Vertebrate prey composition analysis of the Pallas’s cat (Otocolobus manul) in the Gongga Mountain Nature Reserve, based on fecal DNA

Abstract

Diet analysis is essential to fully understanding the biology of a species and its function within the ecosystem, and is also key in identifying food web interactions and the population dynamics of predators and prey. There is currently little information on the diet of small to mid-sized carnivores due to their elusive behavior. We used a DNA-based method to analyze the vertebrate prey of the Pallas’s cat (Otocolobus manul) in the Gongga Mountain Nature Reserve of southwestern China, a global biodiversity hotspot region. We confirmed 14 scat samples containing the Pallas’s cat DNA from 100 small carnivore scats collected at altitudes between 3200 and 4900 m, and then performed polymerase chain reaction (PCR) amplifications using primers targeting the vertebrate mitochondrial 12S rRNA gene with a blocking oligonucleotide specific to the predator sequence. We identified a total of 18 prey taxa, including nine mammals, eight birds and one fish. Our results show that pikas (in 79% of the scats) and birds (in 50% of the scats) are the predominant prey consumed by the Pallas’s cat in our investigation area. The most important finding in our study is that Cypriniformes species were found in the Pallas’s cat’s diet, exhibiting dietary diversification consistent with the accessible fauna of the surrounding environment. In order to increase the detectability of both typical and rare vertebrate prey items, we constructed a blocking primer to inhibit the amplification of the Pallas’s cat DNA.

Molecular Dietary Analysis of Three Sympatric Mustelidae in Northeast China

“…The primers and ambiguous fragments in the sequencing products were removed by the Chromatogam software, and the obtained DNA sequence was compared with the reference sequences in BLAST (basic local alignment search tool) [ 26 ] database in Genbank [ 27 ]. When the sequence identity was higher than 98% [ 3 ], we considered the DNA sequence to belong to the respective species.…”

“…For vertebrate sequences, only those with 100% coverage in the public databases were considered, using the following criteria for taxonomic assignment: (1) When the identity of a query was ≥99% with only one species’ sequence in the database, the query was assigned to this species; (2) When the identity of a query was ≥99% with more than one species’ sequence, we first checked its distribution; if more than one species was present in the study area, the lowest taxonomic level that included all the species was assigned; (3) When the query sequence identity matched between 92% and 99% with the DNA sequences in the database, the query was assigned to the lowest taxonomic level that could include all locally occurring species with the highest identity scores; if a single species showed the highest identity similarity but was not known to inhabit the area, the most closely related local species within the same genus was assigned; (4) When the maximum identity for a query was <92%, the taxon was recorded as unknown. To avoid misidentification of taxa due to insufficient local species records, we kept to conservative taxonomic assignments and only excluded species that showed no occurrence in all of northeast China [ 3 ].…”

“…Studying the details of a species’ diet not only sheds light into their status within the food web but also provides a baseline for comparative purposes as environments continue to change [ 2 ]. Knowledge of a species’ diet can provide valuable information for developing specific conservation plans and management strategies [ 3 ]. In many situations prey choice by predators in the field cannot be established or quantified using direct observation.…”

Low impact of forest conversion on biodiversity: Evidence from small mammals in contrasting forests of Mt. Liangshan

“…Insectivores that prey on invertebrates (e.g., insects) can significantly affect the functioning of forest ecosystems, and herbivorous species (e.g., Tamiops swinhoei ) (including granivores and frugivores) serve as seed dispersers (Urgoiti et al, 2018; Wen et al, 2018). At the same time, small mammals are prey to a variety of birds, reptiles, and mammals (Chubbs & Trimper, 1998; Dawson & Bortolotti, 2000; Shao et al, 2019; Zhao et al, 2020). Understanding the effect of forest compositional change on the diversity and community structure of small mammals is crucial for forest management and biodiversity conservation (Carey & Johnson, 1995).…”

Low impact of forest conversion on biodiversity: evidence from small mammals in contrasting forests of Mt. Liangshan, China

“…Insectivores that prey on invertebrates (e.g., insects) can significantly affect the functioning of forest ecosystems, and herbivorous species (e.g., Tamiops swinhoei ) (including granivores and frugivores) serve as seed dispersers (Urgoiti et al, 2018). On the other hand, they are prey for birds, reptiles and large mammals (Chubbs & Trimper, 1998;Dawson & Bortolotti, 2000;Zhao et al, 2020). In addition, small mammals are easy to investigate and characterized by low dispersal ability and strong ecological adaptability.…”