Marine birds do not get wet when they enter the water. All birds have what is called a preening gland. The preening gland secretes waxes and fats that a bird spreads throughout its feathers in order to make itself waterproof/insulated. Birds also have powder downs, special feathers made of keratin that break into small dust-like pieces. This dust is spread throughout the feathers, aids in waterproofing the bird (because keratin is waterproof).

Many marine birds have what are called salt glands. Because ocean-bound birds often have no choice but to drink salt water, they need a special mechanism by which to evacuate extra salt from their systems. Salt glands concentrate salt from blood in an area near the sinuses. The bird then can rid itself of excess salt by "sneezing" the salt out. Some non-marine birds have facultative salt glands. When these transient, migrants drink salt water, their normally atrophied salt glands increase in size allowing them to excrete extraneous salt, as needed. The majority of the fresh water that marine birds need comes from their prey.

Many predatory sea birds, such as penguins and cormorants have bills with curved projections at the tips that help to direct fish towards the esophagus. The different lengths and curvatures of shorebird bills determine which prey they can reach by probing in the sand. Differences in bill dimensions influence the rate at which food can be eaten.

Pelicans, cormorants and frigate birds have a distensible pouch between the branches of the lower mandible that they use to capture fish. Pelicans dive and scoop fish up in their pouched bills and drain the water before swallowing their catch. Cormorants pursue fish under water, seizing their prey with their hooked bills. Anhingas spear their fish. Frigate birds steal food from other fish-eating birds. Flamingos have beak lamellae that filter small organisms out of the water. They can eat small invertebrates and even blue green algae. Long billed, long legged birds wade in shallow water or along the edge of the water using their bills to probe in the mud or sand to pluck prey items out. Black skimmers skim the surface of the water to catch fish. Penguins dive to great depths to get their meals while terns and gulls will drop from a vantage point in the sky to catch a fish near the ocean’s surface.

There are several lengths of legs and types of feet found on sea birds. Those birds that spend most of their time on the ocean usually have short, stocky legs and palmate or totipalmate feet (partially webbed or totally webbed). The short legs work well as "oars" and the webbed feet work great as the paddle at the end of the oar. Birds that do a lot of swimming have counter current exchange in their feet and legs. Because ocean water can be very cold and even damaging after extended exposure, marine birds need to compensate for the fact that a lot of heat is lost through their feet to the surrounding water. Birds use counter current exchange to warm the cold blood returning from the feet back up. Counter current exchange works by having the arteries pass close by the veins. The warm blood that is in the arteries heats the cold blood in the veins so that it is not exceedingly cold when it reaches the core of the body.

Tube nosed birds have great noses for smelling food—petrels, albatross and shear waters can smell food for up to 30 km!

Birds, in this case aquatic birds, play an essential, and often overlooked role in the ecosystem. They help to keep the ecosystem at a natural equilibrium state by helping to consume the large population of fish in the oceans and lakes, are able to assist in the dispersal of seeds to new environments, and most importantly keep us awe of their beauty and grace. However, it is astounding how quickly their presence can be taken away from us if we infringe too greatly upon their environment. Five examples of humans disturbing their environment include loss of habitat because of human invasion, unnecessary deaths due to by-catch, oil spills, disturbed migration patterns because of global warming, and loss of predatory instincts.

Ecologists worry that oil spills in the ocean will affect fish and other organisms beneath the surface. Oil spills can also have devastating effects upon organisms above the surface. One of the most poignant examples of birds being hurts by oil spills, is that of Exxon plant oil spill in New York Harbor on January 1, 1990. "In all, over 600 wintering birds were killed outright from the spill" (Birds). The birds’ feathers soak up the oil to the point that the birds’ wings are so heavy that they are unable to fly away or even move well. As the oil continues to soak into their feathers, the birds lose the ability to fight off the cold and eventually freeze to death on the water. In addition, "Birds, who preen, and therefore ingest oil, will have membrane damage and dehydration" (Birds).

Loss of habitat and predatory instincts due to human invasion are essentially interrelated. When birds become too dependent on humans, they will lose their ability to obtain food for themselves. One poignant example of this is that the ducks on Lake Chatauqua in Western New York State do not fly south for the winter. They remain on the lake through the coldest depths of winter because they know that the residents will continue to feed them bread every day. If there were ever a period when the people stopped feeding these ducks, the ducks would most likely not know how to fend for themselves and die.

Another danger that seabirds face is death due to entanglement in fishing nets--in other words, becoming by-catch. Death often occurs because the birds see bait dangling from fishing lines and lurch for it. "In fact, in the Southern Hemisphere, it is estimated that more than 40,000 albatross are hooked and drowned every year after grabbing at squid used as bait on longlines being set for bluefin tuna" (The World’s Imperiled Fish). Many sea birds are also killed because they get tangled up in long drift nets, which are pulled through the water and succeed in catching anything in their path.

