Marshall's pygmy chameleon

Marshall's pygmy chameleon
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Iguania
Family: Chamaeleonidae
Genus: Rhampholeon
Species:
R. marshalli
Binomial name
Rhampholeon marshalli
Boulenger, 1906

Marshall's pygmy chameleon (Rhampholeon marshalli), also called commonly Marshall's leaf chameleon, Marshall's dwarf chameleon, and Marshall's stumptail chameleon, is a species of lizard in the family Chamaeleonidae. The species is native to the forests of Zimbabwe and Mozambique in Africa. It grows to a snout-to-vent length (SVL) of 3.5–7.5 cm (1.4–3.0 in) and feeds on insects. When staying still, it resembles a leaf on a branch.

Etymology

[edit]

The specific name, marshalli, is in honor of British entomologist Guy Anstruther Knox Marshall, who collected the holotype.[2]

Identification

[edit]

Marshall's leaf chameleon is unmistakable. It is the only such tiny chameleon in its range (sympatric with Chamaeleo dilepis quilensis, the flap-necked chameleon to a degree). This is a tiny species of 3.2–7.5 cm (1.3–3.0 in) (SVL), females being slightly larger than males. Isolated populations have distinct size variations; for example, those found just to the north of Mutare appear to be larger than those just to the south (separated by deep valleys). It has a dorsoventrally flattened head and body with prominent ribs and apparent venation, giving it the appearance of a leaf. Its colour variations are from deep brown to yellowish green according to the camouflage required for the situation. Males are usually more brightly coloured.[citation needed]

Breeding

[edit]

Males, being slightly smaller, having a distinct penial swelling at the base of the tail, and a greener throat with a row of defining white or yellow tubercle spots, are relatively easy to distinguish from females.[3]

Sympatric species

[edit]

Little habitat overlap occurs as that of C. dilepsis approaches the range of Marshall's leaf chameleon. C. dilepis is rare, found in low, probably transitory population densities at the altitudes inhabited by R. marshalli, preferring the sunnier grasslands and forest margins.[citation needed]

[edit]

Karyotopic taxonomy

[edit]

Wright (1973) confirmed that the number and form of the chromosomes from specimens provided by Broadley put R. marshalli in the genus Rhampholeon with Rhampholeon spectrum, the type species for the genus having 36 pairs of chromosomes like the other members of this genus.

Distribution

[edit]

Rhampholeon marshalli is found largely in the Eastern Highlands of Zimbabwe and the adjacent upland forest of Mozambique.[citation needed]

Habitat

[edit]

The patches of relict montane forest found in the Nyanga, Bvumba, Himalaya and Chimanimani Mountains are the primary habitats of Rhampholeon marshalli. It can be found in the cool, damp interior of the forest, mostly in the undercanopy and on the forest margins. These forest patches are surrounded by vast expanses of montane grassland, but are often so far apart as to be isolated from one another, but forest along the numerous mountain streams may link these very limited habitats. Marked specimens surveyed over a long time appeared not to travel far at all, usually less than 15 m (49 ft).[4]

Natural history

[edit]

Rhampholeon marshalli seems to inhabit the subcanopy and leaf litter of the relict cloud forests. Major canopy trees include Syzygium and Ficus. These forest are rich in fern and liana species. Forest margins have prickly species of Ilex and Rubus briars. How far up the canopy this creature ascends is not known, but it tends to be found in the leaf litter or low shrubs. The winters in these (evergreen) forests are sharp and very cool; a period of brumation seems likely to occur for this tiny lizard. It eat insects, though these forests seem to be fairly depleted now.[citation needed]

Reproduction

[edit]

In the rains (November to March), Marshall's leaf chameleon lays a small clutch of embryonated eggs that hatch quickly. Humphreys[5] photographed a gravid female excavating a hole in the forest soil and laying a clutch. One egg was exhumed and found to contain a fully developed embryo. After 35 days, the eggs hatched and the tiny juveniles dispersed. Juveniles are relatively large at 22–25 mm (0.87–0.98 in) long (SVL).[3]

Conservation

[edit]

Like other small mountain chameleons, Rhampholeon marshalli appears to have population spikes and collapses. Its range does not appear to be threatened and much of its habitat is safe in Zimbabwe in the Nyanga National Park (where introduced tree species of wattle and pine are being eradicated to allow natural forest to re-emerge), Stapleford Forest Reserve, Bunga National Park and Botanical Garden, the Chimanimani National Park, and the Chirinda Forest Reserve. However, the tiny relic cloud forest patches are under constant threat from excessive collection of firewood and clearance for coffee, tea and protea plantations. Also, the corridors that once connected populations have indubitably diminished.[citation needed]

References

[edit]
  1. ^ Tolley, K. (2014). "Rhampholeon marshalli ". IUCN Red List of Threatened Species. 2014: e.T176321A47651599. doi:10.2305/IUCN.UK.2014-3.RLTS.T176321A47651599.en. Retrieved 12 November 2021.
  2. ^ Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. ISBN 978-1-4214-0135-5. (Rhampholeon marshalli, p. 169).
  3. ^ a b Broadley DG, Blake DK (1971). "A review of Rhampholeon marshalli Boulenger with the description of a new subspecies from Mozambique". Arnoldia 10 (5): 1-5.
  4. ^ Broadley DG, Blake DK (1973).[wrong year?]
  5. ^ Humphreys, Clive (1990). "Observations of Nest Excavation, Egg-laying and Incubation Period of Marshalls Dwarf Chameleon". Zimbabwe Science News 24 (1/3): 3-4.

Further reading

[edit]
  • Boulenger GA (1906). "Description of a new Chameleon of the Genus Rhampholeon from Mashonaland". Annals and Magazine of Natural History, Seventh Series 18: 346–347. (Rhampholeon marshalli, new species).
  • Branch, Bill (2004). Field Guide to Snakes and other Reptiles of Southern Africa. Third Revised edition, Second impression. Sanibel Island Florida: Ralph Curtis Books. 399 pp. ISBN 0-88359-042-5. (Rhampholeon marshalli, p. 229 + Plate 95).
  • Broadley DG, Blake DK (1978). "A preliminary report on a field survey of Marshall's Dwarf Chameleon". Rhodesian Science News 5 (10): 310–314.
  • Broadley DG, Blake DK (1979). "A field study of Rhampholeon marshalli on Vumba Mountain, Rhodesia (Sauria: Chamaeleonidae)". Arnoldia 34 (8): 1–7.
  • Wright JW, Broadley DG (1973). "Chromosomes and the status of Rhampholeon marshalli Boulenger (Sauria: Chamaeleonidae)". Bulletin of the Southern California Academy of Sciences 72 (3): 164–165.
  • Longmanns Animal Encyclopedia. p. 422.