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

keep predator-control activities out of the district
during the 1930s and 1940s, but it is possible
that bounty hunters entered the district anyway
(Saguaro NP, unpubl. records). Ironically, the
effort to keep bounty hunters out of the district
was led by Don Egermayer, the park custodian;
but Egermayer himself shot a wolf on the X-9
Ranch in 1947 (Saguaro NP, unpubl. records).
Bighorn sheep occurred in the district
through the 1940’s (Davis and Sidner 1992). A
herd of 14 were observed south of Rincon Peak
in 1942 (Coss 1969), and a weathered horn was
collected on Tanque Verde Ridge in 1957. This
species may have been eliminated by illegal
hunting, although there may have been other
factors as well.
At least two, and probably five, jaguars
were shot in the Rincon Mountains (in 1902,
1912, 1920, and two in 1932) prior to the
establishment of the park (Girmendonk 1994;
Davis and Sidner 1992; specimen records
in Appendix F), and there were occasional
sightings of this species in the park’s early years.
Currently, there are several jaguars known to
be resident in southern Arizona, close to the
Mexican border (Jack Childs, pers. comm.). We
attempted to photograph jaguars during this
study, placing cameras at high elevations along
game trails where cat scat and scrapes were
found, but obtained no photographs and found no
evidence of this species. Although grizzly bears
were once present in the Rincons, it is doubtful
that any were present by the time the park
was established; the last record for the Rincon
Mountains was in 1921 (cited in Davis and Sidner
1992). Both jaguars and grizzly bears would
have been hunted aggressively well before the
establishment of the park.
The last known sighting of a North
American porcupine was near Juniper Basin in
the mid-1990s by District Ranger Bob Lineback.
We made a concerted effort to search for this
species during this study, but with no success.
Porcupines appear to be declining throughout
southern Arizona, possibly due to habitat
changes, although Harley Shaw (pers. comm.) has
suggested that it is due to the large increase in the
population of mountain lions.
86
While hunting and range-wide factors
appear to be important in the loss of some
species, significant changes in habitat for
mammals at lower elevations, as well as habitat
loss, may be responsible for other changes in the
mammal community. Habitat changes include
the large increase in shrubs and forbs since the
cessation of grazing at the district. Active fire
suppression and drought may have also played
important roles in the increase of woody shrubs
(Brown 1994, Bahre 1995, Van Auken 2000),
particularly in the middle-elevation areas of the
district. Habitat loss includes the significant
loss of open space outside the district due
to residential and commercial development,
which has reduced low-lying desert habitat to a
relatively thin strip along the west and south sides
of the Rincon Mountains (see Chapter 2).
Mule deer appear to be declining in
the district for at least the past five decades.
Sumner (1951) reported that mule deer were the
dominant deer species below 6500’ in the Rincon
Mountains, while white-tail deer occurred above
7000’. Today, white-tail deer are commonly seen
in the vicinity of the Cactus Forest Loop Drive
(Don Swann, pers. obs.), and in this study mule
deer were only photographed below 4000’ in
elevation. Mule deer are declining throughout
the western United States, and the cessation
of cattle grazing at the district in the 1950s
and 1960s has led to important changes in the
vegetation community, such as growth of shrubs,
that may favor the white-tail deer. The loss of
mule deer habitat outside the district (due to
increases in the adjacent housing developments)
is probably also a major factor in their declining
population at the district. Similarly, American
badgers were sighted often in the early years
of the park (Saguaro NP, unpubl. records), but
were not photographed or collected during this
study. Two reliable observations (one inside the
Cactus Forest Loop Drive, and one on the district
boundary near Freeman Road) and one recent
photograph of a American badger by Ranger John
Williams at the Wildhorse Gate on Speedway in
March, 2006, indicate that this species still occurs
in the district, but is definitely now rare.