Loon Magic/Loon Magic - Wayzata Technology (8011) (1993).iso/mac/mac text/Loon 50 Questions

Text File | 1993-07-20 | 17KB | 353 lines

NANCY MACMILLER
FIFTY QUESTIONS ABOUT LOONS



The Top Ten: For All Loon Lovers


     1.  Do loons mate for life?
The heart says "yes," but the head says "maybe." There simply isn't
enough information to answer this one. Since the pair bond isn't
strong enough to keep the loon pair together throughout migration
and wintering, it may not be strong enough to insure a lifelong
partnership. There appears to be, however, a strong fidelity to the
nest site. A loon pair probably returns to the same territory and nest
site. If a member of a pair dies, the other will most likely find a new
mate.

     2.  Why is the eye red?
Some scientists believe that the red eye improves fishing abilities
either by improved underwater vision or by its camouflage effect
(the red eye appears gray at depths of fifteen feet or more). Others
feel the red eye is part of the breeding season plumage.

     3.  How can you tell the difference between males and females?
It's not easy. You can wait for one to lay an egg (that's a female),
watch a pair copulate (the male is on top) or notice which bird gives
the distinctive yodel call (only males give this call). There are no
differences in plumage and only slight differences in size.

     4.  How long do loons live?
Most scientists believe the average life expectancy to be fifteen to
thirty years.

     5.  Just how ancient is the loon?
It is no accident that loons are listed first in bird books. They are the
oldest living birds with an ancestry dating back fifty to eighty
million years. The oldest loon fossils date back twenty million years.

     6.  How did the loon get its common name?
This is a multiple choice question. Most reference books relate the
common loon to the English word <lumme> or the Scandinavian word
<lom,> both meaning awkward or lame. Since the loon is very clumsy
on land, these references do make sense.  The <Oxford Book of British
Bird Names>, suggests the word loon was a seventeenth century
corruption of the Old Norse word <aaomr> which referred to the red-
throated loon. The basic meaning of the Norse word is moaning, an
allusion to the loud, wailing calls of the loon. In the seventeenth
century loon meant "a fool." Shakespeare's Macbeth called a servant
"a cream-faced loon" which one Shakespearian scholar translated as
"stupid fellow."

     7.  Do loons use their wings while diving?
No. The wings are used to help execute sharp turns while chasing
prey, but they are not used for propulsion. The large webbed feet
supply the power. Wings are typically held tight to the body during
dives.

     8.  How deep do loons dive?
There are reports of dives in excess of 200 feet, but no scientific
evidence exists for dives to those depths. It's safe to say loons dive to
depths over 100 feet which is amazing enough anyway. Generally
loons fish in shallow water and stay submerged less than one minute.

     9.  Are loons endangered?
Officially the answer is no. Common loons are not on the U.S. Fish and
Wildlife's List of Endangered or Threatened Species. In some parts of
their range, however, the common loon is in trouble. Many states list
the loon as endangered, rare or threatened.

     10.  How fast do loons fly?
Loons have been clocked at speeds over 100 mph. Having wing beats
of around 250 per minute, the common loon is an extremely rapid
flyer considering its adaptations (solid bones for example) which
favor aquatic over aerial freedom.


The Next Ten: For Serious Loon Watchers

     11.  What's the wild calling at night all about?
The extravagant calling at night is probably part of territorial
defense. Loons like to keep track of each other. In daylight they can
see each other, but at night they have only calling. Termed night
chorusing, this calling peaks in early spring and has to be considered
as one of nature's most exciting audio events.

     12.  How large are loon territories?
Territory size will depend upon the quality of habitat and the
density of loons in the region, but twenty to 200 acres cover the
range. In prime northern Minnesota loon country, the average
territory on large lakes is about seventy acres.

     13.  How many species of loons are there?
A very small family, there are only five species of loons-the common,
the red-throated, the arctic, the Pacific and the yellow-billed. There
are no subspecies.

     14.  How large are loons?
Common loons average around ten pounds. There is a size gradient.
Loons from the northeast are larger (averaging about twelve pounds)
than loons from the upper midwest (averaging about nine pounds).
The typical loon is about thirty inches in length with a wingspread of
fifty inches.

     15.  What's the ideal nest site?
Imagine a spot right next to the water on the protected side of a
small island with plenty of low vegetation. Have the water drop off
quickly to a depth of around five feet. Now you have a picture of a
perfect loon nest site. If your lake has only one small island, odds are
high that your loons will be nesting there.

     16.  What does courtship activity look like?
There will never be an X-rated loon movie. Loon courtship is rather
mild: combinations of short dives, bill dipping and bill flicking while
quietly swimming near the shoreline.

     17.  Who builds the nest?
Loons have been liberated for millions of years. Males and females
divide about equally the nest building duties. Loons are not careful
builders. They simply throw whatever vegetation is handy on the
nest.

