Summary Information
Rabbit Population Densities at the Sevilleta National Wildlife Refuge, New Mexico (1992-2004)
Creator:
Individual: Robert Parmenter
Organization: Valles Caldera National Preserve
Physical Address:
Delivery Address: P.O. Box 359, 090 Villa Louis Martin
City: Jemez Springs
Locality: NM
Postal Code: 87025
Phone: US
Email: bparmenter@vallescaldera.gov
Metadata Provider:
Individual: Information Manager Sevilleta LTER
Physical Address:
Delivery Address: 1 University of New Mexico
City: Albuquerque
Postal Code: 87131
Phone: US
Phone: (505) 277-2109
Phone: (505) 277.5355
Email: data-use@sevilleta.unm.edu
Associated Party:
Individual: Sevilleta LTER Field Crew Sevilleta LTER Field Crew
Physical Address:
Phone: US
Email: data-use@sevilleta.unm.edu
Role: field crew
Associated Party:
Individual: Robert Parmenter
Organization: Valles Caldera National Preserve
Physical Address:
Delivery Address: P.O. Box 359, 090 Villa Louis Martin
City: Jemez Springs
Locality: NM
Postal Code: 87025
Phone: US
Email: bparmenter@vallescaldera.gov
Role: lab crew
Publication Date: 2014-01-27
Language: English
Abstract:
This study measured the population dynamics of black-tail jackrabbits (Lepus californicus) and desert cottontail rabbits (Sylvilagus auduboni) in the grasslands and creosote shrublands of McKenzie Flats, Sevilleta National Wildlife Refuge.  The study was begun in January, 1992, and continued quarterly each year.  Rabbits were sampled via night-time spotlight transect sampling along the roads of McKenzie Flats during winter, spring, summer, and fall of each year.  The entire road transect was 21.5 miles in length. Measurements of perpendicular distance of each rabbit from the center of the road were used to estimate densities (number of rabbits per square kilometer) via Program DISTANCE.  Results from 1992 to 2002 indicated that spring was the peak density period of the year, with generally steady declines through the year until the following spring. Evidence of a long-term "cycle" (e.g., the 11 year cycle reported for rabbits in the Great Basin Desert) did not appear in the Sevilleta rabbit populations.
Keywords:
Keyword: populations
Keyword Thesaurus: Core Areas
Keywords:
Keyword: populations
Keyword: measurements
Keyword: long term
Keyword: surface elevation table
Keyword: surveys
Keyword: roads
Keyword: deserts
Keyword: grasslands
Keyword: rabbits
Keyword Thesaurus: LTER Controlled Vocabulary
Intellectual Rights:
Data Policies
This dataset is released to the public and may be freely downloaded. Please keep the designated contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement of the Sevilleta LTER. A copy of any publications using these data must be supplied to the Sevilleta LTER Information Manager.
Distribution:
Online:
URL: http://sevdeims-d.lternet.edu/data/sev-113
Coverage:
Geographic Goverage:
Geographic Description: McKenzie Flats is located within the northeastern section of the Sevilleta NWR, encompassing an area from Black Butte south to Palo Duro Canyon and east to the Los Pinos.
Bounding Coordinates:
West Bounding Coordinates: -106.691
East Bounding Coordinates: -106.691
North Bounding Coordinates: 34.3592
South Bounding Coordinates: 34.3592
Bounding Altitude:
Altitude Minimum: 1615
Altitude Maximum: 1615
Altitude Units: meter
Temporal Coverage:
Date Range:
Begin Date:
Calendar Date: 1992-01-20
End Date:
Calendar Date: 2004-05-03
Purpose:
The purpose of the study was to assess the dynamics of rabbit populations in the grasslands and creosote shrublands of the Sevilleta NWR.  Rabbits are important herbivores in these habitats, and can influence NPP and plant species composition.  In turn, these animals also provide high-quality prey for many of the Sevilleta's mammal and reptile carnivores and birds of prey.  Density data on rabbits can be used to calculate herbivore pressure on the plant communities.
