May 2017 Progress Report
Nesting phenology appears to be delayed a bit this year: Only 5 broods hatched to date, which is much fewer than last year at this time. We saw few hens on leks, especially at Jim Sage, and located fewer nests in proportion to the number of collared hens.
Crews observing leks have reported a high rate of predator flushes of sage-grouse from leks. We have not seen anything like this winter at least since the new millennium, and the harsh winter has been followed by a cold, windy spring.
The mortality rate of collared hens has been higher than the past few years. We don’t have the people power to investigate each mortality immediately while the crews are also trapping full-time, so it’s hard to know whether mortalities are the result of predation or some other cause. At Jim Sage and Sheep Creek, no hens collared this year have died, but crews have recovered mortalities of hens collared in 2015/2016. In contrast, we’ve had >4 hens collared in 2017 that have died at the other 3 sites.
There is a new feedlot south of Malta that might be attracting more ravens in the vicinity of Jim Sage. We are doing point-count surveys on all pastures to estimate density of other bird species and these data will help us determine whether raven density has increased across years or differs among our 5 study sites and could be correlated to nesting success and nesting propensity.
Status at our 5 study sites as of 18 May 2017:
Sheep Creek: We are tracking 22 hens and have located 18 nests: 10 failed, 5 active, and 3 hatched, but 1 of the hens was depredated immediately, so her brood perished. We have 2 hens with live broods.
Brown’s Bench: Tracking ~20 hens and 13 nests: 9 failed, 3 active, and 2 hatched; 1 of those broods did not survive. Eleven collared hens have died, including 5 of the hens collared in 2017.
Big Butte: Had 33 collared hens (26 are still in the area and accounted for) and located 7 nests: 2 failed, 5 active, none hatched yet. Seven of the hens collared in 2017 have died.
Jim Sage: Collared 19 birds and located 10 nests: 4 failed, 6 active, none have hatched yet.
Pahsimeroi: Collared ~20 hens and located 15 nests: 8 failed, 7 active, and none have hatched yet. Four of the hens collared in 2017 have died.
March 2017 Progress Report
We began trapping hens at Brown’s Bench in early February. As of mid-March, we have captured 26 hens and have 4 collars left to deploy. In addition, 11 birds collared in 2015 and 2016 have returned. We are beginning to triangulate hens with the expectation that they will initiate nesting soon.
We have been trapping at Jim Sage since mid-February, with 3 hens collared so far. We have had a difficult time locating hens in the study pastures, but we have 16 birds that returned from 2015/2016.
We have had better success at Sheep Creek, where we have collared 17 hens since mid-February. We have also been scouting leks for potential rocket net deployment. Thus far, only 2 collared hens have returned from 2016.
As of mid-March, roads were still too snowy and muddy for us to access Big Butte and Pahsimeroi study sites, but we expect to begin trapping there by late March.
June 2016 Progress Report
In June, we completed several activities including intensively tracking sage-grouse to find sage grouse nests, our ‘after hatch’ vegetation measurements at nests and random locations (all but for one active nest), insect sampling (sweep netting, pitfall traps, and ant mound surveys), and avian point-count surveys. We continued intensively tracking hens (those who successfully hatched a clutch of eggs), brood survey data collection, brood location vegetation measurements, and less intensively tracking hens without hatched nests. Because of the reduction in workload, we’ve reduced our field staff for the month of June.
In July, we plan on continuing to intensively track hens with hatched nests, conduct brood surveys, less intensively track hens without hatched nests, initiate our ‘utilization’ vegetation measurements, initiate our utilization mapping, continue our brood location vegetation measurements, and proof data. We plan to finish field data collection for the 2016 field season in mid-August. Below is a summary from each of our 5 field sites.
