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