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Abstract
Tail-mounted radio transmitters were attached to 12 juvenile and 3 sub-adult (yearling) Mexican Spotted Owls (
Strix occidentalis lucida) in southwestern New Mexico from 1993 to 1996. Most juveniles dispersed from their natal territories during September. Intervals between dispersal of siblings ranged from 3 to more than 15 days. Juveniles exhibited two types of dispersing behavior; moving rapidly across the landscape (up to 11.3 km/night) and extensive local exploration. Two juveniles moved between separate mountain ranges and crossed at least 25 km of grassland and pinon/ juniper (
Pinus/Juniperus spp.) savanna habitat, suggesting that isolated populations in the southwest U.S. could function as a metapopulation. During dispersal juveniles were found to roost in habitat unlike that normally used by adults, including open ponderosa pine (
Pinus ponderosa) and pinon/juniper habitat. The three sub-adult females paired temporarily with adult males in their first summer, but then left in the fall, suggesting that dispersal can continue through an owl's second year.
Parent Publication
Citation
Arsenault, David P.; Hodgson, Angela; Stacey, Peter B. 1997. Dispersal movements of juvenile Mexican Spotted Owls (
Strix occidentalis lucida) in New Mexico. In: Duncan, James R.; Johnson, David H.; Nicholls, Thomas H., eds. Biology and conservation of owls of the Northern Hemisphere: 2nd International symposium. Gen. Tech. Rep. NC-190. St. Paul, MN: U.S. Dept. of Agriculture, Forest Service, North Central Forest Experiment Station. 47-57.
