Blue foxes’ (Vulpes lagopus) motivation to gain access and interact with various resources
Introduction
The welfare of blue foxes (Vulpes lagopus) is a significant issue. Annually, approximately two million blue foxes are farmed for their fur on commercial fur farms in Europe (Fur Europe, 2015). The housing conditions of blue foxes consist of mesh cages in outdoor sheds. According to European recommendations, the cages must be furnished with a platform for surveillance of the surroundings and an object for oral activities and play (European Convention, 1999). Due to continuous debate on the welfare of farmed foxes in the current housing conditions (e.g. Nimon and Broom, 2001, Akre et al., 2008), various enrichment items, e.g. year-round nest box (Korhonen et al., 2006), sand floor (Koistinen et al., 2008), straw (Korhonen et al., 2002), dog toys (Pedersen, 2004) and scratching plate (Korhonen and Huuki, 2011) have been introduced to fox cages in scientific studies. These resources were designed to promote variable behavioural repertoire in the cage housing and to meet the potential behavioural needs of this species, since these factors are crucial in ensuring animal welfare.
Research on housing conditions show that individual resources may serve several functions (Koistinen and Korhonen, 2013). In such cases, the welfare effects of any single resource remain slightly ambiguous. Nest boxes can be used as a secluded resting area, observation place (roof), defecation/marking site, medium for scratching and gnawing (Korhonen et al., 2006, Koistinen and Korhonen, 2013) 20–30% of daily time (Mononen et al., 1996, Koistinen and Korhonen, 2013). Access to a nest box may increase fearfulness of foxes towards human, but does not affect the prevalence of stereotypic behaviour or adrenal function (Korhonen et al., 2006). A sand floor provides sensory feed-back through the foxes’ paws, an elimination site, a substrate for exploration and digging, and the pebbles can be used for playing (Koistinen, 2009). Blue foxes are willing to work for access to short visits on a sand floor (Koistinen and Mononen, 2008), but a mesh floor is highly preferred in the daily time-budget (Koistinen et al., 2008). Access to a sand floor decreases occurrence of stereotypic behaviour (Koistinen et al., 2008), but no consistent effect to the blood parameters or adrenal function has been detected (review in Koistinen, 2009). Interaction with the platform varies considerably between individuals, from 0 to 60% of day (Mononen et al., 1996, Koistinen et al., 2008, Koistinen et al., 2009a), and does not reveal consistent positive effect to welfare of foxes in the means of stereotypic behaviour or adrenal function (review in Mononen et al., 2012). Instead, the wooden block (Korhonen and Niemelä, 2000) bone (Koistinen et al., 2009a) and probably also some other small objects can be used for gnawing, carrying, play, poking and such short-duration activities, for up to 77 times a day (Korhonen and Niemelä, 2000). Access to these objects decrease occurrence of stereotypic behaviour (Korhonen et al., 2002, Koistinen et al., 2009a) and improve dental health, but do not clearly affect adrenal function (Korhonen et al., 2002, Ahola et al., 2010). Thus, the interaction with these resources and their welfare effects remain somewhat unclear.
In the present study we concentrate on the interaction of blue foxes with a platform, wooden block, nest box, sand floor and empty space. In our earlier study, time-budget calculations revealed that juvenile blue foxes continued interacting with all these resources when they were simultaneously available in a complex housing environment (Koistinen and Korhonen, 2013). An animal’s time-budget provides important information of the resource use (Elmore et al., 2012), but one measurement cannot typically reveal all aspects of the interaction with the resources. In order to accomplish the previous knowledge of the foxes’ interaction with these resources, in the present study, we measure the willingness of the foxes to gain access to the resources and the urge to start interacting with the resource. In this design, the foxes have to push through a weighed door to be able to interact with the resource. The number of entries, visit duration and the resource use are typically affected by the increasing cost to the access to the resource (e.g. Cooper and Mason, 2000). It is hypothesised that, the more the animal tries to sustain the resource use against increasing cost, the more the animal is motivated to gain access to the resource. The latency to start interacting with the resource after entering the resource is measured to show the urge of the foxes to interact with the resource.
Section snippets
Material and methods
The present experiment was approved by the Animal Care Committee of MTT Agrifood Research Finland and carried out on the research station of the former MTT Agrifood Research Finland situating in western Finland, in Kannus.
