Gopherus morafkai, Murphy, Robert W., Berry, Kristin H., Edwards, Taylor, Leviton, Alan E., Lathrop, Amy & Riedle, J. Daren, 2011

Murphy, Robert W., Berry, Kristin H., Edwards, Taylor, Leviton, Alan E., Lathrop, Amy & Riedle, J. Daren, 2011, The dazed and confused identity of Agassiz's land tortoise, Gopherus agassizii (Testudines, Testudinidae) with the description of a new species, and its consequences for conservation, ZooKeys 113, pp. 39-71 : 49-53

Morafka’s Desert Tortoise Gopherus morafkai sp. n. Figs 915

Xerobates agassizii Cooper 1861 (partim)

Testudo agassizii ( Cooper 1861) (partim). Generic reassignment by Cope (1875)

Gopherus agassizii ( Cooper 1861) (partim). Generic reassignment by Stejneger (1893)

Scaptochelys agassizii ( Cooper 1861) (partim). Generic reassignment by Bramble (1982)

Xerobates lepidocephalus Ottley et Velázques Solis 1989. In error by Crumly and Grismer (1994)

Holotype.

CAS (California Academy of Sciences) 33867; juvenile from Tucson (approximate location 32°7'N, 110°56'W, elevation 948 m), Pima County, Arizona, U.S.A, collected on 9 July 1912 by H. Brown and preserved in ethanol.

Paratypes.

ROM (Royal Ontario Museum) 47501, formerly CAS 13165, an immature tortoise collected by H. Brown from 20 miles (32 km) west of Tucson, (presumably the Roskruge Mountains, Pima County) Arizona, USA (approximate location 32°7'N, 111°18'W, where tortoises occur today), on 9 March 1908, received at CAS alive on 23 March 1908, and died 8 July 1908; CAS 34263, a juvenile collected by J.R. Slevin in the Catalina Mountains (Santa Catalina Mountains), foothills at west end of mountains, Pima County, Arizona, USA on 15 May 1912 (approximate location 32°21'N, 110°57'W). Specimens are preserved in ethanol.

Diagnosis.

All of the species of Gopherus and their hybrids can be easily diagnosed using molecular data. Morphologically, Gopherus morafkai can be separated from both Gopherus flavomarginatus and Gopherus polyphemus in having relatively smaller front feet. Whereas the distance from the bases of the first to fourth claws is the same on all feet in Gopherus morafkai , in the latter two species the distance from the bases of the first and third claws on the forelimb is about the same as the distance between the bases of the first and fourth claws on the hindlimb ( Auffenberg and Franz 1978). The diagnosis of living specimens of Gopherus morafkai , Gopherus berlandieri and Gopherus agassizii can be impossible in captive tortoises because of extensive hybridization ( Edwards et al. 2010) and because of abnormalities in shell, head and limb integument from poor nutrition ( Donoghue 2006). However, in non-hybrid individuals, Gopherus morafkai can be separated from Gopherus berlandieri in having a rounded snout when viewed from above as opposed to a wedge-shaped snout in Gopherus berlandieri ( Auffenberg and Franz 1978). Further, in Gopherus morafkai the gular projections do not normally diverge, and it has a single axillary scale preceding each bridge, yet in Gopherus berlandieri the gular projections often diverge and the axillary scales are often paired. Morphologically, Gopherus morafkai can be separated from Gopherus agassizii in having a relatively narrower shell, shorter gular scutes, shorter projections of the anal scutes and in having a flatter, pear-shaped carapace (Table 1). Ecologically, whereas Gopherus agassizii predominantly occurs in valleys and alluvial fan topography, Gopherus morafkai prefers slopes and rocky hillsides ( Riedle et al. 2008), including animals of the isolated population in northwestern Arizona ( McLuckie et al. 1999).

Description of holotype.

A juvenile, with straight-line carapace length at midline (MCL) = 86.5 mm, maximum carapace length is 88.5, curved carapace length from free edge of nuchal scute to that of supracaudal scute = 118 mm, maximum plastron plastron length from tip of gular horn to tip of anal scutes = 86 mm, midline plastron length from gular notch to anal notch = 78 mm, maximum height of shell at 3rd vertebral scute = 40 mm, width at 3rd marginal scute = 64 mm, maximum midbody width = 69, maximum width at 7th marginal scute = 73 mm, and head length from tip of snout to posterior edge of supraoccipital condyle = 25 mm (Figs 8, 12). Eleven marginal scutes present on both right and left edges of carapace. Supracaudal scute single, undivided. Five toenails present on each forelimb, four toenails on each hind limb (Fig. 9). Third nail of each hind limb longer than others. Two enlarged, raised scales present on anterior ventral surface of foreleg of which the ventral-most scale is larger, more protruding than others. Scales on head smooth, asymmetrical, larger anteriorly at snout, becoming much smaller in temporal area (Fig. 12). Areolae and 7 to 8 growth laminae present on all scutes. In alcohol, the color of areolae and adjacent two growth laminae on carapacial scutes (Figs 8, 11) predominantly dark reddish brown grading to reddish black on laminae at or near seams between scutes. Small areas of areolae on 2nd and 3rd vertebral scutes and left 1st costal scute yellowish brown or copper. Color of areolae on plastron light olive brown grading to dark yellowish brown on 2nd through 4th laminae. Laminae at and adjacent to the seams dark reddish brown with a few areas of dark red. Head and neck multi-colored (Figs 8, 9, 13): neck and throat very pale yellowish brown and very pale brown. Dorsal and lateral surfaces of head darken from parietal to frontal scales (Fig. 12). Skin in the axillary and inguinal areas also lighter in coloration, becoming reddish brown to dark reddish brown on lower limbs and pads of feet (Fig. 10). Nails golden brown at tips.

