Pappogeomys bulleri perceives its environment primarily through sound, touch, and smell. Gophers have vibrissae around their face and wrists which aid in navigating in burrows. The ears of P. bulleri are unique when compared with other rodents. The bullae are comprised of very thick bone and show modifications in the stapes. These features are in response to their subterranean lifestyle. They do not have sensitive hearing systems for low or high frequencies, which may protect their ears from incessant underground background noises.
Pappogeomys bulleri communicates with conspecifics vocally. When confronted with each other, two P. bulleri will hiss or click their teeth at each other. In captivity they are known to squeal when angry or in pain.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; vibrations ; chemical
Pappogeomys bulleri populations are currently stable.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Pappogeomys bulleri are serious agricultural pests. They are known to gnaw through plastic irrigation pipes and electric cables and eat a significant portion of crops or food designated for livestock or humans. Studies have shown that gophers can reduce the foliage intended for livestock by twenty percent. Farmers in areas with high populations of gophers have developed a number of ways to deal with gophers. Poisons are lowered into the gophers burrow systems or gophers are baited and caught. Gophers are very efficient diggers, however, and are able to counter many of these strategies. Within the range of P. bulleri, many villages have a “tucero,” a person whose job it is to trap and kill gophers. This job is passed from father to son and the tucero is a respected member of the community.
Negative Impacts: crop pest
Pappogeomys bulleri populations have a positive impact on soil fertilization and plant growth, and may help promote good soils for agriculture.
Pappogeomys bulleri is important to the ecosystem in many ways. Their constant digging and burrowing work to aerate soils, slow runoff, and fertilize soils. These activities enrich the soil and increase yield of the plants the gophers like to eat. The burrows of the gophers become a habitat to other organisms as well. Reptiles, other mammals (moles, squirrels, mice, rats, voles, and weasels), and some birds benefit from their burrow systems. These pocket gophers play an important role in the ecosystem as a host for parasites, including chewing lice, fleas, mites, and ticks. Other ways in which they affect their environment are as an important prey species (see section above) and as herbivores. Large populations of pocket gophers can change plant composition in an area: their mixing of soils causes foods that pocket gophers prefer to eat increase in quantity, while the plants they choose not to eat are no longer as common.
Ecosystem Impact: creates habitat; soil aeration
Mutualist Species:
Commensal/Parasitic Species:
Buller's pocket gophers are strictly herbivorous and eat a variety of plant foods. They prefer forbs, comprising 40% of their diet, but also eat grasses (30% of their diet) and the roots of xerophytic shrubs. They gather most food above ground, and transport it into their burrows by means of cheek pockets. Once underground, the food is either eaten or stored in sealed compartments. Occasionally, P. bulleri eats roots from inside of the burrows. Water is mainly obtained through food in the diet.
Plant Foods: leaves; roots and tubers; wood, bark, or stems
Foraging Behavior: stores or caches food
Primary Diet: herbivore (Folivore )
All nine subspecies of Pappogeomys bulleri are found in western central Mexico, in the states of Nayarit, Jalisco, Colima, and Michoacan.
Biogeographic Regions: nearctic (Native )
Pappogyomys bulleri is a montane species that prefers soils of volcanic origin. It lives at sea level, extending into elevations as high as 3,050 m. It inhabits Jalisco, Mexico, which is well known for a variety of terrains and climates. In Jalisco, seasons are based on rainfall, with 80% of rain coming between July and October. The average monthly temperature in this region is 24.9C. Pine-Oak forests border meadows and agricultural zones. Tropical deciduous forests are also found in the region. Subspecies of P. bulleri are found in all the terrains and climates in the area.
Range elevation: 0 to 3050 m.
Average elevation: 1500 m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: savanna or grassland ; forest ; scrub forest ; mountains
Other Habitat Features: agricultural
The maximum lifespan of pocket gophers is 5 years. The average age of individuals found in collections is 13.6 months for males and 18.6 months for females. The oldest males trapped in the wild were 4 and 5 years old, and the oldest females trapped were 4 years and 9 months.
Range lifespan
Status: wild: 5 (high) years.
Typical lifespan
Status: wild: 1.5 to 5 years.
The morphology of Pappogeomys bulleri is well adapted to fossorial life. They have small, flattened heads, short necks, and short, broad, and muscular forelimbs. The eyes, nose, and ears can be closed by flaps of skin to keep out dirt when digging. Their lips can close behind their incisors, allowing them to dig with their teeth and keep their mouth free of dirt. Their common name, Buller's pocket gopher, refers to the fur-lined cheek pouches in their mouths. They use these pouches to transport food from above ground into their burrows. They have large, sharp claws on their forelimbs and shorter claws on their hind feet.
