Wildlife Population Trends on Hart Mountain
2016 Hart Mountain National Antelope Refuge Biological Program Summary
The U.S. Fish and Wildlife Service released a report of the 2016 Biological Program Activities for the Sheldon-Hart Mountain National Wildlife Refuge Complex this past December. Below is a summary of some of the contents of the report.
Greater Sage-Grouse Population Monitoring
Annual ground surveys are conducted at Hart Mountain NAR to census the number of male Greater Sage-Grouse in attendance at leks in order to monitor general population trends on the refuge. Both USFWS staff and volunteers monitor a subset of known lek complexes each year. In 2016, the trend lek value for the Refuge showed improvement at 44.5 males per lek (vs. 36.7 males per lek complex in 2015), and comparable to the long-term average (45 males per lek complex, 1980 – 2015).
Pronghorn Annual Summer Census
Results from helicopter surveys in July 2016 indicate a minimum population estimate of 3,021 pronghorn on the Refuge. Herd ratios were 33.6 bucks:100 does and 61.8 fawns:100 does. These results represent a 9.2% increase from the 10- year average trend. A total of 8,291 pronghorn were observed in the greater Hart-Sheldon region.
The U.S. Fish and Wildlife Service released a report of the 2016 Biological Program Activities for the Sheldon-Hart Mountain National Wildlife Refuge Complex this past December. Below is a summary of some of the contents of the report.
Greater Sage-Grouse Population Monitoring
Annual ground surveys are conducted at Hart Mountain NAR to census the number of male Greater Sage-Grouse in attendance at leks in order to monitor general population trends on the refuge. Both USFWS staff and volunteers monitor a subset of known lek complexes each year. In 2016, the trend lek value for the Refuge showed improvement at 44.5 males per lek (vs. 36.7 males per lek complex in 2015), and comparable to the long-term average (45 males per lek complex, 1980 – 2015).
Pronghorn Annual Summer Census
Results from helicopter surveys in July 2016 indicate a minimum population estimate of 3,021 pronghorn on the Refuge. Herd ratios were 33.6 bucks:100 does and 61.8 fawns:100 does. These results represent a 9.2% increase from the 10- year average trend. A total of 8,291 pronghorn were observed in the greater Hart-Sheldon region.
California Bighorn Sheep Annual Summer Census
In July 2016, USFWS conducted an aerial helicopter survey of the Refuge and counted a total of 168 Bighorn Sheep. This in an increase from 148 observed sheep in 2014 and a 0.2% increase in the 10-year average trend.
Mule Deer Fall Composition Count
Between November 13th and November 20th, 2016, volunteers and refuge staff observed a total of 337 deer in 57 separate groups. Observed herd ratios were 30.0 bucks:100 does and 39.3 fawn:100 does. These observations were down from the long-term average (1967 – 2015) herd ratios of 31.6 bucks:100 does and 59.7 fawns:100 does.
ODFW Redband Trout Surveys of Rock Creek
Results of surveys of Rock Creek conducted in 2015 by Oregon Department of Fish and Wildlife indicate that the population of redband trout had decreased by 90% compared to previous surveys (2007 – 2012). ODFW researchers suggest that redband in Rock Creek were not redistributing in response to stream drying as a result of successive years of drought and near-drought conditions on the Refuge.
In July 2016, USFWS conducted an aerial helicopter survey of the Refuge and counted a total of 168 Bighorn Sheep. This in an increase from 148 observed sheep in 2014 and a 0.2% increase in the 10-year average trend.
Mule Deer Fall Composition Count
Between November 13th and November 20th, 2016, volunteers and refuge staff observed a total of 337 deer in 57 separate groups. Observed herd ratios were 30.0 bucks:100 does and 39.3 fawn:100 does. These observations were down from the long-term average (1967 – 2015) herd ratios of 31.6 bucks:100 does and 59.7 fawns:100 does.
ODFW Redband Trout Surveys of Rock Creek
Results of surveys of Rock Creek conducted in 2015 by Oregon Department of Fish and Wildlife indicate that the population of redband trout had decreased by 90% compared to previous surveys (2007 – 2012). ODFW researchers suggest that redband in Rock Creek were not redistributing in response to stream drying as a result of successive years of drought and near-drought conditions on the Refuge.
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