Zoology Jottings: Tokay Geckos in Hong Kong: wild and/or feral populations?

Tokay geckos are recognized to happen on the island of Lantau, within the mainland New Territories and on Hong Kong island. The brand new paper on the commerce in Tokay geckos in Hong Kong I referred to in a earlier article discovered ideas that at the very least one of many populations within the New Territories comprises the red-spotted morph, indicating a non-Hong Kong origin and certain the results of introduction both by escape of captive geckos or deliberate launch. The authors concluded:

Our genetic evaluation reveals that TCM [traditional Chinese medicine] commerce in Hong Kong shouldn’t be possible equipped by native wild populations, however by imports from Southeast Asia. Further data from SIA [stable isotope analysis] helps our genetic findings, as we detected little or no overlap in isotopic signatures between TCM and Hong Kong wild tokays. Commerce additionally results in mixing of populations by means of introductions associated to the reside pet commerce. We discovered that at the very least two Hong Kong wild tokay populations had been possible established from launched pets. 

The conclusion that Tokay Geckos are usually not now collected from the wild in Hong Kong suggests a change has occurred because the first discovery of Tokay Geckos within the wild on Lantau Island on 23 February 1950 since that discovery was solely made when the supply of reside geckos on the market in a snake store got here to mild.

The grand previous man of Hong Kong herpetology, John Dudley Romer (1920-1982) wrote within the journal Copeia:

On February 23, 1950, I bought a reside grownup Gekko gecko from one of many snake-dealers, and on making enquiries concerning its origin, was knowledgeable that it had been obtained from Tung Chung. Just a few days later I visited that locality with some buddies and enquiries on arrival without delay revealed that this gecko is well-known to the native Chinese language. One reside grownup specimen was obtained from a lady who had apparently been holding it to promote within the metropolis. Since time was brief we engaged one of many villagers to point out us precisely the place the geckos had been discovered, and after an hour or two of stiff climbing, he lastly halted on a rocky hillside and identified a number of slim clefts in some significantly massive rocks. It was then only some minutes earlier than we noticed one in every of these large geckoes in a cleft in one of many rocks.

John went on to counsel that the gecko could have been extra broadly distributed in Hong Kong because it had not been discovered within the typical habitats of this species, in northern Burma for instance: “homes, huts and timber and at nights are sometimes seen on fence posts. In forests they reside in holes or on the bark of timber.” He concluded:

It appears possible that their absence from dwellings and obvious confinement to the rocks on lonely hill-sides on this colony could also be associated to their extermination from different sorts of habitat.

In different phrases, he was suggesting that the inhabitants on Lantau was a relict of a as soon as a lot wider distribution throughout Hong Kong. The invention of a second inhabitants on Lion Rock within the New Territories may give credence to such a proof.

When the second version of Hong Kong Reptiles and Amphibians was compiled and revealed in 1998, the populations on Lantau and on Lion Rock had been thought-about native; evidently conclusion nonetheless holds.

These arriving or leaving Hong Kong by air will, if sitting on the aspect nearest the mountains of Lantau might be passing the location John Romer described. Nonetheless, his fishing village of Tung Chung is now  the closest city to the Chek Lap Kok airport with a inhabitants of over 1000,000 and nonetheless rising. If vacationers ever return Hong Kong, the Ngong Ping Cable Automobile hyperlinks Tung Chung to the Po Lin Monastery and Huge Buddha. The as soon as tough to succeed in village is now simply one other cease on the MTR.

The web page on the Tokay Gecko from Karsen, Lau and Bogadek’s Hong Kong Amphibians and Reptiles

Dufour PC, Miot EF, So TC, Tang SL, Jones EE, Kong TC, Yuan FL, Sung Y-H, Dingle C, Bonebrake TC. 2022 House and hub: pet commerce and conventional medication impression reptile populations in supply areas and locations. Proceedings of the Royal Society B 289:20221011 doi.org/10.1098/rspb.2022.1011 

Karsen SJ, Lau M W-N, Bogadek A. 1998. Hong Kong Amphibians and Reptiles. Second Version. Hong Kong: Provisional City Council. ISBN 962-7849-05-7

Romer JD. 1951. The prevalence of the lizard Gekko gecko within the colony of Hong Hong. Copeia 1951, 80.