Two's company? Solitary vixens’ motivations for seeking social contact

Abstract

a b s t r a c tThe flexible social organisation in red foxes (Vulpes vulpes) suggests that social contact could enrich the housing of silver fox vixens (a selected line of red foxes) farmed for their fur. To investigate their social motivation, adult vixens housed in an operant apparatus were allowed to pull a loop for full physical contact with a same-aged vixen. The access cost was increased daily and their maximum price paid (MPP) measured. Five test and five stimulus animals were pair housed long-term in separate apparatuses over 5 weeks in November/December wherein each pair could have 12 h daily physical contact in a shared compartment. Prior to the operant trials, two food competition tests were completed to establish dominance relations within pairs. To examine vixens' motives for contact, social behaviour during interaction was also recorded. Subsequently, the test foxes' MPP for a comparator resource, food, was also measured and their relative price paid (RPP, %) for contact calculated. When access to the resource cage was free (FR1), at the start and end of the experiment, time spent in contact averaged approximately 1/6 (2 h) of the available time; this was stable between these periods. Neither visit rate to nor time spent in the shared compartment differed between the start and the end of the trial, indicating that the test subjects' social motivation remained stable during the experimental period. The MPP (mean ± SE) for social contact averaged at 560 ± 160.6 pulls; this was significantly lower (P = 0.015) than the MPP for food (2108 ± 526.6 pulls), representing a RPP of 24.8 ± 3.36%. During social interaction agonistic gaping signals occurred (though never serious fights requiring intervention), but there were also bouts of play, social exploration and high levels of synchronous resting. Aggressive behaviour during the second food test predicted the levels of aggression during operant trials. RPP positively correlated with the total time spent together (r = 0.87, P = 0.054), and with the time spent resting together (r = 0.89, P = 0.046). Differences in RPPs for contact and levels of agonism between pairs illustrate that social contact between adult vixens is enriching for some, but may put welfare at risk for others, especially if they have no opportunity to retreat from aggression. However, levels of agonistic behaviour during, e.g. food competition tests may be a possible indicator of the compatibility between potential cage mates. Due to the low number of animals the result must now be replicated with further animals.

To free, or not to free: Social reinforcement effects in the social release paradigm with rats

“…Conceptualizing social release in terms of social reinforcement has several advantages. First, it is consistent with a longstanding body of literature showing that contingent access to social stimuli can function as a reinforcer across a variety of procedures, including T-maze and operant tasks, and in a range of species, including chimpanzees (Mason, Hollis, & Sharpe, 1962), capuchin monkeys (Dettmer & Fragaszy, 2000), horses (Sondergaard, Jensen & Nicol, 2011), foxes (Hovland, Akre, FlF, Bakken, Koistinen & Mason, 2011), calves (Holm, Jensen, & Jeppesen, 2002), sows (Kirkden & Pajor, 2006), mice (Martin, Sample, Gregg, & Wood, 2014), and rats (Evans, Duvel, Funk, Lehman, Sparrow, Watson & Neuringer, 1994; Humphreys & Einon, 1981; Wilsoncroft, 1968).…”

“…The reinforcer duration we used (10 s) was also relatively brief, and there are good reasons to think that longer social access times would increase social reinforcer value. Evans et al (1994), who found comparable levels of responding for social and food reinforcers, used 45-s access time; in some studies, social access times are even longer (Hovland et al, 2011). Research has also shown an important role for reinforcer quality (Feuerbacher & Wynne, 2015; Holm et al, 2002).…”

“…Gilbertson (1975), for example, found that pigeons responded at a higher rate for access to food than to visual access to their mate. Similarly, foxes (Hovland et al, 2011) and mice (Martin et al, 2014) paid higher prices for food than for social access to a same-sex conspecific. Other studies, however, with capuchin monkeys (Dettmer & Fragaszy, 2000) and rats (Ben-Ami Bartal et al, 2011; Evans et al, 1994; Sato et al, 2015), have reported comparable value of social and food reinforcers.…”

Social preference in rats

“…257‐258). One important type of reinforcing consequence mediated by another organism is the opportunity to engage in social interaction; and indeed, social reinforcement effects have been reported in a range of species, including humans (Jones et al, 2011) chimpanzees (Mason et al, 1962), capuchin monkeys (Dettmer & Fragaszy, 2000), horses (Søndergaard et al, 2011), foxes (Hovland et al, 2011), calves (Holm et al, 2002), pigs (Kirkden & Pajor, 2006), mice (Martin et al, 2014), and rats (Evans et al, 1994; Wilsoncroft, 1968) (see review by (Trezza et al, 2011).…”

Demand for Social Contact in Rats: Toward a Quantitative Analysis of Social Reinforcement Value

“…Palabras clave: reforzamiento social, análisis de demanda, procedimiento de ayuda, ratas There is ample evidence from both field and laboratory research that social contact can serve as a potent source of reinforcement in a broad range of species, including chimpanzees (Mason, Hollis, & Sharpe, 1962), capuchin monkeys (Dettmer & Fragaszy, 2000), horses (Søndergaard, Jensen, & Nicol, 2011), foxes (Hovland et al, 2011), calves (Holm, Jensen, & Jeppesen, 2002), sows (Kirkden & Pajor, 2006), hamsters (Borland et al, 2017), prairie voles (Beery, Christensen, Lee, & Blandino, 2018), mice (Martin, Sample, Gregg, & Wood, 2014), and rats (Evans et al, 1994;Wilsoncroft, 1968) (see review by Trezza, Campolongo, & Vanderschuren, 2011).…”