Whooping Crane Recovery Plan

• Description: related to the Platte River Endangered Species Partnership ‎(aka Platte River Recovery Implementation Program or PRRIP)‎
• State: CO
• State: NE
• State: WY
• Basin: South Platte
• Water Division: 1
• Date: 2/11/1994
• Author: U. S. Fish and Wildlife Service Region 2, Albuquerque, New Mexico
• Title: Whooping Crane Recovery Plan
• Water Supply Pro - Doc Type: Report/Study

31
Table 3. Size and productivity of the whooping crane captive flock at PWRC, 1975 -1993.
Eaus retained at PWRC
a Includes 73 eggs transferred to Grays Lake National Wildlife Refuge in 1976 -1984.
Fertility determined for unhatched eggs by examination of egg contents. Examination
occurred after full -term incubation and eggs containing no detectable embryo were
considered infertile, therefore, the number of fertile eggs listed is considered a minimum
estimate.
b All eggs retained at PWRC were incubated and hatched under sandhill cranes and chicks
were "foster - parent" reared. All eggs transferred to GL were artificially incubated until
transfer.
c All eggs retained at PWRC were incubated under sandhill cranes and chicks were
hand - raised or foster - parent raised by sandhill cranes. All eggs transferred to GL were
incubated under captive pairs of sandhill cranes at Patuxent until transfer this year and
subsequent years.
d No eggs were produced in 1986. Breeding birds were moved temporarily to pens in
Summer 1985 during construction of new pens. The birds were moved into the new pens
in November 1985. These movements were believed to be the disturbance that disrupted
the 1986 breeding cycle. .
e Six new pairs broke the eggs 0 91 they produced.
All
Females
Total
Chicks
Year
Birds
Laying
Eggs'
No.
Fertile
Hatched
Fledged
1975
20
1
3
3
2
1
0
1976
19
2
5
3
1
1
1
1977
21
4
22
8
4
3
2
1978b
22
3
23
8
8
7
3
19790
26
4
21
16
10
8
4
1980
22
2
6
4
1
0
0
1981
20
2
11
11
5
3
1
1982
26
5
28
15
12
9
6
1983
35
5
34
22
18
14
8
1984
32
5
31
21
16
12
4
1985
38
3
13
13
8
7
6
1986°
38
0
0
--
--
--
-
1987
41
5
7
7
3
2
1
1988
46
6
15
15
8
7
3
1989
32
5
19
19
14
9
8
1990
35
4
14
14
5
4
3
1991
40
5
21
21
9
5
2
1992
49
8
48
48'
11
9
8
1993
49
8
35
35
16
15
10
Totals
611
77
356
283
151
116
70
a Includes 73 eggs transferred to Grays Lake National Wildlife Refuge in 1976 -1984.
Fertility determined for unhatched eggs by examination of egg contents. Examination
occurred after full -term incubation and eggs containing no detectable embryo were
considered infertile, therefore, the number of fertile eggs listed is considered a minimum
estimate.
b All eggs retained at PWRC were incubated and hatched under sandhill cranes and chicks
were "foster - parent" reared. All eggs transferred to GL were artificially incubated until
transfer.
c All eggs retained at PWRC were incubated under sandhill cranes and chicks were
hand - raised or foster - parent raised by sandhill cranes. All eggs transferred to GL were
incubated under captive pairs of sandhill cranes at Patuxent until transfer this year and
subsequent years.
d No eggs were produced in 1986. Breeding birds were moved temporarily to pens in
Summer 1985 during construction of new pens. The birds were moved into the new pens
in November 1985. These movements were believed to be the disturbance that disrupted
the 1986 breeding cycle. .
e Six new pairs broke the eggs 0 91 they produced.