We deployed 25 new radio collars in 2016. In addition, 25 radio-marked hens whose collars were deployed in past years were confirmed alive at Brown’s Bench in March (at the outset of the 2016 field season). Since March, we’ve documented 8 hen mortalities (8 of the 50 radio-marked hens). One predator left a head and crop behind so we took advantage of this opportunity and had Roger Rosentreter, a botanist, examine the crop contents. Roger found it contained ~20 ants, ~70% yellow flower parts (Crepis spp. and possibly Microseris spp.), ~9% leaf tissue (likely Crepis spp.), and 1% other material. We are locating hens with hatched nests every 2-3 days and hens without hatched nests once per week. We located 34 nests at the Brown’s Bench study site in 2016 and overall apparent nesting success was 38% (Table 1). We completed our ‘after hatch’ vegetation sampling and insect sampling. We took down the turbo tape and chargers for the temporary electric fence in the Corral Creek pasture. The cattle were moved out of the Browns Creek pasture recently and the temporary electric fence successfully kept cattle out of this pasture (our ‘no grazing’ treatment).
We deployed 25 new radio collars in 2016. In addition, 19 radio-marked hens whose collars were deployed in past years were confirmed alive at Jim Sage in March (at the outset of the 2016 field season). Since March, we’ve documented 4 hen mortalities (4 of 44 radio-marked hens); one of these was found in a Golden Eagle nest. We are locating hens with hatched nests every 2-3 days and hens without hatched nests once per week. We’ve located 21 nests at the Jim Sage study site (one nest was still active as of 28 June) and overall apparent nesting success was 35% (Table 1). Cattle were removed from the Kane Springs pasture on approximately 7 June and the temporary electric fence successfully kept cattle in the pasture. We will leave the temporary electric fence deployed as a neighboring, non-experimental pasture is scheduled to be grazed in summer and fall and, hence, cattle will need to be kept out of the Kane Springs pasture.
We deployed 20 new radio collars in 2016. In addition, 15 radio-marked hens whose collars were deployed in 2015 were confirmed alive in March (at the outset of the 2016 field season). Since March, we’ve documented 7 hen mortalities (7 of 35 radio-marked hens). One mortality was likely due to a fence collision as it was found intact and within 20 m of a barbed-wire fence. We recovered the carcass and had Roger Rosentreter, a botanist, examine the crop contents. It contained approximately 90% ant parts and 10% vegetation. We are locating hens with hatched nests every 2-3 days and hens without hatched nests once per week. We located 28 nests at the Big Butte study site in 2016 and overall apparent nesting success was 29% (Table 1). We completed our ‘after hatch’ vegetation and insect data collection.
We deployed 11 new radio collars in 2016. In addition, 15 radio-marked hens whose collars were deployed in 2015 were confirmed alive in March (at the outset of the 2016 field season). Since March, we’ve documented 2 hen mortalities (2 of 26 radio-collared hens). We located hens with hatched nests every 2-3 days and hens without hatched nests once per week. We located 15 nests at the Sheep Creek study site in 2016 and overall apparent nesting success was 33% (Table 1). We completed our ‘after hatch’ vegetation and insect data collection.
We had a total of 52 nests in the Pahsimeroi. Of those, 12 hatched for a success rate of 23%. There are another 14 collared birds that have either dropped a collar (1) or are in unknown status (13) and another 4 birds have been depredated since collaring. Our first nest hatched on May 1st with the last one hatching on June 21st with the majority of nests hatching the 2nd and 3rd weeks of May. Ongoing work includes brood counts, analyzing nest assessments, and measuring grazing intensity.
Partners and Collaborators:
- Idaho Bureau of Land Management
- Jim Sage, Browns Bench, Big Butte, and Sheep Creek Permittees
- Idaho Department of Fish and Game
- Idaho Office of Species Conservation
- Idaho Cooperative Fish and Wildlife Research Unit
- University of Idaho Rangeland Center
- USGS Forest and Rangeland Ecosystem Science Center
- Idaho Cattle Association
- Public Lands Council
- Idaho Conservation League
- Idaho Rangeland Resources Commission
- Idaho Sage-grouse Advisory Committee