The diet of myrmecophagous mammals is usually studied by investigating the chitinous remains of termites and ants obtained from stomachs, guts, and faeces; however, this process is time and labour intensive. Moreover, faeces of obligate myrmecophagous mammals contain other materials such as soil, sand, rocks, and plant matter, which hinder the accurate and efficient identification of faeces’ contents; this makes estimating the biomass of each prey species difficult. This study tested non-filtering and filtering faecal analysis procedures and compared their identification accuracy and efficiency in the analysis of Formosan pangolin Manis pentadactyla pentadactyla faeces. In the non-filtering procedure, 1 g of dried faeces was distributed over an area greater than 360 cm2 to be able to see most ant capsules and termite mandibles. In the filtering procedure, 0.5 cm3 of filtered chitinous remains of termites and ants was spread over a 45 cm2 area to obtain a high resolution of the diet composition. The filtering procedure can sieve out insect remains from the debris, which facilitates further identification of the insect chitin. Using the two proposed faecal analysis procedures, the prey species composition and the number of prey remains could be obtained. Our results provide a quantitative method to evaluate the diversity of wild pangolin’s diets for determining their ecological requirements and developing in-situ and ex-situ conservation plans.
The Chinese pangolin Manis pentadactyla is critically endangered because of over-exploitation and illegal trafficking and includes three subspecies. However, the taxonomic status of the three subspecies of the Chinese pangolin has not been well resolved, which impedes regional conservation and illegal trade traces. In this study, the complete mitogenome sequence of M. p. pentadactyla, an endemic subspecies of the Chinese pangolin in Taiwan, was determined. The complete mitogenome of M. p. pentadactyla is 16,570 base pairs (bp) in length with 13 protein-coding genes (PCG), 23 transfer RNAs (tRNAs), two ribosomal RNAs and a 1164 bp control region. The overall base composition of the genome showed a slight A + T bias (59.9%), positive AT skew (0.1515) and negative GC skew (-0.3406), which is similar to that of other pangolins. All PCGs started with a typical ATN codon and all tRNAs were typical cloverleaf-shaped secondary structures, except for tRNA-Ser(GCU). Phylogenetic analysis indicated a monophyletic relationship for M. p. pentadactyla and M. p. aurita and was monophyletic for M. p. pentadactyla, but paraphyletic for M. p. aurita. The paraphyly of M. p. aurita resulted from an incomplete lineage sorting. This study enriched the mitogenome database of the Chinese pangolin and the molecular information obtained should be very useful for future research on mitogenome evolution and genetic diversification in M. pentadactyla.
Pangolins are myrmecophagous mammals whose biology and ecology remain poorly studied. Termite mandibles and ant head capsules are the two primary remains found in pangolin feces. Determining the retention time of insect cuticles is important for understanding the digestive physiology of pangolins, while determining the recovery rate of termites and ants in feces is required to estimate the number of these prey items that are consumed by pangolins. In this study, the authors conducted feeding trials with captive Chinese pangolins (Manis pentadactyla). Sixty grams of the fungus-growing termite Odontotermes formosanus (18,816 individuals) and 15-20 g of the yellow crazy ant Anoplolepis gracilipes (14,200 individuals) were fed to each pangolin. After feeding, pangolin feces were collected daily for 1 week. The authors also assessed the accuracy of using chromium (III) oxide powder (Cr 2 O 3 ) as a proxy for determining gut passage time, as has been done in previous studies. The results showed that remaining termite mandibles and ant head capsules in feces peaked at 66 and 90 hr after feeding and their recovery rates were 0.35 ± 0.10 and 0.65 ± 0.04, respectively. In both feeding trials, the retention time of Cr 2 O 3 was much shorter than that of the termite mandibles and ant head capsules, indicating that Cr 2 O 3 is not an appropriate indicator for estimating food retention time of myrmecophagous animals. Our results revealed that the ant head capsules were preserved better in feces compared with the termite mandibles, suggesting that termites may be considerably underestimated in the feces of wild pangolins.
K E Y W O R D Sant, feeding trial, myrmecophagy, pangolin, termite
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