Mark M. Peyton and Jeremiah L. Maher, Central Nebraska Public Power and Irrigation District, Holdrege, Nebraska

INTRODUCTION

In 1992 as a voluntary amendment to its interim license the Central Nebraska Public Power and Irrigation District (Central) began management of nesting areas of the endangered least tern (Sterna antillarum) and threatened piping plover (Charadrius melodus) in the upper Platte River valley.

In 1994 Central personnel surveyed the Platte River valley from Lexington to North Platte. Four areas were identified and monitored at least twice weekly throughout the season.

RESULTS

A total of 42 adult least terns and 10 adult piping plovers were located at the four sites. Least terns nested in three of the four areas producing 21 nests. The number of eggs was not determined due to limitations on entry to the site. Thirty-three (33) chicks were identified with a minimum of 24 fledging for a minimum fledge ratio of 1.14 per adult pair (Table 1).

Piping plovers nested at two of the four areas monitored. A total of 10 adult plovers produced five nests. There were 20 eggs, 17 chicks with a minimum of eight fledged juveniles for a minimum fledge ration of 1.6 per adult pair (Table 2).

SUMMARY OF THREE SEASONS

The 1994 season marked the third year that Central has managed nesting areas for least terns and piping plovers in the upper Platte River valley. Over those three seasons 116 adult least terns constructed 69 nests, hatching 105 chick of which a minimum of 53 reached fledge stage. This represents a cumulative fledge ratio of 0.9 chicks per adult pair. Thompson (1982) calculated a fledge per breeding pair ratio necessary to maintain a stable breeding population of 0.7 per adult pair. The fledge ratio achieved at the four sites was 129% of the minimum necessary to insure a stable population (Table 3).

During the same three seasons 32 piping plovers constructed 14 nests, hatching 50 chicks of which a minimum of 15 reached fledge stage for a fledge ration of 0.9 per adult pair. Ryan et al (1993) calculated a fledged per breeding pair ratio necessary to maintain a stable breeding population of 1.13 for piping plovers. The fledge ratio achieved at these four sites over the three years was 80% of the minimum necessary to insure a stable populations (Table 3).

DISCUSSION

It is still somewhat preliminary to make generalized statements on the success and/or failure of the management strategies employed by Central at the four areas in the upper Platte River valley. However, the results reported here do indicate that these areas are important habitat for both least terns and piping plovers and Central's efforts in managing the habitat for these species is helping to achieve nesting success at these sites.

REFERENCES

Ryan, Mark R., Brian G. Root, and Paul M. Mayer. Status of piping plovers in the Great Plains of North America: A demographic simulation model. Conservation Biology Volume 7, No. 3, Sept. 1993:581-585.

Thompson, B.C. Distribution, colony characteristics, and population status of least terns breeding on the Texas Coast. Ph.D. Dissertation, Texas A&M University, College Station. 124pps.

Return to 1995 Platte River Basin Ecosystem Symposium

Last updated by Darren A. Jack on 6/11/97