Search Results (88)

The Dwarf Ombú, Phytolacca tetramera, is a rare and highly unusual plant endemic to the northeastern Pampean grasslands of Argentina and is currently considered of high conservation priority. In order to better understand its biology, ecology, and conservation requirements, we studied its anatomy, reproductive traits, life history, and distribution based on field observations and herbarium material. Our results show that P. tetramera possesses a combination of traits consistent with the concept of ecological anachronism. The species produces large fleshy fruits whose size and shape are comparable to those interpreted as adapted for dispersal by extinct megafauna. In addition, the plant exhibits morphological and ecological adaptations associated with intense grazing, trampling, and drought tolerance, including robust underground structures and a growth pattern comparable to underground trees from seasonally dry open habitats. These findings suggest that P. tetramera evolved under ecological conditions markedly different from those existing today, including megafaunal disclimax environments that disappeared after the late Pleistocene extinctions. This ecological mismatch may help to explain its present rarity, fragmented distribution, and low population numbers. Our results also indicate that current conservation strategies for P. tetramera should consider the role of disturbance regimes and extinct ecological interactions in shaping the biology of this species. Full article

Bull sharks (Carcharhinus leucas) are highly mobile coastal predators, whose broad movements complicate conservation planning, particularly in the Western Indian Ocean, where key habitats remain poorly understood. Using passive acoustic telemetry, this study assessed the habitat use, residency, and regional connectivity of adult bull sharks within the Bazaruto Seascape, Mozambique, evaluating the area’s ecological role within a wider movement network. Sharks tagged around Bazaruto exhibited high residency (overall R_max = 0.45) and year-round presence, with core habitat concentrated along seaward reef systems and inshore areas off the San Sebastian Peninsula. Although most core habitat areas (82%) overlapped with existing marine protected areas, important habitats extended beyond protected area boundaries. In addition to supporting resident individuals, the seascape functioned as a seasonal waypoint within a regional movement corridor, with transient sharks exhibiting short periods (<5 days) of seasonal residency (primarily between May and November). Movement patterns revealed strong connectivity with other aggregation sites along the southeast African coast and occasional long-distance movements across the Mozambique Channel to Madagascar and beyond. These findings demonstrate that the Bazaruto Seascape provides both critical habitat and acts as a connectivity node for resident and transient bull sharks, highlighting the need for conservation strategies that combine local spatial protection with broader regional and transboundary management frameworks. Full article

We report fungal species used as food sources by mycophagous scarab beetles, with special emphasis on Phanaeus MacLeay, 1819, and confirm that Phanaeus zapotecus Edmonds, 2006 and Phanaeus bravoensis Moctezuma, Sánchez-Huerta & Halffter, 2017 are mycophagous. Mycophagy is confirmed in the P. endymion and P. tridens species groups. We propose a vicariant speciation process for the mycophagous species of the P. endymion species group (P. halffterorum Edmonds, 1979; P. zapotecus; and P. bravoensis) in the mountains of central Mexico, driven by competition, glaciation-induced climatic change, biome and faunal shifts, and access to a new food resource (fleshy fungi) in a new environment (pine–oak forest). We reiterate the revalidation of Phanaeus dionysius Kohlmann, Arriaga-Jiménez & Rös, 2018 as a distinct species and confirm its coprophagous habits. Based on morphological characteristics, we establish the Phanaeus halffterorum species complex within the Phanaeus endymion species -group. Full article

Whale sharks (Rhincodon typus) predominantly inhabit the epipelagic layer, yet dives to at least 1928 m have been reported. Even so, current understanding of the species’ true maximum dive depth is constrained by the technological limitations of depth sensors of commercially available satellite tags, which are generally rated to a maximum depth of 2000 m. Here, we report a new maximum depth range of 1978–2527 m inferred from a Wildlife Computers custom-calibrated SPLASH10-346C finmount tag (2500 m capability), deployed on a 7 m juvenile male whale shark in the Coral Sea, Australia. This extends the currently accepted depth limit by 50–599 m. Full article

