AnimaliaHighest rank in taxonomy. Groups all life into domains: Animalia, Plantae, Fungi, etc.IUCN LCInternational Union for Conservation of Nature — the world authority on species extinction risk, using standardized criteria. — Least Concern — widespread and abundant; not at immediate risk of extinction.In ProgressCurrent stage of this record in the editorial review workflow. Recent Sighting
Heteromys desmarestianus
Desmarest's Spiny Pocket Mouse
Gray, 1868
Detailed Texts Multi-lang
Desmarest's spiny pocket mouse (Heteromys desmarestianus) is a small forest rodent with very distinct anatomical features. Its name comes from the fact that the fur on its back and sides is not soft; rather, it is composed of a mixture of fine hairs and stiff, flat, grooved bristles that resemble small spines, ranging in color from dark brown to blackish. In sharp contrast, its belly and feet are pure white. It has rounded ears, large, bulging eyes adapted for the dark, and a scaly tail that is usually longer than its own body. The most notable adaptation of its family is the 'cheek pouches' (abazones), two external fur-lined pockets extending from the cheeks to the shoulders, which it uses like backpacks to transport seeds.
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TaxonomyBiological classification ranks placing this species within the tree of life, from Kingdom down to Genus.
PhylumRank below Kingdom. Groups organisms sharing a fundamental body plan (e.g., Chordata = vertebrates and some invertebrates).Chordata
ClassRank below Phylum. Subdivides by structural traits (e.g., Mammalia, Aves, Reptilia, Insecta).Mammalia
OrderRank below Class. Groups related families sharing common ancestry (e.g., Carnivora, Primates).Rodentia
FamilyRank below Order. Groups closely related genera (e.g., Felidae = cats, Canidae = dogs).Heteromyidae
GenusRank just above Species. The first word in the two-part binomial scientific name.Heteromys
Taxonomic AuthorityThe scientist who first formally described and published this species, followed by the year of publication.Gray, 1868
Record Completeness
95%Coming soon
Ecology & StatusHow this species lives: habitat preferences, diet, behavior, population status, and role in its ecosystem.
OriginWhether the species is native (evolved here), endemic (found only here), or introduced by human activity.
Native
Population TrendDirection of change in population size over time: increasing, stable, decreasing, or unknown.
Stable
Breeding SeasonTime of year when this species typically reproduces or flowers.
Year Round
Trophic RolePosition in the food chain: producer, herbivore, carnivore, omnivore, decomposer, or parasite.
Herbivore
Recent SightingsWhether this species has been observed in the wild in Costa Rica within recent years.
Yes
Habitat SummaryOverview of the specific ecosystems and environments where this species is found in Costa Rica. Multi-lang
It is a dominant forest floor inhabitant in tropical ecosystems. It prefers primary wet forests, cloud forests, and mature secondary forests with an abundant canopy and dense understory. It rarely ventures into open areas or pastures. It requires soils with abundant wet leaf litter and fallen logs where it can build its underground burrow networks. In Costa Rica, it is ubiquitous in forest reserves from sea level up to 2,400 meters in altitude (such as La Selva Biological Station and Monteverde).BehaviourDaily activity patterns, movement, territory use, foraging style, and seasonal behavioral changes. Multi-lang
It is a strictly nocturnal, terrestrial, and solitary animal. It spends its nights patrolling the forest floor through established corridors under leaf litter and logs, moving at a fast pace or via small nervous hops. It dedicates most of its time to searching, transporting, and burying seeds, palm nuts (like Welfia or Socratea), and fallen fruits. It aggressively defends its seed caches from other rodents. During the day, it sleeps in burrows with multiple entrances that it digs in the soft earth.Social ActivitySocial structure: whether the species is solitary, paired, or colonial; hierarchy and communication. Multi-lang
Strictly solitary and highly territorial. Adults actively avoid each other and can engage in noisy fights if they find themselves competing for the same seed patch.Feeding GuildWhat the species eats, how it forages or hunts, and its role as a consumer in the food web. Multi-lang
Granivore / Frugivore (Occasionally insectivore).Trophic Chain DetailsSpecific interactions in local food webs: prey species, predators, competitors, and scavengers. Multi-lang
Primary consumer (Granivore/Frugivore) and important seed disperser. Due to its immense abundance in healthy jungles, it is the fundamental base prey for almost all terrestrial forest floor predators: venomous snakes (fer-de-lance, palm pitvipers), owls, small felines (margay, ocelot), and mesopredators like opossums, coatis, and weasels.Reproductive BehaviourMating strategies, courtship displays, nesting or spawning behavior, and parental care. Multi-lang
It can breed year-round, although reproductive peaks usually synchronize with seasons of highest fruit and seed production in the forest (generally at the beginning of the rainy season or end of the dry season). After a short gestation of about 28 days, the female gives birth to a small litter (2 to 5 pups) in a deep, dry nest within her burrow. They are born spineless, blind, and deaf, but develop rapidly to leave the nest within a few weeks.Physical Measures
Length (cm)
12.0 - 16.0 cm
Weight (Grams)
50 g - 85 g
Offspring per cycleTypical number of young (live births, eggs, or seeds) produced by one adult in a single reproductive event or breeding season.2 - 5
Sexual DimorphismObservable physical differences between males and females of the same species (e.g., size, coloration, features).No
Lifespan
Sexual MaturityAge at which the individual becomes capable of reproducing for the first time.
3 - 6 Months
Gestation / IncubationDuration from fertilization to birth (mammals) or to hatching (egg-laying species).
27 - 28
Lifespan EstimatedExpected duration of life from birth to natural death under wild conditions.
Males1 - 3 Years
Females1 - 3 Years
Evolutionary AdaptationsInherited traits and behaviors that improve the species' survival and reproduction in its specific environment. Multi-lang
External Cheek Pouches (Seed Pockets): Unlike hamsters, the cheek pouches of this mouse are fur-lined and open outside the mouth. This allows it to collect, store, and transport dry seeds (or even small thorny fruits) without injuring its mouth, swallowing dirt, or wasting saliva.
Spiny Defensive Fur: The stiff, spiny hair on the back not only deters some small predators or makes it difficult for snakes to grab them, but it also serves to repel water and prevent the constant moisture of the tropical forest from cooling their body.
Main ThreatsDocumented pressures reducing the population: habitat loss, hunting, disease, climate change, and invasive species. Multi-lang
Fragmentation and Edge Effect: They are very sensitive to the loss of soil moisture and the entry of intense light. Forest fragmentation dries out the leaf litter and drastically reduces their food sources and survival.
Domestic Predators: In areas where the forest borders rural or agricultural zones, feral domestic cats exert enormous hunting pressure on their populations.
Interesting FactsSurprising or notable facts that highlight what makes this species unique or ecologically important. Multi-lang
Scatter-hoarding: They collect many more seeds than they can eat and bury them in thousands of small, shallow caches throughout their territory for times of scarcity. They forget or die before eating a large part of these seeds, allowing them to germinate. They are literally the gardeners planting the palms and trees of the future forest!
Impressive Carrying Capacity: Despite their tiny size (about 70 grams), they can fill their cheek pouches until their faces are deformed, carrying dozens of heavy seeds in a single trip, sometimes carrying over 15% of their own body weight in their cheeks!