Mammals

Fishing Cat: Males Range Up to 10 Times Farther, GPS Data Show

GPS collars on fishing cats in Colombo and in Nepal both found males ranging far wider than females, by a factor of three in one study, ten in the other.

Last updated: 2026-09-04

A fishing cat standing on muddy ground amid mangrove vegetation, showing its stocky build, short legs, and spotted grey-brown coat
Photo: Srichakra PranavCC BY-SA 4.0

Core summary

Between 2013 and 2019, Anya Ratnayaka and colleagues GPS-collared five fishing cats (Prionailurus viverrinus) living inside Colombo, Sri Lanka, monitoring them for a combined 637 days (mean 127 per cat) and logging 2,278 locations at five-hour intervals; per the comparison table published in a later paper, the resulting home ranges averaged 12.49 square kilometers for males against 1.17 for females, a roughly 10.7-times gap, and all five cats used highly urbanized parts of the city more than the researchers expected. A separate 2025 study in the Journal of Mammalogy by Rama Mishra and colleagues, GPS-collaring 11 fishing cats in and around Koshi Tappu Wildlife Reserve in southeastern Nepal and gathering 2,303 locations, found the largest home ranges yet recorded for the species. Three of the 11 cats had under three months of tracking and were dropped from the range calculation; among the remaining 8, home ranges averaged 29.12 square kilometers by one estimation method and 39.88 by another. Broken down by sex (4 females, 4 males), female ranges there averaged 21.72 square kilometers against 58.03 for males, a significant difference and a far narrower roughly 2.7-times gap than Colombo produced, though that male figure alone is more than double the 22-square-kilometer top estimate any earlier study had reported for a male, a 1984 VHF-collar study in Nepal's Chitwan National Park. Both studies found the cats spending real time in farmland, fish ponds, and settlements, exposing them to persecution, road kills, and dog attacks, while the IUCN has classified the species as Vulnerable since a 2016 assessment estimated a 30 percent population decline across three generations between 2010 and 2015, a status that has not since improved.

Webbed feet and claws that never fully retract

Per the Smithsonian's National Zoo and Conservation Biology Institute, adult male fishing cats weigh 8 to 14 kilograms (18 to 31 pounds) and females 5 to 9 kilograms (11 to 20 pounds), with a body length of 85 to 115 centimeters and a shoulder height just over 40 centimeters, making the species roughly twice the size of a housecat. What separates it from other small wild cats isn't the size, though. Its front paws carry partial webbing between the toes, and its claws, unlike a housecat's, don't fully retract into their sheaths, leaving the tips exposed even at rest, a grip aid on wet mud and slick riverbanks that a cat with fully sheathed claws doesn't get. A double-layered coat, a dense underlayer beneath coarser guard hairs, keeps the animal from soaking through on repeated trips into the water.

To hunt, a fishing cat crouches at the water's edge and taps the surface lightly with one paw, mimicking the ripple of a landing insect; when a fish rises to investigate, the cat plunges its head and forepaws in and pins it against the bank or bottom. According to the IUCN Cat Specialist Group, the species has a wide but fragmented distribution across South and Southeast Asia, from southern Pakistan in the west to Cambodia in the east, tied throughout to wetlands: rivers, marshes, oxbow lakes, and mangrove forests. Unlike a pinniped such as a sea lion, whose limbs have been reshaped into flippers for a life spent mostly in the water, a fishing cat's paws stay recognizably paws, just with webbing and looser claws added on top, letting it hunt from the bank as often as it swims.

Five collars in a capital city, and a 10.7-times gap

Anya Ratnayaka's team GPS-collared five fishing cats living inside Colombo's urban wetlands across two tracking windows, 2013 to 2015 and 2018 to 2019, publishing the results in Mammalian Biology. The cats, two resident females, one resident male, and two translocated males released into the city's wetland parks, were monitored for a combined 637 days, averaging 127 days each, and yielded 2,278 GPS fixes recorded at five-hour intervals, the first study of its kind to track fishing cats with automatic GPS collars inside a city rather than a protected reserve. The paper's own summary is blunt about the headline result: all five individuals used highly urbanized areas more than the researchers expected going in.

A later paper by Rama Mishra's team assembled a side-by-side table of every fishing cat home range study published to date, and it lists the Colombo numbers as an average of 12.49 square kilometers for males against 1.17 for females, calculated using a method called time local convex hull. That's a gap of roughly 10.7 times. Mishra's team, discussing why Colombo's ranges came out so much smaller than their own Nepal results, points to higher rodent prey density in Colombo's built-up core: a resident cat surrounded by concentrated food doesn't need to cover nearly as much ground to eat well.

