April 1, 2008, Kofa Website Situation Update
[Please see archived updates for additional background]
- The next annual survey will be conducted in the fall of 2008. Results of the 2007 survey are available in the December 2007 update.
- As we enter the spring season, water and forage conditions remain excellent across the refuge and the greater Kofa Mountains Complex as a result of good winter rainfall.
- As discussed in the March update, KM03, the large adult male mountain lion captured in the western Kofa Mountains last October, has been an “offending lion” since his second bighorn sheep kill in February. Since that March update, one additional kill has been confirmed for KM03, a desert bighorn sheep ram killed near Yaqui Tank in mid-March and confirmed by biologists in the field on March 18. The lion left the refuge on March 28 and was taken by Department staff on the evening of March 29 in the vicinity of White Tanks in the Tank Mountains east of the refuge.
- The Department’s May 2007 “Kofa Mountains Complex Predation Management Plan” was written as result of the joint Department-U.S. Fish and Wildlife Service investigation into the decline in the desert bighorn sheep herd that occupies the Kofa Mountains Complex of southwestern Arizona, which was found to be at an historic low during the 2006 survey of the herd. For 51 years the Kofa herd has been a critical source of bighorn sheep for bighorn restoration efforts throughout the state of Arizona and the states of Colorado, New Mexico, and Texas. As a result of the decline in the herd, translocation efforts have been cancelled since 2006.
- The joint Department-U.S. Fish and Wildlife Service April 2007 “Investigative Report and Recommendations for the Kofa Bighorn Sheep Herd”, identified a number of potential sources of newly additive bighorn mortality, to include predation by a newly established resident lion population on the refuge that forms the core of the Kofa Mountains Complex. That report established an “offending lion” standard of two bighorn sheep kills within a six-month period. This is the most conservative “offending lion” standard of the major bighorn sheep recovery plans currently being implemented in the western United States. That same standard was used in the Department’s predation management plan.
Cache site for the first confirmed bighorn sheep kill
by collared mountain lion KM03, a mature ram killed
off the refuge in the Tank Mountains, January 2008
- The total confirmed big game kills for KM03 is currently nine: five mule deer and four desert bighorn sheep. Due to the intermittent nature of the data feed from this lion’s GPS collar (a function of limited satellite availability and the lion’s activity patterns), it is likely some kills have not been discovered. As with the two previous collared lions, possible additional kills will be investigated when the data on the recovered collar is downloaded. Any location clusters that may indicate a kill location will be investigated by Department or U.S. Fish and Wildlife Service biologists.
- Efforts to capture and collar additional lions before the onset of the summer continue.
- The U.S. Fish and Wildlife Service continues to develop a mountain lion management plan for the Kofa NWR. The initial step in the planning process will be a public scoping period which could occur as early as April. An plan will undergo a full environmental compliance process, to include all associated public review.
Recreational Impact on Bighorn Habitat:
- The 2008 season will commence on December 1, 2008, and run through the month. The results of the 2007 season are available in the January 2008 monthly update.
Research and Monitoring
- As of March 28, there has been one mortality among the 30 bighorn ewes captured and collared in November 2007 as part of a nutrition study, and a predation monitoring and management program. The satellite uplink function has quit working in three of the 15 GPS collars, but the VHF radio transmitters continue to permit us to monitor those three animals.
Litigation on Kofa NWR Wildlife Waters: