Week 7: Orientation

Question 1

Gray whale

Answer 1

is a baleen whale, filter feeder

reaches a length of about 16meters, a weight of 36tonnes and lives 50–60 years.

consists of the western North Pacific (Asian) and eastern North Pacific (American) populations

Question 2

Migration of the gray whale

Answer 2

The gray whales migrate between winter breeding grounds in low latitude, warm waters and summer feeding areas in higher latitudes, cool waters

Question 3

Piloting

Answer 3

The gray whales have one of the longest migration of any mammal.

How do they find their way?

They find their way by following the west coast of North America.

Coastlines, mountain chains, rivers, water currents, and wind patterns can all serve as orienting cues.

Piloting animals find their way by orienting landmarks.

Question 4

Orientation

Answer 4

The general, generic meaning indicating relationships among things

Question 5

Navigation

Answer 5

Travel or toward a specific location

Question 6

Homing

Answer 6

Is the inherent ability of an animal to navigate towards an original location through unfamiliar areas.

This location may be either a home territory or a breeding spot.

Question 7

Orientation vs navigation

Answer 7

An animal that is merely orienting in a particular direction continues in the same direction but not toward a specified goal.

An animal that is navigating compensates for the displacement and travel toward the specific point.

Question 8

Topographical orientation

Answer 8

finding the way to a specific destination in a familiar area

navigation to home range

1. Guideline orientation
2. Path integration
3. Landmark orientation

Question 9

Geographical orientation

Answer 9

finding the way to a destination in an unfamiliar area

1. piloting
2. distance and direction navigation
3. bicoordiate navigation

Question 10

Guideline orientation

Answer 10

Ants mark their paths with trail pheromones, which are volatile hydrocarbons.

The trail attracts other ants and serves as a guide.

The pheromone must be continually renewed because it evaporates quickly.

When the supply begins to dwindle, the trail making ceases.

Question 11

Path integration in the desert ant

Answer 11

Animals use path integration to estimate their current location based on the movements they made since their last known location

Desert ants live in an unstable, shifting environment of sand dunes.

Desert ants continuously keep track of their locations relative to a starting point and return to it, an important skill to have for creatures that forage for food and then return to a fixed home

Question 12

Landmark orientation

Answer 12

remembering a series of landmarks, and following them in reverse on the return journey

Landmarks in a generalized sense can be visual, auditory, tactile, or olfactory.

Landmarks work best when animals are in familiar areas

Question 13

Use of landmarks in honeybee orientation

Answer 13

When bees are trained to a feeding station past a tree line, then moved to a new location with a tree line in a different direction, they change direction and follow the tree line landmarks.

Question 14

Geographical navigation

Answer 14

1. Piloting
2. Distance and direction navigation
3. Bicoordiate navigation

Many migrating species are able to take direct routes to their destination through environments they have never experienced. They must have mechanisms of navigation other than piloting.

Question 15

Distance-and-direction navigation

Answer 15

European starlings

short winter migration in a southwesterly direction from the Netherlands to coastal France and Southern England (red arrow).

Juvenile starlings that were moved to a site in Switzerland did not fly northwest to their traditional wintering grounds, but flew in the same southwesterly direction they would normally take (blue arrow), which took them to Spain.

Question 16

Bicoordinate orientation

Answer 16

also called true navigation

requires information about latitude and longitude

The flight path taken by a wandering albatross on a foraging journey of over 4000 km from its nest in the Crozet Islands in the southern Indian Ocean, north of Antarctica, and back again

If we know the latitude and longitude of our present position and also the latitude and longitude of the goal, we can plot a course from the one to the other. To determine their latitude and longitude and to plot their course, present-day human navigators use a variety of aids, including compass, maps,

Question 17

Directional information

Answer 17

compass sense: the sense of direction

Types of compass:
- sun
- star
- polarized light
- magnetic

cabbage butterfly (Pieris rapae): keep moving in a particular direction for long periods of time or even through their entire life.

Cabbage butterflies stop in suitable habitat long enough to feed, mate, lay eggs, or spend the night, but then they move on. They are basically transients without a home and keep moving essentially in the same direction. At different seasons, however, the directions may reverse so that individuals or their offspring may end up fairly near where they started. Different individuals in a population may travel in the same or different directions, but each individual seems to have an awareness of its own direction.

Question 18

Sun compass

Answer 18

During the day, the sun can serve as a compass, as long as the time of day is known.

In the Northern Hemisphere, the sun rises in the east, sets in the west, and points south at noon.

Clock-shifts experiments on many species have shown that animals can orient by means of a time-compensated solar compass.

The azimuth angle of the sun is most often defined as the angle from due north in a clockwise direction.

Question 19

Circadian rhythm

Answer 19

any biological process that displays an endogenous, entrainable oscillation of about 24 hours.

are driven by a circadian clock

have been widely observed in plants, animals, fungi, and cyanobacteria.

are adjusted to the local environment by external cues called zeitgebers, which include light, temperature and redox cycles.

Question 20

Clock-shifting experiment

Answer 20

The birds were trained to expect food in the bin at one particular location-south.

After training, no matter what time they were fed, the birds always went to the bin at the southern end of the cage for food.

Clock-shifting experiment: clock-shifted lighting:

Experiment 2: clock-shifted lighting
- The birds were placed in a room with a controlled light cycle.
- Their circadian rhythms were phase-shifted by turning the lights on at midnight and off at noon.

Clock-shifting experiment: Back to the natural lighting:

• They returned to the outdoor cage.
• After clock-shifting, it was sunrise. But the circadian clocks were telling them it was noon.
• Instead of turning south, they looked for food in the direction of the sun–in the east bin.

If food was always in the south bin, and it was sunrise, the birds should have looked for food 90 degrees to the right of the direction of the sun. But because their circadian clocks were telling them it was noon, they looked for food in the direction of the sun—in the east bin. The 6-hour phase shift in their circadian clocks resulted in a 90-degree error in their orientation. These kinds of experiments on many species have shown that animals can orient by means of a time-compensated solar compass.

Question 21

Star compass

Answer 21

Many animals are normally active at night; in addition, many day-active bird species migrate at night.

Young birds were raised in a planetarium. If the star patterns were rotated each night, young birds were able to orient in the planetarium.
But birds raised in the planetarium under a nonmoving sky could not.

Question 22

Overcast days

Answer 22

no directional information from the sun and stars

1. Magnetic fields
   Pigeons are able to home as well on overcast days as on clear days, but this ability is severely impaired if small magnets are attached to their heads.
2. Plane of polarization of light

Question 23

Distance information

Answer 23

Animals that navigate by distance and direction determine distance in part

• a time-compensated solar compass
• an ability to locate a fixed point in the night sky
• energy expended traveling (e.g. honeybees)