Humpback Whale Migration Update: April 25, 2001
Today's Report Includes:
Greetings from the Stellwagen Bank National Marine Sanctuary.
Sad News About Boston's Popular "Inland" Humpback
But the fisheries service did not pass the same rules for mid-Atlantic fishermen despite the fact that young humpbacks are known to spend the winter months feeding off the coast of Virginia and the Carolinas. Inland was one of these young humpbacks, probably about a year old, that stayed in the northern feeding grounds this past winter.
The 30-foot animal was dragged to the shore near Virginia Beach, examined and then buried in sand to hasten decomposition.
Read the news-breaking article for yourself by visiting:
Because the right whale is an endangered species there are many governmental regulations involved with custody
of a dead body. National Marine Fisheries Service is in charge of the endangered species act and is responsible
for the dead whales. The New England Whale Center applied to the NMFS for the skeletal remains, and was given this
whale and was granted permission for its display.
Humpbacks in Cape Cod Bay
There are many more sightings now as the humpbacks return to their summer feeding grounds. The Center for Coastal Studies keeps a list of humpbacks they have sighted this season. To see who has shown up, take a look at the list of names spotted in 2001. Do you recognize any of these names?
Recently, scientists from the Center for Coastal Studies boarded the research vessel Gannet and headed out to
sea. On April 11th,the aerial survey team sighted some humpbacks on the ocean side the Cape Cod Bay. With this
information, and a relatively calm day, the CCS team headed out of the bay and found Jumanji (the 1999 calf of
Dyad), Flounder (the 1997 calf of Vulture) and Nucleus traveling together searching and lunging for food. Circling
high above as a telltale sign that fish were in the area, the researchers spotted a group of northern gannets scouting
out some prey.
Gannets Signal Schools of Food
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Very few marine mammals will pass up on the opportunity to feed on a school of sand lance when they are found at the surface. Humpbacks will happily munch on large mouthfuls when given the opportunity.
Magnificent Marine Mammal Vocalizations
We have so much to learn from this magnificent marine mammal. Although their marine habitat creates some challenges for study, humpback vocalizations have been recorded and studied extensively. And it is fascinating to learn about what has been discovered!
The humpback whales' song is probably the most complex vocalization in the animal kingdom. The song, which is made up of repeated themes, can last for up to 30 minutes and some humpbacks sing for hours at a time! The songs are composed of low and high frequency sound waves. Some are so low that they can not be detected with the human ear. Did you know that whale songs travel really far underwater? Would you believe a humpback's song can travel up to 10,000 miles?
Learn more about this magnificent creature's songs.
News Flash - Athens, Greece
International news report published April 19th in the St. Paul Pioneer Press, documented a rare sighting of a young humpback frolicking in the sea off southern Greece! The report cites, "whale experts scrambling to document the visit of the wayward wanderer." There have only been a few reports of humpbacks passing through the Strait of Gibraltar to enter the Mediterranean.
"The humpback, measuring about 35 feet, is estimated to be about 4 or 5 years old and appeared to be in good health," said marine biologist Emilia Drouga, who heads Delphis, the Greek Society for the Study and Protection of Dolphins and Whales.
Pull out your atlases and find the western opening to the Mediterranean Sea. It would seem that the odds are rather small that a whale could find its way into the Strait of Gibraltar. What can you find out about that narrow opening?
How Many Calves Born to Mural? Discussion of Challenge Question #15
"What is a possible calving history for Mural that incorporates the known sighting history (Hint: on average humpbacks calve every 2-3 years.)?"
Thanks to Jenny Fleming who estimated that Mural may have given birth to up to 7 calves in her 22 years. Here is what Anne Smrcina shared with us:
"Mural may have a calf every three years (on average humpbacks calve every 2-3 years) and may bring her newborn to Stellwagen Bank very early in the season (as she did this year). By the time traditional whalewatching starts in mid-to-late April, she may have already departed with her calf to other feeding grounds (we'll see if she sticks around this year). In the years she doesn't have a calf, she seems to stick around later into the summer. So, she could have had quite a few calves over the past 22 years - if she started having babies at 5 or 6, she could be up to as many as 5 or more calves by now."
Knobby Heads: Discussion of Challenge Question #16
"What are the knobby structures called 'stove bolts' by Yankee whalers, and what is their purpose?"
The knobs on the humpback's head were once called 'stove bolts' by the Yankee whalers. Scientists call these tubercles (two'-bur-kuls) or sensory nodules. Each are about the size of a golf ball. The tubercles are distributed on the humpback's upper and lower jaws and along the lips in about the same area that facial hair is found on humans. The number of tubercles varies from whale to whale, with each possessing a unique tubercle pattern. Each tubercle contains a hair follicle, sometimes with a single light gray vibrrissa about 0.5 to 1.05 inches long. There is some suggestion that the tubercle acts as a sensory organ, but their exact function is unknown.
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The Next Humpback Whale Migration Update will Be Posted on May 9, 2001.
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