The zebra finch (Poephila guttata) is a sexually dimorphic, social estrildid native to the grasslands of Australia. They are opportunistic, year-round breeders which nest in colonies of variable size. Zebra finches form permanent pair bonds and both sexes share the responsibilities of nest building, incubation and rearing of young (Walter, 1973). Morris (1954), however, reported that although both sexes pick up and nibble on fragments of material, males collect most of the nesting material.
The scientific name of the research organism must be stated the first time the organism is mentioned in any of the sections. Thereafter, within each section, either the common name or the abbreviated scientific name can be used.
Studies on the effects of colored plastic leg bands on pair formation show that male zebra finches spend more time sitting next to females wearing black or pink leg bands than females wearing light blue leg bands. The same studies indicate that females spend more time sitting next to males wearing red leg bands than males wearing light green bands. In both male and female, orange leg bands (which are similar to natural leg color) proved to be of intermediate preference (Burley, 1981 and 1982).
The first paragraphs of the introduction provide background information from preliminary or other published studies. This is used to develop the hypothesis or purpose of the experiment and to provide the rationale or reason for conducting the experiment.
The purpose of this study was to test whether or not this preference for certain colors of leg bands generalizes to preference for certain colors of nesting material. It was hypothesized that zebra finches would collect more red or black material than light green, with collection of orange being intermediate.
This paragraph specifically states the purpose of the experiment. It also states the hypothesis the author developed based on background reading and observations.
The zebra finches used in this study were in three colonies in the lab of Dr. J.R. Baylis at the University of Wisconsin, Madison. Each colony contained between thirty and forty individual birds of both sexes, a variety of ages and several plumage types. All animals wore colored leg bands for individual identification and all had been exposed to grass, green embroidery floss and white dog fur as nesting material previous to this study. The colonies were housed in separate rooms, each approximately 17m3 and each contained eight artificial nest boxes. All behavioral observations were made from outside the colony rooms through one-way mirrors.
The methods begin by indicating where the research organisms were obtained.
Specific examples about the organisms are included, e.g. number of organisms, sexes, ages, and morphology.
Previous exposure to colored nest material is described. How organisms were housed, including specific dimensions of cages, etc. and the physical conditions of light and temperature, is also included.
Red, black, orange and light green DMC four-ply cotton embroidery floss was cut into 2.5 cm pieces. During each trial, twenty-five pieces of each color were separated and spread out over the floor of the colony. After the birds had been exposed to the material for a total of two hours, any remaining strands of floss on the floor were collected. The number of strands of each color was counted. It was assumed all other strands (not on the floor) had been used in nest construction. Data from the three colonies were pooled and an X2 goodness-of-fit test was used to determine whether the number of strands of each color used in nest construction different from an expected ratio of 1:1:1:1 (which would indicate no preference).
The types of test materials used are described in detail, as are the methods.
Description of methods includes assumptions made and type of analysis to be performed on the data.
More green material was removed by the finches than red, more red than black and more black than orange. The ratio between material of different colors used in nest construction differed significantly from the expected 1:1:1:1 (X2=63.44, df=3, p<.005). When colors were compared in pairs, the difference between values for green and red were not significantly different (X2=117, df=1, p>.5). However, the values for black and orange were significantly different (X2=36.38, df=1, p<.005).
The author interprets the data for the reader in text form. The author does not expect the reader to interpret the results from a table of data, but instead provides his/her interpretation for the reader.
Burley, N. 1981 Sex-ratio manipulation and selection for attractiveness. Science 211: 721-722.
Burley, N. 1982 Influence of colour-banding on the nonspecific preference of zebra finches. Anim. Behav. 30: 444-445.
(Additional references deleted for brevity.)
All references cited in the body of the paper are listed alphabetically by last name of the first author. Only references cited in the body of the paper are listed here.
See the Introductory Biology 151-152 manual for complete information on how to reference supporting literature both in the body of the paper and in the reference list.