This research provides a new comprehensive assessment of Pikimachay Cave fossil remains of extinct fauna from the Late Pleistocene and Early Holocene, curated in the Florida Museum of Natural History’s Environmental Archaeology Program collections. The collection is the result of excavations carried out by Richard MacNeish during the 1960s and 1970s, during which he proposed pre-Clovis dates for human occupation in South America. Archival records housed across three institutions were compiled to reconstruct the spatial distribution of megafauna within the cave. Taphonomic observations of the bone assemblage were conducted to better understand depositional processes and cave conditions. Based on the spatial distribution of fossil evidence mapped and documented by layer and the taphonomic evidence of the bone assemblage, we conclude that the cave functioned primarily as a giant ground sloth burrow, also used by humans and carnivores. Future research, including additional radiocarbon dates and better contextualization of the deposits, will be essential for better understanding the fossil fauna represented in the cave and the ecological relationships among humans, carnivores and extinct species in the highlands of Perú. Full article

Drones are increasingly used in marine science for detecting and monitoring large megafauna in nearshore areas. Remotely operated, autonomous drone missions have the potential to improve the overall efficiency of drone-based research. We assessed the utility of autonomous drone operations by comparing real-time detection rates of marine megafauna (i.e., dolphins, rays, sharks, turtles) between a remotely operated Drone-In-A-Box (DIAB) system using pre-programmed missions and standard site-operated manual flight procedures. Megafauna were identified in real time during each drone mission, and missed detections were quantified through post-analysis of drone footage. A total of 71 missions were completed, with autonomous and manual flights operating concurrently at either 60 m or 80 m altitude, and a flight speed of 8 m/s. There were 107 and 117 real-time megafauna observations recorded for autonomous and manual operations, respectively. Post-flight analysis determined an overall missed detection of 52.4% for autonomous and 30.4% for manual operations, with undercounting higher for autonomous operations across all faunal groups. Dolphin detection in real time had the highest agreement with post-flight analysis, while real-time turtle detection proved the most difficult. Cloud cover, sea state, time of day, and water clarity significantly affected real-time false negative detection rates, though their relative importance varied across faunal groups and between flight procedures. Overall, remotely operated, autonomous drones have the potential to enhance long-term marine megafauna research, particularly when combined with post-flight analysis. Integrating artificial intelligence into autonomous drone operations will also be beneficial, especially for shark surveillance programs where real-time detection is essential for beach-user safety. Full article

The global demand for renewable energy is rapidly increasing in response to efforts to reduce greenhouse gas emissions, driving the development of novel technologies. Offshore solar energy is an emerging renewable technology with the potential to contribute to the energy transition and decarbonization of electricity generation. Although offshore solar projects are developing at an increasing pace, their ecological implications are not yet well-understood, including interactions with marine megafauna. Given the central ecological roles of birds and marine mammals, assessing and monitoring these interactions is essential before large-scale deployment. Despite extensive research on marine megafauna interactions with offshore wind farms, no studies have yet examined offshore interactions with solar installations. This study uses year-round time-lapse imagery and bird pellet analyses to record species presence, abundance, juvenile occurrence, and behavioral use of these structures in the southern North Sea. Seagulls, as well as grey and harbor seals, were frequently observed resting on the floating solar installations. Bird occurrence showed seasonal variation, likely reflecting breeding and migration patterns. The results indicate offshore solar structures may serve as temporary resting grounds for marine megafauna. These findings emphasize the importance of long-term ecological monitoring to ensure the sustainable co-existence of offshore renewable energy and marine biodiversity. Full article

Marine traffic poses a significantly increasing threat to the marine environment, especially marine megafauna species, due to collisions between large vessels and marine organisms that most frequently result in mortality. The adoption of mitigation methods for collisions is critical to avoid population declines. Selecting the optimal mitigation method depends on a set of criteria and is best assessed using decision-making tools. The current study reviewed the use of decision-making tools for marine traffic applications and discusses the existing gap regarding environmental applications (especially considering the impact on marine biodiversity). Furthermore, the authors propose a method for estimating hotspots of marine traffic that may overlap with marine biodiversity foraging grounds, and the structure for a decision-making tool for mitigating collisions and conserving the marine environment. Full article

