Web lecture: Leopard Cats In Singapore: Surprising discoveries in our forests, but are they here to stay?

I did a web lecture for the Singapore Wildcat Action Group on 4 Jul 2020 about leopard cats in Singapore. The talk summarises what we know about the last wildcat remaining in the city state including its ecology, population genetics, threats (chiefly habitat loss and road mortality), and what can be done to ensure their survival.

The video was recorded and available here:

Two leopard cats rescued from a flat in Singapore to be returned to Malaysia

I am glad these two leopard cats seized from a flat in Singapore will be returned to Malaysia.

Two of the leopard cats on the way to their new home. Photo by Anbarasi Boopal / ACRES.

They were kept illegally and rescued following a tip-off in July 2018. DNA analyses confirmed they were not from Singapore. Instead they matched with known Malaysian animals.

This process highlights the key roles of wildlife groups, including wildlife rescue by ACRES: Animal Concerns Research and Education Society (Singapore), government agencies (then AVA and NParks), and zoo (Wildlife Reserves Singapore) working together to fight wildlife crime and care for the animals.

Also, local biodiversity research was necessary to determine these leopard cats were not from Singapore (well done Tekong, Western Catchment and Central Catchment leopard cats!). The genetic work was done by a government lab and results were compared with Singapore leopard cat DNA sequences.

I feel the $500 fine seems light for the trouble caused. The staff hours, genetic testing, husbandry costs, and prosecution work probably adds up to thousands of dollars. Plus, the trauma these animals have to endure cannot be compensated.

The illegal wildlife trade is harmful to the environment, where the population and ecology are affected, and it hurts the welfare of the animals involved. I hope animal lovers are aware and do not support it.

Do not harm wildlife by taking them from the wild. Photo by Anbarasi Boopal / ACRES.

Chandra, A. 2020. 2 endangered Asian leopard cats rescued from HDB flat to be returned to wild in Malaysia. Today. <https://www.todayonline.com/singapore/2-endangered-asian-leopard-cats-rescued-hdb-flat-be-returned-wild-malaysia-nparks>

Identification of individual Amur leopard cats possible using face and ventral patterns

The Amur leopard cat (Prionailurus bengalensis euptilurus) is the largest leopard cat. Unlike most leopard cats with bold black spots on a tawny background, their spot pattern is rather dim. Some researchers have said is it difficult or impossible to discern the patterns and individual from camera trap images. Until now.

A new research paper from South Korea has demonstrated that it is possible to identify individual Amur leopard cats using their face and ventral patterns.

Comparison of markings from Amur leopard cat A) face from high-resolution images and B) vent from low-resolution camera trap images from Park et al. (2019).

The researchers used high and low resolution camera trap images and the image comparison software HotSpotter to reliably identify leopard cats baited using valerian scent lures.

I too found that face and ventral markings are practical for individual leopard cat identification, and they can be a lot less confusing than the sea of spots on the flanks. Of course, sometimes more data and angles is best. This seems promising for the Amur leopard cat, and I am looking forward to seeing population density estimates using the application of this method.

 

Park H., Lim A., Choi T-Y., Baek S-Y., Song E-G., Park Y.C. 2019. Where to spot: individual identification of leopard cats (Prionailurus bengalensis euptiluris) in South Korea. Journal of Ecology and Environment 43: 39. doi:10.1186/s41610-019-0138-z

Leopard cat activity is higher with increased understory vegetation in oil palm plantations, which seems to result in reduced rat numbers

Leopard cats are known to use oil palm plantations as a hunting ground for rats, and have been proposed as a possible biological control for rodent pests in plantations. Related to this, there have been questions raised regarding how understory vegetation management in oil palm plantations [many places consider these weeds and clear them] may influence leopard cat use of these sites. Finally, a study examines these unknowns.

A recently published study by Hood et al. (2019) showed that leopard cat habitat use is higher with increased understory vegetation. They also demonstrate reduced rat numbers with higher leopard cat activity. The authors suggest that the results indicate that how oil palm plantations are managed can affect leopard cat use, and possible rodent control possibilities. All these only possible with their manipulative experiments on understory vegetation management.

Experimental vegetation treatments in oil palm plantation by Hood et al. (2019) showing reduced, normal, and enhanced understory vegetation.

Curiously, there was no effect of understorey vegetation on rat numbers or rat damage on oil palm in this study. It could be that the rats benefit from more vegetation, but the higher activity of leopard cats in those environment leads to higher rat predation level, which nullified the benefits to rats. Neat if that could somehow be studied in future.

Hood et al. (2019) Understory vegetation in oil palm plantations promotes leopard cat activity, but does not affect rats or rat damageFrontiers in Forest and Global Change 2: 51. doi: 10.3389/ffgc.2019.00051

Leopard cats and roads

The leopard cat is second on the list of “endangered animals killed on the road” in Peninsular Malaysia in the first nine months of 2017. Fourteen leopard cats succumbed during that period according to the Ministry of Natural Resources and Environment in a statement that was reported by Channel News Asia.

