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

Camera Trap Tool Tip: Trap Duration Calculator

An important measure when analysing camera trap data is the trapping effort of each camera trap and the total for a study. This is typically measured in number of trap nights, usually defined as a continuous 24-hour period when a camera trap is set to be active. The information can then be used for other analysis, such as mark-recapture to estimate population size.

As my camera traps are in the field for long periods of time, I like to be able to visualise the camera trap data graphically to track patterns more easily. To do this, I create a master map to visualise how long each trap is active and on which days leopard cats were recorded at each site. This is done with Microsoft Excel to plot dates and shade cells with colour codes when traps were active and when leopard cats were recorded. This also allows me to summarise camera trap effort.

Visual representation of camera trap data

However, being poor in math, calculation of camera trap effort is a real challenge. Imagine the pain of calculating camera trap effort for a time period between 5 Oct 2012 4:42pm to 2 Dec 2012 1:10am! For this, I am glad there are tools which other camera trap practitioners may also find useful.

Web calculator

Timeanddate.com has a web-based time duration calculator that allows the user to enter start and end date and time. Saves time.

Date and time duration calculator from timeanddate.com

Excel alternative

A non-web based alternative is to use this Excel formula: =INT(B2-A2)&””
Where depending on format, A2 is the start date and time [e.g., dd/mm/yyyy hh:mm] and B2 is the end date and time.

Good ole Excel

My poor brain is thankful for all these things.