Neamblysomus julianae (Meester, 1972)

Russell A. Mittermeier & Don E. Wilson, 2018, Chrysochloridae, Handbook of the Mammals of the World – Volume 8 Insectivores, Sloths and Colugos, Barcelona: Lynx Edicions, pp. 180-203 : 199-200

10.

Juliana’s Golden Mole

Neamblysomus julianae

French: Taupe-dorée de Juliana / German: Juliana-Goldmull / Spanish: Topo dorado de Juliana

Taxonomy. Amblysomus julianae Meester, 1972 ,

“Willows, Pretoria (25° 46’ S, 28° 20° E),” Gauteng Province, South Africa .

G. N. Bronner in 1995 reassigned juli- anae to Neamblysomus with N. gunningi . Consistent but subtle morphological differences (dentition and color), preliminary evidence for genetic partitioning, and no indication of gene flow between subpopulations are evident between Kruger National Park subpopulation and Modimolle and Bronberg Ridge subpopulations at extremes of its distribution, suggesting the need for additional investigation into potential cryptic species. Monotypic.

Distribution. NE South Africa, known only from three small, widely separated locations: Bronberg Ridge area in SE Pretoria, Gauteng Province (18 sites), Nylsvley Nature Reserve and surrounding farms on Nyl floodplain in Modimolle district,

Limpopo Province (9 sites), and near Pretoriuskop Camp, Fayi area (Macili and Machulwane), and Numbi Gate in SW Kruger National Park, Mpumalanga Province (4 sites).

Descriptive notes. Head-body 94-111 mm (males) and 92-111 mm (females), hindfoot 12-14 mm (males) and 9-14 mm (females); weight 21-46 g (males) and 23-29 g (females). Juliana’s Golden Mole is one of the smallest golden moles and has slender shape and foreclaws, relatively short skull (less than 24 mm) with wide braincase (width /length index 67-70%), and wide palate (width 30-32% of greatest skull length). M? of adults lack well-developed talonids, although present in some juveniles, but they are rudimentary and peg-like in shape. M, are variably present in specimens from Kruger National Park subpopulation and are small and peg-like if present; they are absent in specimens from Modimolle and Bronberg Ridge subpopulations. Dorsum of specimens from the Kruger National Park is reddish brown, venter is brown, and cheeks and muzzle are almost pure white. Dorsum of specimens from Modimolle and Bronberg Ridge is cinnamon-brown, becoming darker along mid-back and lighter toward flanks; venter is fawn-colored with reddish brown and gray underfur; and upper chest is tinted yellow. Upper parts of forelimbs, cheeks, throat, and muzzle are off-white, and short off-white bristles are present on upper parts of hindfeet. Robust forefeet have four digits and peg-like claws; first claw is very short, barely reaching point where second claw emerges from skin; and second claw is almost equal in length to third and largest claw (length 8-10 mm, basal width 3—4 mm). Fourth digit is stunted and knob-like. Membrane fuses four digits on hindfeet, each with thin curved claw; third claw is very long. Juliana’s Golden Mole closely resembles Gunning’s Golden Mole (N. gunningi ), but smaller size, paler pelage, narrower skull, and subtle chromosomal differences differentiate them. Absence of well-developed talonids on M* and much smaller body size and skull distinguish Juliana’s Golden Mole from the Fynbos Golden Mole (A. corriae ), the Hottentot Golden Mole (A. hottentotus ), the Drakensberg Golden Mole (A. longiceps), Meester’s Golden Mole (A. meester), the Highveld Golden Mole (A. septentrionalis ), and the Robust Golden Mole (A. robustus ). Juliana’s Golden Mole has broader skull, wider palate, and length of upper tooth row relative to palatal length than does Marley’s Golden Mole (A. marleyi ) but is smaller. Small and unspecialized mallei in middle ears of all species of Neamblysomus and Amblysomus are inside crania and represent typical mammalian form. Chromosomal complement has 2n = 30 and FN = 56, with highly conserved karyotype.

Habitat. Mostly open and closed savanna woodlands (bushveld), rocky grasslands, and scrublands varying from Mixed Sour Bushveld and Rocky Highveld Grassland in the Bronberg Ridge area through Clay Thorn Bushveld on the Nyl floodplain or Lowveld Sour Bushveld in the Pretoriuskop, Fayi, and Numbi Gate areas of Kruger National Park. Juliana’s Golden Moles thrive in highly transformed habitats such as urban and rural gardens, cultivated lands, and road edges where narrow passages of suitable soils provide alternative dispersal routes between isolated patches of prime habitats. They are weak diggers due to their small size and gracile foreclaws, and thus they favor soft sandy or loamy soils with tree or vegetation cover, often associated with rocky ridges.

Food and Feeding. Juliana’s Golden Moles are presumably insectivorous and carnivorous. A captive individual ate cockroaches, grasshoppers, beetles, other insects and their larvae, ground beef, and some earthworms but avoided snails and slugs; prey was mostly dragged into a burrow but sometimes eaten on the surface.

Breeding. GravidJuliana’s Golden Moles were found in winter (July-August) and summer (November—February), indicating an aseasonal polyestrous system. Litters have 1-2 young, and postnatal care is relatively long.

Activity patterns. On the Bronberg Ridge, Juliana’s Golden Moles were most active in late morning, late afternoon, and early evening. In Nylsvley Nature Reserve and surroundings, most activity was recorded in late morning (09:00-13:00 h, peak at 11:00 h) and evening (19:00-23:00 h, peak at 21:00 h).

