Biotropica at the Forefront of Tropical Seed Dispersal Ecology

Seed dispersal is one of the most frequently published topics in Biotropica. In this commentary, we highlight Biotropica's main contributions to the fertile field of frugivory and seed dispersal while offering a few ideas to guide the next generation of studies in the journal. Frugivory and seed dispersal are flourishing disciplines that integrate research from zoology, plant science, genetics, and evolution. In the tropics, up to 90% of woody plant species depend on frugivores for seed dispersal, a process that confers several benefits to plants (Jordano 2014). These include escape from competition and natural enemies, directed dispersal, habitat colonization, and maintenance of genetic diversity. Collectively, these processes contribute to the generation and maintenance of biodiversity (Beckman and Sullivan 2023). In recent years, frugivory and seed dispersal have also been recognized for their relevance to pressing Anthropocene challenges, including restoration (Landim et al. 2024), conservation (Mendes et al. 2024), and carbon sequestration (Bello et al. 2015, 2021). Perhaps owing in part to the plethora of approaches, far-reaching consequences, and wide-ranging applications, seed dispersal is the most studied topic in Biotropica (Figure 1A). Here we highlight Biotropica's main contributions to the fertile field of frugivory and seed dispersal while offering a few ideas to guide the next generation of studies in the journal. Considering all articles on the topic (n = 5092; see Figure 1 legend for details on the literature search), Biotropica leads in the number of publications, followed by Oecologia and Oikos (Figure 1B). Among the studies published in Biotropica, 56.5% focused on seed dispersal, 39.1% on frugivory, and 4.4% on both. The major topics covered were frugivore diet and/or behavior (33.5%), dispersal system & strategies (30.3%), seed ecology (11%), seed predation (6.9%), regeneration (5.5%), secondary seed dispersal (4.6%), and interaction networks (4.1%), among others (4.1%). The publications encompassed all levels of ecological organization, a wide range of taxa, and a variety of methods to address key questions in frugivory and seed dispersal (Figure 1C–E). Most studies have been conducted at the species (68.8%) and community (29.6%) levels. These studies primarily aim to understand how seed dispersal affects plant recruitment (e.g., Giombini et al. 2009; Sato 2012; Ramaswami et al. 2016; Peña-Egaña et al. 2018) and to unravel the structure of fruit-frugivore networks (e.g., Palacio et al. 2016; Emer et al. 2020; Béllo Carvalho et al. 2023; Paixão et al. 2023). In contrast, studies at the individual (e.g., Campagnoli et al. 2024; Jayanth et al. 2024; Rompf et al. 2024) and population levels (e.g., Escobar et al. 2023) are scarce, with most contributions emerging only recently (Figure 1C). Unsurprisingly, most research addressed seed dispersal by birds and mammals (especially bats and primates), which are the dominant seed dispersers in the tropics (Fleming and Kress 2011). Nevertheless, studies involving reptiles, fishes, and invertebrates represented an interesting fraction of the published research (e.g., Fialho 1990; Ponce-Santizo et al. 2006; Strong and Fragoso 2006; Costa-Pereira et al. 2018; Ruzi and Suarez 2022) (Figure 1D). It is relevant that 44.5% of the published studies examined frugivory and seed dispersal focusing on specific fleshy-fruited plant species or families. These encompassed 122 species from 84 genera and 45 families, with figs (Moraceae) emerging as the most frequently studied family, followed by palms (Arecaceae) and nutmeg trees (Myristicaceae). The dynamics of fruit-frugivore interactions are complex and often context-dependent, making field assessments of dispersal particularly challenging (Beckman et al. 2020; Quintero et al. 2022). To overcome these challenges, seed dispersal studies published in Biotropica have employed a variety of methods, including the retrieval of fecal and stomach samples, direct field observations, seed removal experiments, and mist netting as the most common approaches (Figure 1E). Altogether, these studies illustrate the breadth and depth of frugivory and seed dispersal research published in Biotropica, using different methods to cover the main stages of the multistep seed dispersal process by frugivores: visitation, transport, and seed deposition (Schupp et al. 2017; Quintero et al. 2022). Notably, these studies have been conducted across a wide range of elevations—from sea level to 3600 m—and span 41 countries (Figure 2). However, our sampling revealed geographical biases, with 67% of studies conducted in the Neotropics and relatively few in the Paleotropics. Additionally, only 6% of studies were conducted in islands and 8.7% in open ecosystems such as tropical grasslands, shrublands, and savannas—habitats where a significant portion of fruiting plants rely on animals for dispersal (Kuhlmann and Ribeiro 2016; Campagnoli