Neamblysomus julianaeJuliana's golden mole

Geographic Range

Juliana's golden moles are native and endemic to South Africa. They have a limited range surrounding Pretoria, and has thus far been found in only three regions; Bronberg Ridge, Nylsvley nature reserve and Kruger National park (Jackson, 2011). It should be noted that the recorded distribution may be due to lack of data, and the range of Juliana's golden moles may be wider. (Jackson and Robertson, 2011)

Habitat

Juliana's golden moles are fossorial in bushveld regions of South Africa, and are often found near large ridges (Jackson, 2008). They have a patchy distribution and small range due to their habitat specificity, only occurring in areas where the soil is sandy and of different particle sizes. These properties give less resistance for tunneling and reduce susceptibility to compaction (Jackson, 2008). (Jackson, et al., 2008a; Jackson, et al., 2008b)

Physical Description

All golden moles are highly autapomorphous, and accordingly Juliana's golden moles share similar morphological traits with other golden moles. These include an absence of an external scrotum, a cloaca, three long bones in the forearms and bones around the occipital area of the skull called tabulars. Juliana's golden moles are unlike other Golden moles in that it does not have a greatly enlarged middle ear ossicle, or malleus, although it is still proportionally larger than that of other mammals (Asher et al, 2010). They are also smaller than other members of their family, with an average length of 100 mm and weight of 35 g. (Asher, et al., 2010)

Juliana's golden moles are adapted to a fossorial life style, with one of their four claws on their forefeet being large and well developed, while their hind feet are webbed for pushing sand and soil behind and retain five toes. They have a hard keratinous nose and streamlined, torpedo like body which aid them in moving through sediment. The eyes and ears are not visible but are instead covered in fur, making the mole impervious to sand and soil (Stuart, 2001). Their fur itself is a light brown, getting lighter around the flanks and nose (Jackson, 2007). (Jackson, 2007; Stuart and Stuart, 2001)

Juliana's golden moles have a dental formula of 3/3, 1/1, 3/2, 2/2,and their molars are zalambodont, although the population in Kruger national park has a third lower molar, which has led some to believe they are a seperate sub-population (Bronner, 1990). They have a wedge shaped skull and disproportionately long dentary bones which help to give it its torpedo like shape (Asher and Avery, 2010). (Asher and Avery, 2010; Bronner, 1990)

  • Sexual Dimorphism
  • male larger
  • Range mass
    21 to 46 g
    0.74 to 1.62 oz
  • Average mass
    35 g
    1.23 oz
  • Average length
    100 mm
    3.94 in

Reproduction

Little is known about mating habits, but in all other studied Golden moles males often force females to mate. The larger size in males may suggest that this is also the case for Juliana’s golden mole. (Mills and Lex, 1997)

Juliana’s golden moles are aseasonal in terms of reproduction, but higher rates of breeding occur in the rainy season. Low rates of reproduction have been observed. Their gestation period is not known. (Schütze, 2002)

  • Breeding interval
    Although reproduction is aseasonal, it seems to occur more frequently in the wet season.
  • Breeding season
    Mating may occur throughout the year.
  • Range number of offspring
    1 to 2

Juliana’s golden moles have 1 to 2 cubs at a time. Young are born naked and atricial, and are weaned by the mother in bare nesting chambers that are linked to tunnel networks. Once weaned the cubs are forced from the burrow and must become independent. (Mills and Lex, 1997; Schütze, 2002)

Lifespan/Longevity

The life span of Juliana’s golden moles is not known.

Behavior

Juliana’s golden mole are solitary and territorial. Moving the sand by pushing it down their flanks, or "sand swimming", they forage close to the surface in the afternoon and at night. Nearer to the surface they make temporary tunnels that collapse behind them as they move, but deeper in the soils stable tunnel networks and burrows are made. After rain activity increases, perhaps because it is easier to move through substrate, and during dry seasons activity decreases or stops. These moles appear to surface more in drier weather (Skinner and Chimimba, 2005). (Skinner and Chimimba, 2005)

Juliana’s golden moles can go into short daily torpor to avoid extreme temperatures. Behavioral thermoregulation has also been observed in these moles. They move toward the surface in the early morning as temperatures rise, and on days where temperatures reach and exceed 38°C they move underground to a shaded area that remains cooler. Through activity like this Juliana’s golden moles maintain body temperature at 31.50 °C where ambient soil temperature is 28.97 °C (Jackson et al, 2009). (Jackson, et al., 2009)

Home Range

The home range is limited by the soil type; unlike members of its family, Juliana’s golden moles are not particularly strong and cannot dig through compacted soils. This limits their range to sandy soils (Jackson et al., 2008). (Jackson, et al., 2008b)

Communication and Perception

Little is known about the means of communication in Juliana’s golden moles. As they cannot see, visual communication can be ruled out. The slightly enlarged middle ear ossicle is thought to be used to detect vibrations from prey, as the moles move very directly towards prey on the surface underground. It is possible that they can also utilize their sensitivity toward vibrations as a means of communication, and foot stomping to cause vibrations has been observed in other closely related species. Many other closely related species use of high pitched chirrups during courtship. (Mills and Lex, 1997)

Food Habits

Juliana’s golden moles eat earthworms, but are primarily insectivores. They will eat a variety of insects including many grasshoppers and beetle larvae. The mainstay of their diet are invertebrates captured underground. However, they may capture their prey above ground and consumes it below, holding it in its forefeet whilst they feeds (Skinner and Chimimba, 2005. Schütze, 2002) Many closely related species disable insects with a bite and caching them in burrows. (Mills and Lex, 1997; Schütze, 2002; Skinner and Chimimba, 2005)

