WAFWA Update - Nebraska
SHEEP STATS
JURISDICTIONAL WAFWA SUMMARIES PROVIDING IN-DEPTH, STATISTICAL SHEEP INFORMATION.
Rocky Mountain Bighorn Sheep
Populations
The Rocky Mountain Bighorn Sheep (RMBS) population consists of five herds totaling approximately 275 sheep scattered throughout western NE. After a nearly 100-year absence to the state, 1981 marked the first of five reintroductions to establish bighorn sheep back into their historic habitats. Over the past 10 years, RMBS numbers have declined by about 30% (Figure 1).From 1981 to present, Nebraska has conducted five translocations of approximately 175 RMBS. One internal translocation was conducted in 2014. Other translocations are being considered in unoccupied habitats as RMBS become available for transplant.
Licenses and Harvest
Since 1998, 32 rams have been harvested in Nebraska with a success rate of 100%. Permits typically consist of one auction permit and one Nebraska resident lottery permit. Any sheep (ram or ewe) is allowed for harvest but only rams have been taken thus far.
FIGURE 1
Bighorn Sheep Population Estimates.
Test and Remove
Over the past few years, the Test and Remove method has been implemented in three of the five herds showing some initial positive results with greater lamb recruitment in some regions. More recently, a bighorn sheep capture took place in February of this year experimenting and evaluating three different Mycoplasma Ovipneumoniae (Movi) detection methods. These included the standard lab tests through the Washington Animal Disease Diagnostic Laboratory (WADDL) as well as the Biomeme field testing unit (Table 1) and Working Dogs for Conservation. While there was not a 100% percent match between methods, having in-field results with possible Movi detections did allow for more immediate management decisions to be made. Initial plans to transplant some of these captured sheep from this previously clean herd were put on hold until further evaluations can be made. Below are comparisons amongst WADDL and the Biomeme unit from the Hubbard’s Gap and Cedar Canyon herds in Nebraska’s southern panhandle. Kate Huyvaert, Washington State University, conducted the Biomeme testing and results analysis. Evaluation from the Working Dogs for Conservation is ongoing.
TABLE 1. HUBBBARD'S GAP (N=25)
| TEST | POSITIVE | INDETERMINATE | NEGATIVE |
| WADDL PCR | 0 | 0.04 | 0.96 |
| Biomeme PCR | 0.12 | 0.04 | 0.84 |
| WADDL cELISA | 0.36 | 0.12 | 0.36 |
TABLE 1. CEDAR CANYON (N=11)
| TEST | POSITIVE | INDETERMINATE | NEGATIVE |
| WADDL PCR | 0.18 | 0 | 0.81 |
| Biomeme PCR | 0.18 | 0.18 | 0.54 |
| WADDL cELISA | 0.36 | 0.18 | 0.45 |
Movi infection and serologic status (portion of total tested) by testing method. Animals were captured by helicopter and sampled during February 2023, Wild Cat Hills, Nebraska.
Disease testing will continue with each herd through future helicopter captures, darting and any mortalities, along with future plans to fill unoccupied habitats with RMBS sheep from clean herds.
—Todd Nordeen, Nebraska Game & Parks Commission
