Birdwatching intensity and its impacts on mental health, happiness, mindfulness and nature connectedness among birders: a cross-sectional study in Brazil

1 Introduction

In recent decades, there has been a growing body of literature supporting the benefits of nature connectedness for health across multiple dimensions, particularly mental health, by promoting feelings of calm and pleasure as well as stress mitigation (Menardo et al., 2021; White et al., 2021). For instance, studies employing electroencephalography in humans exposed to natural environments indicate neurophysiological patterns associated with stress reduction and increased attentional engagement when compared to urban environments (Aspinall et al., 2015). Moreover, a large cross-national study based on data from 18 countries (n = 16,307 individuals) demonstrated that visiting green and blue natural spaces, even for recreational purposes, is associated with more positive emotions and lower levels of stress and mental distress (White et al., 2021).

Among the practices that foster human nature connectedness and natural environments, birdwatching stands out as particularly comprehensive. Birdwatching consists of observing avifauna for recreational or scientific purposes through direct visual observation or by listening to birdsong (Janeczko et al., 2021) and has been positively associated with human wellbeing (Cox and Gaston, 2015; Liu et al., 2021). Birdwatching can be considered one of the most sustainable practices within the ecotourism spectrum, in addition to being a hobby that often develops into a lifestyle for practitioners (Janeczko et al., 2021).

Beyond its potential individual benefits, birdwatching represents one of the main gateways to engagement in citizen science and biodiversity conservation actions, as positive experiences with birds are associated with sustained participation, strengthened bonds with nature, and the adoption of pro-environmental behaviors. Thus, understanding how the intensity of birdwatching practice relates to psychological outcomes may inform integrated strategies for promoting human health and avian conservation (Cox and Gaston, 2015; Martin et al., 2020; Janeczko et al., 2021).

In Brazil, the first ornithological clubs emerged during the 1970s and 1980s (Pivatto et al., 2007) and now it is estimated there are between 30,000 and 40,000 birdwatchers in the country (Develey, 2021). Moreover, Avistar Brasil has become one of the largest birdwatching events in Latin America, promoting activities centered on the observation and conservation of Brazilian birds. Hosted annually at the Butantan Institute of the University of São Paulo (USP), in São Paulo, the event represents one of the main organized spaces for birdwatching in the country. Yet, unlike in countries such as the United States, where birdwatching is already well established in both tourism and conservation, knowledge about the practice and its participants in Brazil remains limited. Institutional support from government and local research bodies is still comparatively weak, and the few systematic data available derive primarily from censuses and surveys conducted with Avistar participants in 2016 and 2017. Furthermore, studies examining birdwatching as a potential promoter of mental health remain scarce, especially in urban settings where forest remnants are limited (Cox and Gaston, 2015).

In light of this, the present study aimed to examine the association between birdwatching intensity and the following outcomes: Happiness (PHI), Mindfulness (MAAS), Nature Connectedness (CNS), and Psychological Distress (SRQ-20). We also assessed the internal consistency and initial validity of the Birdwatching Intensity Index (BII), developed for this study, as a composite measure of engagement in birdwatching practice.

2 Materials and methods

2.1 Study design and participants

This was an observational, cross-sectional study conducted with 444 birdwatchers residing in Brazil. Participants were recruited by convenience sampling through social media platforms, mailing lists, and groups associated with birdwatching practice. Eligible participants were adults (≥18 years) who reported engaging in birdwatching at varying levels of involvement, ranging from occasional practitioners to highly engaged birdwatchers.

All participants provided informed consent digitally. Data were stored anonymously and analyzed in aggregate form, ensuring confidentiality. The study followed the ethical principles of the Declaration of Helsinki and was approved by the Research Ethics Committee of the Botucatu Medical School, São Paulo State University (UNESP) (Approval No. 2.577.496/2018).

2.2 Instruments and variables

The questionnaire consisted of three main sections:

2.2.1 Sociodemographic data

This section included information on gender, age, educational level, marital status, place of residence (capital city vs. inland areas of the state of São Paulo), profession, and income level. These variables were used to characterize the sample and as control variables in the statistical models. A detailed description of this sample profile, as well as the relationship between birdwatching practice and nature connectedness, has been previously reported (Patricio et al., 2025).

