CLASS AVES MARINE BIRDS

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CLASS AVES - MARINE BIRDS
Marine birds are grouped by their feet and bills.
They determine the type of food eaten and habitat.
All marine birds must return to shore to nest,
thereby insuring sea grass planting.
Anatomical adaptations
- thin, hollow bones, semi-rigid skeleton (only
neck is jointed)
- senses great vision, hearing and smell are
average to low, poor sense of taste
- feathers provide warmth. Oil from the preen
gland located at the base of nose or tail is used
to waterproof feathers.
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In sunlight, Vitamin D is formed from older oil
that is then ingested by birds.
- molting occurs gradually except in penguins who
cant eat during molting because of the cold water
- buoyancy is increased by extra air sacs
attached to lungs and by preening swimming birds
must exhale all the air
Puffins
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- salt excreted by pores near beak or eyes
- excrete nitrogenous paste (Guano) to conserve
water
- 4 chambered heart with rapid heart beat
endothermic
- birds eat large quantities of food to maintain
warm body and supply energy for flight
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Some species breed in high latitudes and feed at
low latitudes. Arctic terns migrates between
poles - a trip of 20,000 miles every year.
Competition within communities is reduced by
having different foods, different nests,
territories, and nocturnal-diurnal activities.
Egrets nest in rookeries in the tops of trees.
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Bird populations have been hurt most by loss of
habitat. The effects of DDT and oil pollution
also caused birth defects and soft shells.
Some species mate for a season others can
recognize the voice of their life-time mate after
6 months apart even on a beach crowded with
thousands of other birds.
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Reproduction is internal fertilization. Most
birds have only one ovary that releases an egg
cell located on the yolk.
The yolk is covered by albumin (egg white) while
in the fallopian tube for about 3 hrs.
Then it takes about an hour for the membrane to
be added in the isthmus.
The egg spends about 20 hrs. in the uterus
getting a shell and pigments to color the shell.
The motion of the egg determines whether it will
have spots or streaks, and how many layers of
colors.
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Some species release eggs daily, other
seasonally. If fertilized, the yolk and protein
albumin provide food for the developing embryo.
The hen releases an egg whether fertilized or not
and will usually keep releasing eggs until the
nest is full.
Marine birds are altricial - born blind, naked
and helpless. Unlike precocial song birds and
ducks who are ready to feed as soon as their down
has dried.
The young learn to behave by watching the adult
who feeds them. This type of mimic behavior is
called imprinting. It is a simple, quick,
irreversible type of learning.