Exam 10: Mechanisms of Orientation and Behavior

Lohmann and Lohmann (2006) exposed young loggerhead sea turtles that had never been in the ocean to magnetic fields characteristic of three widely separated regions along the migratory route of the warm, rich waters of the North Atlantic gyre. The loggerheads oriented to each distinctive field by swimming in a direction that would have kept them in the favorable waters of the gyre if they had been migrating. This demonstrated that hatchling loggerheads

It has been determined that, in birds, light dependent magnetoreception

Quinn and colleagues (2006) demonstrated that wild salmon return to the specific location of the natal stream in which they were born with remarkable precision. They used temperature changes during incubation of pre-hatch sockeye salmon embryos to cause banding patterns on the ear bones of the fish. They did this because

The idea for a time-compensated sun compass began when Gustav Kramer found that, when the sun was replaced with a stationary light source, the birds

If you were a loggerhead sea turtle traveling tens of thousands of miles across the Atlantic Ocean you would be guided primarily by

Polarized light appears to be used in a variety of ways. Some animals use it

When homing salmon navigate up a river, they

Wittlinger and colleagues (2007) experimentally manipulated the length of the legs of desert ants (Cataglyphis bicolor), shortening some and lengthening others. This was done to test the ants' ability to use stride length to determine

We know the most about the mechanism of star compass orientation in the indigo bunting (Passerine cyanea) through Stephen Emlen's systematic planetarium studies. These experiments indicate that the indigo bunting orients by relying on the region of the sky within 35º of

Stephen Emlen demonstrated that young indigo buntings (Passerine cyanea) have to learn where north is rather than being born with that information already programmed. He did that by having birds that would orient appropriately relative to the center of star rotation even though they had been reared in a planetarium with

Birds have been placed on an artificial light-dark cycle in a laboratory that initially corresponds to the natural lighting conditions outside; the lights are on from 6:00 a.m. to 6 p.m. The light period is then shifted so that the lights come on at 9:00 a.m. In this case, the animal's body time would be set

Three groups of pigeons, none of which had experience outside of its loft, underwent surgery: Group 1 had their trigeminal nerves cut. Group 2 had their olfactory nerves cut. Group 3 had sham surgery. The pigeons were then released 50 km from home. The initial orientation of Groups 1 and 3 was in the general direction of home, while that of Group 2 was in the opposite direction. In addition, 23 of 24 birds from both Groups 1 and 3 returned home within 24 hours, while only 4 of 24 from Group 2 made it home. These results suggest that

Most light consists of a great many waves that are vibrating in all possible planes perpendicular to the direction in which the light is traveling. Such light is described as

Research evidence suggests that some species, such as the eastern red-spotted newt and the Australian silvereye, may have

Magnetite

You are an experimental pigeon that has been reared in a loft where a distinctive odor, that of cotton candy, for example, always comes from the north, in addition to natural breezes. Another bird is reared in a similar loft, but exposed only to natural winds. If you are both exposed to the smell of cotton candy as you are displaced from your home lofts and taken to a release site 30 km away, you are likely to _____ and the other bird is likely to _____.

We group animal strategies for finding their way between home and a goal into three levels of ability: piloting, compass orientation, and true navigation. Which of them makes the greatest use of familiar landmarks?

What features of the earth's magnetic field might provide an animal with positional information for a magnetic "map"?

Use of the sun for orientation is complicated by its apparent motion across the sky. Compensation for the sun's apparent motion is especially important for species that