Contact:
Position Title: Information Manager
Organization: LTER Network Office
Physical Address:
Delivery Address: UNM Biology Department, MSC03-2020
Delivery Address: 1 University of New Mexico
City: Albuquerque
Locality: NM
Postal Code: 87131-0001
Phone: USA
Phone: 505 277-2535
Phone: 505 277-2541
Email: tech-support@lternet.edu
URL: http://www.lternet.edu
Contact:
Individual: Information Manager Sevilleta LTER
Physical Address:
Delivery Address: 1 University of New Mexico
City: Albuquerque
Postal Code: 87131
Phone: US
Phone: (505) 277-2109
Phone: (505) 277.5355
Email: data-use@sevilleta.unm.edu
Publisher:
Individual: Information Manager Sevilleta LTER
Physical Address:
Delivery Address: 1 University of New Mexico
City: Albuquerque
Postal Code: 87131
Phone: US
Phone: (505) 277-2109
Phone: (505) 277.5355
Email: data-use@sevilleta.unm.edu
Publication Place: Sevilleta LTER
Method Step:
Description:
When the samples were collected: The samples were collected in winter, spring, summer, and fall, of each year.  Rabbit populations were sampled during a single night during each of these four seasons per year.  Dates of collection varied in some years, but generally the sampling was conducted in January, April, July, and October. Sampling Design: The rabbits were sampled along 21.5 miles of roadway that was broken up into four "legs" of varying lengths. Leg A:  Black Butte southward to Five Points (5.7 miles). Leg B:  Five Points eastward to the turnoff before Palo Duro Canyon (4.1 miles). Leg C:  Palo Duro turnoff northward to the old McKenzie Headquarters site (6.1 miles). Leg D:  McKenzie Headquarters site northwestward to Black Butte (5.6 miles). Measurement Techniques: The rabbit surveys were conducted at night using spotlights. Surveys began one hour after sunset, when no trace of sunlight or dusk remained.  Beginning in 1998, samples were taken only during full-moon periods. A pickup truck was driven slowly (8-10 miles per hour) along the road of the 21.5 mile circuit.  Two (or more) observers stood in the bed of the pickup truck, and scanned the left and right sides (respectively) of the road with spotlights, while the driver kept watch for rabbits directly in front in the road.  During 1992, the spotlights were Q-Beam 500,000 candlepower spotting lights, with both flood and spot settings (spot settings were used during the rabbit sampling).  From 1993 through 1996, Q-Beam spotlights with 1,000,000 candlepower were used.  In 1997, new spotlights with 3,000,000 candlepower were used; these lights were set permanently on "flood", but illuminated well at distances previously reached by the spot settings of the less-powerful spotlights.   In addition to the spotlights used by the standing observers in the bed of the pickup truck, two spotlights mounted on the pillar posts of the truck's cab were turned on and set for the roadsides ahead of the truck; these lights, coupled with the high-beam setting of the truck's headlights, illuminated the road in front of the truck for approximately 100 meters. When a rabbit was observed, one person's spotlight illuminated the spot at which the rabbit was first seen.  The second person's spotlight would track the rabbit, so that it was not counted twice.  A meter tape was walked out from the center of the truck bed (which equalled the center of the road) in a perpendicular direction from the road to the location at which the rabbit was first observed.  That distance was measured and recorded to the nearest meter. If a rabbit was observed in the middle of the road, the distance was recorded as zero.  Beginning in January, 2000, perpendicular distances to the rabbits were taken with a laser range finder, with accuracies of less than 1 meter (accuracies were tested before field use and confirmed to be <1m).  Generally, rabbits within 100 meters of the road could be seen relatively clearly with all three types of spotlights. Other data recorded included (1) the odometer reading in miles from the beginning of the sample at Black Butte (odometers were reset to zero at the start of the sample), (2) whether the rabbit was on the Left or Right side of the road, and (3) the species of rabbit.  In addition, incidental data were recorded on weather conditions, presence of clouds and moon, and the time at which the survey was begun, along with the times at which each Leg was begun and finished.  Finally, the names of the people on the sampling crew were recorded. Analytical Procedures: The perpendicular distance data were entered into Program DISTANCE to estimate the total density of rabbits in the study area. Values were computed as numbers of individuals per square kilometer In the analyses, if there were sufficient numbers of rabbits (>10 per leg), the difference legs were analyzed separately, and the resulting mean densities were estimated by averaging the four leg estimates.  In the results tables below, these instances are indicated by the category, "MEAN".  If sample sizes were too small to estimate the four legs separately, then all the rabbit observations were pooled together, and a density estimate for the entire 21.5 mile survey was calculated. These results are indicated by the category, "ALL".
