This species occurs in Gran Chaco of Paraguay and southeast Bolivia, and possibly northeast Argentina though this needs confirmation (Woods and Kilpatrick, 2005). It is found at around 175 to 400 m. According to Bidau and Lessa the species does not occur in Argentina (pers. comm.).

Conover's tuco-tucos are endemic to the Chaco in both Bolivia and Paraguay, occurring at an altitude of 250 m. They are found from 20 degrees S to 23 degrees S and 60 degrees to 63 degrees. This species has one of the smallest ranges of the thirty-eight currently recognized species in the genus Ctenomys. As a genus, tuco-tucos are considered to exhibit considerable ecologic plasticity. The fossil record dates back to the Pliocene in this range. Currently, it is thought that a vicariant event cannot explain present distributions.

Biogeographic Regions: neotropical (Native )

Conover's tuco-tucos are large for this genus, and can reach weights in excess of 1 kg. This species strongly resembles North American pocket gophers (Geomyidae). As a fossorial species, they have a robust and cylindrical body, large head, short and sparsely haired tail, and short, muscular neck and forelimbs. The eyes are medium-sized and positioned to enable these animals to look out of the burrow without exposing the whole body. The external ears are very small, another adapation to fossorial living. The forelimbs are slightly shorter than the hindlimbs, and all digits have claws. The claws on the forefeet are the longest, and are used for loosening packed earth.

The skin seems loosely applied to the body, possibly making it easier for these animals to turn around in narrow burrows. The soles of the hind feet are equipped with comb-like bristles, composed of hair fringes, and are used to groom dirt from the fur.

Conover's tuco-tucos have a tan dorsum with a faint mid-dorsal line. The top of the head is a gray-brown, lightening to flecking on the back of the head. The cheeks are a brownish-yellow, and touches of white surround the mouth and chin. The ventrum is also a light yellow. Generally, the fur is thick and long.

Like other Ctenomys, Conover's tuco-tucos have a broad, flattened skull. They lack a sagittal crest but have prominent ridges along the parietals. The zygomatic arches are strongly bowed outward, and the jugal bone does not contact the lacrimal bone. They are equipped with large auditory bullae and large paroccipital processes. The dental formula is 1/1, 0/0, 1/1, 3/3 = 20. Ctenomys concoveri is noted for prominent broad and heavy proodont incisors; each of the anterior surfaces has an inner and outer wide lateral groove and three shallow, narrow median grooves. These incisors, covered by a bright orange enamel, are used to gnaw roots when digging. This species also has kidney-shaped hypsodont molars for chewing vegetation, with the last molar being reduced.

Although males are reported to be larger than females, the following measurements apply to both sexes. Total length of these animals ranges from 338 to 442 mm (average = 403.3 mm); head and body length varies from 245 to 328 mm (average = 293.3 mm); tail length ranges between 93 and 137 mm (average = 110.0 mm); hindfoot length is between 52 and 62 mm (average = 58.0 mm); and ear length (notch to tip) is between 10 and 16 mm (average = 13.4 mm). The average adult weighs about 900 grams.

Average mass: 0.900 kg.

Range length: 338 to 442 mm.

Average length: 403.3 mm.

Sexual Dimorphism: male larger

Habitat and Ecology

Systems

• Terrestrial

Ctenomys concoveri is a primarily fossorial species. Conover's tuco-tucos are found in areas of sandy or loamy soils. In the Paraguayan Chaco, the landscape is primarily savannah grassland and shrub forest. The shrub forest is characterized by thorny bushes, shrubs, and cacti, with scattered trees up to 13 m high. The dominant species in the forest include Prosopis ruscifolia, a thorny legume, and Opuntia sp. Much of the grassland is under severe agricultural pressure.

Average elevation: 250 m.

Habitat Regions: tropical ; terrestrial

Terrestrial Biomes: savanna or grassland ; scrub forest

Other Habitat Features: agricultural

Ctenomys conoveri is entirely vegetarian, feeding on roots, stems, and grasses of the Chacoan region. Its preference for plant material makes it a pest because of damage to cultivated crops--much like the North American pocket gophers (Geomyidae). It builds separate food burrows for food storing.

Plant Foods: leaves; roots and tubers

Foraging Behavior: stores or caches food

Primary Diet: herbivore (Folivore )

The strong foraging habits of Conover's tuco-tucos have been crucial to maintaining habitat openings and providing regrowth forage for wild and domestic ungulates; They also aerate the soil through their burrowing behaviors. They present vital habitat via burrows to many species of mammals, lizards, toads, invertebrates, and, at times, birds. They are also a prey species for a viariety of raptors and carnivorous mammals.

