Appendix D
Input Data for Figures 5-6A and 5-6B
“Use-days” is combined number of days that each crane spent on the Platte River in fall and spring of that year, “sightings” are numbers of cranes in fall and spring of that year seen on the Platte River, “population” is the total number of cranes in the Aransas-Wood Buffalo population during that year, “ratio” is the number of cranes divided by the number of birds in population, and “use ratio” is the number of use-days divided by total population in that year. Double counts of crane sightings in Platte River were omitted. Data collected prior to 1975 were not used in these analyses because the data collection effort was extremely variable before 1975. Data for 2003 were not yet complete during committee’s deliberations.
Year |
Use-Days |
Sightings |
Populationa |
Ratio |
Use Ratio |
1950 |
1 |
1 |
31 |
|
|
1959 |
2 |
2 |
33 |
|
|
1966 |
10 |
2 |
43 |
|
|
1974 |
4 |
2 |
49 |
|
|
1975 |
36 |
12 |
57 |
|
|
1976 |
0 |
0 |
69 |
0 |
0 |
1977 |
1 |
1 |
71 |
0.01408 |
0.01408 |
1978 |
0 |
0 |
75 |
0 |
0 |
1979 |
0 |
0 |
76 |
0 |
0 |
1980 |
6 |
2 |
78 |
0.02564 |
0.07692 |
1981 |
0 |
0 |
73 |
0 |
0 |
1982 |
0 |
0 |
73 |
0 |
0 |
Year |
Use-Days |
Sightings |
Populationa |
Ratio |
Use Ratio |
1983 |
13 |
8 |
75 |
0.10667 |
0.17333 |
1984 |
0 |
0 |
86 |
0 |
0 |
1985 |
10 |
7 |
97 |
0.07216 |
0.10309 |
1986 |
12 |
3 |
110 |
0.02727 |
0.10909 |
1987 |
40 |
5 |
134 |
0.03731 |
0.06716 |
1988 |
41 |
3 |
138 |
0.02174 |
0.2971 |
1989 |
34 |
8 |
146 |
0.05479 |
0.23288 |
1990 |
12 |
6 |
146 |
0.0411 |
0.08219 |
1991 |
0 |
0 |
132 |
0 |
0 |
1992 |
25 |
15 |
136 |
0.11029 |
0.18382 |
1993 |
19 |
10 |
143 |
0.06993 |
0.13287 |
1994 |
18 |
14 |
133 |
0.10526 |
0.1203 |
1995 |
14 |
8 |
158 |
0.05063 |
0.08861 |
1996 |
34 |
15 |
160 |
0.09375 |
0.2125 |
1997 |
80 |
10 |
182 |
0.05495 |
0.43956 |
1998 |
120 |
10 |
183 |
0.05464 |
0.65574 |
1999 |
24 |
5 |
188 |
0.0266 |
0.12766 |
2000 |
45 |
4 |
180 |
0.02222 |
0.19444 |
2001 |
7 |
7 |
176 |
0.04545 |
0.1875 |
2002 |
151 |
17 |
185 |
0.08649 |
0.67568 |
aPopulation data are from Lewis et al. (1994) and Canadian Wildlife Service and U.S. Fish and Wildlife Service, unpublished report (2003). |