are some). During this time, whales are in danger of being struck by large
ships that are moving perpendicular to them. When whales and ships meet, it's usually
the whale that suffers the most damage.
News from the Calving Area
Chris Slay from the New England Aquarium reported some good news in late February
this year. Survey teams reported sightings of 15 or more right whale calves swimming
at their mothers' sides! The sightings were made from all along the coast from Hatteras
to Canaveral. Moms and calves were found up high on the shelf, most within 10 fathoms.
Many were found where they always are, between Savannah and St. Augustine, with a
strong presence off American Beach, Florida. Chris writes, "All babies look
healthy and strong, and 15 babies is 3 MORE than the average dozen babies per year.
We'll take it!"
How do they see the whales? Most of these sightings are made from airplanes. Sometimes
researchers will tag a mother-calf pair in the calving grounds. This tag, a radiotag,
allows scientists to follow the movements of the whale. From a boat, the researchers
must be within two miles of the whale; from the air, the researchers can be some
20 (sometimes 30) nautical miles away from the transmitter.
Challenge Question #15:
"Why do you think the scientists can follow the whale from 20-30 nautical miles
in a plane, but only 2 miles from the boat?"
(To respond
to this question, please follow the instructions below.)
2001--A Memorable Year
Recorded Births for Northern Right Whale
(* estimated as of 3/02)
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Year
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Recorded Births
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1996
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22
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1997
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18
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1998
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5
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1999
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4
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2000
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1
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2001
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30
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2002
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15*
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The Right whale made big news last year with sightings of 30 new calves added to
the small population. This was a record number, and whale enthusiasts were ecstatic.
Although the bumper crop of right whale calves in 2001 gave hope to many, it turned
out to be a year with a record high number of deaths as well. Four calves died, two
from ship collisions. Three adults are known dead, and two of these were entangled.
One carcass was sighted on Middle Bank, Nova Scotia in December, the cause of death
unknown.
Challenge Question #16:
"The information in the chart shows 7 years of data of the recorded births of
northern right whales. What other kinds of information would you need to have before
you could get a better idea about this whale population?" (Be as specific as
you can about other factors you would need to know.)
(To respond
to this question, please follow the instructions below.)
Whales Share Shipping Lanes: Be On Alert!
Courtesy National Marine Fisheries Service
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The death of ANY right whale is very serious for the population. What are we doing
to prevent death of this species by ship strikes? These maps are an example of efforts
among many groups to protect our precious right whale population. To help reduce
the number of ship strikes, NOAA (National Oceanic and Atmospheric Administration)
and the U.S. Coast Guard have "Mandatory Ship Reporting
Systems." When ships greater than 300 gross tons enter two key right
whale habitats -- the summer feeding grounds off the northeast U.S. and the winter
calving grounds off the southeast U.S.-- the ships are required to report to a shore-based
station. In return, ships receive a message about right whales, their vulnerability
to ship strikes, measures the ship can take to avoid hitting a whale, and locations
of recent whale sightings.
Take a look at the map of the Cape Cod Bay area. Do you see these 3 things?
- The bay is the destination for many ships that run cargo up and down the eastern
seaboard.
- This shipping lane is the same one often used by migrating right whales.
- A large area labeled "Ship Reporting System Area" is outlined on the
map.
You can learn more or read about individual sightings made in this Ship Reporting
Area by visiting this site:
NOAA and NMFS
Right Whale Sighting Advisory System (SAS)
Did You Know?
Northern right whales are large and slow, with thick layers of oil rich blubber and
long racks of once-valuable baleen, up to 6 or more feet in length. The whales often
feed right at the surface, and they float when killed. This makes them easy to spot
and kill, so whalers called them just the "right" whale to hunt.
Muddy Mouthfuls: Discussion of Challenge Questions
#12 and #13
Challenge Question #12 asked: "List at least two or three special habitat needs
of Cliff Swallows in their nesting area."
First graders Jack, Andrew and Megan of Ferrisburgh Central School in Vermont used
their reasoning skills to come up with a great answer! They wrote, "Cliff Swallows
need mud to build their nests. They will need to be near to the water and have some
type of clay soil. When clay gets wet, it gets sticky. We are using clay at our school
right now, and we have to get it wet in order for the pieces to stick together. The
swallows have to build their nests somewhere that the nests can stay dry like under
roofs.
Challenge Question #13 asked: "Why are all the mud pellets that make up a Cliff
Swallow nest about the same size and shape?"
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Cliff Swallows
Photo James R. Gallagher
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First graders Lane, Daniel, Jenna, Gabriella and Alicia at Ferrisburgh Central School
paid attention to the movie
clip we linked to. They send this great answer for us to learn from: "We
watched the movie of the swallows building their nests. It said that the swallows
took up the mud with their beaks and shaped their home with those mud bits. It can
take over two weeks to make the nest. The pellets are all the same size and shape
because the beakfuls would all be the same size. They would always carry about the
same amount. As you can see by the little bumps on the nest, each bump is a mouthful
of mud for the nest."
All in the Muscles: Discussion of Challenge Question
#14
"If a falcon caught a swallow, would its dinner be mainly red meat or white
meat?"
Fifth Graders Andrew, Joseph, Ryan and Stephen of Ferrisburgh Central School wrote,
"The meat would be mainly red because the swallows use their muscles a lot."
That's precisely right! One ornithologist calculated that swallows fly about 600
miles a day just zipping around feeding, so every day is a long marathon for them,
and their pectoral muscles need red fibers to keep from getting tired. Their leg
muscles might have a lot of white muscle fibers, but their legs are so tiny and weak
that a falcon would hardly taste them at all!
Please Report "Signs of Spring" From Your Part of the
World!
Report your "Signs of
Spring" sightings to Journey North. |
Remember to share your sightings of first frogs, earthworms, red-winged blackbirds,
barn swallows, emerging leaves, flowing sap, melting ice and other spring events.
Your observations will be incorporated into "Signs of Spring" updates according
to the schedule above. Thanks for sharing!
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-spring@learner.org
2. IMPORTANT: In the Subject Line of your message write:
Challenge Question #15 (OR #16).
3. In the body of the message, give your answer to the question above.
The Next Signs of Spring Update Will be Posted on April 5, 2002
Copyright 2002 Journey North. All Rights Reserved.
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