In recent years, an increase in global temperature, linked to the increased emission of fossil fuels, has been blamed for a decline in the population of sea birds. Global warming has caused both a rise in the average temperature of the open ocean, as well as a melting of the ice caps at the two poles. The warmer water in the open ocean has caused a decrease in the plankton population, which has significantly impaired the diet of seabirds. The melting of the ice caps at the poles means that birds who have depended of the ice environment (a source of algae) are needing to find new ways to obtain food (Climate change harms ocean life).

Parts of this lesson plan were modified from a lesson plan on the teacher’s guide web site,

http://www.inhs.uiuc.edu/chf/pub/virtualbird/teacher/lespl10.htm.

Several of the web page’s pictures were borrowed from: http://bonita.mbnms.nos.noaa.gov/sitechar/bird.html.

• One shower lufa
• Overhead Projector and accompanying translucent sheets
• Preserved specimens of whole birds, beaks, legs, and feet
• Pictures (on overhead, computer, posters, handouts, etc…)
• Poster in the shape of a bird and accompanying feather shaped construction paper pieces
• Pick-Up sticks or chop sticks
• One regular-sized bag of marshmallows
• Regular-sized kitchen forks, sporks (a combination spoon/fork), and fat forks (almost as broad as a spoon)
• Toothbrushes (the quantity depends on the size of the group, it is not necessary for the entire group to participate at once)
• One large and two smaller glass bowls
• Glitter
• Four large sheets of construction paper
• Adhesives (Velcro, glue, tape, ect…)
• Play-dough
• Pictures http://www.1000pictures.com/animals/bird-wtr/index.htm (on overhead, on computer, posters, handouts, etc...)

Pictures should be prepared ahead of time (i.e., put pictures in a power point presentation, on overheads, in handouts, on posters, etc...). A poster in the shape of a large bird should be made for kids to tape their "feather facts on". Paper feathers should be made ahead of time, also. An overhead projector and a television and VCR will be useful if you want to show photocopied pictures and video clips. If sample birds (preserved or alive) can be obtained, they need to be set up ahead of time. Colleges usually have specimen collections that birds can be borrowed from. Birds that demonstrate each of the different physical features that are discussed will be best for the presentation as models for reference. If real birds cannot be obtained, cut outs of beaks, legs and feet should be made for demonstration purposes.

In Tucson, the University of Arizona has an excellent preserved bird collection. For more information, please contact Tom Huels.

Tom Huels
Department of Ecology & Evolutionary Biology
University of Arizona
Tucson, AZ 85721
(520)621-7292
TRHuels@u.arizona.edu

http://eebweb.arizona.edu/Collections/birds.htm

Worksheets that help to reinforce ideas learned can be made. A worksheet that asks students to match beaks with prey items would be ideal for this lesson. If desired, a fun activity would be to make origami paper birds. These are easy and fun to make.

Adaptations

1. First, find out what kinds of marine birds the kids know. Get the kids involved in helping you list what makes marine birds different from terrestrial birds. Mention that birds found at the ocean can either be migratory or permanent. Discuss migration.
2. Ask the kids what they think marine birds eat and then ask how they think birds get their food. Talk about the beaks of different birds and what prey they might be best at catching. Have the kids match bills to prey items on a worksheet or poster.
3. Point out the different types of bird legs and feet. Ask questions to see if students can deduce the utility of different feet and different leg lengths. Discuss counter current exchange if time permits.
4. Ask what would happen if all the kids drank salty water (they would get sick or die). Have them generate ideas as to how the kids think birds with little access to fresh water deal with only having salt water to drink. Talk about the salt gland and make sure to mention that a good percentage of a bird’s water intake comes from their food. Mention that migratory birds have a somewhat atrophied salt gland that works somewhat facultatively.
5. Talk about the functions of feathers. Ask the students if they think that marine birds get wet. Tell them about the mechanisms used to achieve and maintain dryness.
6. Describe tube nosed birds. Ask the kids why they think these birds would need to have such a great sense of smell (to find food). Note that this would be a great trait for birds that like to steal food from other animals.

Beak and Leg Investigation



Students use different implements that mimic seabird beaks and feet in order to explore how the different beaks and feet work in similar habitats.

