WHAT DOES THE SCIENCE SAY?

“ZOO INTERACTION PROGRAMS AND ANIMAL WELFARE”

A 22-Year Review Finds Significant Gaps in What Science Can Tell Us

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Animal interaction programs have become a common feature of modern zoos. They can include petting and handling opportunities, animal feeding, ambassador animal encounters, swim-with programs, shows and presentations, photography sessions, walk-through exhibits, riding programs, keeper experiences and other planned interactions between visitors and animals.
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According to a 2026 scoping review published in Applied Animal Behaviour Science, more than 75% of accredited zoos worldwide advertise at least one animal interaction program. But how much do we actually know about the welfare of the animals participating in them?
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Researchers Bridget Cooper-Rogers, Paige Klingner, Alex Whittaker, Rebecca Forder and Eduardo J. Fernandez examined the peer-reviewed scientific literature addressing that question. Their review, “Program animal welfare: A scoping review of animal interaction programs and their welfare impact on zoo-housed animals,” evaluated research published from 2002 through 2024.
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The authors identified a substantial gap between how commonly animal interaction programs are offered and how extensively their animal-welfare effects have been studied.
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22 YEARS OF RESEARCH — 49 ARTICLES

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Using the PRISMA-ScR framework, the researchers searched Scopus, PubMed and Web of Science, including CAB Abstracts, and used Google Scholar to identify additional relevant publications. To be included in the final analysis, studies had to involve an animal interaction program at a zoological facility, present quantitative primary research, include a comparison such as an interaction condition versus baseline, and explicitly evaluate animal welfare using behavioral, physiological or physical measures.
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After screening the available literature, 49 peer-reviewed articles representing 50 studies met the review criteria. The researchers found that the number of published studies remained limited despite the widespread use of animal interaction programs.
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WHAT TYPES OF PROGRAMS HAVE BEEN STUDIED?

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The review classified animal interaction programs according to whether they involved direct or indirect contact and whether the animal’s participation was scripted or unscripted. Direct interactions included physical contact such as petting, feeding, riding or swim-with experiences, while indirect programs included non-contact experiences such as demonstrations, walk-through exhibits or photography sessions.
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Across the 49 articles, the researchers identified 54 instances of animal interaction programs. Direct-contact programs accounted for 70.4% of those instances. Among individual program types, walk-through programs were the most frequently studied, followed by petting and handling programs, ambassador animal programs, swim-with programs and feeding programs. Other experiences—including photography, riding programs, guided tours and keeper talks—received considerably less research attention.
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MOST OF THE RESEARCH HAS FOCUSED ON MAMMALS

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The scientific literature was also heavily weighted toward certain groups of animals. Approximately 82% of the taxonomic representation in the reviewed studies involved mammals. Birds accounted for approximately 10%, reptiles about 4%, with arachnids and cartilaginous fishes such as rays receiving still less research attention.
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The authors found that this distribution did not accurately reflect the diversity of species currently participating in animal interaction programs in zoos. Even within mammals, research was concentrated among particular species and groups. The review therefore cautions that existing findings cannot necessarily be generalized across taxa, species or interaction programs.
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SMALL SAMPLE SIZES ARE COMMON

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The number of animals included in individual studies ranged from 2 to 98, with an average sample size of 16 animals. Nearly half of the reviewed articles—46%—studied only three to seven individual animals.
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The authors recognize that zoological research can involve practical limitations on sample size, but they also identify limited sample sizes as one factor restricting the ability to draw broader conclusions about the welfare effects of animal interaction programs.
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HOW WAS WELFARE MEASURED?

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Researchers used both behavioral and physiological or physical indicators of welfare, although behavioral measurements were substantially more common. Of the welfare-measure categories identified in the review, 70% were behavioral measures, while 30% were physical or physiological measures.
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Activity budgets were the most commonly used behavioral measure. Physiological and physical measures included cortisol or corticosterone concentrations, heart rate, weight, blood parameters, respiration rate and temperature.
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More than half of the reviewed articles used only one welfare measure. Only 18.4% incorporated measures from both behavioral and physiological or physical categories. The authors emphasize that animal welfare is multidimensional and recommend that future research incorporate multiple measures rather than relying upon a single indicator.
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WHAT DID THE STUDIES FIND?

