Introduction

The domestic cat, Felis catus , is a very popular domestic animal and is currently one of the most common carnivores in the world (O’Brien et al., 2007). Unlike most domesticated animals, cats’ behavior has only been slightly modified by domestication, as they generally retain the ability to survive even in the absence of human support (Crowley et al., 2020a). As a result, cats have widely varying degrees of dependence on humans depending not only on the local ecological and cultural context but also on whether they have an owner and the level of control exercised by that owner. Crowley et al. (2019) distinguish a spectrum of cats ranging from feral cats that are neither dependent on nor controlled by humans to indoor cats that are fully confined with their food, reproduction, and movements being closely controlled by humans. Many developed countries have very large pet cat populations. In France, for example, the pet cat population reached 15.1 million in 2020 (up from 10.7 million in 2008) (FACCO/KANTAR-TNS survey 2020), with potentially significant consequences on their wild animal prey.
Cats are generalist predators introduced by humans globally, and their potential impact on wildlife is the subject of growing international interest and concern (Loss et al., 2017; Crowley et al., 2020a). They hunt many types of prey, including invertebrates and vertebrates, mainly mammals, birds, and reptiles (e.g., Barratt, 1997; Castaneda et al., 2019, 2020). The ecological impacts of cats have been shown to be particularly severe on island ecosystems, where island vertebrates have never coexisted with such introduced mammalian carnivores, and cats are a major driver of extinctions of insular endemic birds, mammals, and reptiles (Medina et al., 2011; Bonnaud et al., 2012; Doherty et al., 2016; Palmas et al., 2017). On continents, cats have been shown to be responsible for high vertebrate mortality (e.g., Blancher, 2013; Loss et al. 2013), although the extent to which their predation represents a form of compensatory or additive mortality is currently under debate (Loss et al., 2017), as they consume the most abundant prey and rarely the most vulnerable or declining species. For example, cats are probably the single greatest source of anthropogenic mortality for birds and mammals in the United States (Loss et al., 2013), although prey population dynamics are rarely considered simultaneously with cat predation pressure. In Australia, cats were shown to cause higher mammal mortality than another threatening process, namely land clearing (Murphy et al., 2020).
The majority of research to date has focused on the behavior and impacts of feral cats (see the recent review of Loss et al. 2022), which are dependent on the abundance and availability of natural prey species. However, most pet cats that are fed by their owners retain some tendency to hunt, and as they can reach very high population densities in areas where humans are also numerous (Baker et al., 2005; Sims et al., 2008), their overall impact can be severe. Several studies have shown that pet cats have highly variable predation rates. For example, Baker et al. (2008) and Thomas et al. (2012) respectively showed in the cities of Bristol and Reading, UK, that approximately 60% of pet cats did not return prey home in the study period. Loyd et al. (2013) observed a very similar proportion (56%) in a suburban area of southeastern USA. Similarly, Tschanz et al. (2011) observed that pet cats in a rural Swiss village considerably varied in their hunting activity, with 16% of cats accounting for 75% of the recorded prey, thus highlighting the importance of identifying the factors that determine the predation rates of individual cats. Cechetti et al. (2021a) recently reviewed the drivers of hunting behavior in domestic cats. For the authors, whereas general cat hunting is mainly driven by evolutionary constraints and the associated physiological and nutritional requirements, the causes of variation in hunting behaviors among pet cats mainly relate to prey availability in the environment and the owners’ practices. These practices include the level of outdoor access given to their cats, the amount and quality of the food provided, and the amount of time spent playing with the cat (Cechetti et al., 2021b).
Variations in hunting activity have also been linked to the individual characteristics of cats such as their sex, age, and body size (Kays et al., 2004; Moseby et al., 2015), although a number of studies have failed to find an association with these factors (Woods et al., 2003; Tschantz et al., 2011; Loyd et al., 2013; Cordonnier et al., 2022). Recently, Cecchetti et al. (2021a) hypothesized that personality could be a significant factor contributing to variations in hunting activity between cats. Over the past few decades, it has been recognized that in numerous animal taxa ranging from invertebrates to vertebrates, individuals show different behavioral tendencies that are consistent over time and across ecological contexts, a phenomenon commonly known as animal personalities (Réale et al., 2007, 2010; Wolf et al., 2012). For example, boldness, aggressiveness, or sociability are commonly studied animal personality traits (Réale et al., 2007). Personality traits are frequently correlated: for example, animals that are bolder in risky situations also have a tendency to be more aggressive toward conspecifics, resulting in what is known as “behavioral syndromes” (Sih et al., 2004). Animal personalities have substantial consequences for numerous ecological processes (Wolf et al., 2012; Spiegel et al., 2017; Brehm et al., 2019). Regarding predator-prey interactions, several studies have shown that individual differences in predator behavior can influence hunting (Pettorelli et al., 2011). For example, in several predator fish species, bolder individuals have a markedly higher predation rate compared with shyer ones (Ioannou et al., 2008; Rhoades et al., 2019). In their review of the drivers of hunting behavior in domestic cats, Cecchetti et al. (2021a) speculated that cats with certain personality traits, particularly those with high levels of boldness and extraversion, could potentially be more motivated to hunt wild prey. To our knowledge, this hypothesis has never been investigated. It is therefore the main objective of our study to examine this potential link between personality and predation in domestic cats.
Presently, in behavioral ecology studies, personality traits are usually estimated with the following approaches (Freeman et al., 2011): behavioral coding in which behavioral observation data are collected by researchers in either natural (i) or experimental settings (ii), and trait assessments (iii) in which the people who know the animal complete a survey describing the degree to which it shows particular personality traits. In domestic cats, although the first studies tended to use behavioral coding (Gartner et al., 2013), personality trait assessments based on a survey of the people familiar with the animals, usually their owners, are now more common (Wedl et al., 2011; Bradshaw et al., 2016), as they are both a reliable and time-efficient method (Bennett et al., 2017). These studies (reviewed in Gartner et al., 2013; Vitale Shreve et al., 2015; Mikkola et al., 2021) usually produced between one and seven personality factors, with the three most common factors being the personality traits of sociable, dominant, and curious, albeit with varying names. In this study, we used the Feline Five personality model of Litchfield et al. (2017), which consists of five personality dimensions in domestic cats: neuroticism, extraversion, dominance, impulsiveness, and agreeableness (see further details in the Methods section).
In this study, our primary objective is to determine whether the personality traits of pet cats are related to their hunting activity. To this end, we surveyed a large sample of cat owners living in France and estimated the personality traits of their cats using the Feline Five personality model of Litchfield et al. (2017) as well as the frequency of birds and mammals returned home by the cats as reported by their owners. Following Cecchetti et al. (2021a), we expected that cats with “low neuroticism (boldness, leading to travelling, exploring) or high extraversion (curiosity, leading to boredom), would potentially be more interested in hunting wild prey.” To control for potential confounding factors, we also included questions about variables previously shown to influence pet cat predation: type of environment around the home, time spent outdoors, individual characteristics, and breed (Robertson, 1998; Lepczyk et al., 2004; Kauhala et al., 2015; Salonen et al., 2019; Castañeda et al., 2019, 2020; Cordonnier et al., 2022).