Two fishing cats, one larger and one smaller, walking together in daylight near Koshi Tappu Wildlife Reserve, Nepal
Photo: Sanjay Tha Shrestha, taken at Koshi Tappu Wildlife Reserve — CC BY-SA 4.0

Nepal's ranges are the biggest on record, and the reason isn't exotic

Rama Mishra, Babu Ram Lamichhane, and colleagues published a comparison table of five fishing cat home range studies, running from 1984 to their own 2021-2022 fieldwork, in their 2025 paper in the Journal of Mammalogy: a 1984 VHF-collar study in Chitwan National Park found males ranging 16 to 22 square kilometers, a 2009-2010 study in Thailand's Khao Sam Roy Yot National Park found 8.75 for males and 3.85 for females, and a 2011-2012 camera-trap study in India's Kishanpur Wildlife Sanctuary found a single male at 18.46. Their own 11-cat, GPS-collared study in and around Koshi Tappu Wildlife Reserve, publishing 2,303 locations gathered over the tracking period, came out far above all of them. Three cats had under three months of tracking and were excluded from the range estimate; among the remaining 8 (4 females, 4 males), home ranges averaged 29.12 square kilometers under a minimum-convex-polygon method and 39.88 under a more modern autocorrelation-corrected kernel method, with females averaging 21.72 and males 58.03, a statistically significant split (p < 0.001 in the paper's model).

The authors give two concrete reasons their numbers dwarf the older studies rather than treating the gap as a mystery. First, GPS collars record a location automatically on a fixed schedule, while the VHF radio-collars used in the older studies required a researcher with a directional antenna to physically locate the signal, a method that regularly failed to find cats that had moved out of range and mechanically undercounted how far they'd actually gone. Second, Koshi Tappu appears to have lower prey availability than the sites of the earlier studies, which would push cats to cover more ground to find enough food. Habitat-use tracking backed up the wetland link driving all of this: fishing cats there showed up most often in tall grassland and shrub (31.51% of locations) and wetland (27.36%), but statistical preference indices, which weigh use against how much of each habitat was actually available, still ranked wetland as the most selected-for habitat overall, with cats using wetlands and settlements more at night and tall grassland more by day. Male ranges also consistently overlapped several nonoverlapping female ranges rather than the reverse, the same land-tenure pattern documented in other solitary felids. Over a third of the average home range, though, fell inside human-dominated land, fish ponds, farms, and settlements, where the study's authors flag persecution, road kills, and dog attacks as documented causes of death.

Vulnerable since 2016, with no sign of a turnaround

The IUCN listed the fishing cat as Vulnerable in a 2016 Red List assessment led by Shomita Mukherjee and a team of co-authors that included Anya Ratnayaka, the same researcher who led the Colombo GPS study, estimating a roughly 30 percent decline in the global population across three generations between 2010 and 2015. Per the IUCN Cat Specialist Group, the classification stands today, and the species carries an Endangered listing on the national red lists of Bangladesh and Nepal specifically, a sharper local designation than its global one. Wetland destruction and direct killing by local people, retaliation for raiding fish ponds and poultry among them, are the threats the assessment names as driving the decline, the same conflict-with-farmers dynamic that shows up directly in the Koshi Tappu tracking data.

That combination, a specialized physical build tied to one habitat type and an official status that hasn't moved in a decade, echoes the position of a very different animal: fennec foxes are still trapped from the wild in North Africa despite a physiology so specialized for one environment that captivity can't fully substitute for it. The fishing cat's case has one advantage the leopard seal's doesn't: its Red List status has actually been reassessed since 2016, rather than resting on a circumpolar count that's now a quarter-century old, but reassessment alone hasn't been enough to move the number.

Frequently asked questions

How much farther do male fishing cats range than females?

It depends on the setting. Rama Mishra and his co-authors, in their 2025 paper, put together a table stacking up Ratnayaka et al.'s Colombo GPS study as finding average home ranges of 12.49 among males and just 1.17 among females (both figures given in square kilometers), roughly a tenfold split. His own GPS study, run around that same reserve in Nepal's southeast and working from the 8 (of 11 collared) cats tracked long enough to calculate a range, found a narrower gap that still cleared statistical significance: 58.03 for males against 21.72 for females (again, square kilometers), roughly 2.7 times over.

Do fishing cats really have webbed feet?

Yes. Zoo researchers describe a partial web joining the toes on the front paws, plus claws that stay partly exposed rather than sheathing away completely, adaptations that help them grip wet riverbanks and mud while hunting fish and other aquatic prey.

Are fishing cats endangered?

This species carries a Vulnerable rating from the IUCN, set in a 2016 assessment that put the global decline at about three in ten animals over three generations, 2010 to 2015. That assessment body has not revised the rating since; separately, Nepal and Bangladesh each list the animal as Endangered on their own national red lists, a sharper local call than the global one.

Do fishing cats live inside cities?

Yes, at least in Sri Lanka's capital, Colombo, where a resident population lives inside urban wetland parks within the city itself. A 2021 GPS-collar study led by Anya Ratnayaka found all five tracked cats spent more time in built-up parts of town than the research team had expected going into the study.

What is the largest fishing cat home range ever recorded?

A 2025 GPS-collar study centered on the reserve at Koshi Tappu, in Nepal's southeast, collared 11 cats; among the 8 tracked long enough to calculate a home range, the first of two estimation approaches put the average at 29.12, a newer one that corrects for signal autocorrelation at 39.88, both figures in square kilometers. The 4 males in that subset, per Mishra's research team, averaged 58.03 square kilometers. That's over twice the largest male figure any prior study of the species had put on record: a top estimate of 22, from a different, earlier 1984 study inside Chitwan, a separate protected area elsewhere in Nepal.

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