Vampire bats likely first appeared in South America in the early Miocene (~20 Ma) and evolved to feed upon the blood of native South American mammals of medium to large body size, in particular, xenarthrans–ground sloths, armadillos, pampatheres, and glyptodonts, and native ungulates–notoungulates and litopterns. Following the formation of the Panamanian Isthmus (~5 Ma), vampire bats immigrated into North America as participants in the Great American Biotic Interchange, following their preferred prey species, probably xenarthrans. The earliest records of vampire bats are the extinct species Desmodus archaeodaptes from three early Pleistocene faunas in Florida. The large extinct vampire D. stocki occurs in 18 late Pleistocene faunas in the southern US and Mexico. The giant extinct vampire D. draculae is known from eight late Pleistocene faunas from Mexico and Belize south to Brazil and Argentina. The late Pleistocene extinction of D. draculae and D. stocki coincided with the extinction of their primary source of blood, the mammalian megafauna. The common vampire bat D. rotundus survived and now occurs throughout tropical America because it had a broader prey base, feeding on the blood of a variety of medium- to large-sized mammals, and currently preying preferentially on non-native domestic livestock. Full article

Satellite tracking has dramatically improved research on wide-ranging large marine vertebrates such as sea turtles. Traditionally, sea turtle tracking has relied on Argos-based satellite telemetry tags, which estimate location via Doppler shift and can also transmit sensor data. GPS-equipped Argos satellite tags represented a significant evolution, offering higher location accuracy. More recently, GPS-equipped satellite tags transmitting via the Iridium satellite network have become available for sea turtle tracking, and this study aims to assess whether they offer additional advantages. The performance of three satellite tag types—Argos-only, Argos-GPS, and Iridium-GPS (Iridium)—was assessed using data on 116,074 positions from 48 sea turtles representing five species and multiple ocean basins. Performance was evaluated using three indicators: the proportion of days with location data, the duration of gaps between locations, and the number of positions per day. Bayesian generalized linear mixed models assessed the effect of satellite tag type, technical settings, species, and activity (migration, foraging, internesting). Results indicate that Iridium satellite tags generally perform similarly to both Argos-based satellite tags, but performance improves significantly when programmed with high-frequency GPS acquisition (>24 positions/day), a result made possible by their tenfold higher transmission capacity compared to Argos. This capacity also enables transmission of more sensor data. Performance, however, varied by species and activity. These findings highlight the potential of Iridium tags to enhance fine-scale movement studies by improving the spatial and temporal resolution of sea turtle tracking, with important implications for ecological research and conservation planning. Full article

The reproductive biology of the whale shark (Rhincodon typus), the world’s largest fish, remains poorly understood, in large part due to the rarity of observations of neonates and of breeding behaviours. Although several regions in Indonesia, including Saleh Bay (West Nusa Tenggara Province), have been identified as aggregation and sighting sites for juvenile whale sharks (2–7 m total length, TL), smaller individuals from these potential nursery areas have not been previously documented. In August 2024, fishermen operating lift-net fishing vessels (bagans) in eastern Saleh Bay reported five separate sightings of a small whale shark estimated at 1.2–1.5 m TL and approximately four months old. Subsequently, on 6 September 2024, a male neonate measuring approximately 135–145 cm TL, estimated to be around four months old, was incidentally caught inside a bagan lift-net. These observations represent the first records of neonatal whale sharks in Indonesia and among the smallest free-swimming individuals ever documented globally, and suggest that Saleh Bay may serve as a pupping and early nursery area for whale sharks. These findings highlight the ecological significance of Saleh Bay for the early life stages of whale sharks and underscore the importance of collaborative monitoring and citizen science involving bagan fishermen in advancing the research and conservation of this endangered species. Full article

