Mark M. Peyton, Central Nebraska Public Power and Irrigation District, Gothenburg, Nebraska
INTRODUCTION
The American burying beetle (Nicrophorus americanus), a federally listed endangered species, was once found throughout temperate eastern North American. Recent collections, however, have come only from Rhode Island, Oklahoma, Arkansas and Nebraska.
Nine specimens of N. americanus had been collected in Nebraska prior to 1988 (Ratcliffe, 1992). In 1988 a specimen was collected approximately two kilometers south of the South Platte River near North Platte, Nebraska. This is the western most collection site for this species in the United States (Ratcliffe, 1992) and was the first indication that this species may inhabit the Platte River ecosystem.
An extensive survey using carrion-baited pitfall traps and light traps conducted near Sutherland, Nebraska, 32 kilometers west of the 1988 collection site, resulted in the collection of 3,492 specimens of Nicrophorus from 23 May - 16 October 1990. However, no specimens of N. americanus were collected (Ratcliffe, 1990).
A survey utilizing similar methods was conducted in the Platte River valley near Kearney from 15 to 30 July 1991. Seventy specimens of Nicrophorus were collected along with five other species of Silphids. However, again no specimens of N. americanus were found (Jameson, 1991).
Six specimens of N. americanus were found in 1992 on the Valentine National Wildlife Refuge in Cherry County, approximately 150 kilometers north of the North Platte site (Ratcliffe, 1992). Two additional specimens were located on the refuge in 1993 and a second specimen was taken at the North Platte site in 1993 (Ratcliffe, personal communication).
On 11 July 1994 I found three dead specimens of N. americanus in an inactive mammal pitfall trap along the Platte River in western Dawson County, south of Gothenburg, Nebraska. Following the discovery, I developed a plan to survey for N. americanus in the upper Platte River valley between North Platte and Lexington. The results of that survey are presented here.
METHODS
Anderson (1982) described the habitat for the American burying beetle as northern deciduous and riparian forest, thus the 11 July find matched the expectation that if the species was present in an area, it would be along the river. Based upon that assumption, I placed 15 traps at five sites within the riparian forest along the Platte River between the confluence of the North and South Platte Rivers near North Platte and the J-2 river return near Lexington.
However, because the finds in Cherry County and those near North Platte were in open, upland grasslands, I also placed eight traps at three grassland sites south of this same river stretch (Figure 1).
Utilizing the protocol developed by Kozol (1990), I began trapping on 5 August 1994. After capturing 21 N. americanus at two of the original three grassland sites I added three new grassland sites on 19 August and three more on 24 August for a total of nine grassland sites.
Originally there were three traps placed about 100 meters apart per site. The grassland locations added on 19 and 24 August had one trap per site. Traps were checked each morning prior to 9 a.m., when possible. Specimens were photographed and released immediately except when specimens were temporarily held to await verification by Brett Ratcliffe and Mary Liz Jameson of the University of Nebraska State Museum and Wally Jobman from the U.S. Fish and Wildlife Service.
The purpose of the survey was to verify the presence of N. americanus in the area. The traps were dismantled after specimens were found at a specific site.
RESULTS
From 5 August to 29 August 1994, I operated 31 pitfall traps at 14 locations for a total of 211 trap nights. I collected 37 live N. americanus from one riverine and seven grassland locations between North Platte and Lexington, Nebraska. Thirty-six specimens were taken from the upland grassland sites south of the Platte River and one specimen was taken from the riparian forest along the river. Collection information is summarized in Table 1.
SUMMARY AND DISCUSSION
After finding three dead specimens of the American burying beetle along the Platte River south of Gothenburg in Dawson County, Nebraska, I was able to trap, photograph and release 37 live specimens from seven upland grassland and one riverine location.
Originally, using Kozol's protocol which called for beef liver as bait, only a few Nicrophorus were found in each trap. I also noticed that there was little or no odor associated with the liver so I began to collect roadkill animals and use them as bait. All collections of N. americanus were in traps utilizing roadkill (Table 1) and the number of individuals of other species of Nicrophorus found in each trap increased dramatically with the change in bait.
NEED FOR FURTHER STUDY
It is possible that this population, combined with those present in Cherry County, identify a third large population of N. americanus in the Midwest Geographic Recovery Area as outlined in the Recovery Plan for this species.
The University of Nebraska State Museum, using USFWS Section Six grant funds made available through the Nebraska Game and Parks Commission, will be instituting a two-year study of the Gothenburg population starting in the spring of 1995. The purpose of this study will be to determine population size, examine minimal versus optimal prey size, assess interspecific Nicrophorus competition and determine the geographic range of this species in correlation with any habitat preferences (Ratcliffe, personal communication).
The UNSM study will concentrate on a 15-mile wide band extending south from the Platte River between North Platte and Lexington. Surveys of a variety of other areas extending in all directions from the Gothenburg and Cherry County sites are necessary in order to provide data on range, habitat preference and population size for this species. The need for these surveys is outlined in the Recovery Plan developed by the U.S. Fish and Wildlife Service, however to date, this has not been done in Nebraska.
REFERENCES
Anderson, Robert S. 1982. On the decreasing abundance of Nicrophorus americanus Olivier (Coleoptera: Silphidae) in eastern North America. Coleopterists Bulletin, 36:362-365.
Jameson, Mary Liz and Brett C. Ratcliffe. 1991. A survey to determine the occurrence of Nicrophorus americanus Olivier (the American Burying Beetle) on the Platte Rive islands near Kearney. Final report to the United States Department of the Interior, Fish and Wildlife Service, Rainwater Basin WMD. 10pp.
Kozol, Andrea J. 1990. Suggested survey protocol for Nicrophorus americanus, the American burying beetle. Report to the U.S. Fish and Wildlife Service. 6pp.
Ratcliffe, Brett C. 1990. A survey to determine the occurrence of Nicrophorus americanus Olivier (the American Burying Beetle) in the Gerald Gentleman Station Rail Spur Project Area. Final report to the Nebraska Public Power District.
Ratcliffe, Brett C., and Mary Liz Jameson. 1992. New Nebraska occurrences of the endangered American burying beetle. Coleopterists Bulletin 46:(4):421-425.
U.S. Fish and Wildlife Service. 1991. American burying beetle (Nicrophorus americanus) recovery plan. Newton Corner, MA. 80pp.
Return to 1995 Platte River Basin Ecosystem Symposium 
Last updated by Darren A. Jack on 9/8/97