2.2.2 Characterization of birdwatching practice and the birdwatching intensity index

Participants answered a questionnaire containing questions about years of practice, temporal frequency of practice (daily, weekly, monthly, yearly), number of hours per week dedicated to birdwatching, use of equipment for this practice (binoculars, cameras, apps), number of Brazilian species already observed or photographed, and how many they are able to identify on their own in nature, in addition to participation in birdwatching groups or events. Questions were also included about where they usually observe birds, their motivations for birdwatching, and where they usually publish their lists and records.

Participants’ degree of involvement in birdwatching was measured through the creation of the BII, developed specifically for this study. The index was designed to capture gradients of engagement in birdwatching practice by considering different aspects related to experience, frequency, and skills associated with the activity.

The initial version of the BII consisted of five indicators: (1) years of practice devoted to birdwatching; (2) weekly temporal frequency of the activity; (3) weekly dedication in hours; (4) average number of Brazilian bird species already observed or photographed; and (5) average number of species that the birder can correctly identify on their own in the field.

The selection of these variables was based on an inductive and pragmatic approach, grounded both in the consolidated social practice of birdwatching and in the empirical literature, which recurrently uses indicators such as time invested, frequency, cumulative exposure, and identification skills to characterize different levels of involvement in nature-based activities and their effects on psychological, emotional, and behavioral outcomes (e.g. Kaplan and Kaplan, 1989; Cox and Gaston, 2015; Martin et al., 2020; Hammoud et al., 2022).

Given the current absence of a formal theoretical framework defining “birdwatching intensity” as a unitary psychological construct, the BII was conceived as a composite measure design to capture functional gradients of engagement in the practice, rather than as a reflective scale intended to measure a specific latent trait. Thus, the indicators composing the index are understood as complementary components that, together, express the individual’s level of engagement with the activity, without assuming conceptual or temporal equivalence among them.

The decision to recruit participants with different levels of involvement in birdwatching, including highly engaged practitioners, was intentional and conceptually necessary, since one of the study’s objectives was to investigate gradients of practice intensity and to develop a birdwatching-specific index, which presupposes minimum experience and prior familiarity with the activity. This strategy allowed the exploration of dose-response associations between engagement in birdwatching and psychological indicators.

The BII score is obtained by the simple sum of the points assigned to each response, ranging from 5 to 24 points, such that the higher the score, the greater the intensity of birdwatching practice. For the analyses, the BII was categorized into quartiles: Q1 (lowest intensity) to Q4 (highest intensity). The quartile boundaries (≤14, 15–17, 18–20, ≥21 points) correspond to the empirical distribution of BII scores observed in this sample, rather than to an a priori theoretical classification. This categorization makes it possible to understand gradual differences in practitioners’ profiles and experiences and was used in the statistical analyses as the main independent variable. Score calculation and interpretation are presented in Table 1, with the full item-level scoring rules detailed in Supplementary Table S1.

Table 1. Score ranges and interpretation of the BII.

These score bands were defined a priori by the research team, drawing on the field expertise of co-authors with decades of birdwatching experience, the contribution of an ornithologist co-author, and consultation with four experienced birders external to the research team, in the absence of a pre-existing validated instrument in the literature to serve as a basis for this classification. They are conceptually distinct from the sample quartiles used as the independent variable in Tables 2–5, which were derived empirically from this sample for regression purposes only. A criterion validity check testing whether each band's descriptive content is observed in this sample is reported in Supplementary Table S3: the general ordering (Q1<Q2<Q3<Q4) was supported, but Q1 (n=5) was too small for a reliable test, and the Q4 description overstates the typical (modal) participant.

The descriptive labels and score bands presented in Table 1 were defined a priori by the research team, informed by the field expertise of co-authors with decades of birdwatching experience, and consultation with experienced birders, given the absence of a pre-existing instrument to draw on. To assess whether this a priori classification is supported by the collected data, we conducted a criterion validity check, comparing the behavioral profile of participants within each band against the band’s descriptive content (Supplementary Table S3).