The pelage varies by subspecies, but is generally pale to dark grey basally and tawny to cinnamon brown dorsally. Long, soft and fine, their fur lies near the body and falls in one direction. They sometimes have a white or buff nasal patch, although it is often missing. Their tails are naked and white, extending a distance less than half the length of the body and head. Pappogeomys bulleri is sexually dimorphic with males larger than females, but this difference is not as pronounced as in other gopher species (Geomyidae). Variation in size also exists among subspecies. On average, the total body length of males is 214 to 237 mm and the total body length of females is 130 to 175 mm. Males continue to grow in body size throughout their lifetime, while females stop growing at sexual maturation. Average measurements are as follows (in mm): length of head and body 130-175; length of tail 50-85; length of ear 6.5-8; length of hind food 28-35; occipitonasal length 36.2-44.0; zygomatic breadth 21.4-27.8; width across squamosals 20.3-27.2; breadth of interorbital constriction 6.5-8; length of nasals 11.8-16.2; length of maxillary toothrow 7.5-10.2; width of upper incisors at cutting edge 3.8-4.9; length of rostrum 16.6-21.4. Overall, the skull of P. bulleri is small and narrow.
The teeth are similar to those of other rodents and gophers. They have two large, central incisors that they use in digging. These incisors have a single, medial sulcus that runs down the entire labial surface of the tooth. Like those of other rodents, the incisors are continually worn down and regenerated. Lower incisors are regenerated significantly faster than upper incisors. The first molar has a thin enamel plate that extends across the posterior wall of the tooth and is variable among subspecies. Pocket gophers have 20 teeth total, with the dental formula: i 1/1, c 0/0, p 1/1, m 3/3.
Average mass: 225 g.
Range length: 192 to 237 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Pappogeomy bulleri is most susceptible to predation while above ground. Pocket gophers are important prey for a variety of predators, including weasels, coyotes, birds of prey, foxes, bobcats, domestic cats, snakes, and skunks. Although snakes will live in the burrows of P. bulleri, they are physically unable to kill them while underground due to space restrictions. Avian predation has the most impact on populations of pocket gophers, but studies have found that the main selective pressures on population size are food and habitat availability, not predation.
Known Predators:
Anti-predator Adaptations: cryptic
Pappogeomys bulleri is thought to have a polygynous mating system. The range of one male overlaps with those of several females but ranges of the females do not overlap. Other than interacting while mating, individuals remain solitary.
Mating System: polygynous
The mating season for P. bulleri is year round, with the most active period being between late winter and early summer. Mating behavior and breeding activity begins at about nine months to one year of age for both sexes. Females are sexually mature once their pubic symphysis has opened, widening the birthing canal. After the first breeding season, the pubic symphysis is completely absorbed at the command of relaxin, an ovarian hormone. Males are sexually mature when the baculum and sex glands are fully developed.
Breeding interval: Pocket gophers breed one to two times in a breeding season.
Breeding season: The mating season is year round, but Pappogeomys bulleri most frequently mate in late winter, spring, and early summer.
Range number of offspring: 2 to 11.
Range gestation period: 18 to 20 days.
Range weaning age: 35 to 40 days.
Average time to independence: 2 months.
Range age at sexual or reproductive maturity (female): 6 to 12 months.
Range age at sexual or reproductive maturity (male): 9 to 12 months.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Female P. bulleri have six mammae: one pectoral pair and two lingual pairs. A female will have anywhere from 2 to 11 young in a litter. The gestation period is around 20 days. Newborn Buller's pocket gophers are altricial. On average, they weigh between 2.5 and 4 g, with cheek pouches not fully developed and eyes that are still under a thin layer of skin. In about one month, their cheek pouches, eyes and ears are opened and one week later they are able to use their cheek pouches to carry food. After two months, siblings begin to fight with one another, undergo weaning, and disperse soon afterwards. Juveniles molt to show adult pelage when they are near 100 days old.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
Buller's pocket gopher (Pappogeomys bulleri) is a species of gopher that is endemic to Mexico.
It is monotypic within the genus Pappogeomys.[1][2] It includes the Alcorn's pocket gopher (P. b. alcorni) as a subspecies. Previously, this subspecies was considered a separate species.[1][2]
Pappogeomys bulleri is endemic to west central Mexico.[3] The total body length for this species is typically under 270 mm, and its body mass is typically under 250 g.[4] The fur of P. bulleri can vary from a light shade of gray, to a darker shade depending on its geographic distribution [4][5][6] and the tail, often naked and white, has a length that is half the head and body of this species.[3][5][6] This pocket gopher is well adapted to burrowing, which is evident in the characteristic stocky build, fusiform shape, powerful jaws and incisors, large powerful forelimbs, and reduced hind limbs and hips often observed in this species.[4] The diet of this species includes roots of xerophytic shrubs, grasses, and forbs.[3]
The habitat dispersal of this species varies widely, ranging from forested highlands, mountain meadows, vegetated plains, and coastal lowlands including areas near sea level to above 3,000 m in elevation.[4][5][6] P. bulleri can primarily be found in mountainous regions, inhabiting deep soils usually of volcanic origin.[3] This species can also be found in semitropical environments where tropical shrubs can be used as a food source, as well as near propagated soil used for growing crops.[3]
This species is highly successful in creating burrow systems that can be used for protection, both from environmental insults and predation, as well as for food storage and raising young.[7] Burrows typically consist of a main passage which splits into many branches. Shallow tunnels near roots and other food sources are used for foraging, whereas the deeper tunnels are used as nesting sites and food storage. The average depth of a burrow inhabited by P. bulleri is 19.9 cm, with a mean tunnel diameter of 8.9 cm.[7]
