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

ABSTRACT

The presence of piping plovers (Charadrius melodus) along the shore of Lake McConaughy was first documented in 1978 (Rosche, 1994), with the first record of nesting reported in 1985 (Johnsgard, 1990). In recent years the numbers of birds observed at the lake has increased significantly. The sandy beaches surrounding the lake have become one of the most important nesting areas for this species within Nebraska with 50 nests being recorded in 1994 and a total of 199 since 1992. Potential conflict arises because of high recreational activity at the lake. Observation of this subpopulation of birds has shown the birds to be remarkably tolerant of human activity. Experimental management practices using minimal protection measures appear to be successful.

INTRODUCTION

Study Area. Lake McConaughy formed by Kingsley Dam is located near Ogallala, Nebraska and is the largest reservoir on the North Platte River. The three mile wide dam created a lake about twenty-one (21) miles long with approximately 30,500 surface acres at capacity and 105 miles of shoreline.

Because of its size and the extensive white sand beaches, Lake McConaughy not only provides habitat for wildlife, it is a major recreational area for people interested in boating, skiing, wind surfing, fishing, and beach camping. Estimates of recreational use of the beaches exceed seven hundred thousand visitor-days per year. Precisely because Lake McConaughy attracts large numbers of people and birds, there are inevitable conflicts. It is for this reason that recent attention has focused on habitats used by threatened and endangered species.

Background. The presence of piping plovers (Charadrius melodus) along the shore of Lake McConaughy was first documented in 1978 (Rosche, 1994), with the first record of nesting reported in 1985 (Johnsgard, 1990). In recent years the number of birds observed at the lake has increased significantly. Systematic surveys for piping plovers were first conducted at Lake McConaughy in 1986 (Wingfield, 1993). Regular censusing, however, did not start until 1990, and management of beach areas for piping plover nesting did not begin until the spring of 1992.

The census of 1986 consisted of a one day search in late May by Nebraska Game and Parks personnel. In 1990 and 1991 two cooperative surveys were conducted by Central, NGPC and NPPD. One survey was conducted in May and the second in June (Wingfield, 1993). Beginning in 1992 Central, as a voluntary addition to its annual license for the operation of FERC Project 1417, implemented management plans for protecting piping plovers and least terns along the shores of Lake McConaughy and selected sand pits in the upper Platte River valley. These plans included the census of piping plovers and least terns, monitoring the nesting success of these two species and, when necessary, the isolation and protection of nests from human activity.

METHODS

Since 1992 Piping Plover surveys have been conducted weekly starting in mid May and running until late August. Nests located during the census were noted and management practices were undertaken as needed. Single nests located in high recreational use areas were isolated with diamond shaped exclosures measuring approximately 200 meters square. These exclosures were simply bright orange twine strung between fence posts with "Keep Out" signs placed on the fence posts warning people of the nest. Nests located in areas where human activity was minimal were noted and observed, but no identification or fencing was used. At two sites historical use by least terns and a somewhat higher density of plovers resulted in the fencing of relatively large areas, one a 37 acre tract and the second a 30 acre tract. These areas were fenced with woven wire around the entire area effectively excluding all human activity.

Each nest was monitored a minimum of twice weekly. The success of each nest, determined by the hatching of at least one chick, was recorded and the ratio of fledged young (defined as the ability to fly) to adult pairs was calculated. Causes of nest and/or bird loss were determined when possible.

RESULTS

Population. The number of birds sighted at Lake McConaughy increased from eight (8) in 1986 to a high of 138 in 1993 (Table 1), however, the increase of beach area with the lower reservoir storage in the early 1990s, the change in survey protocols and the timing of the surveys, and a significant increase in the intensity of effort involved in the process make a comparison of pre and post 1992 numbers difficult.

For convenience the lake was divided into twelve areas (See Fig. 1) and the fledgling success for each area was recorded. During the past three seasons 199 nests produced 720 eggs from which 386 chicks hatched (54%). Of the 386 chicks 247 successfully fledged (65%) for a ratio of fledged chicks to adult pair of 1.47 (Table 2).

Root et all (1993) using a stochastic population growth model determined that a minimum annual production of 1.16 fledged chicks per adult pair is necessary in order to effect a 1% annual growth in population. The 1.47 fledge ratio achieved at Lake McConaughy in the three years of District management is 127% of that minimum growth value.

Nest Site Management. Because of the status of the piping plover as a threatened species a rigorous experimental program was not followed to determine the success of the fencing efforts used to protect the nests. However, the data and anecdotal evidence collected indicated that the psychological fencing is a valuable management tool which may result in an increased probability of successful nesting by piping plovers.

From 1992 to 1994 a total of 129 individual nests were protected by the orange twine psychological fencing and protective signs. Of the 129 fenced nests 102 (79%) were successful in producing at least one chick. Fifty-five (55) nests were not fenced because they were located in areas where human recreation is at a minimum; of these, 35 (64%) were successful in producing a minimum of one chick. Fifteen (15) nests were located in the two areas where all human activity was excluded; of these, 13 (87%) were successful in producing at least one chick.

Nest Losses. At Lake McConaughy, over the past three seasons, 59 nests were lost prior to hatching. Five nests were lost directly by human activity. These five represent 2.5% of the total nests initiated. Of these five nests, four were protected by exclosures, however, three losses occurred during the first year of management, one in the second and none in the third. Other nest losses were 6 to cattle, 5 to predators, 7 to weather, and 36 were due to unknown causes.

SUMMARY

Lake McConaughy is one of the most important recreation areas in Nebraska. Data collected since 1990 shows that the lake is also an important nesting site for segments of the Great Plains population of the piping plover. Conflict between human activity and nesting habitat for the piping plover along the beach is inevitable and thus management of the area for the protection of piping plover nests and young is necessary.

Since 1992 Central has provided extensive monitoring and management of the piping plover nesting habitat located at Lake McConaughy. Since management practices were begun only five nests were identified as being lost directly to human activity despite the intensive recreational use of many beach areas. In 1994 record numbers of visitors were recorded on the beach, however, not one nest was lost as a direct result of human activity. Success, however, can be measured not just in terms of reducing losses to vacationers, but in terms of adding birds to the population.

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