 Wysłany: Nie 11:55, 20 Mar 2011 Temat postu: resulted in estimates of breeding air max 2011 |
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| Radio-telemetry data on Mexican spotted owls from studies in Arizona, New Mexico, Colorado, and Utah resulted in estimates of breeding season home ranges that varied from 563 to 1,cartier watches,250 acres (228-506 ha),air max 2011 while nonbreeding season home range estimates varied from 902 to 2,540 acres (365-1,028 ha). In a ponderosa pine-Gambel oak forest of Arizona, nonbreeding home range size were significantly (P=0.008) larger than breeding home ranges [24]. However, in the Sierra National Forest there was an interaction between cover type and season on California spotted owl territory size, such that nonbreeding territories were larger than breeding territories in mixed-conifer forest but smaller in oak/pine woodland [60].
Other sources of variability in home range size include habitat requirements and prey availability. Spotted owls likely require a certain amount of old-growth forests. A literature review states that a pair of northern spotted owls uses an average of 2,000 to 2,500 acres (10 km2) of old-growth forests [55]. In areas where this resource is clumped and abundant, spotted owl home ranges are generally smaller. For example,cheap jerseys in coniferous forests in southwestern Oregon, northern spotted owl home range size varied from 1,320 acres (533 ha) in clumped mixed-conifer forest to 7,190 acres (2,908 ha) in fragmented Douglas-fir forest [10]. Several articles[32][58] note the inverse relationship between home range sizes and the amount of old growth within them. Spotted owls also require less area in certain cover types[16][40][60]. For instance, Mexican spotted owl home ranges in the Sacramento Mountains of New Mexico dominated by mixed-conifer forests were significantly (P<0.04) smaller than those dominated by ponderosa pine forests and pinyon-juniper woodland. In addition, home range size was inversely related (P≤0.003) to the amount of mixed-conifer forest in the home range [40].cheap rolex watches The variation between different habitat types may be related to the availability of spotted owl prey [10][32]. For instance, the low numbers and inconsistent availability of prey on Washington's Olympic peninsula was suggested as a cause for the large northern spotted owl home ranges in this region [32]. |
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