Ecosystem Impact: creates habitat; soil aeration

As rodents in the Chacoan ecosystem, C. conoveri serve as an important food item for many predators, including owls, diurnal raptors, carnivorous mammals such as the maned wolf and the pampas fox, and feral cats. The males are aposematic, meaning that they elicit alarm calls as an antipredatory adaptation; additionally, the placement of the eyes allows these animals to look out of their burrows without exposing the rest of the body.

Known Predators:

• great horned owls (Bubo virginianus)
• pampas foxes (Lycalopex gymnocercus)
• diurnal raptors (Falco)
• feral cats (Felis silvestris)

Anti-predator Adaptations: aposematic

Ctenomys conoveri is prey of:
Buteo
Bubo virginianus
Felis silvestris
Pseudalopex gymnocercus

This list may not be complete but is based on published studies.

Conover's tuco-tucos, like all other tuco-tucos, earned their common name in part for the alarm call emitted by males due to territoriality or fear. The calls last 10 to 20 seconds, beginning at a slow rate and increasing throughout. In reality, the sound is more of a "tloc tloc tloc" than a "tuco tuco."

Although details are not available, it is also likely that these animals communicate with one another through visual signaling. They also are likely to have tactile communication, especially between mates, parents and offspring, and rivals.

Communication Channels: visual ; tactile ; acoustic

Perception Channels: visual ; acoustic

The mean lifespan in the wild for Conover's tuco-tucos is probably less than three years, as they are an important prey species in the Chaco.

Average lifespan

Status: wild: 3 years.

Observations: Little is known about the longevity of these animals, but one specimen lived 2 years in captivity (Richard Weigl 2005).

Sexual size dimorphism and enlarged testes are observed in this and other Ctenomys species, suggesting polygynyis the primary mating system.

Mating System: polygynous

Female C. conoveri are monoestrus, bearing one litter per year. They construct lined nest chambers, typically below the level of the main tunnel.

Gestation length is not available for this species, but other species in the genus Ctenomys range from about 102 to 120 days. Litters range in size from 1 to 7 young. Young of this genus may be born at varying levels of altriciality. Some young are precocious, coming out fully furred and looking like miniature adults. Others are only slightly furry at birth, and may have their eyes closed. The condition of C. concoveri at birth has not been reported.

Young of Ctenomys talarum are reportedly able to fend for themselves by about 10 days of age, even though they are not the most precocious members of their genus at birth. Nursing is said to continue for 5 weeks, and sexual maturity is reached sometime around 8 months of age, for both males and females. It is likely that C. concoveri is similar.

Breeding interval: Conover's tuco-tuco breeds once a year.

Breeding season: The exact breeding season for these animals has not been reported.

Average gestation period: 203 days.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous

Ctenomys conoveri has altricial young. The females are generally responsible for care and feeding of the young. Male parental care has not been reported.

Parental Investment: no parental involvement; altricial ; pre-fertilization (Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Protecting: Female)

Conservation efforts for this taxa are frought with taxanomic dispute and disregard for them by ranchers. Differentiation of the genus Ctenomys was historically based on pelage and morphological differences; it is now shifting to DNA and molecular sequencing, due to their substantial chromosomal variation. This species is highly understudied and misunderstood by local inhabitants. They are often persecuted by people, and desire and funding to study this species is often low. Conover's tuco tucos are not listed by CITES or IUCN.

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

Population

Population Trend

Major Threats

Conservation Actions

Similar to the prairie dog controversy in the American west, Conover's tuco-tucos create burrows that damage agricultural and graze areas. Additionally, as herbivores, they have done a lot of agricultural damage through their preference for roots, stems, and grasses. Many people believe their burrows result in injury and death for livestock, while others feel their foraging habits outcompete domestic livestock.

Negative Impacts: crop pest

Although often unrecognized, Conover's tuco-tucos do provide positive services for humans. Through their burrowing habits, they maintain wildlife habitat, which assists resource managers and ecotourists. Their excrement also provides a fertilizer for the soil and crops. Similarly, their burrowing habits may aid agriculturists in aerating and maintaining the soil. Their foraging habits oftentimes stimulate faster plant growth rather than halting it. More research is being conducted on them as interest in the Chacoan ecosystem and Ctenomys species continues to grow. They are also becoming more commonly listed on many pet trade web pages.

Positive Impacts: pet trade