Suggestions for Effective -‘Tracking Paper’ - Design

Based on the research conducted on wild reptiles at Korapuki Island (under the supervision of Dr Dave Towns)

and the trial tracking on captive skinks at Waitakere Foothills (under the permit of Simon Chapman), the following

generalisations could be made:

1. General Experimental Outcome:

1.     The Gotcha Traps Ltd’s Black Trakka papers [Figure 1.1 (a) & (b)] have been found to produce skink and gecko prints effectively.

2.     The newly made blue tracking papers, with uniform thickness and negligible migration of ink, as in Figure 1.1 (a), produce better prints and account for relatively higher consistency from the 1^st to last prints [see Figure 1.1 (c) & (d)]. These tracking papers can be used for getting prints of adults (over 55mm SVL) effectively.

3.     The Green Trakka papers, which were originally made for insect tracks, can be used to get the prints for juvenile skinks & geckos. 

4.     The ink does not affect the climbing ability of the skinks and geckos significantly, nor persist for considerable time. 

Figure 1.1 (a) New Blue Tracka               Figure 1.1 (b) Old Black Trakka paper

paper with less migration of ink              with highly migrated ink

Figure 1.1 (c) prints taken from the               Figure 1.1 (d) Prints taken from the

papers shown in Fig 1.1 (a)                             papers shown in Fig. 1.1 (b)

 2. Specific Issues

 2.1 Adsorption of ink

 When the animals move through the ink pad, it is the belly and tail regions that get more ink. Most of the species raise the front 1/3 of the body, as shown in Figure 1.2, using their neck and forelimbs.

                   Lifted portion                                          Contact area 

 Figure 1.2 An adult Moko skink – raising its anterior 1/3 portion of the body.

 The degree of adsorption of the ink stain is mainly influenced by the following aspects (still not confirmed but based on observations & inferences):

 1.     Stockiness of the body (which is assumed to be proportional to the weight): Heavier the individuals, the greater would be the ink adsorbed. Species such as Robust skinks get more ink in their belly. Slim bodied animals such as Shore skinks and Moko skinks [Figure 1.2 & 1.3 (b)] get through the ink-pad fairly quickly, and thus get less ink.

 2.     Length of the limbs:

Increased length of the limbs, raises the body more and help passing the ink-pad with minimum contact. Moko skinks raise their body easily with longer limbs [see Figure 1.3 (b)] and get less ink.

  (a)                                                                           (b)

  Figure 1.3 Limb span of Ornate skink (a) and Moko Skink (b)

 3.      Nature of the skin –under surface:

Oily or waxy nature of the ventral side (e.g. Moko skink) prevents adsorption of the ink (see Figure 1.4). The coarse appearance and scale patterns, as in Robust skink, increases the degree of adsorption.