2.2.3 Scales used to measure outcomes such as happiness, mindfulness, nature connectedness, and psychological distress

These are scales widely used in research and adapted for the Brazilian population, aimed at assessing complementary dimensions of psychological and ecological well-being.

• Subjective Happiness (PHI – Pemberton Happiness Index): assesses hedonic and eudaimonic dimensions of subjective wellbeing through two components, each expressed on a 0–10 range. Remembered well-being is the mean of 11 items rated 0–10. Experienced well-being is a derived 0–10 score obtained from 10 dichotomous (yes/no) items describing positive and negative experiences on the previous day. The combined PHI total score therefore ranges from 0 to 20 (Hervás and Vázquez, 2013).
• Mindfulness (MAAS – Mindful Attention Awareness Scale): consists of 15 items that assess the capacity for attention to and awareness of the present moment, on a Likert scale from 1 to 6. A Portuguese-validated version is available (Barros et al., 2015).
• Nature Connectedness (CNS – Connectedness to Nature Scale): consists of 14 items on a scale from 1 (strongly disagree) to 5 (strongly agree). The Brazilian version of the Connectedness to Nature Scale was applied (Mayer and Frantz, 2004; Pessoa et al., 2016).
• Psychological distress (SRQ-20 – Self-Reporting Questionnaire): an instrument of the World Health Organization (Mari and Williams, 1986) for screening common symptoms of psychological distress, consisting of 20 binary items (yes/no). Scores equal to or above 7 indicate probable mental distress according to Brazilian validation.

All scales demonstrated satisfactory internal consistency, with Cronbach’s alpha values exceeding 0.80 for PHI and MAAS, 0.85 for CNS, and 0.88 for SRQ-20.

2.3 Statistical analysis procedures

Analyses were performed using R software (version 4.4.0). Sensitivity analyses (median regression, Negative Binomial regression, proportional-odds ordinal regression, and Horn’s Parallel Analysis) were conducted in Python (version 3.14.6), using the pandas (3.0.3), scipy (1.18.0), statsmodels (0.14.6) and pingouin (0.6.1) packages. Initially, variables were described using measures of central tendency and dispersion. Correlations between the BII and scale scores (PHI, MAAS, CNS, SRQ-20) were evaluated using Spearman’s coefficient, given the non-normal distribution of the variables.

Next, multiple linear regression models were constructed, with the scales as dependent variables and the BII as the main independent variable, adjusting for sex, cohabiting with a partner, and place of residence (capital city vs. inland).

To assess the consistency and initial validity of the BII, an exploratory psychometric analysis was conducted based on the responses of the 444 participants included in the study. The index consisted of five items representing different dimensions of engagement in the practice: years of observation (TPOOBS), weekly temporal frequency (FREQOBS), weekly dedication in hours (DEDOBS), average number of species already observed (QTEOBS), and average number of species the participant is able to identify (QTEIDENT).

Internal consistency was initially assessed using Cronbach’s alpha coefficient, complemented by corrected item-total correlations. Next, an exploratory factor analysis (EFA) was conducted using principal component extraction with varimax rotation in order to identify the underlying structure of the index and verify its unidimensionality. The adequacy of the correlation matrix was verified using Bartlett’s test of sphericity and the Kaiser–Meyer–Olkin (KMO) measure.

Statistical significance was set at p < 0.05, and all analyses met assumptions of homoscedasticity and absence of multicollinearity. To assess the robustness of the regression models to the ordinal and bounded nature of the outcome variables, a series of sensitivity analyses was conducted. For MAAS, PHI and CNS (near-continuous scores derived from summing 15, 21 and 14 Likert items, respectively), the original OLS models were complemented by median (quantile) regression, which does not assume normally distributed residuals, and by a proportional-odds ordinal model using outcome tertiles. For SRQ-20, a bounded count of 20 binary items, a Negative Binomial regression model was additionally fitted, with incidence rate ratios (IRR) reported. Residual normality (Shapiro-Wilk) and homoscedasticity (Breusch-Pagan) were formally assessed for all original OLS models. Full results are reported in Supplementary Table S2. For the BII, dimensionality was further examined using Horn’s Parallel Analysis (1000 random-data simulations), a more conservative criterion than the eigenvalue > 1 rule.