et al. 2025; Nogales et al. 2024). Only one study focused on urban systems (Silveira et al. 2024), indicating a gap in understanding seed dispersal dynamics in human-modified landscapes. Despite the relevance of all papers published in Biotropica to tropical seed dispersal ecology, a few contributions deserve special attention. One of the most influential is Snow's (1981) seminal paper providing a global overview of the plants in the diets of birds. Cited nearly 700 times, this study synthesized data from multiple bibliographic sources, analyzing fruit traits and composition in the diets of both specialist and generalist frugivores. This paper was published during the early conceptual developments of the field, including influential discussions on the specialization continuum of seed dispersal strategies (Snow 1971; McKey 1975; Howe 1993). Snow's paper was one of the first attempts for broad patterns in frugivory and seed dispersal, an approach attracting a lot of attention decades later with the rise of interaction networks (e.g., Dugger et al. 2019; Messeder et al. 2020; Mendes et al. 2024). Inspired by Snow, Wheelwright et al. (1984) conducted a follow-up study, documenting over 700 records of birds feeding on 171 plant species at a single site in Costa Rica. This effort further inspired pattern- and trait-based research in the field. Other influential studies include Kubitzki and Ziburski's (1994) work on seed dispersal in Amazonian flooded forests, which highlighted the roles of fish and water as effective dispersal mechanisms. Similarly, Fleming and Heithaus (1981) investigated the seed shadow created by bats in a Costa Rican dry forest, highlighting implications for seedling establishment and plant distribution. Biotropica has also been instrumental in publishing research on the key roles of large animals, such as elephants (e.g., Bunney et al. 2017; Tan et al. 2021), rhinoceroses (McConkey et al. 2022), tapirs (e.g., Campos-Arceiz et al. 2012; Paolucci et al. 2019), and primates (e.g., Gross-Camp and Kaplin 2005; Nuñez-Iturri and Howe 2007). These vertebrates, often targeted by hunting and poaching, face threats with cascading effects to ecosystem regeneration, plant population dynamics, and community structure (Dirzo et al. 2014; Young et al. 2016). Indeed, several studies published in Biotropica have also highlighted the ecological consequences of hunting and defaunation, emphasizing their profound impacts on seed dispersal interactions and the long-term resilience of tropical forests (e.g., Beckman and Muller-Landau 2007; Peres and Palacios 2007; Trolliet et al. 2017; Pedrosa et al. 2019). Furthermore, studies published in Biotropica have also contributed to testing influential hypotheses that have shaped the field of frugivory and seed dispersal, such as the specialization-generalization continuum of seed dispersal systems (e.g., Wenny 2000; Watson 2013), staggered fruiting phenology and competition for dispersers (e.g., Stevenson et al. 2000; Schubert and Walters 2022), keystone fruiting resources (e.g., Palacio et al. 2016; Peabotuwage et al. 2019; Messeder et al. 2020), and Janzen-Connell dynamics (e.g., Matthesius et al. 2011; Rosin and Poulsen 2018; Zang et al. 2021). To move the field forward while continuing to establish Biotropica as a leading journal for seed dispersal ecology in the tropics, we envision several promising research directions. Studying seed dispersal ecology in undersampled regions and vegetation types will provide a broader picture of the relative importance of seed dispersal across biogeographic regions and ecosystems. Additionally, the identification of knowledge gaps and research priorities in these understudied regions or systems will be essential for guiding future research. For example, forests and open ecosystems drastically differ in species composition and ecosystem functioning, so expanding seed dispersal to open ecosystems is needed to test long-standing hypotheses developed in tropical forests (e.g., Janzen-Connell hypothesis). Similarly, island systems and other biodiversity hotspots remain understudied despite their unique ecological dynamics, high levels of endemism, and vulnerability to anthropogenic pressures (Nogales et al. 2024). Biogeographic regions also exhibit substantial differences in species composition of both fauna and flora, so to what extent knowledge obtained in the Neotropics (the most studied biogeographic region) can be generalized to the Palaeotropics is unknown. A promising pathway is to promote studies focusing on individual and population levels (Schupp and Fuentes 1995; Bolnick et al. 2011). While frugivory and seed dispersal interactions are typically examined at the species level, interactions in nature occur among individuals (Clark et al. 2011). Intraspecific variation in fruit and seed traits has increasingly been recognized as a key factor shaping seed dispersal dynamics, yet its magnitude and evolutionary implications remain poorly understood (Schupp et al. 2019; Snell et