Sunda leopard cat roadkill adjacent to oil palm plantation in Borneo. Photo by Koh Lian Pin.

Other species killed include Malayan tapir, elephant, binturong and leopard.

Malaysia’s Department of Wildlife and National Parks (PERHILITAN) has since put up warning signs for motorists, is in talks with driving schools to improve drivers’ awareness, and are avocating more wildlife-friendly viaduct crossings to be built at road developments.

Based on a recently published study (Laton et al.), most leopard cat roadkills seem to be on tarmac roads adjacent to areas where there are secondary forest and plantations.

One reason for this is that leopard cats, like many carnivorans, seem to be fond of roads near forested areas. Perhaps this is because it is easier to travel, find, and catch prey along roads. However, this put them right in harms way, and many end up as roadkill.

Road mortality is not just a problem for the leopard cat but also wildlife in general. But it is an issue that can only be effectively solved with multiple decision makers. Signs in Singapore and Malaysia show that this is coming together. Hopefully, with sound science-based decisions for policy planning and roadkill mitigation, wildlife roadkills would not exacerbate the ongoing biodiversity crisis in Southeast Asia.

Laton, M.Z., Mohammed, A.A., Yunus, H. 2017. Roadkill incidents of the leopard cat (Prionailurus bengalensis) in the exterior wildlife reserved: A selected plantation area case. Journal of Entomological and Zoology Studies 5(4): 1507-1513.

The leopard cat is now 2!

It’s true, the IUCN Cat Specialist Group now recognise 2 species of leopard cats:

  1. Mainland leopard cat, Prionailurus bengalensis (Kerr, 1792)
  2. Sunda leopard cat, Prionailurus javanensis (Desmarest, 1816)

Distribution of tentative subspecies of mainland leopard cat and Sunda leopard cat. Borders between subspecies are speculative. From Kitchener et al. (2017).

This split is mainly because of evidence from molecular studies, morphological differences and biogeographic separation.

There was already some suggestion that there could be 2 species of leopard cats since the molecular study by Tamada et al. (2008). However, it looks like the findings by Patel et al. (2017) [which I wrote about in the previous post] who found a “deep split” between mainland and Sunda animals, solidified the decision by the IUCN Cat Specialist Group. This despite Patel et al. (2017) choosing to regard the leopard cat as one species.

With this change, a re-appraisal of the biology of both species, including reassessments for the IUCN Red List, is probably necessary. What is interesting too is the question of how similar are the two species ecologically? We may need to re-examine studies in the past that regarded the two as the same. Despite this, the mainland leopard cat still remains the most widely distributed small wild cat in Asia.

Although both species are regarded as being of “low conservation concern”, there remains some research priorities recommended by specialist group for these two species of leopard cats in terms of phylogeography and morphology.

Our data indicate those in Singapore to be the mainland species. So do I have to change the name of this site to “Through the Eyes of the (Mainland) Leopard Cat”?

 

Kitchener, A.C., et al. (2017) A revised taxonomy of the Felidae. The final report of the Cat Classification Task Force of the IUCN/SSC Cat Specialist Group. Cat News Special Issue 11. 80 pp.

Leopard cat publication update 2015 to 2017

Some leopard cat publications were out in the last two years, and I try to keep track of as many as possible. Some quick thoughts and summary:

Nakanishi & Izawa took a look at the importance of frogs in the diet of the leopard cats from Iriomote Island, Japan. I must say that the Japanese are the gold standard in leopard cat species biology work with the population on Iriomote Island. They examined the stomach contents and compared the results to scat analysis, which is traditionally more frequently used as it is less invasive. Frogs appeared to be important, but under represented compared to scat studies.

Meanwhile. Srivathsa et al. were one of the first to use camera traps to estimate leopard cat population density in India. The density in in forests there appear to be similar to Sabah, but below what we have on Pulau Tekong, Singapore.

Going back about 5,000 years ago, it seems that leopard cats had some close interaction or relationship with Neolithic people in China. The authors (Vigne et al.) use the term “domestic”, but I’ll hesitate to do so in the strict sense of the word.

And finally, a molecular phylogeography of the leopard cat sampled across its global distribution. Rather important that this is done, and the coverage is quite admirable. I cannot say the results are unexpected though (see image below).

Distribution of leopard cat subspecies suggested by Patel et al. (2017). Image from paper.

Arjun Srivathsa, Ravishankar Parameshwaran, Sushma Sharma, K. Ullas Karanth. (2015) Estimating population sizes of leopard cats in the Western Ghats using camera surveys. Journal of Mammalogy 96(4): 742-750. doi: 10.1093/jmammal/gyv079

Nakanishi, N. & Izawa, M. (2016) Importance of frogs in the diet of the Iriomote cat based on stomach content analysis. Mammal Research 61: 35. doi:10.1007/s13364-015-0246-9

Riddhi P. Patel, Saskia Wutke, Dorina Lenz, Shomita Mukherjee, Uma Ramakrishnan, Géraldine Veron, Jörns Fickel, Andreas Wilting, Daniel W. Förster. (2017) Genetic Structure and Phylogeography of the Leopard Cat (Prionailurus bengalensis) Inferred from Mitochondrial Genomes. J Hered 2017 esx017. doi: 10.1093/jhered/esx017

Vigne J-D, Evin A, Cucchi T, Dai L, Yu C, Hu S, et al. (2016) Earliest “Domestic” Cats in China Identified as Leopard Cat (Prionailurus bengalensis). PLoS ONE 11(1): e0147295. https://doi.org/10.1371/journal.pone.0147295

Leopard cat (and other rainforest biodiversity) art by Loy Xingwen

I was brought to the attention to this artwork of Loy Xingwen by a colleague of mine, Jeremy Yeo.