3 Results

A total of 518 responses were received, of which 444 were considered valid and therefore were included in the analysis. The 74 excluded responses corresponded to cases with incomplete data (n = 39), non-compliance with inclusion criteria (n = 18; e.g., birdwatching practice of less than one year or age under 18 years), duplicate questionnaires (n = 13), and lack of consent for data analysis (n = 4).

Participants ranged in age from 19 to 77 years (mean = 42 ± 13.7 SD), came from different regions of Brazil, with a predominance from the state of São Paulo (43.7%), and were mostly male (67%). Most participants had completed higher education (78%) and lived in urban areas (90,1%). The group with the highest proportion of birdwatching experience reported more than 10 years of practice (36.2%), followed by those with 5 to 10 years of practice (26.5%), with wide variability in frequency and level of engagement. For further details about the profile of this sample, see Patricio et al. (2025).

Table 2 shows that there was a statistical association between BII score and the variables sex, age, cohabiting with a partner, and living in the capital city.

Table 2. Sociodemographic characteristics of birdwatchers according to Birdwatching Intensity Index (BII) score (n = 444).

*The variables “sex,” “living with a partner,” and “living in the capital city” were considered confounders. Subsequent statistical tests were adjusted accordingly.

MAAS and SRQ-20 scores were significant as birdwatching intensity increased, with p = 0.036 and p < 0.001, respectively (Table 3).

Table 3. Scores on nature connectedness (ECN), mindfulness (MAAS), happiness (PHI), and psychological distress (SRQ-20) scales according to birdwatching intensity score (BII) (n = 444).

Regarding the SRQ-20, psychological distress scores decreased as birdwatching intensity increased. The median declined from 5 (0–18) in the BII ≤ 14 group to 2 (0–14) in the BII ≥ 21 group, suggesting that individuals who are more active in birdwatching report lower levels of Common Mental Disorders (CMD).

A statistically significant difference was also identified for mindfulness (p = 0.036), with higher scores in the groups with greater practice intensity: 60 (34–87) in the BII ≤ 14 group, increasing to 65 (41–90) in the BII ≥ 21 group.

For subjective happiness (PHI), although a slight upward trend in the medians was observed, from 15.30 (7.52–19.59) in the lower-intensity group to 16.28 (4.47–19.82) in the higher-intensity group, the difference was not statistically significant (p = 0.101). A sensitivity analysis using median regression suggested a possible association not fully captured by the mean-based model (b = 0.91, p = 0.038); this exploratory finding should be interpreted with caution and warrants confirmation in future studies with larger or more heterogeneous samples.

Similarly, for nature connectedness (CNS), there was a slight increase in scores as practice intensity increased, but without statistically significant differences between groups (p = 0.176). The medians ranged from 62 (44–70) in the lower-intensity group (BII ≤ 14) to 64 (42–70) in the higher-intensity group (BII ≥ 21), according to Table 3.

The multiple linear regression model for the outcome psychological distress (SRQ-20) revealed a significant inverse association between birdwatching intensity and psychological distress scores. Individuals with greater engagement in birdwatching (BII = 3 and BII = 4) showed significantly lower SRQ-20 scores compared with the lowest-intensity group (BII = 1), with coefficients ranging from β = –1.43 (95% CI: –2.41 to –0.45; p = 0.004) to β = –1.62 (95% CI: –2.68 to –0.57; p = 0.003). The association remained significant after adjustment for sex, living with a partner, and residence in the capital city, highlighting a potential inverse association between birdwatching and psychological distress, independent of sociodemographic factors. As SRQ-20 is a bounded count outcome, an additional Negative Binomial regression model was fitted as a methodologically more appropriate alternative (Table 4; Supplementary Table S2). The model confirmed the direction and significance of the association: participants in the higher-engagement BII groups showed approximately 24–29% lower incidence of common mental disorder symptoms than those in the lowest-engagement group (IRR = 0.72, 95% CI 0.52–0.98, p = 0.037 for the highest quartile), adjusted for sex, cohabitation with a partner and residence in the capital. .

