1

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.

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.

2

In sunlight, Vitamin D is formed from older oil that is then ingested by birds.

- molting occurs gradually except in penguins who can’t 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

3

- 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

4

Some species breed in high latitudes and feed at low latitudes.Arctic terns migrate 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.

5

Bird populations have been hurt most by loss of habitat.DDT and oil pollution 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.

6

Reproduction is by internal fertilization

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.

7

Some species release eggs daily, other seasonally. If fertilized, yolk and protein albumin provide food for the developing embryo.

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.

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 helplessSong birds and ducks are precocial - ready to feed as soon as their down has dried