In: “Russian Journal of Herpetology”, Vol.9, No.1, 2002, pp. 77-79

CAPTIVE BREEDING AND CONSERVATION

BREEDING OF BLACK MANGROVE SNAKE

Boiga dendrophila gemmicincta (DUMERIL, BIBRON ET DUMERIL, 1854)

[SERPENTES: COLUBRIDAE: COLUBRINAE]

FROM SULAWESI ISLAND (INDONESIA)

Sergei A. Ryabov¹ and Nikolai L. Orlov²

Tula Exotarium, Oktyabr'skaya ul., 26, Tula 300002, Russia.

E-mail: rept@tula.net

Zoological Institute, Russian Academy of Sciences, Universitet-

skaya nab., 1, St. Petersburg 199034, Russia.

E-mail: azemiops@zin.ru

Submitted February 25, 2002.

Key words: breeding, Boiga dendrophila gemmicincta; Sulawesi Island; Indonesia.

INTRODUCTION

Eight subspecies of Boiga dendrophila inhabit coastal regions of Indo-China, the Philippines and the islands of the Great Sunda Archipelago (Indonesia) (Boulenger, 1896; De Rooij, 1917; Brongersma, 1934; Haas, 1950; Taylor, 1965; Leviton, 1970; Manthey and Grossmann, 1997; Welch, 1988; Vogel, 2000; Orlov and Ryabov, 2002).

The black mangrove snake B. dendrophila gemmicincta is the endemic of the island of Sulawesi in Indonesia [Boulenger, 1896; Brongersma, 1934; Haas, 1950 (as B. d. atra), In Den Bosch, 1985; Welch, 1988]. It is the only subspecies of this widely distributed and variable species with bright banded juvenile color pattern that is changed with age to unicoloured-black adult coloration.

There is an opinion that this form is the most dif­ferent from all other subspecies of Boiga dendrophila (Vogel, 2000).

At the same time the data on its natural history are very scarce and fragmentary; Brongersma (1934) gives the most complete information on its feeding in the wild. The data on its reproductive biology are completely absent.

We collected our data on reproduction of captive bred group of Boiga dendrophila gemmicincta in Tula Exotarium.

Forming of the Breeding Group and Conditions of Their Keeping

For the first time we received a pair of Boiga dendrophila gemmicincta in 1997 from the zoofirm "C. V. Prestasi" (Jakarta, Indonesia) which special­izes on keeping and breeding of reptiles.

Both adult animals soon died because of a very strong helminthiasis. But the female still had time during the first days after the arrival to lay 3 fertilized eggs from which in 118 days in March of 1998 hatched 3 young snakes. They had bright transverse­ly-banded coloration, very different from unicolored black coloration of their parents.

A pair of boigas hatched from this clutch was raised to sexual maturity which they attained in two-year-old age at the length of 120- 130 cm (female No. 1 and male No. 1).

In 1999 from the same zoofirm we received one more pair of adult wild-caught specimens of this sub­species (female No. 2 and male No. 2). Some time af­terwards we were able to adapt them to the terrarium conditions.

We keep large snakes in separate plastic boxes with the sizes 60 x 35 x 40 cm with comfortable crossbars for climbing, hiding-places and water-dishes. Newspaper is used as a substrate. The temper­ature during the active period is maintained within +27 - 31°C during the day and +23 - 25°C at night. The necessary humidity is provided by regular spray­ing imitating the rain.

Once in 7 - 10 days boigas eagerly eat adult labo­ratory mice, young rats (at the age of 10 - 30 days), chickens and Japanese quail.

TABLE 1. Data on Clutches of Boiga dendrophila gemmicincta

No. of clutch	No. of female and origin*	Date of clutch	Date of Hatching ncuba- Tion Period, days		Number of eggs	Sizes of eggs				Average Number of males weight and females hatched of egg, g from the clutch
						length, mm		diameter, mm
1	owe	28.11.97	26.03.98	118	3	were not measured					2♂♂ 1♀
2	1CB	26.02.00	15.06.00	109	6	35	-44	20	-21	13.08	4♂♂ 2♀♀
3	1CB	5.05.00	23.08.00	110	4 eggs +	40	-48	21	-22	15.55	l♂ 3♀♀
					1 unfert. unfertilized
4	1 CB	14.07.00	03.11.00	112	5 eggs +	41-46.5		21	-23	16	1♂ 3♀♀
					1 unfer. uuuuuunfertiunfertilized
5	2 WC '	2.08.00	24.11.00	114	4	51	-55	19	-20	17.5	4♀♀
6	1CB	2.03.01	2.07.01	122	7	43,5	-48.5	22.5	-24.5	15.4	3♂♂ 4♀♀
7	2WC	17.04.01	9.08.01	114	6	44	-51	21.5	-22.5	15.5	3♂♂ 3♀♀
8	1CB	25.04.01	19.08.01	116	9	43.5	-48.5	21	-25	15.22	6♂♂ 3♀♀
9	1 CB	13.07.01	17.11.01	127	7	41-50.5		22	-25.5	17.57	3♂♂ 3♀♀
10	2WC	16.07.01	19.11.01	126	6	51	-57	20.5	-23	17.58	5♂♂ 1♀

WC, wild-collected specimen; CB, captive bred specimen.

TABLE 2. Comparison of Sizes of Young Boiga dendrophila gemmicincta Received from Female No. 1 (clutches Nos. 2 and 9)

	Clutch No. 2	Clutch No. 9
Body length, cm Tail length, cm Weight (average), g	26.5-31.5 7.5-8.5 8.18	36-39 9.4-10.4 14.32

ship behaviour only after dark. Later on in the behav­iour of newly-hatched B. d. gemmicincta. we also ob­served a more marked positive phototaxis than in many other species of boigas. Basking was also noted. Of course, it does not mean that the Black mangrove snake has a pronounced diurnal activity, but some elements of it are present.

During the winter months the temperature for the snakes was dropped up to +17 - 19°C, humidity and light day were reduced. Under this regime they were kept during 1.5-2 months and they were not eating during this time.

After such hibernation the temperature, humidity and photoperiod were gradually (during 7-10 days) returned to the previous level.

Copulations were observed already in 2-3 weeks after the cooling period was over. During that time both males and females had time to eat 2 - 3 times. Males sometimes can skip 1-2 feedings and search for the female actively moving round the terrarium, climbing on branches and crumpling the paper.

The duration of copulation was repeatedly re­corded, it lasts 2.5 - 4 h. Also, it is interesting to point out some unusual details in the courtship bahaviour of B. d. gemmicincta. We observed sexual activity of males immediately after putting the breed­ers together, both during the day and at night. At the same time, according to our data males of many other species of boigas such as B. d. dendrophila, B. d. me-lanota, B. cynodon, B. guangxiensis, B. cyanea, B. ni-griceps, B. kraepelini, and others begin their court-