Number of entries and visit duration in the RC and CC
Only three out of 10 foxes passed through the heaviest, 8 kg door for all resources. Six foxes passed through the 8 kg door for 2–4 resources, and one fox never passed through the heaviest 8 kg door, but passed throughout the 7.5 kg door for platform, empty space and nest box. When looking at the number of foxes passing through the heaviest 8 kg door, 7, 4 and 6 foxes, out of 10, passed through the heaviest door in the case of sand floor, platform and empty space, respectively; whereas, 6 out of 8,
Discussion
We succeeded in making the entry through the one-way door to the RC more difficult, as the number of entries to the RC decreased with increasing workload and not all foxes passed through the one-way door loaded with the heaviest, 8 kg of extra weight. However, since adult blue foxes (Koistinen et al., 2009b) and mink (Cooper and Mason, 2000) can pass through one-way doors loaded with a weight close to their own body weight, i.e. 8 kg in foxes with body weight of 9–10 kg and 1 kg in mink with body
Acknowledgements
The authors are grateful to Hanna Huuki, Eija Korpela and Martti Koskinen for practical assistance, Paula Martiskainen for drawing (Fig. 1), to Vesa Kiviniemi for statistical assistance and to Roseanna Avento for language check. The study was financially supported by independent funding from Ministry of Agriculture and Forestry, the former MTT Agrifood Research Finland and Finnish Cultural Foundation North Savo Regional fund.
References (28)
- et al.
Gnawing bones as enrichment for farmed blue foxes (Vulpes lagopus)
Animal
(2010) - et al.
Increasing costs of access to resources cause re-scheduling of behaviour in American mink (Mustela vison): implications for the assessment of behavioural priorities
Appl. Anim. Behav. Sci.
(2000) - et al.
Differing results for motivation tests and measures of resource use: The value of environmental enrichment to gestating sows housed in stalls
Appl. Anim. Behav. Sci.
(2012) - et al.
Responses of farmed silver foxes (Vulpes vulpes) to excessive food availability: implications for using food as a yardstick resource in motivation tests
Appl. Anim. Behav. Sci.
(2007) - et al.
Complex housing environment for farmed blue foxes (Vulpes lagopus): use of various resources
Animal
(2013) - et al.
Blue foxes’ motivation to gain access to solid floors and the effect of the floor material on their behaviour
Appl. Anim. Behav. Sci.
(2008) - et al.
Blue foxes’ (Alopex lagopus) preference between earth floor and wire mesh floor
Appl. Anim. Behav. Sci.
(2008) - et al.
Bones as enrichment for farmed blue foxes (Vulpes lagopus): interaction with the bones and preference for a cage with the bones
Appl. Anim. Behav. Sci.
(2009) - et al.
Relative value of a nest box, sand floor and extra space during the breeding season in adult blue fox males
Appl. Anim. Behav. Sci.
(2009) - et al.
Exploratory activity as a measure of motivation in deprived hens
Anim. Behav.
(1991)
Periparturient behaviour in farmed blue foxes (Alopex lagopus)
Appl. Anim. Behav. Sci.
Changes in meal pattering by mice measure the cost imposed by natural obstacles
Appl. Anim. Behav. Sci.
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Preference for and use of oral enrichment objects in juvenile silver foxes (Vulpes vulpes)
2016, Applied Animal Behaviour ScienceCitation Excerpt :For instance, enrichments reduce pecking injuries in turkeys (Sherwin et al., 1999) and stereotypy levels in several farm and laboratory species (e.g. Mason et al., 2007); improve reproductive productivity in female mink (Buob et al., 2013); induce optimistic affective states in pigs (Douglas et al., 2012) and the mere announcement of enrichment increases play behaviour in piglets (Dudink et al., 2006). Knowledge about the type of enrichment that silver foxes would prefer is scattered and based on experience from commercial situations and generalizations made from research on related species such as blue foxes (Vulpes lagopus), dogs and other captive carnivores (e.g. Koistinen et al., 2016; Koistinen and Korhonen, 2013; Pullen et al., 2010; Cloutier and Packard, 2014). Based on certain similarities between silver and blue foxes’ biology, it is reasonable to assume that silver foxes’ preferences and need for activity objects may parallel that of blue foxes.
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2017, The Ethology of Domestic Animals, 3rd Edition: An Introductory Text