Table 4. Negative binomial regression model predicting psychological distress (SRQ-20).

IRR = incidence rate ratio. Model adjusted for sex, cohabitation with a partner, and residence in the capital city. Full model coefficients and comparison with the original OLS model are reported in Supplementary Table S2. The acronym IIBW (Portuguese order) was also standardized to BII, matching the term used in the manuscript text.

The multiple linear regression model for the outcome mindfulness indicated a positive trend between birdwatching intensity and mindfulness levels. Although the coefficient for the highest-intensity group (BII = 4) approached the threshold of statistical significance (β = 3.11; 95% CI: –0.11 to 6.33; p = 0.058), an upward gradient in MAAS scores was observed as dedication to birdwatching increased. The remaining predictors – sex, living with a partner, and living in the capital city – were not significantly associated with mindfulness scores, which may suggest a possible association between mindfulness levels and engagement in the practice, according to Table 5. This association was further supported by two sensitivity analyses not assuming normally distributed residuals: median regression (b = 4.00, p = 0.048) and a proportional-odds ordinal model on MAAS tertiles (p = 0.027), both consistent in direction and significance with the original model (Supplementary Table S2).

Table 5. Multiple linear regression model predicting mindfulness scores (MAAS).

Finally, as shown in Table 6, the internal consistency analysis indicated that the BII presented a Cronbach’s alpha of 0.62 when the five original items were considered, a value adequate for an instrument in the exploratory phase. Corrected item-total correlations showed greater contribution from the items related to weekly dedication to birdwatching, the number of species observed, and the number of species identified, all with moderate to high correlations.

Table 6. Internal consistency and factor loadings of the Birdwatching Intensity Index (BII).

Exploratory factor analysis was performed using principal component extraction and varimax rotation. KMO = 0.72; Bartlett's test of sphericity: χ²(10) = 148.3; p < 0.001. First-factor eigenvalue = 2.8; explained variance = 56%. Dimensionality was further supported by Horn's Parallel Analysis (1000 random-data simulations, Supplementary Table S2), which retained only the first component. The acronym IIBW (Portuguese order) was also standardized to BII, matching the term used in the manuscript text.

The exploratory factor analysis revealed a unidimensional structure, with an eigenvalue of 2.8 for the first factor and factor loadings above 0.55 for the three central items, which explained approximately 56% of the total variance. The matrix adequacy tests were satisfactory (KMO = 0.72; Bartlett’s χ² = 148.3; p < 0.001), confirming the appropriateness of the analysis.

When only the three strongest items—weekly dedication, number of species observed, and number of species identified—were considered, alpha increased to 0.80, indicating excellent internal consistency. This estimate was accompanied by a 95% confidence interval (0.79–0.82) and a mean inter-item correlation of 0.57, indicating that the increase in alpha reflects genuine inter-item coherence rather than an artifact of scale length. Dimensionality was further confirmed with Horn’s Parallel Analysis: only the first component’s eigenvalue (2.21) exceeded the 95th percentile of eigenvalues obtained from 1000 random-data simulations (1.21), supporting the unidimensional structure of the reduced BII beyond the alpha coefficient alone. These results provide initial evidence of construct validity, supporting the use of the BII, preferably in its reduced three-item version, as an indicator of birdwatching practice intensity.

A criterion validity check of the a priori BII classification (Table 1) showed a monotonic gradient across all four bands for years of practice, observation frequency, and species knowledge, supporting the general ordering of the classification (Supplementary Table S3). However, this analysis also revealed a marked imbalance in band sizes (Q1 n=5 to Q4 n=211), consistent with the sample having been recruited during Avistar Brasil, the largest birdwatching event in Latin America. The very small size of Q1 precludes a reliable test of its descriptive content, and the modal participant in Q4 (300–600 species observed) fell short of the “large number of species” implied by that band’s description. These findings support the classification as a directional, expert-informed framework, while indicating that its specific wording should be treated as provisional pending validation in more heterogeneous samples.

