The species was identified as a rusty-spotted cat (Prionailurus rubiginosus) based on body structure and characteristic body patterns: a slightly reddish grey pelage that gets darker towards the back, with elongated reddish brown/brown spots arranged longitudinally along the length of the body, extending throughout the body to the legs (Yapa & Ratnavira, 2013, p. 470), and a comparatively darker, unmarked bushy tail (Lamichhane et al., 2016). Further, the characteristic four lines that run longitudinally in the body, starting from just above the eyes (Aegle Creations, 2022), confirm their identity. According to the literature, it is shown that rusty spotted cats are mistaken for leopard cubs and therefore get killed in rural areas of India. 

Based on the location of the specimen collection, it can be predicted that this species is becoming a victim of habitat fragmentation due to development schemes, including expressways. Therefore, it can be assumed that the road and expressway network in the wet zone of Sri Lanka are major risk factors that contribute to the declining numbers of P. rubiginosus. Besides, studies conducted in India and Nepal also identify deforestation and the spread of cultivation as major threats to the survival of the species in India and Sri Lanka (Adhikari & Joshi, 2019; Patel, 2011). Based on this preliminary study, it is therefore required to systematically collect information and assess their vulnerability and mortality along the roads of the wet zone to propose solutions and future mitigation measures to conserve this globally threatened species. Furthermore, information on their population status, movement patterns, dietary preferences, habitat choices, and ecology is required for the management to be effective. Fairly fewer studies about the species have been conducted within Sri Lanka and the world as a whole. Therefore, only a little detail is known about its habitat preferences (Pawar et al., 2021), ecology, and reproduction.  

Considering the location and also according to Patel (2011), it can also be stated that the management plans need to be implemented and expanded even beyond the protected areas since several populations of this felid can survive and are under threat.    

The parasite assay could not find any external or internal parasites inside/on the specimen since it was conducted several days after death. Literature mentions that P. rubiginosus is highly susceptible to parasites, both internal and external ones as well (Langle 2019). Heavy worm infestations of roundworms in the stomach and intestines leading to severe congestion and hemorrhages have been recorded previously (Sabapara, 1999). Further, upon previous studies that included fecal analysis, it has been found that feces contained a large number of eggs of Toxascaris leonini, Trichuris, and Anchylostoma. The liver, spleen, and lung tissue samples have also revealed occurrences of Pseudomonas (Langle, 2019). Infestations of Toxocara, Coccidia, and Toxascaris have also been recorded at the Frankfurt Zoo in Germany (Dmoch, 1997). Therefore, based on this international research work and also as an extension of this preliminary study, it is suggested to analyze the internal tissue samples of P. rubiginosus for further understanding regarding the parasites.      

Their diet often consists of rodents, other small mammals, birds, and insects (Yapa & Ratnavira, 2013, p. 471). However, it is also known that some hunt frogs (Patel, 2006) and domestic fowl (Phillips 1935; Pocock, 1939; Sunquist and Sunquist, 2002) as well.  Dietary analysis of the food items in the stomach confirmed the clear presence of a rodent limb along with some other mammal residues.

In carnivorous animals, the identification of residues, including hair, feathers, bones, and scales, can all yield information about the food types consumed by them (Jordan, 2005). The analysis of dietary content can become less accurate when going further in the digestive tract; the further the food passes, the more it gets digested. Therefore, considering the results of the fecal analysis alone would not produce reliable results and can affect both qualitative and quantitative analyses as softer and readily digested food may be absent when it comes to the latter part of the digestive tract and therefore can go unnoticed in fecal analysis. This is a major drawback of post-digestion/ fecal analysis, which produces biased results. Thus, to avoid this effect, analyses were conducted separately for stomach, small intestine, and rectum content. 

The fragmented and digested food particles enter the feces. So, fecal analysis is useful for identifying the remaining food particles, skeletal remains, and fur of any animal.

According to Langle (2019), P. rubiginosus is distinguished from P. bengalensis (Leopard cat), considering its body measurements. The total length of the leopard cat is comparatively and visibly greater than that of P. rubiginosus (Table 01). The body measurements were performed manually, which again increased the occurrence of human errors. Instead, using software to take the measurements would have increased the reliability and accuracy. The author also mentions that when the body length values overlap, the next factor to consider is the coat patterns. Therefore, the correct identification of hair colour and pattern is important.  

Hair analysis serves as a crucial tool for examining and identifying different species by studying the morphology and microscopic structure of hair samples. This includes characteristics such as hair type, pigmentation, cuticle scale pattern, medulla patterns, cross sections, and hair dimensions, which are analyzed using a light microscope and hair imprinting techniques. Mammalian hair, being highly resistant to digestion, remains intact in feces, allowing for easy species-level diagnosis through microscopic analysis. The cuticular scales, medulla, and cross-sectional features enable the differentiation of closely related species (Brunner & Coman, 1974; Teerink, 1991). To ensure reliable results, hair samples are collected from multiple body sites.

In this study, hair analysis was conducted, focusing on uni-color and bi-colored hairs in the abdominal region of the dorsal side. Unique characteristics of the patterns in the cuticle and medulla of the hair are used to distinguish different species. This also provides insights into the environmental adaptations and genetic diversity of the species. According to the results, the microscopic analysis reveals coronal scales with a mosaic pattern and a multiseriate ladder medulla in the shaft, transitioning to a lattice structure in the shield region of guard cells in both hair types within the abdominal region (Amerasinghe, 1983).

Several hair analyses were carried out to confirm the presence of different species in the stomach, intestine, and feces. Varied types of bones were found in each region, prompting hair analysis of guard hairs from the mammalian species in the stomach. Uni-colored hairs, with an average length of 11.50 mm and an average width of 0.13 mm, were identified, confirming the species as a rodent. This determination was based on the identification of cuticle patterns as coronal scales with a mosaic pattern and a lattice-type medulla (Amerasinghe, 1983). Furthermore, the study includes a color analysis of hair from different body parts of the rusty-spotted cat. 

Skull measurements and dentition of mammal skulls allow differentiation between species. The skulls of the five species in the Prionailurus genus are visibly different (Langle, 2019). Nasals being strongly compressed with a height of 23.93 mm and a breadth of 9.30 mm and the maxilla is greatly expanded, are two of the most distinguishable features of P. rubiginosus. P.rubiginosus also does not have a very prominent sagittal crest, unlike other species. 

The presence of only two upper premolars is also an important feature (Pocock, 1939) when considering the dentition of the specimen. The archetypal cat carnassial pair of molars which is seen typically in members of Felidae are known to provide the shearing and cutting action of prey (Sicuro,2011). According to Langle (2019), the dental formula of P. rubiginosus generally is i 3/3, c 1/1, p 2/2, m 1/1 all summing up to 28. However, in this specimen, only 1 premolar was seen in the upper jaw which can be due to the injury.     

Since a previous study has not been conducted with the morphometrics of the rusty-spotted cat, this study aims to fill the knowledge gap and lay the foundation for future research associated with the species. The social structure and behaviour of rusty spotted cats remain less studied. However, they are known to be terrestrial with arboreal tendencies (Ratnayaka, 2021b). The presence of short, retractable claws, like in all felids, helps them grip and climb trees. Their agile bodies are capable of maintaining good balance, making navigation on branches and other uneven surfaces easy.    

Differentiation of P. rubiginosus from P. viverrinus is often done by comparison of their tail lengths in relation to head and body length and hind foot length (Langle, 2019). The tail of P. rubiginosus is greater than one-half the length of the head and body and more than twice as long as the hind foot, while in P. viverrinus, the tail is less than one-half the head-body length and less than two times the length of the hind foot.