     18.  About the eggs, how many and how big?
Loons aren't like ducks which lay clutches of a dozen or more eggs.
Generally, loons lay two eggs, sometimes only one and very rarely
three. Of course if ducks laid eggs which averaged 3[bu38];pr;pr in
length and 2[bu14];pr;pr in diameter, they would not lay a dozen
either. Loons incubate their eggs an average of twenty-eight days,
but successful incubation can be as short as twenty-five or as long as
thirty-three days. The eggs are turned (very carefully) with the
loon's open mandibles at irregular intervals.

     19.  What predators go after loon eggs?
The masked bandit (raccoon) we all know and love is presently loon
enemy ;ns1. Primarily nocturnal, raccoons are aggressive enough and
large enough to barge into a mainland loon nest, chase away the
adult and feast on loon eggs. Before New Hampshire's loon rangers
started using artificial nest islands (raccoons can, of course, swim but
they rarely bother loons on islands), raccoons destroyed up to eighty
percent of all loon eggs on some New Hampshire lakes. Raccoons,
though, tend to be a problem only where people with their garbage
have inflated raccoon populations. In wilderness areas, avian
predators such as ravens or crows probably take more eggs than
mammals.

     20.  Are loon eggshells getting thin?
Pesticides, especially DDT, have created problems for many birds.
While eagles, ospreys and peregrines have suffered from eggshell
thinning, though, loons have continued to successfully reproduce.
Loon eggshells are about ten percent thinner than eggshells from the
pre-DDT era.


Ten More: Casual Readers Beware

     21.  If the egg hatches, what are the odds the chick will survive?
Very good. Since the parental care of chicks is excellent (by human
standards, obsessive), adult loons usually see their chick(s) through
to fall migration. One New Hampshire study determined that eighty-
four percent of all hatched chicks survived, but the intensive
protection efforts there may have increased the rate. Around fifty
percent is a good estimate.

     22.  What time of year gives loons the most trouble?
It's certainly not summer when loons enjoy a season of easy fishing
and slight stress. Very few dead adult loons are found on northern
lakes. Disease often affects loons in the fall when large numbers
congregate: thousands of loons have succumbed to botulism on Lake
Michigan. But winter is the loon's worst season. The stress of coping
with salt water, violent winter storms, marine pollution and parasites
make life on the coast tough for loons. Off the coasts of the Carolinas,
Florida or Texas, natural selection does its best work.

     23.  How often do loons come ashore?
Usually only to nest. A loon is a total water bird. It is not
inconceivable that a loon (if it did not mate) could live out its entire
life without placing a foot on terra firma.

     24.  Can loons walk?
Not really. Loons sort of push themselves along on land but cannot
stand erect and walk like a duck or goose. The legs are simply too far
back on the body. Ninety-nine percent of all the mounted specimens
are lies, showing loons standing up straight on their two huge feet.

     25.  What do loons eat?
Mainly fish. If a loon lives on a lake with an abundant fish
population, the loon will probably eat fish ninety-nine percent of the
time. Favored prey are perch, suckers, bullheads, sunfish, smelt and
minnows. Non-fish items on the menu include frogs, salamanders,
crayfish and leeches. Keep in mind that loons are very flexible
feeders: they eat what they find.

     26.  Do loons eat game fish?
Sure. They love trout if they can find them. Small northern pike, bass
or walleye all look the same to a hungry loon. Unlike people, loons
don't distinguish between game fish and rough fish-a meal is a meal.

     27.  What about salt water diets?
Fewer studies of salt water feeding habits have been done but it's
safe to say loons use the same opportunistic fishing strategies there.
Herring, sea trout, rock cod, flounder would certainly be on the
menu.

     28.  How big a fish can a loon handle?
Since loons have a rather elastic esophagus, they can swallow fairly
large prey including trout up to eighteen inches. Spiny prey like
sunfish or walleye may present a problem. Loons have been found
dead with two pound walleyes stuck in their gullets. Such large prey,
however, are the exception: the average loon prey can be weighed in
ounces rather than pounds.

     29.  What is the "penguin dance?"
Well named, the loon's penguin dance is the bird's most dramatic
territorial display. Loons literally stand on the water by violently
kicking their feet while holding their head down with their bill tight
against their breast. While this defensive display might drive away
some natural enemies, it does not work well with people. Some
uninformed fishermen or boaters think it's entertainment and
stimulate the display. It requires a lot of energy to perform (try it
next time you're swimming). Anyone accidently stimulating the
dance should retreat immediately.


The Thirties: Fanatics Only

     30.  Why do chicks climb on their parent's back?
The back-riding of chicks is primarily to protect against heat loss but
also serves as protection from underwater (snapping turtles or pike)
or overwater (eagles) predators.

