Systematic Investigation of the Stability of Food Preferences in Captive Orangutans: Implications for Positive Reinforcement Training

Abstract

Using preference-assessment tests with humans in conjunction with behavioral modification sessions has been a regular component of almost all operant conditioning programs with mentally challenged humans. This has been very effective in improving the efficiency of behavioral training in these settings and could be similarly effective in zoological and research environments. This study investigated the preferences of 9 captive orangutans for different food items. The study used a pairwise presentation to record each nonhuman animal's preferences for 5 different foods on 6 different occasions over the course of 6 months. Results of a Friedman's 2-way ANOVA indicated that the orangutans showed a clear overall preference for apple. However, there was significant variability among different orangutans in preference ranking for the 5 foods, as shown by a Kendall's tau. In addition, there was variability in preference rankings across time for each orangutan. Because the orangutans' preferences change over time and vary according to individual, regular assessments should identify items to be used as rewards in behavioral husbandry training or as part of feeding enrichment strategies.

Systematic assessment of food item preference and reinforcer effectiveness: Enhancements in training laboratory-housed rhesus macaques

“…Out of our 21 subjects, eight showed low consistency (Kendall’s W < .3) across time, nine showed moderate consistency (.3 < W < .6), and only four showed high consistency (Kendall’s W > .6). This finding is consistent with previous studies showing changes in preferences across time (Clay et al, 2009; DeLeon et al, 2001; Kennedy & Haring, 1993; Mason et al, 1989) and illustrates the need for frequent retesting of preferences for maximum accuracy. Unlike the paired-choice tests used in previous animal studies, the ease and brevity of the MSWO procedure allows for frequent reassessments, ideally conducting a preference assessment just prior to a training session, increasing the effectiveness of this technique in identifying highly preferred items that may also serve as effective reinforcers.…”

“…In humans, the majority of preference research has been conducted to determine effective reinforcers in clinical settings for children with developmental disabilities (e.g., Carr et al, 2000; Pace et al, 1985) or in educational settings (e.g., Mintz et al, 2007). In animals, food preference assessments have been conducted for a variety of reasons, including nutritional/palatability assessments (e.g., Tobie et al, 2015), comparative studies (e.g., Remis, 2002), measurements of cognitive capacity (e.g., Benz et al, 1992), pest control (e.g., Morgan, 1990), and a few assessments aimed at determining possible training reinforcers in applied animal settings (e.g., Clay et al, 2009; Fernandez et al, 2004; Gaalema et al, 2011). These preference assessments can be broadly categorized based on how the items are presented to the subject; whether they are presented one at a time, in pairs, or in groups.…”

“…Fisher et al (1992) found that this forcedchoice procedure resulted in greater differentiation among stimuli and also was a better predictor of which stimuli would subsequently serve as effective reinforcers. Paired-choice procedures are widely used to determine food, toy, or activity preferences in humans with developmental disorders (e.g., DeLeon et al, 2001; Fisher et al, 1992; Piazza et al, 1996) and have also been used to determine food preferences for a variety of animal species, ranging from great apes to possums (e.g., Benz et al, 1992; Cameron et al, 2013; Clay et al, 2009; Fernandez et al, 2004; Gaalema et al, 2011; Harlow & Myer, 1952; Mehrkam & Dorey, 2014; 2015; Polidora & Schneider, 1964; Remis, 2000; Vicars et al, 2014). …”

“…Preferences have been found to vary across time and context in both humans (DeLeon et al, 2001; Kennedy & Haring, 1993; Mason et al, 1989) and animals (Clay et al, 2009). DeLeon et al (2001) used a pre-treatment, paired-choice procedure to identify initial preferences in developmentally disabled individuals.…”

Advancing Behavior Analysis in Zoos and Aquariums

“…This journal joins three other scientific periodicals focused on zoo and aquarium research, International Zoo Yearbook (f. 1960), Der Zoologisches Garten (f. 1859), and Zoo Biology (f. 1982). Applied behavior analytic research has been published in specialized zoo journals (e.g., Bloomsmith et al 2003;Chang et al 1997;ForthmanQuick 1984;Holden et al 2006), and other animal behavior and welfare-oriented journals have also accepted papers from behavior analysts and their zoo-based collaborators (Clay et al 2009;Elmore et al 2012;Gaalema et al 2011;Jensen et al 2013;Laule 1993;Lukas 1999;Marranzino 2013;Pomerantz and Terkel 2009;Savastano et al 2003).…”