standardization of records keeping in indian zoos - Central Zoo ...

Figure4: Ventral scale clipping system for marking snakes. Diagrams are ventral, posterior
views. A. Enumeration of ventrals proceeding anteriorly from anal scute; 10‟s, 100‟s and
1000‟s series on observer‟s left, units series on right. B. A freshly – marked snake,No. 718 C.
Same individual three years after initial marking, showing appearance of scars.
The basic plan is shown in Fig….Ventrals are counted anteriorly from the anal
scute in series of 10‟s ( from 10-90 ), 100‟s (from (100-900), and 1000‟s (if
necessary) on the observer‟s left, in units (from 1-9) on the observer‟s right. By
removing half of a given ventral, a combination of 1-3 clipped scutes will enable an
investigator to 989 individuals before advancing to the 1000‟s series. Examples of a
freshly-marked snake (Fig.1B) and the same individual three y ears later (Fig. 1C) are
shown, scars were readily identifiable in this individual, typical of many we have
marked in this fashion (Parker and Brown, 1973).
Using a sharp pointed pair of dissecting scissor (for large animals) or tiny
micro-surgical scissors (for hatching or small snakes), marking may be best done as
follows :
1. Insert a tip of the scissors under the posterior edge of the scute to be clipped, push
it forward beneath the width of the entire scute, and cut, Make two such incisions, one
on each side of the intended block to be excised.
2. Insert the scissors under and across the top (anterior edge) of the scute and make a
third cut transversely to remove the entire section. Depth of the cuts is important : the
entire excision should include all layers of the skin (including the dermis) to exposed
the underlying ventral musculature. Muscles should be visible and the section
removed should be large enough to cover half of a given ventral. In cases of dual
numerals involving the same scute (55,66, etc.) clip all the way across and leave some
lateral traces of the scute so that its position can be counted after healing. There is an
apparent tendency for adjacent scutes to „invade‟ an excised area (Fig. 1c) or to
adpress against an excision zone after removal of an entire scute. Number involving
adjacent scutes on the same side (eg. 190‟s, 1900‟s) should be omitted. Occasional
anomalies such as half-ventrals protruding laterally and ending at the midline (cf.
Clark and callison,1967) may be separately photographed / sketched (or otherwise
recorded whether counted or not) when critical to a snake‟s later recognition.
They noted minimal pain and bleeding, no instances of post-marking infection,
and no difference in behavior between marked vs. unmarked animals in the field.
They have used this technique to mark 1,046 C.constrictor (Brown, 1973;
Brown and Parker, 1974), 242 M. taeniatus and 211 P. melanoleucus (Parker, 1974)
as well as lesser numbers of Diadophis punctatus (Parker and Brown, 1974a) and
Crotalus viridis (Parker and Brown,1974b) between 1969-1973 at communal
hibernacula in Utah, ventral scale marking has worked well for these species and
should be applicable to population and demographic studies of virtually any snake
species.
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