By Benjamin Klopf
Geographic Range
Orthogeomys heterodus is found in central and southern Costa Rica in the Cordillera Central and Cordillera de Talamanca mountains. (Emmons, 1997)
Biogeographic Regions:
neotropical
.
Habitat
Orthogeomys heterodus tends to be found in clearings and agricultural areas. Its burrow consists of a central nest, food storage areas, excrement areas, and several paths to different foraging areas. (Emmons, 1997)
These animals are found in the following types of habitat:
tropical
; terrestrial
.
Terrestrial Biomes:
savanna or grassland
; mountains
.
Other:
agricultural
.
Physical Description
(14.15 to 22.53 oz)
Orthogeomys heterodus weighs between 402 and 670 g. The fur is thick and relatively long and is gray-brown on top and pale gray on the underside. Orthogeomys heterodus has several adaptations for fossorial living: such as long claws, reduced ears and eyes, and a flattened skull. (Hafner, 1991; Patton, 2001)
Some key physical features:
endothermic
; bilateral symmetry
.
Reproduction
Variable pocket gophers breed 1 to 4 times throughout the year.
Mating occurs throughout the year.
Although taltuzas are usually solitary, females will move into an adjacent male burrow to breed. (Patton, 2001)
Mating systems:
polygynous
.
Females are reproductively active after about 70 days. Females will breed from one to four times a year depending on environmental factors such as temperature, moisture, and vegetation quality. Gestation period is approximately 17 to 21 days. The young are born with eyes, ears, and mouth pouches closed. The eyes, ears, and pouches open after approximately 25 days. The young are then weaned at about 40 days. (Patton, 2001)
Key reproductive features:
iteroparous
; year-round breeding
; gonochoric/gonochoristic/dioecious (sexes separate); sexual
; viviparous
.
The female will care for the young for approximately 40 days before weaning them. The male plays no apparent role in the upbringing of the young. (Patton, 2001)
Parental investment:
female parental care
.
Lifespan/Longevity
No lifespan for Orthogeomys heterodus was specifically mentioned. However, members of the pocket gopher family generally live for only a year in the wild. (Patton, 2001)
Behavior
Orthogeomys heterodus is a solitary species, only sharing burrows during breeding season for a short period. Males tend to compete among themselves for burrows. Orthogeomys heterodus is most active in the morning hours but is also somewhat active day or night. Orthogeomys heterodus spends almost its entire life underground, unless it is foraging for food, or building a new burrow. (Patton, 2001)
Home Range
No information could be found on the extent of the variable pocket gopher's home range.
Key behaviors:
fossorial
; crepuscular
; motile
; sedentary
; solitary
.
Communication and Perception
No specific information was found on communication in variable pocket gophers. Because they are fossorial, the pocket gopher family has enhanced olfactory and tactile senses. Their vision and hearing are reduced because of the reduced size of their ears and eyes. (Patton, 2001)
Food Habits
Orthogeomys heterodus feeds on grasses, seeds, and forbs above ground, but most of its diet comes from below ground in the form of grass roots and tubers. (Patton, 2001)
Plant Foods:
leaves; roots and tubers; seeds, grains, and nuts.
Predation
- hawks (Accipitridae)
- snakes (Serpentes)
The main adaptation of the variable pocket gopher to avoid predation is its fossorial lifestyle. Hawks were the only predators mentioned for this species, although snakes are also likely to prey on them. (Patton, 2001)
Ecosystem Roles
Orthogeomys heterodus plays an important role in its ecosystem. These gophers aerate the soil by burrowing and disperse seeds when foraging. (Patton, 2001)
Key ways these animals impact their ecosystem:
disperses seeds; soil aeration
.
Economic Importance for Humans: Negative
Even though they are burrowing mammals, there was no mention of the variable pocket gopher being an agricultural nuisance because they live in a region that is not heavily farmed. However, other members of the genus Orthogeomys are considered agricultural pests.
Economic Importance for Humans: Positive
Humans benefit from the variable pocket gopher because this species increases soil porosity, thereby decreasing water runoff. (Patton, 2001)
Conservation Status
IUCN Red List: [link]:
Lower Risk - Near Threatened.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
Orthogeomys heterodus is listed on the IUCN red list due to habitat destruction and fragmentation. It is not listed on CITES or on the US ESA. ()
Contributors
Benjamin Klopf (author), University of Wisconsin-Stevens Point.
Chris Yahnke (editor), University of Wisconsin Stevens Point.