     31.  How high can loons fly?
According to information from radar, at least 7,000 feet. Most flights
in summer are at altitudes of only several hundred feet.

     32.  Can loons lay more than one set of eggs a season?
Yes, if their eggs are lost to predators, loons will lay another clutch of
eggs. Sometimes loons will even nest a third time if the second batch
of eggs is lost.

     33.  Do loons have a "brood patch?"
While loons do not have a featherless brood patch (an incubation hot
spot), they do have an area of their breast where blood vessels in the
skin increase in size during the roughly one-month incubation
period. This physiological change better transfers the bird's body
heat to the eggs.

     34.  What does the "wing flap" signify?
The "wing flap" is done by many water birds. It probably has no
social significance and is simply a way to shake water out of feathers.

     35.  Why don't loons nest every year?
Being a long-lived bird with the potential to raise dozens of young,
loons don't need to attempt a nest each year. If the conditions aren't
quite right, they often forego nesting. Typically, loons nest three of
every four years.

     36.  What is a "rogue loon?"
The term has been given to non-territorial birds or unsuccessful
parents that wander around lakes in late summer. Occasionally, they
kill other loons' chicks. This is not unusual behavior in the animal
kingdom. Young, unattended birds and mammals are often killed by
nonparent adults.

     37.  Do loons have accents?
No. Loons from Minnesota sound just like loons from Maine or New
Hampshire.

     38.  Will loon eggs die if the nest is left uncovered?
Loon eggs are susceptible to cooling. If left uncovered for long
periods, the embryo could die. However, on hot days an egg might
survive six or eight hours without incubation. Typically large eggs
hold heat better than small eggs so loon eggs are better protected
than the eggs of most birds.

     39.  Why do some loons tolerate people better than others?
It appears that loons habituate to people over time. Apparently each
loon has individual characteristics regarding tolerance of disturbance.


The Final Ten: Beyond Fanaticism

     40.  Do some loons have green heads?
Looks are deceiving. A loon's head sometimes looks green but it's
really jet-black. When the feathers on the head are slightly raised (a
display loons use in social gatherings) sunlight refracting through the
feathers creates the green, iridescent effect. In an argument, bet on
black.

     41.  Do loons nest on the ocean?
No. There has never been a report of a loon nesting on the coast.
However, loons are commonly seen off the coasts of Maine and New
Hampshire during the summer breeding season. These birds are
either travelers from inland lakes or single loons unable to find
freshwater breeding territories. Loons do nest in protected areas of
Lakes Superior, Michigan and Huron -  almost oceans.

     42.  Okay, what is this foot waggle business?
All serious loon watchers know about the foot waggle. Every ten to
twenty minutes loons will extend a foot and wave it. It could be that
the foot is being used as a crude solar collector to pick up heat. The
waggle certainly conserves heat since the blood vessels in the foot
would release heat to the water. Supporting this notion is the fact
that after the waggle, the foot is usually tucked up under the wing-a
place to keep it warm. Or it could be that the foot waggle is part of a
stretching exercise, loon yoga perhaps.

     43.  Are small lakes better habitat for loons than large lakes?
Small lakes are probably better habitat for loons, especially if one
pair is able to claim the entire lake as its territory. This reduces
competition for food and other resources and allows the loons to
focus all of their attention on raising their young. Chicks may actually
develop more rapidly on small ponds than on large lakes.

     44.  When does the molt begin?
The fall molt seems to vary by region-earlier in the west and later in
the east. The first noticeable loss of feathers is usually mid-to-late
September. New breeding plumage is donned in March and April.
Loons lose their wing feathers only once-in late winter, usually
February.

     45.  In summer, do loons travel much?
Recent research indicates loons travel a lot in summer, especially late
summer after nesting duties are completed. One Wisconsin loon,
tracked with a radio transmitter, flew twelve miles from its home
lake to feed in another lake.

     46.  How many loons have been banded?
Five-hundred and eighty-seven. Next question...

     47.  How old are loons before they return to the northern lakes?
Unlike ducks or geese, loons hang around their coastal homes for a
full two or even three years before reaching sexual maturity and
flying north for the first time. These immature loons do not have the
black and white plumage. This delayed breeding might give loons the
time they need to learn the fishing and general survival skills
necessary to successfully raise young.

     48.  Will loons reject a chick touched by humans?
No. Many chicks have been handled for banding and have been
safely returned to their parents. Other chicks, which were
abandoned, have been rescued by people and subsequently adopted
by adult loons.

     49.  How long after copulation will the eggs be laid?
That's a rather personal question and no biologist seems to have the
answer. It is a short period of time though, measured in days rather
than weeks.

     50.  Where do I find out even more about loons?
You are an over-the-edge loon fanatic. But if you want information
on loons in your region, contact the North American Loon Fund
affiliate closest to you.