CITY OF TUCSON

HABITAT CONSERVATION PLAN

Cactus Ferruginous Pygmy Owl Subcommittee

Meeting Notes

Topic: Stressors and threats to Cactus Ferruginous Pygmy Owl

Date: May 9, 2005, 10 a.m

Location: U.S. Fish and Wildlife Service office

Participants: Mike Ingraldi, Dennis Abbate, and Sean Lowrey, Arizona Game and Fish Department; E. Linwood Smith, EPG; Trevor Hare, Sky Island Alliance; Marit Alanen and Scott Richardson, U.S. Fish and Wildlife Service; Ken Kingsley and Leslie Liberti, SWCA

Dennis discussed movements of a female that is currently being tracked. This and others that have been radio tracked have shown that females do a major dispersion trip, presumably in search of a mate with a good territory. Males find a territory and stay put, calling in the hopes of finding a mate. This generally takes place in fall. Spring calling apparently is about territorial defense.

The consensus of the group was that CFPOs have been severely impacted by historical losses of or changes to habitat, but that their historic habitat needs are poorly known. Current population size is unknown but small, and the Northwest Tucson (Marana) birds appear to be down to only one or two.

Current understanding is that the home range during the breeding season is about 35 acres. It is unlikely that there is now or will be any CFPO breeding territories in any of the City planning area. If the Rillito River were included, then there might be some possibility. However, in the Altar Valley, owls were successful in breeding at very low saguaro densities, so areas with low saguaro densities (but with some saguaros) should not be completely written off.

The only reasonable hope for lands in the planning area serving the needs of this species is to provide connectivity between populations to the south and north. The effort should be on maintaining and improving factors that provide for connectivity. The Important Riparian Areas defined by Pima County may serve this function in the Avra Valley. Birds are not likely to occur in the Southlands. Currently, there is no effective connectivity for the Southlands to known CFPO populations, but it is possible that there may be opportunities to create, enhance, and maintain connectivity. The most likely avenue of approach would be for owls to move up the Santa Cruz River valley, and across the Southlands to connect with conservation lands, such as Saguaro National Park, to the east.

There has been no detected movement across the Avra Valley from Brawley Wash. It may be wise to manage the vegetation to increase size of trees by thinning in areas with dense small mesquites. The best areas for investment of resources are the City-owned lands immediately north and south of Ajo Way and on the extreme west side of the Avra Valley, and the Santa Cruz River. It would be helpful to look at all the pieces of the puzzle to see how they fit with current conditions and plans, and what is currently known about the species.

The CFPO is dependent on several other species populations for its survival. One concern expressed is that there are areas with saguaros and few or no nest holes within the potential range of the owl. There appear to be few or no woodpeckers in those areas. An understanding of woodpecker distribution and needs may be helpful in planning and managing for CFPO. Use of nest boxes is considered to be of extremely limited potential value in this area.

The owl is a “mesopredator” (preying on some animals, preyed on by others), and needs a good food supply but limited resources for, or sheltering resources from, predators. There has apparently been a historic increase in competitors and predators, and that may have an important role in endangering the owl. It is possible that the most important resource limitations occur in the winter. CFPOs do not migrate (unlike elf owls, which do). Many of the resources needed by small owls are not available, or available in short supply, in winter. If the goal is to manage for survival and recovery of the owl, then a good understanding and effective management of the resources the owl needs is necessary.

Some types of fences may be a problem, both by impeding easy movement of CFPOs and providing perches for predators such as red-tailed hawks and Cooper’s hawks. Placing trees near, on both sides of, fences such as the CAVSARP chain-link fence, may facilitate owl movement over it. Dealing with predators would be more difficult.

Invasive plants may be a problem, in that they may increase fire risk and damage from fires to potential CFPO habitat. Good habitat does not come back after fires, or it takes a very long time. It may be good to protect saguaros by reducing or eliminating invasive plants, weeds and grasses, around them. With regard to invasive animals, cats appear to be a problem, and have been known to kill owls.

Disturbance by people is becoming an increasing problem, especially where illegal traffic comes close to owl nests and many people pass by the nests each day. A possible solution might be in the judicious placement of water stations away from sensitive areas. In areas that are sensitive, restriction of potentially disturbing activities during dispersal and mate finding seasons (late July-mid November) may be helpful. A list of restrictions for use in Section 7 consultations has been prepared and should be incorporated into management of this species. ORVs may be harmful, due to disturbance (noise and movement) as well as impacts to habitat and potential for increased fires.

The group recognizes that there are limitations as to what the City can do with regard to this species.

See attached table for specific points.