Mustela africanatropical weasel

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Geographic Range

Amazon weasels (Mustela africana), also known as tropical weasels, are found in South America. Early scientific records regarding Amazon weasels inaccurately described their native range as Africa, which has led to some confusion about their scientific name. This species is believed to be native to Bolivia, Brazil, Colombia, Ecuador and Peru, but their range may also include the Amazon Basin in Brazil. (Emmons and Helgen, 2012; Mares and Schmidly, 1991)

Habitat

Amazon weasels have been found in humid areas, mainly in forests close to the banks of rivers. Along with a few other weasels, they have interdigital webbing, which may allow them to move through the water with more ease and could explain why they live so close to river banks. (Emmons and Helgen, 2012; Harding and Smith, 2009)

Physical Description

Amazon weasels are small animals, the area from the tip of their nose to their tail is less than 400 mm. Along with other weasels, Amazon weasels have short legs and long bodies. They are very similar in appearance to long-tailed weasels. Both are brown with a pale underside and neither have markings on their faces. The only visually apparent difference between them is the dark brown stripe that runs down the stomach of Amazon weasels. (Emmons, 1997)

  • Average length
    400 mm
    15.75 in

Reproduction

There is currently no mating information available specific to Amazon weasels, however; in general, female weasels have been known to mate with multiple males. (King and Powell, 2007)

Reproduction information on Amazon weasels is scarce. However, well-known weasel species, such as least weasels, have a 34 to 37 day gestation period. If food is plentiful, the females can quickly go into heat again after taking care of their first litter. The breeding season usually occurs during the warmer months. Offspring tend to become independent by about the fifth week. (King and Powell, 2007)

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual
  • viviparous
  • Breeding interval
    The breeding interval of Amazon weasels is not known.
  • Breeding season
    In general, weasels tend to breed during the warmer months.
  • Average gestation period
    34-37 days
  • Average time to independence
    5 weeks

In general, weasels do not spend much time caring for their offspring, providing only milk and some protection from predators. When food is plentiful, females are more focused on producing another litter than spending time with their previous litter. When there is not an overabundance of food, females will hunt and bring back prey for her offspring without help from the male. (King and Powell, 2007)

Lifespan/Longevity

Currently there is no specific information available regarding the lifespan of Amazon weasels because they are difficult to find and study. However, similar species, such as least weasels (Mustela nivalis) and long-tailed weasels (Mustela frenata), have a maximum captive lifespan of 9 years and 8 years, respectively. (Tacutu, et al., 2013a; Tacutu, et al., 2013b)

Behavior

Since Amazon weasels are hard to find and observe, there is no information available about their behavior. Other weasels, such as least weasels, stand on their hind legs, which allows them to observe their surroundings while foraging. Weasels also perform a dance behavior, which is said to distract prey so they do not expect an attack. (King and Powell, 2007; King and Powell, 2007)

Home Range

Currently there is no information available regarding the home range size of Amazon weasels.

Communication and Perception

There is currently very little information available regarding Amazon weasels since they are not very well known. However, in general, species in family Mustelidae exhibit enlarged scent glands. These glands are the source of a thick secretion known as musk. This scent is used for communication with other species and for defense purposes. Weasels also mark their home range to establish their territory. Amazon weasels may also have many different ways of communicating using vocalizations like other members of the weasel family. Weasels make a hissing sound when they feel threatened and a high-pitched sound when encountering a mate. Overall, weasels have a good sense of vision, hearing and smell. Many species of weasels depend mostly on hearing while hunting but also use their sense of smell. Weasels are also able to detect ultrasonic vocalizations. Their enhanced olfactory capabilities may be somewhat based on their muzzle construction. The placement of their eyes allows them to see in front and on the sides. They are able to see fairly well during the day and at night. (Erlinge and Sandell, 1988; Feldhamer, et al., 2007; King and Powell, 2007)

