Subject: Humpback behaviour, integument, diseases, calves
n.patenaude@auckland.ac.nz
Mon, 17 Mar 1997 16:25:46 GMT+1200
Subj: humpback whales
Thanks for your help. I am a seventh grader from Dwight D.
Eisenhower Middle School in Wyckoff, New Jersey. I am going a project on whales.
I was wondering if you can help me answer these questions as soon as possible.
1.) Is there any other behavior such as breaching, sounding, spy
hopping,lobtailing, and spyhop? What are they and what are they called? What
is lobtailing?
I presume you are asking about the acrobatic displays of humpback.
Humpback whales (and many other whales for that matter) can almost completely leap out of
the water and fall back onto the water with a big splash, this is called breaching. They
may also lift their head vertically out of the water so that their eyes are just above the
water line, this is called spyhopping. Lobtailing or tail-slapping, is when a whale slaps
the water really hard with its fluke while most of the rest of their body stays just below
the surface. They sometimes roll over at the surface and slap their pectoral flipper onto
the water- this is called flipper (or pectoral) -slapping. A sounding dive is a deep and
usually prolonged dive. Humpbacks typically lift their fluke out of the water before they
strat a sounding dive.
2.) Why are the humpback whales on the endanger species list? Is there
anything us seventh graders can do to make them get off the list?
Before commercial whaling, humpback whales numbered more than 150 000 individuals
world-wide. Because of their tendency to gather in groups on their summering and wintering
grounds, often near coasts with easy access, they were an easy prey for whalers. As a
result, there numbers were seriously reduced, and recovery of this species has been really
slow. The current world-wide population is less than 10 000 whales. Because there are
comparatively so few humpbacks left, they are on the endangered species list.
It may take a while before humpback whales are off the endangered list. But there is hope
yet, if we think of the gray whale. This specie was so severely depleted by whaling that
they past a law in 1937 to protect them from the harpoons of whalers. Today, the gray whale
are approaching their original numbers have been removed from the list.
One of the most important things you can do to help the plight of the humpback and indeed
any other marine mammal is to raise awareness at your school and in your community about the
need to protect the environment. Humpbacks are part of the ecosystem, and although it is
difficult to directly monitor them, you can certainly help them by minimising your impact on
the environment. You can do so by making sure you keep your waste to a minimum by reducing,
reusing and recycling. You can start a used oil collection in your neighbourhood to be
disposed of properly instead of people dumping it in the sink and ending up in the ocean. I
think have ecologically sound practices in your school and at home will help in the long
run. You can also make some sound choices about what you will and will not support. For
instance, you may choose to protest the large scale fishing industry that is depleting the
ocean of whale and dolphin food sources, or protest against the dumping of garbage into the
oceans.
3.) What is the percentage of the epidermis, dermis, blubber, connective
tissue,fascia, and muscle in the body? Indivially? What is dermis and
fascia? What are they made out of? What do they do?
That's a pretty though question. I am a molecular ecologist, not a morphologist but I'll
give it my best shot. The skin of all mammals (this includes whales and dolphins) is mad eup
of two parts: an outer layer called the epidermis and a inner layer called the dermis. The
epidermis of cetaceans is very thin, in large whales it is about 2/10 inches thick. The
dermis is a layer of dense connective tissue, with blood vessels, nerves and glands embedded
into it. The dermis provides the skin with stengh and elasticity. The skin has multiple
functions, among which is to help regulate the body temperature. It also acts as a
protective barrier for underlying tissue and linked to sensation of hot/cold, or pain. The
skin is the largest organ of the body. For instance, the skin in blue whales has been
measured at about 225 square yards. This would cover an entire tennis court. Although it is
very larger it is very thin. I would guess that it represents less than 5% of the body mass.
Beneath the dermis lies a layer of fat or blubber and then tissue below the skin called
connective tissue. The blubber is constructed of hard and fibrous connective tissue. The
thickness of the blubber varies at different times of the year and depending on the age and
the physiological condition of the animal. For instance, younger animals generally have
thicker layers of blubber than adults, and pregnant females have more blubber than other
adults. So it is difficult to say exactly what is the percentage of blubber in humpbacks.
In blue whales it is about 27% of the body weight, and in sperm whales it is 32%.
Between the connective tissue and the muscle lies the fascia. The fascia is composed of
sheets of connective tissue and serves in covering, supporting and seperating muscles. I
wouldn't know what % of body weight it represents. The muscle mass in large whales
represents between 40 and 55% of their body weight while the squeleton accounts for about
17%.
4.) What diseases can humpback whales died from? Any colds?
Little is known about humpback whale diseases. They apparently have a lot of endoparasites
(those are parasites that live within their bodies), like tapeworms and flukes. Many
species of nematodes (type of worm) live in the stomachs and intestines of whales. Some of
them infest the kidneys, others the bronchi and lungs. Some flukes live in the liver, lung
or even in the brain. If a whale is infested by lots of these nasties, that could cause
death or at least make the whales really weak for them to catch secondary infections. We
already know that parasitism is an important cause of death in small cetaceans and in some
large whales. Humpbacks can catch colds, and some humpbacks even have tuberculosis.
5.) Are there any stages that have names when a calf turns into an
adult? What happens? how long does it happen? When does it start?
When a humpback calf is born it is usually called a 'neonate' (another name for newborn) and
measures between 4 and 5 m long. Then it's called a calf as long at it is suckling (for a
bout 5 months or so) and the calf stays really close to it's mom. By then end of the
suckling period the calf measures between 7.5 and 9 m long. Between the time when calves are
independent of their moms but not yet of reproductive age they are called subadults.
Subadults are young whales between the ages of 6 months to 4 of 5 years of age. Although
during the first year a subadult is sometimes called a 'yearling'. Then the females start
ovulating and males testis and production of sperm increases during breeding period and they
are sexually mature. They are now called adults.
Nathalie Patenaude