Randall D. Babb

Reaction of lizard populations to a catastrophic wildfire in a central Arizona mountain range

Abstract In April 1996, the Lone Fire denuded over 90% of the vegetation in 130 km 2 around the Four Peaks area of the Mazatzal Mountains in central Arizona. To understand the reaction of a relatively immobile guild of species to a wildfire, we pit-trapped lizards from 1996 to 1999 in both burned and unburned interior chaparral and Madrean evergreen forest. In 26,214 trap nights, we found relative abundance was up to 10 times greater in burned than unburned vegetation. Species richness and diversity values were also greater in burned sites. Our data indicate a rapid settlement of burned areas primarily by individuals that survived the fire. Increased capture rate, diversity and richness values in 1998 and 1999 indicate that many species of lizards may even prefer early successional stages in chaparral and Madrean evergreen forests. Resident species of Teiidae and Sceloporus undulatus were more adapted to disturbed habitats than other resident Phrynosomatidae or Crotophytidae.

Distribution and habitat use of the Pacific treefrog (Pseudacris regilla) on the lower Colorado River and in Arizona

Abstract Prior to 1987, the Pacific treefrog (Pseudacris regilla) was known from only 4 sites on the lower Colorado River, which borders Nevada, California, and Arizona. We conducted surveys on the lower Colorado River from Princess Cove on Lake Mohave to the Bill Williams River confluence and upstream on the Bill Williams River to Planet Ranch from 1987 through 2002, and we consulted museums and herpetologists working in the area for P. regilla localities. We found this frog to be well distributed along 90 km of the lower Colorado River and its backwaters from Davis Camp, just below Davis Dam, to Castle Rock in upper Lake Havasu. We report 33 new localities and confirmed presence at 1 historical site. We found P. regilla primarily in cattail and bulrush marshes along the main channel and in backwaters. What limits its distribution on the lower Colorado River is unknown, because cattail and bulrush marshes occur both north and south of the current range. Pseudacris regilla populations below Davis Dam are probably currently disjunct from those on the Overton Arm of Lake Mead and in the Las Vegas Valley. In Arizona, this species also has been recorded as an apparent introduction at Middle Spring and a nearby stock tank in the Virgin Mountains, Mohave County, and at 2 central Arizona plant nurseries. The species persisted for at least 19 years and successfully bred at 1 nursery, where it was reportedly introduced by frogs hitchhiking on ornamental plants imported from San Diego.

ECOLOGY OF THE ANTELOPE JACKRABBIT (LEPUS ALLENI)

Abstract The antelope jackrabbit (Lepus alleni) is a lagomorph indicative of Neotropic savanna and thornscrub in south-central Arizona, west-central Sonora, and western Sinaloa <1,200 m elevation. We found populations in Arizona are most abundant in tropic–subtropic areas of low relief, characterized by velvet mesquite (Prosopis velutina) with an herbaceous understory (= Sonoran savanna grassland), and receiving a mean annual rainfall of between 200 and 450 mm, >90 mm of which falls as summer precipitation. In Mexico, this hare most commonly occurred in savanna grasslands or thornscrub interrupted by open areas receiving between 200 and 450 mm of precipitation per annum. Cacti were important habitat components for the hares and mean annual temperatures were >18°C with <60 d a year having temperatures below 0°C. Although sympatric with Lepus californicus over portions of its range, the two species preferred different habitats and rarely occurred together, and L. alleni was more prone to occur in groups than was L. californicus. We calculated the distributional range of L. alleni as ca. 102,000 km2 in Arizona and Mexico.

Status of the Porcupine (Erithizon dorsatuh) in Arizona, 2000–2007

ABSTRACT Concern over an apparent paucity of recent porcupine (Erithizon dorsatum) observations in Arizona, prompted us to replicate Walter P. Taylors (1935) letter requesting information from U. S. Forest Service and other government agency field personnel on the animals status. On the basis of 162 reports of >314 porcupine observations we concluded that porcupines are thinly and unevenly distributed throughout the state with animals reliably sighted in select habitats near prairie dog towns, in certain suburban settings, and on the North Kaibab Plateau. We attribute this general scarcity to predation by mountain lions (Puma concolor) and possibly black bears (Ursus americanus), and agree with Taylor that predator control efforts resulting is a depressed lion population is the most likely explanation for the high number of porcupines reported during the 1924–1934 period. Although the porcupine does not appear to be endangered, there is no evidence to suggest that lion numbers are decreasing and that porcupine numbers may again increase. Prédation, and perhaps increased mortality from night-time road kills, has made porcupines an unusual animal in most of Arizona.

Further Comments on Ear-flashing as a Predator Confusion Adaptation in Hares (Lepus)

Previous authors have commented on color patches located on animal appendages and attributed these markings to an evolutionary strategy to confuse predators (see e.g., Vorhies and Taylor [1933] and Powell [1982]). Specific examples include black patches on the ears of black-tailed jackrabbits (Lepus californicius) and Cape hares (L. capensis), both of which have been documented flashing their ears during high speed chases (Kamler and Ballard 2005, Kamler 2008). We too have noted this behavior, and one of us (CS) photographed a stationary black-tailed jackrabbit flashing its ears in response to a perceived aerial threat (Fig. 1A and 1B). This behavioral strategy appears widespread among the genus Lepus, most species of which inhabit open country. Black ear tips are also present in white-tailed jackrabbits (L. townsendi), arctic hares (L. arcticus), and snowshoe rabbits (L. americanus) in both summer brown and white winter pelage. In Eurasia black ear tips (and often the dorsum of tails) can be found in the mountain hare (L. timidus), desert hare (L. tibetanus), Chinese hare (L. sinensis), Yunan hare (L. comus), and wooly hare (L. oistolus) (Smith and Yan Xie (2008). It is also of interest that black or dusky patches are restricted to the inner ears of the white-sided jackrabbit (Lepus callotis) and absent in the tropicsubtropic antelope and Tehuantepec jackrabbit s (L. alleni, L. flavigularis, respectively). These species flash their white sides and rumps when alarmed, thus supporting the use of contrasting color swatches as a predator confusion hypothesis (Vorhies and Taylor 1933, Leichleitner 1958, Brown et al. 2014).

Previously Undocumented Squamate Prey Brought To Nest By Red-Tailed Hawks (Buteo jamaicensis)

Abstract I observed a nest of a red-tailed hawk (Buteo jamaicensis) for 13.5 h over a 4-day period in April 2012 along the Mexican border in southwestern Arizona. I documented prey items (N = 7) brought into the nest, including six representing the following three previously undocumented species of reptiles: Yuman Desert fringe-toed lizard (Uma rufopunctata), sidewinder (Crotalus cerastes), and western shovel-nosed snake (Chionactis occipitalis).