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Vascular Plant and Vertebrate Inventory of Saguaro ... - USGS

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<strong>and</strong> non-r<strong>and</strong>om camera areas using one-way<br />

analysis <strong>of</strong> variance. Because cameras were open<br />

for differing lengths <strong>of</strong> time (Appendix K), we<br />

st<strong>and</strong>ardized effort for each camera by dividing<br />

observed species richness by the number <strong>of</strong> days<br />

that a camera was open. We then log-transformed<br />

these data to meet assumptions <strong>of</strong> normality. At<br />

r<strong>and</strong>om sites, we tested for differences in species<br />

richness among strata <strong>and</strong> type <strong>of</strong> camera (e.g.,<br />

directly on r<strong>and</strong>om point, in nearest mapped<br />

drainage, <strong>and</strong> at site chosen by field personnel)<br />

using one-way analysis <strong>of</strong> variance.<br />

Results<br />

Species Richness<br />

We confirmed a total <strong>of</strong> 59 species <strong>of</strong> mammals<br />

in the Rincon Mountain District (Appendix D).<br />

This included 12 species confirmed through<br />

specimens, 32 species confirmed through<br />

photographs, nine species captured for which<br />

a voucher specimen previously existed, five<br />

species confirmed through a combination <strong>of</strong><br />

voucher specimens <strong>and</strong> photos, <strong>and</strong> one species<br />

confirmed through reliable observation. One<br />

species included in this total (eastern cottontail)<br />

was confirmed by photographs in appropriate<br />

high-elevation habitat, but requires further<br />

documentation. We confirmed three species<br />

<strong>of</strong> mammals not previously confirmed for the<br />

district: western red bat, fulvous harvest mouse,<br />

<strong>and</strong> Virginia opossum. The latter two species<br />

represent significant range extensions. We<br />

observed only one species listed by the U.S. Fish<br />

<strong>and</strong> Wildlife Service as endangered, the southern<br />

long-nosed bat. Three species <strong>of</strong> non-native<br />

animals were documented for the district (feral<br />

cat, domestic dog, <strong>and</strong> domestic cattle) but we<br />

do not believe that any <strong>of</strong> these species have<br />

established feral populations in the district.<br />

There have been a total <strong>of</strong> 66 species<br />

observed or documented in the district in the last<br />

few decades based on this <strong>and</strong> previous studies<br />

(Appendix D). We did not document the presence<br />

<strong>of</strong> 11 species that were previously documented<br />

for the Rincon Mountain District. We did not<br />

confirm the deer mouse, captured in the early<br />

1950s near Manning Camp (Appendix F). We<br />

78<br />

did not confirm the banner-tailed kangaroo rat<br />

(Dipodomys specatabilis), previously confirmed<br />

by specimen voucher (H<strong>of</strong>fmeister 1986), <strong>and</strong><br />

did not observe any <strong>of</strong> the distinctive sign <strong>of</strong> this<br />

very large kangaroo rat. Three species <strong>of</strong> bats<br />

that we did not observe, the western small-footed<br />

myotis, Yuma myotis, <strong>and</strong> western pipistrelle,<br />

have been confirmed recently (Davis <strong>and</strong> Sidner<br />

1992; Sidner 2003) <strong>and</strong> undoubtedly still occur<br />

at the district. One species <strong>of</strong> rodent (southern<br />

grasshopper mouse) is also present; a roadkilled<br />

individual found by Don Swann in 1997 was<br />

confirmed by Yar Petryzyn at the University <strong>of</strong><br />

Arizona mammal collection. Four species are<br />

extirpated from the district (grizzly bear [Ursus<br />

arctos], jaguar [Panthera onca], Mexican gray<br />

wolf [Canis lupus], <strong>and</strong> bighorn sheep [Ovis<br />

canadensis]), <strong>and</strong> a fifth species (North American<br />

porcupine) may be extirpated, though it remains<br />

on the species list.<br />

Small Mammals<br />

We trapped 544 individual rodents (including<br />

recaptures) in 2001 <strong>and</strong> 2002, <strong>and</strong> documented<br />

13 species through our trapping effort, as well as<br />

three species <strong>of</strong> diurnal squirrels (Table 6.3). One<br />

species, the fulvous harvest mouse (4 captures)<br />

was a new species for the district. We did not<br />

capture two species that have been previously<br />

documented for the district (the southern<br />

grasshopper mouse <strong>and</strong> banner-tailed kangaroo<br />

rat).<br />

Small mammal species richness was<br />

highest in the middle-elevation stratum (Table<br />

6.3), though sampling effort was also greater<br />

in that stratum. Therefore, after accounting for<br />

differences in sampling effort, species richness<br />

did not vary among strata (F 2,35 = 0.16, P =<br />

0.86, one-way ANOVA, log-transformed data).<br />

Species richness was higher on non-r<strong>and</strong>om plots<br />

than on r<strong>and</strong>om plots in all strata (Table 6.3).<br />

At both high- <strong>and</strong> low-elevation strata, relative<br />

abundance <strong>of</strong> all rodents combined was higher<br />

on non-r<strong>and</strong>om plots than on r<strong>and</strong>om plots, but at<br />

middle elevations, relative abundance was higher<br />

on r<strong>and</strong>om plots (Table 6.3). In general, relative<br />

abundance was higher at both low <strong>and</strong> high<br />

elevations than at middle elevations.

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