forest.birds <-
structure(list(abundance = c(5.2999999999999998, 2, 1.5, 17.100000000000001, 
13.800000000000001, 14.1, 3.7999999999999998, 2.2000000000000002, 
3.2999999999999998, 3, 27.600000000000001, 1.8, 21.199999999999999, 
14.6, 8, 3.5, 29, 2.8999999999999999, 24.300000000000001, 19.399999999999999, 
24.399999999999999, 5, 15.800000000000001, 25.300000000000001, 
19.5, 20.899999999999999, 16.300000000000001, 18.800000000000001, 
19.899999999999999, 13, 6.7999999999999998, 21.699999999999999, 
27.800000000000001, 26.800000000000001, 16.600000000000001, 30.399999999999999, 
11.5, 26, 25.699999999999999, 12.699999999999999, 23.5, 24.899999999999999, 
29, 28.300000000000001, 28.300000000000001, 32, 37.700000000000003, 
39.600000000000001, 29.600000000000001, 31, 34.399999999999999, 
27.300000000000001, 30.5, 33, 29.5, 30.899999999999999), patch.area = c(0.10000000000000001, 
0.5, 0.5, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 4, 4, 
4, 4, 5, 5, 6, 6, 7, 7, 8, 9, 10, 11, 12, 12, 13, 15, 17, 18, 
19, 22, 26, 29, 32, 34, 40, 44, 48, 49, 50, 57, 96, 108, 134, 
144, 973, 1771), year.of.isolation = c(1968L, 1920L, 1900L, 1966L, 
1918L, 1965L, 1955L, 1920L, 1965L, 1900L, 1926L, 1890L, 1973L, 
1972L, 1900L, 1900L, 1962L, 1965L, 1960L, 1953L, 1973L, 1923L, 
1965L, 1967L, 1890L, 1960L, 1965L, 1960L, 1973L, 1910L, 1962L, 
1960L, 1963L, 1960L, 1968L, 1966L, 1920L, 1966L, 1973L, 1918L, 
1963L, 1965L, 1974L, 1965L, 1962L, 1960L, 1928L, 1972L, 1967L, 
1963L, 1976L, 1964L, 1964L, 1940L, 1970L, 1933L), dist.nearest = c(39L, 
234L, 104L, 66L, 246L, 234L, 467L, 284L, 156L, 311L, 66L, 93L, 
39L, 402L, 259L, 130L, 26L, 26L, 40L, 259L, 234L, 26L, 39L, 372L, 
93L, 159L, 285L, 133L, 266L, 350L, 337L, 27L, 159L, 133L, 146L, 
146L, 389L, 40L, 266L, 311L, 597L, 545L, 208L, 66L, 285L, 93L, 
259L, 1427L, 398L, 467L, 39L, 402L, 467L, 146L, 337L, 332L), 
    dist.larger = c(39L, 234L, 311L, 66L, 246L, 285L, 467L, 1829L, 
    156L, 571L, 332L, 93L, 39L, 402L, 259L, 623L, 26L, 26L, 40L, 
    259L, 519L, 2205L, 39L, 372L, 226L, 1009L, 882L, 133L, 266L, 
    1868L, 519L, 27L, 159L, 133L, 146L, 398L, 2595L, 3188L, 1302L, 
    2672L, 597L, 770L, 208L, 345L, 178L, 93L, 1297L, 1557L, 1461L, 
    467L, 519L, 4426L, 2213L, 319L, 1323L, 332L), grazing.intensity = structure(c(2L, 
    5L, 5L, 3L, 5L, 3L, 5L, 5L, 4L, 5L, 3L, 5L, 2L, 1L, 5L, 5L, 
    3L, 3L, 3L, 2L, 2L, 5L, 3L, 1L, 3L, 3L, 3L, 4L, 4L, 5L, 3L, 
    4L, 4L, 4L, 2L, 3L, 5L, 2L, 4L, 5L, 1L, 3L, 1L, 1L, 2L, 3L, 
    3L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 1L), .Label = c("light", 
    "less than average", "average", "moderately heavy", "heavy"
    ), class = "factor"), altitude = c(160L, 60L, 140L, 160L, 
    140L, 130L, 90L, 60L, 130L, 130L, 210L, 160L, 210L, 210L, 
    120L, 145L, 110L, 140L, 190L, 90L, 220L, 120L, 130L, 100L, 
    170L, 150L, 130L, 210L, 120L, 90L, 110L, 175L, 110L, 200L, 
    190L, 120L, 100L, 190L, 150L, 90L, 140L, 130L, 190L, 110L, 
    120L, 190L, 120L, 180L, 140L, 165L, 175L, 70L, 160L, 190L, 
    190L, 260L), yrs.isolation = c(15, 63, 83, 17, 65, 18, 28, 
    63, 18, 83, 57, 93, 10, 11, 83, 83, 21, 18, 23, 30, 10, 60, 
    18, 16, 93, 23, 18, 23, 10, 73, 21, 23, 20, 23, 15, 17, 63, 
    17, 10, 65, 20, 18, 9, 18, 21, 23, 55, 11, 16, 20, 7, 19, 
    19, 43, 13, 50)), row.names = c(NA, -56L), class = "data.frame")