al. 2019). Addressing this gap could provide insights into how interindividual trait variation drives natural selection and evolutionary processes in seed dispersal systems, encompassing both plant and frugivore species (Zwolak 2018; Snell et al. 2019). For instance, exploring whether species-level patterns hold true at the individual level could reveal how interindividual variation structures seed dispersal dynamics (Quintero et al. 2025). Examining how seed dispersers respond differently to species-level trait averages versus interindividual variance, as well as how trait variation in both plants and animals influences dispersal patterns, could provide further clarity (Schupp et al. 2019). Such studies could clarify whether interindividual differences generate distinct ecological or evolutionary outcomes that are obscured by species-level analyses. Building on Biotropica's tradition of publishing species-level studies, we also advocate for increased focus on the behavioral ecology of frugivore species. Frugivore behavior and personality directly influence habitat selection and resource tracking with consequences for seed fate, influencing the stages of seed dispersal from initial fruit selection and consumption to seed deposition and post-dispersal processes (Sih et al. 2012; Zwolak and Sih 2020; Graf et al. 2024). Understanding these mechanistic links will be essential to unravel how animal behavior shapes plant regeneration and community structure. Furthermore, investigating the interplay between frugivore resource preferences, movement patterns, and behavior with fruit traits—particularly in early-successional stages—can offer important insights into restoration dynamics and functional connectivity of plant communities (Camargo et al. 2020; Landim et al. 2025). For instance, our understanding of how different initial assemblages of fleshy-fruited plant species can influence restoration trajectories and the re-assembly of plant communities during succession remains limited. Addressing these knowledge gaps could foster the development of seed dispersal-based strategies, ultimately enhancing the effectiveness of ecosystem restoration and conservation programs. We highlight the potential of relatively new techniques, such as stable isotopes, molecular tools, GPS tracking and telemetry, and camera traps in advancing frugivory and seed dispersal research. While their use has expanded in recent years (Quintero et al. 2022), these techniques remain underrepresented in the research published in Biotropica. Embracing these new tools could deepen our understanding of dispersal processes across spatial and temporal scales, especially as technological advancements make them more cost-effective (Tosa et al. 2021). Moreover, linking seed dispersal to broader ecosystem processes, such as biogeochemical cycles and carbon dynamics, represents an exciting frontier. Such an integrative approach could bridge community and ecosystem ecology, fostering insights into how seed dispersal contributes to large-scale ecological dynamics while addressing pressing challenges in the Anthropocene. For example, evaluating the dynamics of frugivory mutualisms under climate change would help us to understand how its effects propagate through ecological communities (Schleuning et al. 2016), the extent of plants and animals capacity to track climate change (Corlett 2009; Fricke et al. 2022), as well as their role in carbon sequestration in regenerating landscapes (Bello et al. 2024). By fostering some of the suggested avenues, Biotropica can continue to inspire influential research and serve as a cornerstone for progress in frugivory and seed dispersal. Finally, we would like to emphasize that Biotropica's most significant role extends beyond publishing relevant tropical studies. Over the years, the journal has consistently supported early-career researchers from tropical and developing countries by offering a platform for their opening publications, which have often served as a springboard for successful careers. Notably, many ecologists, including ourselves, started their publication journey with Biotropica, highlighting its importance in fostering the next generation of tropical ecologists and celebrating the geographic diversity of its contributors. We thank Jennifer Powers for encouraging the conceptualization of this essay. We are grateful to Tomás A. Carlo for providing many useful comments and suggestions. J.V.S.M. acknowledges his PhD scholarship funded by the Fulbright Commission, the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Penn State Biology Department, and financial support from the Hill Memorial Fund, Association for Tropical Biology and Conservation Seed Research Grant, and American Philosophical Society Lewis & Clark Exploration Grant. F.A.O.S. acknowledges grants by FAPEMIG. We thank the subject editor Asmita Sengupta and three reviewers for their comments to improve our manuscript. The authors declare no conflicts of interest. The authors have nothing to report.