Specific Comments on Platte River Draft EIS

• File Number: 8461.100
• Description: Adaptive Management Workgroup
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 9/17/2004
• Author: CWCB
• Title: Specific Comments on Platte River Draft EIS
• Water Supply Pro - Doc Type: Board Memo

End
2.2 WHOOPING CRANE USE OF THE PLA'
1942-2002
In order to extend the analysis of whooping crane
confirmed sighting data was collected for the pei
analyzed with respect to whooping crane use of tr
2.2.1 C
the
RIVER IN CENTRAL NEBRASKA
se of the Platte River was reported by EA (1985),
)d of 1942 through 2002 (West Corporation) and
Platte River.
Since 1942, the Aransas whooping crane popul tion has dramatically increased (Table 1). The
confirmed sightings data from 1942-2002 is the ost accurate data regarding whooping crane Platte
River habitat use (Figure 1). Pre-1942 data is subject to varying interpretation, and is highly
questionable.
Critical habitat was designated in 1978. Durin€
population increased from 20 to 72. From 1942
only eight years (1942, '43, '44, '50, '59, '66,
(Figure 2).
Over the period 1978 to 2002, the population in
observations occurred in all but 6 years (1978, '7
increasing observations likely reflects the comb
observational effort, which is now both systemati
the latter, considering the percentage of stopovers
population has grown exponentially (see discussio
2.2.2
Each year, the entire population of whooping crar
southerly migrations. Each overflight provides
percentages for whooping cranes are derived fr
confirmed sightings in a year is divided by the stc
doubled (2 flights over the Platte river per year).
From 1942-2002, 1.6% of the whooping cranes
Platte, with a low of 0% and a high of 10.5% I
percentage was 1.00%, with a low of 0% and a h;
From 1978-2002 the average stopover percenta
(Figure 6). During this period of intense obsen
2.4% of the whooping cranes flying over the P
though the population increased from 75 to 185.
the period of 1942 to1977, the whooping crane
to 1977, Platte River stopovers were observed in
74, and '75), or about 1 out of every 4.5 years
-eased from to 75 to 185. From 1978 to 2002,
'81, '82, '84, and '91) (Figure 3). The trend of
ation of population increase and the increase in
and intense, but probably are more reflective of
y whooping cranes has only slightly increased as
below).
flies over the Platte River twice in northerly and
stopover opportunity for each bird. Stopover
i the information in Table 1. The number of
ver opportunities, which is the yearly population
ing over the Platte River were observed on the
;ure 4). From 1942-1977, the average stopover
of 10.5% (Figure 5).
was 2.4%, with a low of 0% and a high of 6.3%
ion, following designation of critical habitat, only
;te River were observed on the Platte River, even