Artificial Nest Have Often Been Used When Biologists Study Predation

question 6

Essay

Artificial nest have often been used when biologists study predation on birds.It is usually assumed that predators will respond to artificial nests in the same way they do to real birds' nests.A recent experiment was performed to check this assumption for predators of the American robin (Turdus migratorius)by comparing the egg loss in three experimental treatments: (1)natural robin's nests, (2)artificial wicker-basket nests placed 30 meters in a random direction from natural robin's nests, and (3) artificial wicker-basket nests placed in a 180 m by 240 m grid around robin's nests. The data below are cumulative counts of eggs predated (stolen or broken and eaten)at 5, 10, and 15 day points of the experiment.

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Definitions:

Tertiary Plane

A plane that is oriented to intersect or be parallel with the primary and secondary planes in a three-dimensional coordinate system.

Primary Datum

A reference point, line, or plane from which dimensions are measured in technical drawing or CAD modeling.

Secondary Datum

A reference point, line, or surface used in conjunction with primary datums to establish a part’s orientation or location for measurement and manufacturing.

Geometric Tolerances

Specifications on a technical drawing, denoted by symbols, that dictate the allowable deviation in the form, orientation, location, and profile of a part's features.