24 December 2015

Breeding Season Survey Results Issued for Niobrara Scenic River

Several common breeding season species present in the Niobrara River valley during 2015 were denoted by bird surveys underway to monitor bird occurrence and distribution.

The Mourning Dove, House Wren, Field Sparrow, American Crow, Spotted Towhee, Chipping Sparrow and Yellow-breasted Chat were among the “most common species” present, according to a “resource brief” issued mid-December for the Niobrara National Scenic River. The surveys during mid-May to mid-June are among many done by the Northern Great Plains Network Inventory and Monitoring Program, of the National Park Service. The Bird Conservancy of the Rockies, based in Colorado, provides training and oversight for the people doing the surveys.

The Niobrara River valley is notable for its confluence of several ecosystems where several species of birds are known to hybridize. There was no information issued in the briefs for 2014 and 2015 in regards to avian hybridization.

Overall, there were 78 species noted at the 13 grids along the scenic river eastward of Fort Niobrara NWR.

Results from a similar 2014 effort, denoted 77 species during counts on five days in June, and three days in July.

During the two years of summer surveys, there have been 89 species noted. There were 25 species of concern denoted, the 2015 resource brief, with this classification based upon state and national designations.

Considering the Dickcissel, there were 62 observations in 2015, compared to 161 in 2014. More Grasshopper Sparrows were seen in 2015, than in 2014, comparing 110 to 79, respectively. For the Yellow-breasted Chat, there were 105 detections in 2015, compared to 67 in 2014. The only towhee species recorded, was the numerous Spotted Towhee, according to a list of observations indicated by the published brief. There was a decline in the detections of the Common Yellowthroat, comparing 30 in 2015 to 58 in 2014.

There were very few orioles amidst the survey sites, with only one each of the Baltimore and Bullocks’s Oriole observed in 2015, with five of the Baltimore species noted in 2014. These two species are especially notable for hybridization, based upon historic studies.

Black-headed Grosbeak numbers declined to 5 in 2015, a decrease from 14 in 2014. No Rose-breasted Grosbeaks were seen during any of the surveys in the past two years. This is another species known for the occurrence of hybrids.

Survey efforts are a long-term means to monitor bird distribution and occurrence along the Niobrara River, as well as other locales in the northern Great Plains.

Bird monitoring objectives, according to survey protocols, are:

  • “to integrate existing bird monitoring efforts in the region to provide better information on distribution and abundance of all breeding birds, especially for high priority species;
  • “to provide basic habitat association date for most bird species to address habitat management issues;
  • “to provide long-term status and trend data for all regularly occurring breeding species” … “with a target of detecting a minimum rate of population change” …
  • “to maintain a high-quality database of that is accessible to all of our collaborators as well as to the public on the worldwide web, in the form of raw and summarized data, and;
  • “to generate decision support tools that help guide conservation efforts and provide a better measure of conservation success.”

Although the survey locations were along the river, there were no records of either the Least Tern or Piping Plover.

Neither the 2014 nor 2015 brief included any details on habitats were the surveys were done.

Federal funds pay the expenses associated with these surveys, intended to “detect biologically significant changes in population parameters over time,” including evaluation of population size and birds as indicators of ecosystem conditions.

Surveys will continue in 2016.