Coloration of the species in life.

Coloration of Gopherus morafkai varies considerably by size and age as well as by location. Adult tortoises generally have hues and chromas of the integument in dark colors, e.g., very dark greyish brown, dark brown, very dark brown, olive brown, dark olive brown, reddish brown, dark reddish brown, dark grey, black, and occasionally to rarely xanthic tones ( GretagMacbeth 2000). Neonates and young juveniles tend to be bi-colored, with orange to reddish areolae and reddish brown to dark brown laminae. As the juveniles age, they become darker. Coloration of limb scales tends to mirror that of the shell. Based on observations of the authors, the protected skin in axillary and inguinal areas is generally in lighter colors for all sizes and ages of tortoises.

Variation.

Variation in coloration and morphology deserve further research with respect to location, vegetation and soil types, as well as by size, sex, and age of the tortoise. All future studies should include genetic documentation of non-hybrid specimens.

Distribution.

Gopherus morafkai occurs naturally east and south of the Colorado River in Arizona, as well as in Sonora, including Tiburon Island, and Sinaloa on the west side of the Sierra Madre Occidental, Mexico ( Berry et al. 2002). The species appears to have been recently introduced from Sonora into at least one home in La Paz, Baja California Sur, Mexico as pets, where it successfully reproduced (Patricia Galina, personal communication to RWM). It likely occurs as introduced individuals or populations in North America and possibly elsewhere, although in this case many individuals are likely hybrids of Gopherus morafkai x agassizii.

Natural history.

Gopherus morafkai occurs in upland habitats in the Sonoran Desert scrub ( Brown et al. 1979) with rocky outcrops and palo verde-saguaro cactus communities and ecotonal desert grasslands ( Van Devender 2002). Within these habitats, Gopherus morafkai is generally found along rocky slopes, or bajadas, of desert mountain ranges, with breeding populations occurring as high as 1,420 m elevation and individual observation records occurring to 2,380 m ( Flesch et al. 2010). The species typically occupies excavated or eroded burrows underneath rocks or boulders. Consequently, geology and resultant burrow availability among mountain ranges is an important determinant in regulating population density ( Averill-Murray et al. 2002a, b).Low density populations of Gopherus morafkai also occur along alluvial fans and in intermountain valleys, where individuals utilize desert washes and associated caliche caves as shelter sites ( Riedle et al. 2008; Grandmaison et al. 2010). These peripheral populations provide important genetic linkages between disjunct mountain ranges ( Edwards 2003; Edwards et al. 2004; Averill-Murray and Averill-Murray 2005).

Gopherus morafkai exhibits both a spring (mid-March to May) and a late summer activity period (late July to late September). Activity patterns are rainfall-dependent, with increased activity related to increased precipitation during the late summer monsoons ( Averill-Murray et al. 2002b). Monsoonal storms within the range of G. morafkai result from warm season winds pushing tropical moisture northwards from the Pacific Ocean and northern Mexico (Turner and Brown 1994). Female activity begins earlier than male activity in the spring, possibly because females might need to forage to develop shelled eggs before oviposition in June and July ( Averill-Murray et al. 2002a). Activity is higher for both sexes during late summer monsoons, with courtship and breeding occurring in July–September ( Averill-Murray et al. 2002a). Females develop ovarian follicles before entering brumation in the fall ( Henen et al. 2000). The follicles probably mature in the spring with oviposition shortly afterwards ( Henen et al. 2000; Averill-Murray 2002). Clutch size ranges from 1-12 eggs with a mean of 5.7 eggs ( Averill-Murray 2002).

Female Gopherus morafkai mature at larger sizes (220 mm carapace length) ( Averill-Murray 2002) than does Gopherus agassizii (176-190 mm carapace length) ( Turner et al. 1986; Germano 1994a; Karl 1998). Clutch sizes between the two species are similar ( Averill-Murray 2002), but Gopherus morafkai only produces 1 clutch every 1-2 yr ( Averill-Murray 2002) while Gopherus agassizii may produce 1-3 clutches every year ( Turner et al. 1986; Wallis et al. 1999). Harsher, more arid climates in the Mojave Desert may have led to increased female reproductive investment to offset hatchling and juvenile mortality ( Heppell 1998; Hellgren et al. 2000), but information is limited for juvenile tortoises of both species.

Annual survivorship for juvenile Gopherus morafkai at three sites in Arizona ranged from 0.84 to 0.93 ( Averill-Murray et al. 2002a). Adult survivorship was high (0.89-0.97). Seasonal differences in mortality reflected seasonal differences in activity patterns ( Riedle et al. 2010). Adult survivorship was similar between both species (Table 1), although little was determined about hatchling or juvenile survivorship. Primary sources of mortality for Gopherus morafkai in Arizona included the following: 1) falls related to steep rocky habitat; 2) being overturned during combat and mating rituals; and 3) predation by mountain lions, Puma concolor ( Riedle et al. 2010). Prehistorically, Native Americans ate Mojave and Sonoran tortoises ( Schneider and Everson 1989) and historically, Native Americans and Mexicans hunted the tortoise for food ( Cooper 1861; Cox 1881), although Cooper (in Cronise 1868: 480; see True 1881) reported that they were "not very well flavored."

Etymology.

The new species is a patronym for the late Professor David Joseph Morafka in recognition of his many contributions to the biology and conservation of the species of Gopherus and his unsurpassed way of facilitating research, even among researchers with very different perspectives.