  • Animal Foods
  • insects
  • terrestrial worms

Predation

Moles are subject to predation primarily from birds of prey and domestic pets (Schütze, 2002) (Schütze, 2002)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Although the ecological roles of Juliana’s golden moles are not fully understood, they are important, like many fossorial mammals, in biopedturbation. The digging and maintenance of tunnels and burrows increase soil porosity which leads to higher rates of aeration, water drainage and nutrient cycling. Chambers in which the mole defecates add small areas rich in nutrients (Walter, 1999). These roles are important for vegetation, especially in dry, nutriet poor soils. Juliana’s golden moles may also be important in controlling insect populations, as their diets are largely insects and their larvae. (Whitford and Fenton, 1999)

Economic Importance for Humans: Positive

It is likely that Juliana’s golden moles are important in the maintenance of healthy soils, which is important for agriculture (although agricultural practices are a major threat to the mole). They may also be important in pest control. This benefits humans gardening endeavors and Juliana’s golden moles can help protect plants from insect pests.

  • Positive Impacts
  • controls pest population

Economic Importance for Humans: Negative

There appear to be no negative effects implicated by the moles toward humans.

Conservation Status

Juliana’s golden moles are classified as vulnerable on the IUCN Red List and they are listed as the third most endangered animal in South Africa. Since their discovery in 1972, there has been an estimated 80% drop in their population. They are found in only three sub-populations with little genetic mixing, so the mole is highly susceptible to environmental changes. Habitat is under threat from urban development and agricultural practices (IUCN Red List, Bronner, 2012). Soil compaction can significantly hinder the moles movement and destroy burrows. Global warming patterns predict higher temperatures and lower levels of precipitation in the range of Juliana’s golden moles, which would cause soils to dry and harden, essentially immobilizing them. (Bronner, 2012)

Contributors

Elliot Taylor (author), University of Alaska Fairbanks, Link Olson (editor), University of Alaska Fairbanks, Laura Podzikowski (editor), Special Projects.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

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

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

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

fossorial

Referring to a burrowing life-style or behavior, specialized for digging or burrowing.

insectivore

An animal that eats mainly insects or spiders.

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.

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

sexual

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

soil aeration

digs and breaks up soil so air and water can get in

stores or caches food

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

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

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 savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

vibrations

movements of a hard surface that are produced by animals as signals to others

viviparous

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

year-round breeding

breeding takes place throughout the year

References

Asher, R., M. Avery. 2010. NEW GOLDEN MOLES (AFROTHERIA, CHRYSOCHLORIDAE) FROM THE EARLY PLIOCENE OF SOUTH AFRICA. Palaeontologia Electronica, Vol.13/issue.1: 5-7.

Asher, R., S. Maree, G. Bronner, N. Bennett. 2010. A phylogenetic estimate for golden moles (Mammalia, Afrotheria, Chrysochloridae). BMC Evolutionary Biology, 10: 1-3.

Bronner, G. 2012. "

Neamblysomus julianae
" (On-line). Accessed November 16, 2012 at http://www.iucnredlist.org/details/1089/0.

Bronner, G. 1990. New distribution records for four mammal species, with notes on their taxonomy and ecology. Koedoe, Vol.33/issue.2: 1-7.

Jackson, C. 2007. The Ecology and Conservation of Juliana's Golden Mole (Neamblysomus julianae). University of Pretoria: 5-10. Accessed November 16, 2012 at http://upetd.up.ac.za/thesis/available/etd-07282008-145115/unrestricted/dissertation.pdf#page=36.

Jackson, C., N. Lubbe, M. Robertson, J. Van De Waals, T. Setsaas, N. Bennett. 2008. Soil properties and the distribution of the endangered Juliana's golden mole. Journal of Zoology, Volume 274/Issue 1: 13, 15-16. Accessed November 15, 2012 at http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.2007.00351.x/pdf.

Jackson, C., T. Setsaas, M. Robertson, M. Scantlebury, M. Bennett. 2009. Insights into torpor and behavioural thermoregulation of the endangered Juliana's golden mole. Journal of Zoology, Volume 278/Issue 4: 299-307. Accessed November 16, 2012 at http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.2009.00575.x/full.

Jackson, C., H. Trine, P. Mark, C. Nigel. 2008. Ecological variables governing habitat suitability and the distribution of the endangered Juliana's golden mole.. African zoology., Volume 43/Issue 2: 246-247. Accessed November 15, 2012 at http://www.bioone.org/doi/pdf/10.3377/1562-7020-43.2.245.

Jackson, C., M. Robertson. 2011. Predicting the potential distribution of an endangered cryptic subterranean mammal from few occurence records.. Journal for Nature Conservation, Volume 19/Issue 2: 87-94. Accessed November 16, 2012 at http://www.sciencedirect.com/science/article/pii/S1617138110000531.

Mills, G., H. Lex. 1997. The complete book of Souther African mammals. Johnic Comunications LTD: Struik.

Schütze, H. 2002. Field Guide to Mammals of the Kruger National Park. 80 Mckenzie Street, Cape Town 8001, South Africa: Struik.

Skinner, J., C. Chimimba. 2005. The Mammals of the Southern African Sub-region. The Water Club, Beach road, Granger bay, Cape Town 8005, South Africa: Cambridge University Press.

Stuart, C., T. Stuart. 2001. Field Guide to Mammals of Southern Africa. Johnic Comunications LTD: New Holland Publishing.

Whitford, W., K. Fenton. 1999. Biopedturbation by mammals in deserts: a review. Journal of Arid Environments, Vol.41: 203-230.