4 Discussion

The present study investigated the association between birdwatching intensity and indicators of happiness, mindfulness, nature connectedness, and psychological distress in a sample of 444 Brazilian participants. The objective was to understand whether different levels of engagement in birdwatching are related to psychological and emotional benefits, providing empirical evidence about the potential restorative and preventive effects of this nature-based activity. Although the cross-sectional design does not allow causal inference, the consistent pattern of reduced psychological distress and increased mindfulness across birdwatching intensity quartiles suggests the presence of a functional gradient, reinforcing the plausibility of a meaningful association between greater engagement in the practice and better mental health indicators. This study therefore provides some of the first empirical evidence in Brazil that birdwatching intensity is associated with greater mindfulness and lower psychological distress.

A positive association was observed between the intensity of birdwatching practice and mindfulness levels, accompanied by a negative association with psychological distress. In other words, the greater the engagement in the practice, the greater the capacity for presence and focus on the “here and now,” and the lower the symptoms of anxiety, tension, and depressive mood. These results suggest that birdwatching may act simultaneously as a restorative activity and as a regulator of attention and emotions, contributing to the mental well-being of its practitioners.

These findings converge with the recent literature on the role of experiences in natural environments in promoting mental health and mindfulness (Cox et al., 2017; Methorst et al., 2021; Hammoud et al., 2022), extending such evidence to the Brazilian context. The increase in mindfulness among more intensive birdwatchers corroborates the hypothesis that birdwatching functions in practice as a natural contemplative exercise. Searching for birds in natural environments stimulates a state of “fascinated attention,” characterized by spontaneous and sustained attentional capture through sensory stimuli present in the environment, such as colors, sounds, and movement, inducing relaxation and mental clarity. This pattern aligns with Attention Restoration Theory (Kaplan and Kaplan, 1989) and recent reports on “therapeutic ornithology” (Tryjanowski et al., 2022), which describe the hobby’s potential to promote mindfulness and reduce rumination.

Other researchers point out that walking in green environments may increase environmental awareness (Nisbet et al., 2020). In addition, the literature shows that mindfulness and nature connectedness proceed in parallel (Howell et al., 2011; Djernis et al., 2019), and that outdoor mindfulness practices may strengthen the emotional and perceptual bond with the natural world (Schutte and Malouff, 2018). Thus, birdwatching may be seen as an informal form of mindfulness training (Basu et al., 2018), cultivating presence and emotional regulation through aesthetic and sensory immersion.

Birdwatching involves sensory stimuli particularly conducive to fascinated attention, such as unpredictable movement, diversity of forms and colors, complex vocal patterns, and the need for attentive listening, characteristics that may favor states of presence and attentional engagement more intensely than other forms of passive contact with natural environments. One study showed that psychiatrists who participated in ornithological walks reported greater centeredness and mental clarity after observing birds (Murawiec et al., 2021), and meta-analyses of mindfulness in natural environments indicate consistent positive effects on psychological well-being (Djernis et al., 2019). Thus, the results presented here reinforce that birdwatching may serve as an accessible and unintentional pathway to mindfulness training, with tangible psychological benefits.

Convergently, participants with greater practice intensity showed lower levels of psychological distress, as measured by the SRQ-20. In the present study, the mean difference of approximately three points on the SRQ-20 between the lowest and highest intensity groups was statistically significant and potentially clinically relevant, as it suggests an approximately 60% reduction in symptoms among the most engaged birdwatchers. Since the CMDs assessed by the SRQ-20 encompass early manifestations of psychological distress (Coelho et al., 2009), this association reinforces the preventive potential of birdwatching for anxiety, depression, and psychosomatic disorders (Peterson et al., 2024). In addition, the literature shows that higher mindfulness levels are associated with reductions in anxious and depressive symptoms (Hofmann et al., 2010; Segal et al., 2002; Kuyken et al., 2016) and better management of cardiovascular stress (Loucks et al., 2015), reinforcing the plausibility of the findings observed.