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Because individual studies sometimes examined multiple species, variables or welfare measures, the researchers identified 89 separate welfare outcomes. Of those outcomes, 46.1% were classified as neutral, 28.1% as positive and 25.8% as negative.
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However, the authors emphasize that these percentages should not be interpreted as evidence that animal interaction programs as a whole are beneficial, neutral or harmful. Many studies produced mixed results, and outcomes were influenced by differences in species, program type, methodology and individual animals.
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WELFARE OUTCOMES DIFFERED AMONG PROGRAM TYPES

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The review also examined outcomes associated with different categories of animal interaction programs. Among petting and handling programs, 43.8% of recorded welfare outcomes were negative, 31.3% were neutral and 25% were positive. For ambassador animal programs, 44.4% were neutral, 33.3% were positive and 22.2% were negative. Walk-through programs produced 52.4% neutral outcomes, 33.3% negative outcomes and 14.3% positive outcomes.
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Other program categories also produced mixtures of positive, neutral and negative findings. The authors caution against using these percentages to rank different programs because the scientific literature is unevenly distributed among species and program types.
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For example, particular species were disproportionately represented within some categories, making it difficult to determine whether an observed welfare outcome was associated with the interaction program itself or with species-specific responses.
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INDIVIDUAL ANIMALS AND PROGRAM DESIGN MATTER

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The review identified several factors that may influence welfare outcomes but have received limited investigation. These include age, sex, rearing history, previous experience with people, duration and intensity of interactions, social needs, reinforcement methods and the amount of choice available to the animal.
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Some individual studies illustrate the importance of these variables. One study cited in the review found elevated cortisol and corticosterone during longer handling periods compared with shorter periods. Another reported reduced biting behavior in penguins when the animals were provided with greater choice over how an interaction progressed. Other research found differences associated with rearing history and reinforcement.
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The authors conclude that these factors require considerably more investigation before consistent patterns can be established.
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NEUTRAL DOES NOT MEAN POSITIVE

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One of the review’s central conclusions concerns how animal welfare is evaluated. Historically, the absence of negative welfare indicators has sometimes been interpreted as evidence that an interaction is acceptable. The authors caution against that approach.
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They note that contemporary animal-welfare science increasingly evaluates positive welfare indicators, rather than defining good welfare simply as the absence of negative responses. Accordingly, the review states that the absence of observable negative effects should not, by itself, be used to justify continuation of an animal interaction program.
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Future research, the authors argue, should examine whether programs support positive welfare rather than whether animals simply show no measurable negative response.
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THE EXISTING EVIDENCE IS NOT YET SUFFICIENT FOR COMPREHENSIVE POLICY

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The researchers conclude that the available scientific literature is currently insufficient to create comprehensive evidence-based policies, guidelines or frameworks governing animal interaction programs. They identify several reasons.
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Research does not adequately represent the range of species participating in these programs. Frequently offered programs have not necessarily received the greatest scientific attention. Many studies use small sample sizes, most rely primarily on behavioral measures, long-term welfare effects are rarely assessed, and factors that may influence an individual animal’s response remain poorly understood.
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The authors recommend future research that better reflects the programs actually offered in zoos, includes a broader diversity of species, evaluates individual differences and uses multiple complementary welfare measures. They also recommend greater attention to positive welfare indicators.
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WHAT DOES THE SCIENCE SAY?

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Animal interaction programs are widespread throughout modern zoological institutions. The scientific literature examining their welfare effects is not.
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After reviewing peer-reviewed research spanning 2002 through 2024, the authors found no consistent welfare outcome that can be generalized across animal interaction programs. Positive, neutral and negative outcomes have all been reported, and the available evidence varies substantially by species, program type, study design and individual animal.
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The review therefore concludes that considerably more research is needed before the welfare effects of these programs can be understood well enough to support comprehensive evidence-based policies.
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As the authors state in their conclusion, future evaluation should move beyond assuming that the absence of negative welfare indicators demonstrates good welfare.
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The scientific question increasingly becomes not simply whether an animal appears to tolerate an interaction, but whether measurable evidence demonstrates positive welfare.
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Source: Cooper-Rogers, B., Klingner, P., Whittaker, A., Forder, R., & Fernandez, E. J. (2026). Program animal welfare: A scoping review of animal interaction programs and their welfare impact on zoo-housed animals.
Applied Animal Behaviour Science
 

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