Posted Wednesday, October 30, 2002

Parker Mountain Sage-grouse project

Quarterly progress report

Utah State University control number: 5-43228

Period covered: April 1 – June 1, 2002

Project investigator(s): Terry A. Messmer, Renee chi, and David Dahlgren, Jack H. Berryman Institute, UMC 5230, College of Natural Resources, Utah State University, Logan, Utah 84322-5230. Phone: (435) 797-3975, E-mail: terrym@ext.usu.edu

Agency Project Officer: Dean L. Mitchell, Upland Game Program Coordinator, Utah Division of Wildlife Resources, 1594 West North Temple, Suite 2110, P.O. Box 146301, Salt Lake City, Utah 84114-6301. Phone 801-538-4786, E-mail: deanmitchell@utah.gov

Date submitted: 5-30-02

NARRATIVE

Radio-collared hens:

Going into the winter, there were a total of 19 collared hens. Over the course of the winter three known mortalities occurred. The exact causes of the mortalities are unknown. Although, there was some evidence that one of the mortalities was caused by predation. One collar was anonymously dropped off at a DWR office mailbox.

The birds wintered in the lower elevations (Bull Roost and Black Point areas) as has been documented in previous years. As early as the end of February, there were observations of lekking behavior at Mud Lake of approximately 30 males.

We officially started counting leks the last weekend in March. The counts continued intermittently through the end of April. The largest leks, Bull Roost and Black Point, seemed to have a general decreased attendance. At the same time, higher elevation, smaller leks were experiencing unprecedented high attendance rates. We hypothesize the dry winter and spring has negatively affected the attendance of lower elevation leks due to a lack of water and vegetation. In addition to the increase of lek attendance at the higher elevations, we identified a lek that has not been noticed before. The lek is difficult to observe from the road but appeared to sustain a significant number of strutting males (~39). We will have to count this new lek in future years. The total number of males on the leks this year exceeded 2001 counts by 20 percent with the new lek and 13 percent without the new lek (see Graph 1).

Concurrent with the lek counts was the spring trapping efforts. We planned to collar hens to replace collared hens that died, batteries died in collar, or birds disappeared. We determined 11 hens had operating collars that would last throughout the nesting and brood-rearing period. Our goal was to collar an additional 14 hens. In the past, we have collared hens on Bull Roost lek. We attempted to trap on the traditional flats opposite Bull Roost and near the lek with no success. Due to the increased attendance apparent on the higher elevation leks, we attempted to trap hens on and around the Cedar Peak lek, Hare Lake lek, Otto's Reservoir lek, and the new lek. We were successful and attached 14 new collars to hens.

Of the 23 hens we have been able to locate, 19 of them (83%) initiated nesting. At this point, 8 nests have successfully hatched, 5 nests have been depredated, and one nest has been abandoned. There does not seem to be a particular pattern in the elevations of identified nests. Hens that are nesting for the second or third time, are nesting in the same general area as they did previously. From here on out, we will continue monitoring the hens and their ensuing brooding locations.

Experimental treatments:

To review, there are 16 experimental plots, each plot one hundred acres in size. Four are control plots, 4 are Spike-treated plots, 4 are Dixie Harrow-treated plots, and 4 are Lawson aerator-treated plots. These plots were identified as areas needing big sagebrush thinning to increase the grass/forb component in the understory. In the literature, grasses and forbs have been identified as critical for broods.

The spike treatments were applied during the fall of 2000. Those plots are presently entering the second post-treatment growth season. The first year of growth did not show a significant difference from the untreated control plots. We expect to see a response from the grasses and forbs this season.

The Lawson Aerator and Dixie Harrow treatments were conducted last fall (2001). The Dixie Harrow plots were seeded. We have collected two years of pre-treatment vegetation data on these plots. This summer (2002) will be the first growth season post-treatment. We do not expect to see an understory response from the vegetation until the second year, especially if we do not get some more precipitation. So far, the land is very dry out there considering the time of year.

Vegetation collection will be collected during June and July to coincide with the brood-rearing periods of time. We will try to determine what composition of grasses and forbs might be available for broods going through the treated versus the untreated areas.

Rabbit herbivory exclosures

Last year (2001), we built 16 x 16 foot exclosures to measure vegetation that was not being eaten by any large herbivores. By the end of the summer, it looked as if the rabbits had feasted on the vegetation inside all the exclosures. Taking advantage of an interesting opportunity to look at rabbit herbivory, we will be building some additional rabbit-proof exclosures (see Diagram 1). We will be measuring the difference between the vegetation inside and outside the rabbit-proof exclosures.

Summary of Biological Information

I. Lek Counts 1998 >273 males
              1999 >350 males, up> 25%
              2000 >350 males, still up but down slightly from 1999
              2001 >450 males, up ~20% from last year... highest count in 30 years
              2002 >600 males, up ~13%, still highest count in 35 years

II. Nest Initiation       Y     A
                    1998  8/19  8/9    (57%)
                    1999  6/16  16/17  (67%)
                    2000   * 13/26    (50%)
                    2001   * 17/25    (68%)
                    2002 12/14  7/9    (83%) 

    Nest Predation  
                    1998  6     (19%)
                    1999  10/19 (53%)
                    2000  2/13  (15%)
                    2001  6/17  (35%)
                    2002  STILL NESTING

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Graph 1. Notice the lek count for 2002 is significantly higher than any count in last 35 years.

Diagram 1. The far left square is open to all herbivores, the middle square is closed to large herbivores, and the right square is closed to rabbits and larger herbivores.