These findings are consistent with recent evidence indicating that encounters with birds and natural environments improve mental well-being across diverse populations (Hammoud et al., 2022; Randler et al., 2022; Peterson et al., 2024) as well as significantly reduce negative affect, with rumination mediating this relationship (White et al., 2021). Probable mechanisms include reductions in physiological and emotional stress, activation of parasympathetic relaxation responses, positive distraction from negative thoughts, and a sense of belonging and purpose. Furthermore, the social dimension of the hobby—through group outings, virtual interactions, and sharing of records – may provide additional emotional support and reinforce community bonds, strengthening protective effects.

On the other hand, happiness (PHI) and nature connectedness (CNS) showed high scores throughout the sample, but without significant differences across intensity levels. When this same sample was analyzed in relation to CNS without comparing BII levels, it was found that as observers’ temporal observation frequency increased, CNS scores also increased. Those who observed daily obtained 9.3 points more; those who practiced weekly obtained 7.65 points more; and those who practiced monthly scored 7.19 points higher than those who observed only annually on the nature connectedness scale (Patrício et al., 2025). This suggests a possible ceiling effect, reflecting that even occasional practitioners already have high levels of connection with nature. The homogeneous profile of the sample, composed mostly of engaged individuals with prior environmental affinity, reduces observable variation in these indicators. This lack of gradient does not contradict the benefits of birdwatching, but may result from the type of sample investigated, in which participants already started from a high baseline of happiness and biophilia, which may have limited detectable incremental gains.

Future studies with more heterogeneous samples, including beginners or non-practitioners, may clarify whether regular practice progressively strengthens these domains in individuals with less previous contact with nature. It is worth noting that a sensitivity analysis using median regression suggested a possible association between BII and PHI not captured by the mean-based model; while this should not be over-interpreted given the exploratory nature of the check, it indicates the relationship deserves closer examination in future, larger samples.

Taken together, the findings indicate that frequent birdwatching seems to simultaneously enhance internal resources (mindfulness, emotional regulation) and reduce psychological risk factors (psychological distress). This balance is particularly relevant in urban contexts, where everyday contact with nature is limited. From an applied perspective, the study suggests that simple, pleasurable, and low-cost activities such as birdwatching may be incorporated into mental health promotion and green prescription programs, and could be recommended by healthcare professionals, aligning individual and collective benefits for health and conservation (Britton et al., 2020; Harper et al., 2021; García-Jiménez et al., 2021). Another relevant point is that most participants lived in urban areas, as does most of the global population today. Urban environments, with noise, pollution, and sensory overload, are known to be associated with a higher prevalence of stress and mental disorders (Marselle et al., 2021). In this context, birdwatching offers an accessible form of reconnection with nature in everyday urban life, creating restorative “microdoses” of attention and tranquility. Even observing birds in squares, from windows, or in backyards may counterbalance the deleterious effects of excessive urbanization, as shown by studies demonstrating the benefits of brief daily encounters with birds (Hammoud et al., 2022).

The predominance of men in the sample is also noteworthy, replicating international findings (Janeczko et al., 2021). While women tend to adopt more formal self-care practices (Courtenay, 2000), they also face structural barriers related to safety and access to natural spaces, in urban or rural contexts (Sreetheran and van den Bosch, 2014). On the other hand, the literature on men’s health indicates that men tend to adopt fewer formal self-care practices and to express emotional suffering less openly (Galdas et al., 2005). In this sense, birdwatching may represent a symbolic and socially accepted route to mental care, allowing experiences of contemplation, aesthetic sensitivity, and connection with nature without the connotation of fragility often unfairly or prejudicially associated with psychological care. Thus, the hobby may function as a restorative and preventive strategy for a group frequently underserved in mental health policies. Health services could incorporate this health-promotion tool, with low cost and high potential for integration into public policies such as Brazil’s Unified Health System, especially for more vulnerable populations.

