Calcochloris obtusirostris (Peters, 1851)

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 : 197-198

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Yellow Golden Mole

Calcochloris obtusirostris

French: Taupe-dorée du Mozambique / German: Gelber Goldmull / Spanish: Topo dorado amarillo

Taxonomy. Chrysochloris obtusirostris Pe- ters, 1851,

Inhambane, coastal Mozam- bique.

The species obtusirostris has been vari- ably assigned to Chrysochloris , Amblyso- mus, or Calcochloris . The name Calc- ochloris predates Chrysotricha, commonly used for this genus until 1953, and also Huetia . G. N. Bronner in 1995 placed C. obtusirostris in the subgenus Calcochloris , and C. leucorhinus in the subgenus Huetia , which previously included C. tytonis . Huetia has since been elevated to full generic status, leaving Calcochloris to include only C. obtusirostris . Three subspecies recognized.

Subspecies and Distribution. C. o. obtusirostris Peters, 1851 — Save and Changane river systems of C & S Mozambique, with marginal intrusion into SE Zimbabwe and Limpopo Province of NE South Africa. C. o. chrysillus Thomas & Schwann, 1905 — from Maputo, S Mozambique, S to Maputaland, NE KwaZulu-Natal, E South Africa. C. o. limpopoensis Roberts, 1946 — from around mouth of Limpopo River S to coastal plains near Maputo, SE Mozambique.

Descriptive notes. Head-body 88-110 mm (males) and 82-110 mm (females), hindfoot 10-13 mm (males) and 9-14 mm (females); weight 25-33 g (males) and 15-37 g (females). The Yellow Golden Mole is among the smallest of the southern African species of golden moles, with pronounced sexual dimorphism in size (males are larger and heavier). Subspecies are discriminated by subtle morphological differences but intergrade in size, making distinguishing among them difficult. Yellow Golden Moles are easily distinguished by their yellow-orange venter, which is grayish in all other chrysochlorids. Dorsum can vary considerably from light yellow-orange through orange, bright reddish brown, to dull brown and dark brown; this variation can be attributed to pelage becoming darker and more grizzled with time between molts. Muzzle, throat, and chin are buffy white, and unique foliaceous projections occur on nostrils. Skull is short with broad palate, zygomatic arches lack broad plates sweeping backward, mallei of inner ears are relatively small and unspecialized, and no external bullae are visible. M? are absent, P1 are molariform (tricuspid), lower

molars lack talonids, and canines are bicuspid. Claws on forefeet are slender and flattened, claw on third digit is largest, claws on first and second digits are similar in length, and fourth digit is small with short claw. Chromosomal complement has 2n = 28 and FN = 56.

Habitat. Mosaics of southern African subtropical forest and savanna woodland with light sandy soils, sandy alluvium, and coastal sand dunes. Nominotypical subspecies obtusirostris inhabits Acacia and Colophospermum mopane (both Fabaceae ) savanna (thornveld woodland) and lowveld and Nyadu Sandveld grasslands; subspecies limpopoensis occurs in miombo savanna (woodland); and subspecies chrysillus occurs in Coastal Bushveld—Grassland and Subhumid Lowveld Bushveld. Yellow Golden Moles also thrive in rural and urban gardens and occur in cultivated lands, pastures, and commercial forestry plantations.

Food and Feeding. The Yellow Golden Mole is predominantly insectivorous. It responds to vibrations produced by live insect prey including beetle larvae, termites, grasshoppers, flies, moths, and small lizards.

Breeding. Breeding of the Yellow Golden Mole can be aseasonal, but breeding individuals have been recorded in October and January, suggesting thatit takes place primarily in wet summer months. Littersize is two.

Activity patterns. Yellow Golden Moles are strictly fossorial and predominantly nocturnal, particularly active after rains. They can move at surprising speed in and out of sand in porpoise-like fashion. They construct shallow subsurface foraging tunnels and deeper (up to 20 cm) tunnels that lead to nesting chambers, often among tree roots. Deep tunnels are well established and maintained; subsurface foraging tunnels can be temporary and can extend up to 50 m from nesting areas. Yellow Golden Moles are highly sensitive to disturbance, and they are known to burrow downward in a spiraling pattern when disturbed in subsurface tunnels.

Movements, Home range and Social organization. Adult Yellow Golden Moles are solitary and have been recorded to move distances of up to 50 m between nest chambers and foraging areas. They emit high-pitched squeaks when agitated.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Yellow Golden Mole is generally widespread and locally common in suitable sandy habitats. Parts of distributions of subspecies obtusirostris and chrysillus occur in protected areas, but this is not the case for limpopoensis, which has not been recorded in any conservation area.

Bibliography. Asher et al. (2010), Bronner (1995a, 2013b), Maree (2015a).

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)

Subspecies and Distribution. C. o. obtusirostris Peters, 1851 — Save and Changane river systems of C & S Mozambique, with marginal intrusion into SE Zimbabwe and Limpopo Province of NE South Africa. C. o. chrysillus Thomas & Schwann, 1905 — from Maputo, S Mozambique, S to Maputaland, NE KwaZulu-Natal, E South Africa. C. o. limpopoensis Roberts, 1946 — from around mouth of Limpopo River S to coastal plains near Maputo, SE Mozambique.