The data file birds.csv contains measures on breeding pairs of landbird species collected from 16 islands around Britain over the course of several decades reported in Pimm et al. [1988]. For each species, the data set contains an average time of extinction on those islands where it appeared; the average number of nesting pairs (the average over all islands where the birds appeared, of the nesting pairs per year); the size of the species (categorized as large or small); and migratory status of the species (migrant or resident). It is expected that species with larger numbers of nesting pairs will tend to remain longer before becoming extinct. Pimm et al. were interested in whether, after accounting for number of nesting pairs, size or migratory status has any effect. Furthermore, they were also interested in whether the effect of bird size differs depending on the number of nesting pairs. If any species have unusually small or large extinction times compared to other species with similar values of the predictor variables, it would be useful to point them out. Develop a regression model to predict the time to extinction using the number of nesting pairs and the two categorical variables as predictors; follow the guidelines outlined in section 5.4. Compare your model to the model reported in Pimm et al. [1988].