- A GPS-collaring study in southeastern Nepal found that fishing cats could have much larger home ranges than previously recorded.
- Contrary to popular belief among local communities, some fishing cats were found to inhabit human-dominated landscapes, rather than only visiting them at night.
- Researchers suggest that low prey density in Nepal’s Koshi Tappu Wildlife Reserve and more accurate GPS tracking may explain the larger home ranges observed.
- The study highlights the need for community engagement in conservation, as fishing cats help control rodent populations and face threats from habitat loss and human-wildlife conflict.
The home range of fishing cats (Prionailurus viverrinus), found in parts of South and Southeast Asia, could be more expansive than previously thought, a recent GPS-collaring study focusing in and around Koshi Tappu Wildlife Reserve in southeastern Nepal suggests.
The study also found that some of these small cats live in human-dominated landscapes round the clock, contrary to popular belief that they only visit such areas at night, preferring to live within protected areas during the day.
“The findings of the study are important as so many individuals were GPS-collared and tracked for the first time,” said Rama Mishra, lead author of the study.
As part of the study, Mishra and her team captured and collared 11 fishing cats — six females and five males — with satellite GPS collars and monitored their movement between August 2021 and January 2023. However, one male was found dead 40 days after collaring and one female after three months.
These collars collected location data, which was then used to estimate the cats’ home ranges using the minimum convex polygon (MCP) and area-corrected autocorrelated kernel density estimation (AKDE) methods.
Before the study, researchers had collared only up to six individuals at one go so far. “GPS-collaring is very expensive, and it takes a lot of time to do it,” said Mishra, and that’s why the sample sizes in GPS-collaring studies seem small compared to other studies employing other methods such as those involving non-invasive genetics.
Prior to this study, the largest home range for fishing cats was recorded to be 16 to 22 square kilometers (6.2 to 8.5 square miles) for males in Nepal’s Chitwan National Park. And at the Khao Sam Roi Yot National Park, Thailand, where studies were carried out between 2009-10, males averaged 8.75 km2 (3.4 mi2), and females as low as 3.85 km2 (1.5 mi2). However, the study by Mishra and her team estimated the home range of fishing cats to be around 29.12 km2 (11.2 mi2) with a variation of 16.89 km2 (6.5 mi2) using the MCP method and 39.88 km2 (15.4 mi2) with a variation of 26.16 km2 (10.1 mi2) using the AKDE.
“The numbers we have estimated are quite large compared to previous studies,” said Mishra. “This suggests that the density of the animals is low in the area and that they travel long distances each day. As a result, the same fishing cat may be spotted by different people across a wide area, leading to an overestimation of the population size due to observer duplication bias,” she told Mongabay.
Fishing cats are one of the least understood small cats. Although their name suggests they feed on fish, dietary analysis in Nepal and elsewhere show that fish is a significant diet but not the only thing the cat eats. It also preys on amphibians, crustaceans, mollusks and even rodents.
“The numbers estimated by the study are indeed quite large,” said Yadav Ghimirey, one of the pioneering small-cat researchers in Nepal who wasn’t involved in the study. “We wouldn’t expect such a small cat to travel long distances the way the big cats do,” he added.
The researchers suggest two plausible reasons for this. The first one is that GPS-based collars provide more accurate location data compared to their predecessors over a wider area. Secondly, the study area could be home to a lower population of prey species compared to other locations surveyed in the past.
For example, in Colombo, Sri Lanka, where a smaller home range was reported in an urban environment, a larger population of rodents could explain the smaller space requirements of fishing cats, the authors of the Nepal study suggest.
In addition to this, even in the case of Koshi Tappu, the average estimated home range size in the buffer zone, a human-dominated landscape with fishponds and agriculture, was slightly smaller than that of inside the wildlife reserve adjacent to Koshi. Here, the authors hypothesized, the abundance of prey, specifically fish in the fish ponds and rodents in agricultural fields, is likely higher in the human-dominated areas compared to the core areas within the reserve, and the bigger home range inside the protected area.
They also argue that high fishing pressure in the natural wetlands and Koshi River within the protected area may have led to a depletion of fish stock, contributing to lower prey densities and, hence, the larger home range of fishing cats.
IUCN, the global conservation authority, categorizes fishing cats as ‘vulnerable,’ and identifies the loss and fragmentation of habitats as one of the leading threats to the animal found in inland wetlands, grassland, forest and shrubland in Nepal, Bangladesh, Cambodia, India, Myanmar, Nepal, Pakistan, Sri Lanka and Thailand.
According to the authority, developmental activities such as urbanization, industrialization, agriculture and spread of aquaculture (prawn and shrimp farms instead of fish) have increased threats to the species, especially in South Asia. Additionally, persecution for fish depredation is also a challenge as local communities often overestimate the number of fishing cats in their neighborhood and assume that the cats only eat fish, said Mishra.
“The study is important as it yet again shows that communities should be engaged in conservation efforts,” said Yadav Ghimirey. He said that as the cats live around humans and contribute to the local ecology by killing rodents, people should understand their value.
Mishra said that the findings from the study could serve as a baseline for future studies. “When we understand the home range of fishing cats, we can piece together plans to help save them,” she said.
Banner image: A fishing cat photographed by a camera trap in Nepal. Image courtesy of Rama Mishra.
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Citation:
Mishra, R., Lamichhane, B. R., Leirs, H., Subedi, N., Adhikari, S., Acharya, H. R., & de Iongh, H. H. (2025). Cats in farms: ranging behavior of the Fishing Cat (Prionailurus viverrinus) in a human-dominated landscape. Journal of Mammalogy. doi:10.1093/jmammal/gyae150
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