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APPENDIX I - BIOLOGICAL RESOURCES Northern Harrier (Circus cyaneus) State Listed: Species of Special Concern'Priority 2;° No federal listing The former name of this bird was the "marsh hawk," which denotes its dependency upon marsh and seasonal wetland habitats for its survival. It is well adapted to capturing rodents in dense, low vegetative cover by gliding low over an area and dropping quickly on exposed prey. It is also unique among hawks in that it nests on the ground instead of high in trees. The harrier is sexually dimorphic,with the male having a gray plumage and the female a brown coloration. This species appears to be non-migratory in the area of the project site. The reason for this nonmigratory behavior is unknown. The harrier's decline in past decades has been a direct result of marsh drainage and conversion to agricultural land,thus,its designation as a state species of concern(Remsen, 1978). Like the Swainson's hawk, the loss of the marsh feeding habitat of the northern harrier has been partially buffered in the Central Valley by agricultural crops and moderately grazed pasture which support large rodent populations. A pair of northern harriers was seen on two visits to the project site in November 1991. Both observations were made in the south Tracy Lakes basin area. As with the Swainson's hawk,the extent to which nesting pairs in the area use the project site as a foraging habitat could not be determined at this time of year, since "nesting pairs" will only use the site during the spring/summer nesting period. Black-shouldered Kite (Elanus caerulea) State Listed: California Fully-Protected Species;' No federal listing This raptor is a feeding specialist on the California meadow vole. Because of its habit of hunting by hovering in place above areas of vole activity, its easily observable presence is usually a good indicator of the abundance of this key prey species in a given area. Several sightings of single hovering kites were made at various locations along the lake basin-grassland edge,indicating an abundance of meadow voles. ' A loosely defined category based on listings in separate CDFG publications covering fish, amphibians and reptiles, birds, and mammals. This category contains species or subspecies of animals without current Threatened or Endangered status, but whose current population decline in California and continued loss of critical habitat would likely result in their placement in the above categories if measures are not taken to reverse their present ecological conditions. ° Definitely in decline. S A California Department of Fish and Game fully protected species, as described in Section 4700 of Chapter 8, Section 5050 of Chapter 2, Division 6, Chapter 1, Section 5515. 18