Quality Control:
Description:
The program DISTANCE command codes were as follows: Options; Title='SEVILLETA RABBIT DENSITIES'; Type=Line; Length/Units='Miles'; Area/Units='Hectares'; Distance=Perp/Measure='Meters'/Exact; Object=Single; End; Data; Stratum/label='DATE ENTERED HERE'; Sample=1/Label='ALL LEGS, DATE ENTERED HERE'/Effort=21.5; DISTANCE DATA ENTERED HERE, SEPARATED BY COMMAS; End; Estimate; Est /key=uniform /adj=cosine  /select=sequential /criterion=AIC /monotone=weak; Est /key=uniform /adj=hermite /select=sequential /criterion=AIC /monotone=weak; Est /key=hnormal /adj=cosine  /select=sequential /criterion=AIC /monotone=weak; Est /key=hnormal /adj=hermite /select=sequential /criterion=AIC /monotone=weak; Pick=AIC; Density by sample; End;
Data Table:
Entity Name: sev113_rabbitdens_20040226
Entity Description: Data for SEV113
Object Name: sev113_rabbitdens_20040226.txt
Size: 2058
Data Format:
Text Format:
Number of Header Lines: 1
Record Delimiter: \r\n
Attribute Orientation: column
Simple Delimited:
Field Delimiter: ,
Distribution:
Online:
URL: https://pasta.lternet.edu/package/data/eml/knb-lter-sev/113/119299/4331627b0b4744799a51b758dca11046
Coverage:
Temporal Coverage:
Date Range:
Begin Date:
Calendar Date: 1992-01-20
End Date:
Calendar Date: 2002-07-23
Attribute List:
Attribute Name: day
Attribute Label: day
Attribute Definition: The day of the month in which data were collected.
Storage Type: date
Measurement Scale:
Datetime:
Format String: DD
Attribute Name: month
Attribute Label: month
Attribute Definition: The month in which data were collected.
Storage Type: date
Measurement Scale:
Datetime:
Format String: MM
Attribute Name: year
Attribute Label: year
Attribute Definition: The year in which data was collected.
Storage Type: date
Measurement Scale:
Datetime:
Format String: YYYY
Attribute Name: #legs
Attribute Label: #legs
Attribute Definition: Number of roadway sections sampled from.
Storage Type: string
Measurement Scale:
Nominal:
Non Numeric Domain:
Text Domain:
Definition: Number of roadway sections sampled from.
Attribute Name: #observed
Attribute Label: #observed
Attribute Definition: Number of rabbits observed.
Storage Type: string
Measurement Scale:
Nominal:
Non Numeric Domain:
Text Domain:
Definition: Number of rabbits observed.
Attribute Name: density_estimate
Attribute Label: density_estimate
Attribute Definition: Estimate of density of rabbits.
Measurement Scale:
Ratio:
Unit:
Custom Unit: numberPerHectare
Numeric Domain:
Number Type: real
Attribute Name: s.d.
Attribute Label: s.d.
Attribute Definition: Standard error.
Storage Type: string
Measurement Scale:
Nominal:
Non Numeric Domain:
Text Domain:
Definition: Standard error.
Attribute Name: estimator_used
Attribute Label: estimator_used
Attribute Definition: Model name.
Storage Type: string
Measurement Scale:
Nominal:
Non Numeric Domain:
Text Domain:
Definition: Model name.