1. A fork, spoon and a spork will be used to imitate webbed (palmate or totipalmate), lobate and normal, un-webbed feet, respectively. Reiterate the previous discussion about how different feet are used. Given the choice of webbed, lobate and normal feet, have the kids match the different types of feet up with the different silverware items. Show specimens or pictures of birds that have each of the different types of feet. Allow each child to stir the spork, spoon and fork in a bowl of water, in order to see why the webbed foot, or spoon, is the best for swimming.
2. Next, discuss why leg length is important. Point out that longer legs allow birds to wade in deep water without getting wet, while shorter legged birds have an easier time swimming (if they have webbed feet), and searching for small prey items on the ground. Show specimens or pictures of birds with different leg lengths and mention the depth of the water that each bird might encounter, as well as the kinds of foods that you might expect each of the birds to be eating.
3. Reiterate the points of the discussion about bird beaks. For this investigation, stabbing, grabbing and filtering beaks will be examined. To demonstrate the utility of short, grabbing beaks, place plastic bugs on the surface of a bowl full of dirt. Given a toothbrush, a stick or a clothespin, have the kids decide which beak implement is going to be effective for picking the bugs off of the dirt. Allow the kids to grab the bugs with clothespins, after confirming that everyone understands why the clothespin would be the best implement for grabbing bugs.

Ecological Dependence Exercise

Show the students this poster. Ask them to guess what animals or objects might appear in the blank spaces of the circle. Explain the relationship between the original objects on the poster and those that the students placed there. Make sure they understand the objects are all linked together in an ecological cycle (Global warming effects the ocean temperature, which hurts the coral, which impedes on the health of the fish, which decreases the food source for birds). This exercise gives a similar, but slightly different message, as the following activity so the two can be used in conjunction or separately.

Students use their own bodies to demonstrate how human actions can negatively affect their environment. Every student is going to be in one of four groups–each group will be a specific component of the marine food chain. We are going to learn about what happens when one part of the chain is eliminated because of either habitat destruction, , global warming, oil spills, or being caught by a fishing net. Only when we really understand how interconnected the animals in the marine food chain are do we realize how greatly we can hurt one animal by harming another.

1. This activity is not time consuming, yet it still addresses the ideas being discussed in a clear, concise manner. Pick four different aquatic organisms (sea gulls, sardines, plankton, and the grey whale) then ask the students to number off until the class is divided into four equal groups. All the "sea gulls" go to one corner of the room, the "sardines" to another, etc.
2. As the students move to their corners, clear a space in the center of the room.
3. Assign each group a concept:

"Sea gulls" =loss of habitat because of human invasion

"Sardines" =by-catch

"Plankton" =oil spills

"Grey Whale" =global warming

4. Now it’s time to form a circle! This is done by building the circle in chains of loss of habitat, by-catch, oil spills, and global warming. A student from each of the four groups walks toward the cleared area. The four students stand next to each other, facing in toward what will be the center of the circle. Four more students–one from each group–then join the circle. Keep adding to the circle in sets of four until all of the students are part of at least one of the circles.
5. All students should now be standing shoulder to shoulder, facing the center of the circle.
6. Ask the students to turn toward their right, at the same time taking one step toward the center of the circle. They should be standing parallel to each other with each head looking at the head in front of them.
7. At this point the students should put their hands on the shoulders of the person in front of them and as the instructor counts to three, slowly sit down on the knees of the person directly behind them. At that point you then say, "Separate human and bird habitats and there will be no habitat destruction, no by-catch, oil spills, or global warming–these are all conditions sea birds need to survive in their habitat.
8. After the student’s laughter has subsided (from falling down) ask them about actions they can take to help prevent these concepts from affecting the sea bird’s lifestyle in a negative way (i.e. write to their congressmen). Also, ask them why these problems are so detrimental to the sea birds.
9. After the students understand the major point, let them try the circle again. This time ask them to hold their lap sit posture. As the students lap-sit, pick out one of the students from the outermost circle and say that lately there has been an excessive amount of sea bird deaths due to by-catch. The student represented by the "sardine" suffering from by-catch will need to leave from the lap-circle. At that point, the circle will collapse, or at least suffer disruption. Go through each of the three remaining circles until each of the different concepts have been chosen from each of the circles. Explain to the kids that loss of habitat by human invasion, by-catch, oil spills, or global warming can eliminate birds from the habitat, which can disturb the entire ecosystem.
10. Ask the students to talk about the purpose of the activity.
11. This activity was modified from its original form put out by the Illinois Department of Natural Resources, Office of Land Management and Education, in conjunction with the Illinois Natural Resources Information Network. Information on their lab sit activity can be found at the following web site:

1. Make a list of all of the creatures that you think are directly and indirectly affected by the presence of a selected bird in an ecosystem. What happens to these creatures when this bird is removed from the system?
2. How do you think the survival ability of a sea gull is impacted by the presence of humans in their natural habitat?
3. How and why do you think that different birds evolve to develop different physical characteristics?
4. Why do you think that land birds evolved to live in the sea?