Changes to habitat affects different species of wildlife differently. Birds that hunt for insects on the ground, for example, may be less affected by clearing rainforest than those that feed on plant nectars, like hummingbirds, or that extract insects from trees, like woodpeckers. Root (1967) defines a guild as "a group of species that exploit the same class of environmental resources in a similar way." The mist-netted birds in the example from Section 4.2.3 were classified into guilds according to their feeding habits. The guilds are labeled by food source as Air-Arth, Leaf-Arth, Wood-Arth, Ground Arth, Carnivore, Fruit, Seeds, and Nectar, where "Arth" means arthropod (insect and spider). We wish to know whether the relative abundance of birds from different guilds is related to the amount of habitat "degradation" at the six locations. Degradation is defined here as a factor with three levels representing how much the habitat has changed from its original forested state. The two forest locations are "Low," the forest edge and forest fragment are "Moderate," and the two pasture locations are "High." The data are given in Table 3.4. Perform an analysis to determine which guilds are affected more or which are affected less by habitat degradation.
