Grade Level: 1st to 8th grade

Objectives
Students will learn that whales are divided into two groups based on the presence or absence of baleen. Students will learn about four common methods some whales use to feed and students will simulate these methods.

Background Information
Whales are divided into two groups, mysticetes with baleen, and odontocetes (also known as toothed whales) without baleen. For the purposes of this activity we will dividing mysticetes into three groups skimmers: gulpers, and bubblers and calling the odontocetes biters.

Baleen hangs down from a whale's top jaw and is made of keratin, the same protein from which hair and fingernails are made. It is a filter which whales use to strain large quantities of water, capturing prey in their mouth. There are three distinct methods used by different baleen whales that will be simulated in this activity. The bowhead and right whales are skimmers; they swim through the water with their mouths open. They have no baleen at the tip of their mouths in front, so as they swim water and prey move to the backs of their mouths. The force of the flowing water pushes the water through the inside of the baleen and out, but the prey gets stuck on the baleen. The roqual whales (blue, humpback, fin,sei, minke and Bryde's) are gulpers; they have pleats in their throats allowing them to expand and take in large amounts of water and prey. gulpers then use their tongues to push the water out between the baleen plates. Both gulpers and skimmers will use their tongue to aid in pushing the water out. Humpback whales are roqual whales and feed like gulpers but they may also feed as a group. This group feeding method is called bubble netting hence the term bubblers and is most often used to catch small schooling fish like sand lance. The whales bubbles are bigger then the fish. By blowing a circle of bubbles (the net) in the water column, they herd fish into a concentrated ball. The whales then swim through fish with their mouth open filling their pleated throats. Then they strain out the fish as gulpers.

Odontocetes, such as the sperm whales, dolphins (which include orcas), beluga whales and porpoises use their teeth to capture, and kill their prey, basically using the method of capture, bite, and swallow, or shake off a chunk and swallow. In this activity the biters will use the above method. Some orcas are know to eat other marine mammals.

Materials
Photos of the different whales for the introduction
Large bottle of dry parsley
Dish pans with water
Straws
Plastic pocket combs (combs without handles work best)
Plastic sandwich bags
Tongs
Absorbent paper towels
Small pieces of Styrofoam

Procedure
1. Fill one plastic tub full with water. Label four paper towels, one for each whale group (biters, skimmers, gulpers, bubblers). Put about 2 tablespoons of parsley in the water, to represent food items (krill, copepods or other zooplankton). The combs represent the baleen.

2. Skimmers: The bowhead and right whales are examples of baleen whales that feed by skimming the surface of the water with their mouths open. To simulate them feeding have students take a comb and move the comb through the parsley as if the they were a skimmer swimming. Remove the parsley from the baleen by tapping it on the labeled paper towel. Set the labeled results aside.

3. Place more parsley in the water. Gulpers: The roqual whales (blue, humpback, fin, sei, minke, and Bryde's) have pleats in their throats that allow them to expand and take in large amounts of water and prey. Take a plastic sandwich bag that represents the throat of a gulper. Move the bag through the water, filling it with water and parsley. Place the comb in front of the open end of the sandwich bag. Position it so that it traps the parsley inside the throat. Carefully squeeze the water out of the bag through the comb a little bit at a time. Remove the parsley from the comb by tapping it on the labeled paper towel. Do this until all the water is drained from the bag, as if the gulper were closing its pleated throat.

4. Place more parsley in the water. Bubblers: Pass out straws to the students. Have three or four students simulate bubble netting by gently blowing bubbles into the water. Working as a group, they should be able to move the food to the center of the tub. Have one student bring a plastic bag up from the bottom of the tub through the center of the concentrated food. Strain the parsley from the water in the bag through a comb as before. Remove the parsley from the comb by tapping it on the labeled paper towel.

5. Place more parsley in the water and add pieces of styrofoam. Biters: Have the students simulate the biters using the tongs. The styrofoam represents fish, squid, or seals. Have the biters take a couple turns at catching the prey. Put the prey on the labeled paper towel.

Conclusions
To compare the methods the students can observe the amounts collected and record their visual estimates. If scales are available the amounts can be weighed. Of the three methods for mysticetes which method worked best? Did one method work best for all the students? Or did different students prefer different methods? Based on their success at feeding with the different methods used by mysticetes, which baleen whale would students want to be? Which prey should they concentrate on as a biter? How much can they bite in one feeding?

Additional Information
Gray whales do not feed using the above methods. Gray whales have special feeding methods that include sucking silt and mud from the ocean bottom to feed on amphipods. They are also seen running kelp through their baleen.

But some Odontocetes have developed specialized feeding methods, stunning prey with their sonar or by slapping the water with their tails. Others have developed methods of herding prey on to sloping beaches, coming part way out of the water to eat the prey as they struggle. However, in beaked whales and narwals their teeth are actually ornamental and some beaked whales teeth never erupt from the jawbone.