Co-integration analysis of capture–recapture method in toad, Phrynoidis aspera (Gravenhorst, 1829)

• Main Authors: Anuar Mohd Sar Shahrul, Taofik Oyedele Dauda, C.C. Hong, Evan Quah, Taiwo Omodele
• Format: Article
• Language: English
• Published: Elsevier 2019-03-01
• Series: Journal of Asia-Pacific Biodiversity
• Online Access: http://www.sciencedirect.com/science/article/pii/S2287884X18301833

The Asian giant toad, Phrynoidis aspera, research is faced mainly with twin challenges of conservation and efficient sampling techniques for research purposes. This research is therefore conducted to assess the co-integration feature of the capture–recapture methods and to evaluate both long- and short-term effect of capture on the recapture of P. aspera using Titi Kerawang waterfall (N05° 24.23/E100° 13.41/), Teluk Bahang. Toads encountered in the study area were caught and marked using PIT tags weekly. Data obtained were subjected to summary statistics (mean, standard error, and variance), correlogram, cross-correlogram, stationary test, and exogenous and endogenous variable determination. Mean Asian giant toad recaptured fell between three for the 2nd week and 25 for the 14th week. For the capture, the range was between zero for the 12th week and nine for the 3rd week, while the 1st capture was 12 toads. There was no visible similarity in the variances of the toad indices indicated by the correlogram of both capture and recapture as well as their cross-correlogram. The cross-correlogram ranged between 0.6665 and 0.4029. From these results, randomness of data as well as their independence can thus be established. Also, the results portray that the summary statistics does not present any visible stationary trend in both toad capture and recapture. The raw data can therefore be said to be nonstationary (that is variance of toad capture/recapture in a week, xt is not dependent on preceding week, xt-1). The augmented Dickey–Fuller statistics of both capture (−0.97294 to −3.92035) and recapture (−1.13288 to 4.00443) indicated strong evidence that both capture and recapture series of the nontransformed data on the long run are I(1). The short-run co-integration according to this study contrast with the long-run co-integration. Keywords: Endogenous, Equilibria, Exogenous, Long-run, Stationary