Despite its contributions, this study has important limitations. The cross-sectional design prevents causal inference, and it remains necessary to investigate longitudinally whether increasing engagement in birdwatching leads to improvements in mindfulness and mental health, or whether healthier individuals tend to engage more in the practice. In addition, the BII was conceived as an exploratory measure of engagement in the practice, integrating behavioral dimensions relevant to recreational ornithology and citizen science, such as time invested, accumulated experience, and familiarity with species diversity, rather than as a closed clinical instrument. Although the BII showed satisfactory internal coherence and a consistent unidimensional structure, this remains an initial and exploratory validation.

The instrument still requires additional psychometric testing to confirm its robustness and applicability in different contexts. To address the ordinal and bounded nature of some study outcomes, we complemented the original models with quantile regression, ordinal proportional-odds models, and Negative Binomial regression for the count-based SRQ-20 outcome; these sensitivity analyses are detailed in Supplementary Table S2 and support the robustness of the main conclusions.

Future studies should conduct confirmatory factor analyses (CFA) in independent samples, including invariance testing across groups (for example, sex, age, and place of residence), as well as assessments of convergent and discriminant validity with other indicators of engagement with nature and recreational specialization. Test–retest analyses are also desirable to estimate the temporal reliability of the index.

In addition, it is advisable to compare BII scores with objective indicators of practice, such as observation records on digital platforms (e.g., eBird), allowing the assessment of criterion validity. Longitudinal and cross-cultural studies may also verify whether the index is sensitive to behavioral changes, consolidating it as a standardized tool for measuring birdwatching intensity. Based on the evidence obtained, preferential use of the reduced three-item version is suggested: weekly dedication, number of species already observed, and number of species the participant is able to identify, since this version showed better psychometric performance and greater internal consistency.

The sample, recruited through voluntary participation, may have introduced selection bias, predominantly including people already interested in nature and well-being. The measures used were self-report instruments, subject to social desirability and memory biases.

These limitations do not diminish the relevance of the findings, but they do indicate clear directions for future research, especially longitudinal and experimental studies capable of testing mediating mechanisms, such as mindfulness, in the relationship between birdwatching and mental health. Investigation of other outcomes, such as creativity, cognitive functions, or pro-environmental engagement, is also recommended, as well as testing whether mindfulness acts as a partial mediator in the relationship between birdwatching and reduced psychological distress. Finally, there is potential to evaluate structured public health interventions, such as guided birdwatching walks in urban parks, as an accessible, sustainable, and biodiversity-aligned strategy for promoting well-being.

5 Conclusions

The study identified a positive association between the intensity of birdwatching practice and mindfulness levels, as well as a negative association with psychological distress, as measured respectively by the MAAS and SRQ-20. By showing that greater intensity of birdwatching is associated with lower psychological distress and greater mindfulness, this study supports the potential of birdwatching as an accessible, sustainable, and culturally adaptable practice capable of generating simultaneous benefits for human mental health and for strengthening the bond with nature through birds.

Although no significant differences were observed in subjective happiness (PHI) and nature connectedness (CNS) across practice levels, the sample investigated showed a slight upward trend from the lowest-intensity group to the highest-intensity group. These results indicate that birdwatching is related to better psychological indicators of well-being, especially greater mindfulness and lower psychological distress, highlighting its potential as a health-promoting practice and a source of psychosocial balance.

The analysis also showed that the BII presents satisfactory initial internal consistency and construct validity, making it a promising instrument for measuring birdwatching intensity. The reduced three-item version proved more stable and reliable, offering a practical and comparable measure that can be improved and validated in future studies.

In summary, this study adds innovative evidence that birdwatching may be more than a recreational hobby: it may represent a restorative practice associated with cultivating presence, reducing psychological distress, and strengthening the bond with nature, thereby contributing to the promotion of mental and connection with nature in times of increasing environmental disconnection.

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Supplementary material

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fbirs.2026.1879457/full#supplementary-material

Supplementary material Supplementary material at the source

Supplementary material Supplementary material at the source

Supplementary material Supplementary material at the source

Footnotes

Edited by: Seunguk Shin, University of Missouri, United States

Reviewed by: Mário Gabriel Santiago Santos, University of Trás-os-Montes and Alto Douro, Portugal

Larissa Tinoco, Universidade Anhanguera-Uniderp, Brazil