Movements, Home range and Social organization. Burrow systems of Juliana’s Golden Moles consist of superficial foraging tunnels in upper soil layers (3-15 cm), visible as raised ridges or broken soil on the surface when fresh, and deeper permanent tunnels for resting, giving birth, and raising young. Some tunnels spiraled down 40-50 cm, but no chambers or nests were found. Foraging activity peaks in wet summer months, declining substantially in cold and dry winter months, although foraging continues in deeper tunnels. Subsurface foraging increases markedly a few days after rain when soil is moist and invertebrate prey is plentiful, but signs of these runways/furrows disappear on the surface during dry conditions. Juliana’s Golden Moles are locally common in suitable habitat. One individual that was radio-tracked for six consecutive days in Nylsvley Nature Reserve used 3964 m* and moved 303-8 m. Fluctuating body temperatures (T,) and shallow torpor were used when ambient temperatures (T) were high, with evidence of behavioral thermoregulation to reduce daily energy expenditure. The individual returned to the same cool area for resting during heat of the day and used passive heating to increase its T, in the early mornings when T, were rising. Adult Juliana’s Golden Moles are solitary except during breeding and when females raise young. Sexes are very territorial; brutal aggressive behavior toward conspecifics occurs in captivity.

Status and Conservation. Classified as Endangered on The IUCN Red List. The Bronberg Ridge subpopulation is classified as Critically Endangered. Conservation status of distinct lineages of Juliana’s Golden Moles in widely separated subpopulations might require revision after taxonomy is clarified. Total extent of occurrence is severely fragmented and totals ¢.747-5 km?* ¢.12-5 km* on Bronberg Ridge, ¢.718 km? on the Nyl floodplain, and c.17 km? in Kruger National Park. Estimated area of occupancy is only ¢.160 km? due to specialized habitat requirements, narrow habitat tolerances, and poor dispersal abilities. Currently, two subpopulations are protected in Kruger National Park and Nylsvley Nature Reserve. Only 1% of the Bronberg Ridge subpopulation falls in the Faerie Glen Nature Reserve. Major threats are habitat loss and fragmentation from urbanization (Bronberg Ridge and Modimolle), quartzite mining (Bronberg), infrastructure development (Bronberg, Modimolle, and Kruger National Park) and agriculture (Modimolle). Informing policy makers, developers, and the public are needed to bolster existing conservation activities and enhance protection of remaining suitable habitat. Minor threats include harassment by humans (e.g. gardeners and landowners) and predation (domestic pets, wild carnivores, snakes, and owls). Most captive Juliana’s Golden Moles die from dehydration within a few days after capture because as they refuse to eat, become sluggish, as if in a state of torpor, and then die.

Bibliography. Bronner (1990, 1995a, 1995b, 2013b), Bronner & Bennett (2005), Driver et al. (2012), Freitag & Van Jaarsveld (1997), Gilbert et al. (2008), Jackson, C.R. (2007), Jackson, C.R. & Robertson (2011), Jackson, C.R., Lubbe et al. (2008), Jackson, C.R., Maree et al. (2007), Jackson, C.R., Setsaas, Robertson & Bennett (2008), Jackson, C.R., Setsaas, Robertson, Scantlebury & Bennett (2009), Kuyper (1979), Maree (2015e, 2015f, 2017), Maree, Bennett & Bronner (2016), Maree, Bronner et al. (2003), Martin (2015), Meester (1972), Meester et al. (1986), Skinner & Chimimba (2005).

Figures

0. Yellow Golden Mole (Calcochloris obtusirostris), 1. Hottentot Golden Mole (Amblysomus hottentotus), 2. Robust Golden Mole (Amblysomus robustus), 3. Highveld Golden Mole (Amblysomus septentrionalis), 4. Marley’s Golden Mole (Amblysomus marleyi), 5. Fynbos Golden Mole (Amblysomus corriae), 7. Congo Golden Mole (Huetia leucorhina), 8. Somali Golden Mole (Huetia tytonis), 9. Gunning’s Golden Mole (Neamblysomus gunningi), 10. Juliana’s Golden Mole (Neamblysomus julianae), 11. Arend’s Golden Mole (Carpitalpa arendsi), 12. Sclater’s Golden Mole (Chlorotalpa sclateri), 13. Duthie’s Golden Mole (Chlorotalpa duthieae), 14. Stuhlmann’s Golden Mole (Chrysochloris stuhlmanni), 15. Cape Golden Mole (Chrysochloris asiatica), 16. Visagie’s Golden Mole (Chrysochloris visagier), 17. Rough-haired Golden Mole (Chrysospalax villosa), 18. Giant Golden Mole (Chrysospalax trevelyani), 19. De Winton’s Golden Mole (Cryptochloris wintoni), 20. Van Zyl's Golden Mole (Cryptochloris zyli), 21. Grant's Golden Mole (Eremitalpa grant)

Distribution. NE South Africa, known only from three small, widely separated locations: Bronberg Ridge area in SE Pretoria, Gauteng Province (18 sites), Nylsvley Nature Reserve and surrounding farms on Nyl floodplain in Modimolle district, Limpopo Province (9 sites), and near Pretoriuskop Camp, Fayi area (Macili and Machulwane), and Numbi Gate in SW Kruger National Park, Mpumalanga Province (4 sites).