Leopard cat by Loy Xingwen

Leopard cat by Loy Xingwen

This series of illustrations, including this beautiful leopard cat, was made using PowerPoint (Microsoft Corporation, Washington – [with ref. to this in Science]). PowerPoint! While the rest of us are struggling with re-sizing AutoShapes,  he is creating these sleek layered and shaded masterpieces. He has kindly given permission for his artwork to be reproduced here.

Accompanying the image is a write up:

This beautiful animal was once believed to be national extinct but a recent study has found that they are definitely still hanging on. Win! Nevertheless, they remain critically endangered in Singapore. Here, they are mainly threatened by the clearing of forests. The leopard cat is similar in size to a domestic cat and is a predator, hunting small animals such as rats, lizards and birds. Needless to say, it is very elusive and rarely seen.”

Xingwen is a plant ecologist at the University of Queensland, and started this project to raise awareness about Singapore’s natural heritage through his art. See the rest of the planned 40 rainforest biodiversity of Singapore art at his Facebook album here.

New publication: Density, spatiotemporal use and diet of the leopard cat in a human-modified succession forest of Singapore

Our publication on Density, spatiotemporal use and diet of the leopard cat in a human-modified succession forest of Singapore is out in Mammal Research.

I will not reproduce the abstract here, but a TLDR summary is that leopard cat population density and occurrence is higher in oil palm areas next to secondary forest compared to within secondary forest on the island of Pulau Tekong, Singapore. In the oil palm areas, they were completely nocturnal and ate more rats compared to elsewhere on the island, where they had more diurnal activity and hunted more birds, insects and lizards. These finding suggest that leopard cats are oil palm adapters that take advantage of the rich prey resource in the oil palm area.

Some thoughts:

  1. Am glad that this came out between the education manager job that I was initially assigned with at the natural history museum, the massive museum move, and sperm whale carcass salvage operation that took place. I also feel incredibly thankful to have the opportunity to work on something that I had always wanted to do. Most of this fell in place because of the people who made it possible. Majority of this work was done on an island that is out of bounds to the public, and I am hoping to have the privilege to be back for some follow up work.
  2. Being relatively early and inexperienced in the research and publishing circuit, I went with the kitchen sink approach for the manuscript. Eventually, a weaker component eventually got the axe with the almost unequivocal agreement of 4 reviewers. So the lesson learnt is that telling a succinct story with the best data is something I need to work on.
  3. In this study we almost quantified the obvious—someone has to do that—to answer basic ecology questions. One finding was that Pulau Tekong has the highest population density of leopard cats of any study done till date (89.4 ind./100 km2). However, leopard cats in Singapore remain nationally critically endangered. Not surprising because Singapore is tiny, and the suitable habitats for the species are limited and fragmented. These will be crucial in ensuring the long term survival of the species here.
  4. We recorded leopard cats on reclaimed land for the first time in the world. This is novel habitat created from the sea by filling it with sand. Secondary succession took over and leopard cats colonised it. Pretty neat (but marine habitat destruction in land creation). As the reclaimed part was separated from the original island by a channel, I remember telling my survey team, “we are just going to put up cameras and do transects to prove they [leopard cats] are not here…”. Happy to be proven wrong by data and these resilient little beasts.

Leopard cat on RL

Publication updates and leopard cat featured in a children’s book

Some updates and news regarding leopard cats in Singapore:

Our first international peer-reviewed publication from the leopard cat study has been accepted in Mammal Research. Look out for it soon.

Meanwhile, I was asked to contribute some sighting records to Singapore Biodiversity Records of the Lee Kong Chian Natural History Museum earlier this year:

1. Chua, M.A.H. 2015. Leopard cat in Western Catchment Area. Singapore Biodiversity Records 2015: 6. [PDF]
2. Chua, M.A.H. 2015. Leopard cat in Central Catchment Nature Reserve. Singapore Biodiversity Records 2015: 20. [PDF]

Was pleasant surprised when I was informed that the leopard cat is featured in a children’s book, Timmy and Tammy Discover Singapore’s Wildlife Wonders by Hwee Goh. Had worked with the author to facilitate another section of the book about the natural history museum, and was glad when she informed me that she was featuring the leopard cat. The book is available in book stores now, and is a good introduction to wildlife in Singapore for children.

SWW - leopard cat

Page excerpt from Timmy & Tammy Discover Singapore’s Wildlife Wonders by Hwee Goh.

 

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