The southeastern pocket gopher (Geomys pinetis) is a species of pocket gopher that is native to the southeastern United States. It occurs in Alabama, Georgia, and Florida, where it is the only pocket gopher.
The southeastern pocket gopher is rather smaller than the plains pocket gopher (Geomys bursarius), with a total length of 260 mm (10.2 in) including a tail of about 86 mm (3.4 in). Males are larger than females and average 176 g (6.2 oz) in weight while the females average 136 g (4.8 oz). The dorsal fur is cinnamon brown with the underparts rather paler and tinged with buff or reddish-yellow. The feet and tail are white or pale buff. As with other members of this family, the external cheek pouches can be turned inside-out for grooming purposes. It is well adapted for living underground with large, protruding incisor teeth, used for tearing at roots, and powerful claws on the forefeet for digging.
This gopher is restricted to the southeastern part of the United States, where it occurs in Alabama, Georgia and Florida. It occupies several different dry, sandy habitats; it occurs in sand-hill country with longleaf pine (Pinus palustris) and turkey oak (Quercus laevis), and it also occurs in slightly moister hammocks (low mounds) among the sand-hills with Quercus virginiana and other hardwood trees. Away from the sand dunes, it occurs in longleaf pine woodland and scrubby sand pine (Pinus clausa) habitats. Its presence in any area is obvious because of the numerous piles of sandy soil it pushes to the surface.
G. pinetis is a solitary animal and creates shallow tunnels above which are a series of mounds of excavated material. The soil is pushed upwards by the front limbs and chest and creates a fan-shaped mound with the tunnel at one side. The burrow entrance is immediately blocked with soil. These shallow tunnels are connected to a deeper tunnel system by a spiral "staircase". Down below are the food chambers and a nest chamber which may contain dried vegetation and plant fibres.
Breeding takes place in spring and summer, peaking around February/March and June/July. The gestation period is about four weeks and the average litter size is two. Despite this low level of fecundity, the southeastern pocket gopher is a common animal, implying that there is good survivability of the offspring. The presence of green forage in the diet and the fact that owls sometimes feed on them show that the gophers do emerge above ground sometimes. However, predators underground are few, the chief dangers being snakes and weasels.
The southeastern pocket gopher is active throughout the year. It feeds on roots and rhizomes below ground, and on green plants such as grasses, sedges and weeds which it can reach from near the entrance to the burrow. Large quantities of vegetation are gathered and carried back to store chambers in the burrow. A number of arthropods share the burrows with the gophers, including about fourteen species that are found nowhere else. The gophers are attracted to cultivated land, particularly sweet potato crops, and can also be a pest in peanut and pea crops, and sugarcane plantations.
The range of G. pinetis extends from southern Georgia and southeastern Alabama to northern and central Florida. Geomys pinetis consists of five subspecies which together form this range. Geomys pinetis austrinus resides in central Florida, G. p. floridanus is in northern Florida and southern Georgia, G. p. goffi was in eastern central Florida, G. p. mobilensis is found in southeastern Alabama and northwestern Florida, and G. p. pinetis is mostly found in southern Georgia. (Pembleton et al. 1978)
Biogeographic Regions: nearctic (Native )
This pocket gopher is a medium-sized rodent with a total length of about 290 mm in males and 261 mm in females. This sexual dimorphic species has a size difference of roughly 10%. The cylindrical body has sepia fur, shaded orange-cinnamon on the sides of the shoulders and flanks, with white hairs on the throat and forearms, a white patch from the forehead to the nostrils, and grayish underparts. All pocket gophers' fossorial adaptations include small eyes, reduced pinnae, strong-clawed forelimbs, nearly naked tail, external fur-lined cheek pouches, and a thick body. The teeth are all evergrowing and the cheekteeth have reduced enamel. The large exposed incisors function as picks while burrowing. The dental formula is i 1/1, c 0/0, p 1/1, m 3/3, total 20.
A major distinguishing characteristic of this species is the hourglass-shaped nasals which are constricted near the middle. Geomys pinetis can be further distinguished from some other Geomys as follows: from G. fontanelus by the missing fontanel between the parietal and squamosal bones on the skull; from G. cumberlandius by a greater angled zygomatic arch which is not extended posteriorly; and from G. colonus by a broad V-shaped, rather than U-shaped interpterygoid space. (Pembleton et al. 1978, Lee 1980, Ross 1980)
Other Physical Features: endothermic ; bilateral symmetry
This pocket gopher generally resides in either the sandhill ecosystem or the xeric hammock ecosystem. Longleaf pines (Pinus palustris) and turkey oaks (Quercus laevis) are the two dominant trees within the sandhill ecosystem. The terrain is rolling and the soil is well-drained. The xeric hammock ecosystem is dominated by live oaks (Q. virginiana) and other hardwood species. The soil contains more organic material and is slightly moister than that of the sandhill ecosystem. In areas where sandhill and xeric hammock habitats are disappearing from modern land-use practices, pocket gophers are adapting by burrowing into road shoulders, power line rights of way, railroad embankments, fields along airport runways, parks, lawns, orchards, cemetaries, baseball fields, and golf courses. (Wilkins 1986, Lee 1980)
Terrestrial Biomes: savanna or grassland ; forest
The bulk of this pocket gopher's diet includes roots and other herbaceous material. While burrowing, these pocket gophers collect plant roots, tubers, bulbs, and stems, which they transport in their cheek pouches to underground storage chambers for later consumption. It occasionally emerges above ground and feeds on grasses, forbs, and sedges (Humphrey 1992, Wilkins 1986)
Perception Channels: tactile ; chemical
This pocket gopher breeds throughout the year. Females exhibit two major peaks of activity during February through March and June through August, whereas males display a more constant higher level of activity from January through August. Males have alternating cycles of spermatogenic activity and inactivity, and they produce sperm at a higher rate with increased age. The range of litter sizes is one to three with averages of 1.7 0.51 and 1.52 0.11 in separate studies. Females may produce two litters per year corresponding with their two peaks of sexual activity. Pocket gophers are born tail-end first and average 50 mm and 5.8 g. The eyes, ears, and cheek pouches are closed at birth. Young pocket gophers are usually weaned and dispersed by one month, and reach sexual maturity by the age of four to six months. (Pembleton et al. 1978)
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Four of the five subspecies of G. pinetis are common throughout their range. G. p. goffi was listed as endangered by the Florida Game and Fresh Water Fish Commission in 1990. It is now considered to be extinct and is therefore no longer being considered for listing by the U.S. Fish and Wildlife Service. (Humphrey 1992)
IUCN Red List of Threatened Species: least concern
Over 203 articles were published between 1888 and 1976 regarding the damage caused by pocket gophers. Suggestions to control these pests included traps, poisons, anticoagulants, repellents, gas-chambers, and mechanical burrow-diggers. Most pocket gophers are quickly exterminated from lawns, golf courses, parks, and cemeteries. (Avise et al. 1982)
Pocket gophers play several important roles in the functioning of their ecosystems. They return leached nutrients to the surface of the soil, pushing up to 81,600 kg/ha of burrow soil to the surface per year. The soil mounds create numerous small sites for colonization and secondary succession within grasslands, sandhills, and scrub. (Humphrey 1992)
The family name, Geomys, comes from the Greek words Geo and mys, meaning "earth" and "mouse", respectively. The species name, pinetis, comes from the Latin word Pinetum which means "a pine wood". (Pembleton et al. 1978)