Food Habits

There is no information available on the foraging habits of Amazon weasels specifically, but the foraging behaviors other weasels have been documented. Weasels have an elaborate foraging process. They use all of their senses to find prey. Since their bodies are close to the ground, they tend to search under everything. Weasels usually search for prey for a short amount of time and rest before trying again. Weasels are able to carry their prey, which most likely means they take it back to their den. Weasels are considered small predators and they usually go after smaller prey including rabbits, squirrels, rats and voles. Weasels are good hunters and are able to go after and successfully take down prey bigger then themselves. (King and Powell, 2007)

  • Primary Diet
  • carnivore
    • eats terrestrial vertebrates
  • Animal Foods
  • mammals

Predation

Weasels are generally hunted by larger predators such as foxes, coyotes, owls and hawks. However, predators that do kill weasels may not eat them because they do not taste good. (King and Powell, 2007)

Ecosystem Roles

There is not sufficient information for Amazon weasels specifically. However, least weasels are found in temperate farmlands and forests and have been known to consume large amounts of small prey species in their territories. Least weasels can also carry skin parasites such as lice, ticks and mites. Amazon weasels likely encounter these same skin parasites. (King and Powell, 2007)

Economic Importance for Humans: Positive

Weasels kill many rodents and store the ones they don’t eat for later, this may help control the pest population. (King and Powell, 2007)

  • Positive Impacts
  • controls pest population

Economic Importance for Humans: Negative

Weasels sometimes raid birds' nests and eat the eggs and kill any adults that are present. Birders may have a very negative reaction to this type of predation. (King and Powell, 2007)

Conservation Status

Amazon weasels are listed as a 'Least Concern' species on the IUCN Redlist of Threatened Species because scientists believe they still have a sizable population living in the Amazonian forest. This weasel is also considered a Data Deficient species because scientists do not know much about them. It is not known whether this species can handle anthropogenic disturbances in the environment. (Emmons and Helgen, 2012)

Contributors

Ashley Mattice (author), Northern Michigan University, John Bruggink (editor), Northern Michigan University, Leila Siciliano Martina (editor), Animal Diversity Web Staff.

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

polyandrous

Referring to a mating system in which a female mates with several males during one breeding season (compare polygynous).

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"

tactile

uses touch to communicate

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

ultrasound

uses sound above the range of human hearing for either navigation or communication or both

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

Emmons, L. 1997. Neotropical Rainforest Mammals. Chicago, Illinois: University of Chicago Press.

Emmons, L., K. Helgen. 2012. "Mustela africana" (On-line). IUCN Redlist of Threatened Species. Accessed March 17, 2013 at www.iucnredlist.org.

Erlinge, S., M. Sandell. 1988. Coexistence of Stoat, Mustela erminea, and Weasel, M. nivalis: Social Dominance, Scent Communication, and Reciprocal Distribution. Nordic Society Oikos, 53: 242-246.

Feldhamer, G., L. Drickamer, S. Vessey, J. Merritt, C. Krajewski. 2007. Mammalogy. Baltimore, Maryland: The John Hopkins University Press.

Harding, L., F. Smith. 2009. Mustela or Vison? Evidence for the taxonomic status of the American mink and a distinct biogeographic radiation of American weasels. Molecular Phylogenetics and Evolution, 52: 632-642.

King, C., R. Powell. 2007. The Natural History of Weasels and Stoats. New York: Oxford University Press.

Mares, M., D. Schmidly. 1991. Latin American Mammalogy. History, Biodiversity, and Conservation. Publishing Division of the University: University of Oklahoma Press.

Tacutu, R., T. Craig, A. Budovsky, D. Wuttke, G. Lehmann, D. Taranukha, J. Costa, V. Fraifeld, J. de Magalhaes. 2013. "Mustela frenata" (On-line). AnAge: The Animal Ageing and Longevity Database. Accessed August 28, 2013 at http://genomics.senescence.info/species.

Tacutu, R., T. Craig, A. Budovsky, D. Wuttke, G. Lehmann, D. Taranukha, J. Costa, V. Fraifeld, J. de Magalhaes. 2013. "Mustela nivalis" (On-line). AnAge: The Animal Ageing and Longevity Database. Accessed August 28, 2013 at http://genomics.senescence.info/species.