Bird Dissemination of Dwarf Mistletoe on Ponderosa Pine in Colorado
Hudler GW, Oshima N, Hawksworth FG. 1979. Bird Dissemination of Dwarf Mistletoe on Ponderosa Pine in Colorado. The American Midland Naturalist. 102(2):273-280
Dwarf mistletoe distribution and the role of birds as vectors of the parasite were studied in a Colrado ponderosa pine forest. Occurrence of the parasite at distances from a source greater than those attributable to explosive seed discharge was erratic and infrequent. In 24 cases, ages of initial infections in single or multiple tree infection centers were determined. Age analyses indicated that once every 4 years in 150 ha. of healthy ponderosa pine. A total of 411 birds representing 21 species were trapped in an infected pine stand during dwarf mistletoe seed dispersal in 1974-1976. Mountain chickadees and pygmy nuthatches were primary vectors of the parasite. Field observations and laboratory experiments suggested that birds ingested dwarf mistletoe seeds infrequently but such seeds were not viable when voided in feces. Viable seeds apparently were transported by birds only when they adhered to feathers and were transferred to foliage as subsequently foraged.
- Type
- Journal Article
- Authors
- Hudler, George; Oshima, Nagyoshi; Hawksworth, F
- Units
- SODN
- Keywords
- Colorado, dwarf mistletoe