Many modern zoos maintain charismatic megafauna, such as elephants, as their iconic residents, as these animals have been shown to hold the zoogoers’ gaze more adeptly than demurer animals. This study sought to determine zoo supporters’ perceptions of elephants’ emotions and welfare under conditions in which elephants receive rewards and demonstrate behaviors within elephant–caregiver interactions in a zoo to generate key themes associated with those perceptions and to compare those perceptions to zoo professionals’ through the lens of The Five Domains animal welfare assessment model. This qualitative study employed multiple methodological strategies, including surveys, autoethnography, interviews, and welfare assessments. The article explores two themes that were generated regarding participants’ perceptions: elephants’ autonomy and participation in labor. The discourse of elephant labor in a zoo is timely, as animal labor among domestic animals is a growing topic in social sciences research. Elephants’ welfare was perceived as largely positive, though there was a small number of participants who felt the elephants did not enjoy their labor. Participants’ perceptions were mostly aligned with zoo professionals’ perceptions. As this is the first article to discuss zoo animal labor, it makes a unique contribution to the current literature and may have applications to other species’ labor within zoos. Full article

Manta ray tourism has become a multi-million-dollar industry proposed as a conservation tool in recent decades; however, its impacts remain unclear. We use drones and Markov models to quantify the effects of diver presence on a juvenile population of the recently described Atlantic manta ray (Mobula yarae) off the coast of Florida. We contrast diver effects on behavioral states (avoidance, feeding, and neutral), examine the responses of individual manta rays, and estimate the energetic costs of diver presence. Diver presence significantly influenced manta ray behavior. Manta rays spent 37% of their time avoiding divers, with neutral and feeding manta rays having an increased probability of transitioning to avoidance states in the presence of divers. We found a significant difference in the proportion of time individual manta rays spent in avoidance, with some individuals being highly avoidant (up to 70%), while others were less affected by diver presence (<20% avoidance). While wingbeat frequency did not change in the presence of divers, manta rays with divers spent significantly more time with their cephalic fins unfurled. Our findings suggest that tourism could negatively impact this small, vulnerable population, making it unsuitable for development. We recommend similar behavioral and kinematic assessments to guide sustainable wildlife tourism management. Full article

Cleaning stations on seamounts play a crucial ecological role in the health and behavior of marine megafauna, yet interspecific interactions at these sites remain understudied. This study investigates potential hierarchical dynamics between reef manta rays (Mobula alfredi) and pelagic thresher sharks (Alopias pelagicus) at two cleaning stations atop a seamount in the Philippines. Using over 960 h of autonomous video recordings across 119 survey days, we examined species-specific site preferences, visitation types, and behavioral responses to interspecific encounters. Results indicate that, while manta rays used both stations equally, thresher sharks showed a strong preference for the deeper, sloped station. Interruptions during cleaning suggest a hierarchy: all manta-to-shark interactions resulted in thresher sharks vacating the station prematurely, possibly before completing cleaning. In contrast, manta–manta interactions showed more balanced outcomes, with no significant impact on cleaning duration. Shark presence decreased as the flow speed intensified and was lowest during high tide, suggesting that sharks’ decision to clean may be dictated by factors affecting the effectiveness of the cleaning process. These findings also suggest that manta rays may outcompete thresher sharks for access to cleaning services. Understanding such interspecific dynamics is vital for effective marine habitat management and the conservation of vulnerable pelagic species. Full article

Social media has emerged as a dominant platform for sharing human–animal interactions, creating a powerful tool for public engagement and wildlife conservation. Consequently, we sought to determine whether analyzing user preferences for animals on social networks could inform the management of effective conservation campaigns. We analyzed 5129 videos from three channels (Brave Wilderness, BBC Earth, and Nat Geo Wild) available on YouTube, which have millions of followers each. The mean number of “likes” was used as a proxy for animal species preferences. Contrary to the general expectation that humans predominantly prefer charismatic animals (e.g., terrestrial mammals), the most preferred animals on these channels were from the classes Amphibia, Arachnida, and Insecta, which significantly outperformed mammals and birds. Viewers most frequently consumed videos of stinging insects or threatening animals, and domestic animals received more likes than wild animals. Furthermore, contrary to expectations, body mass, IUCN conservation status, and daytime activity of mammals and birds did not significantly influence human preferences. Our results suggest that although viewing animal videos may have a negligible direct conservation impact, the analysis of preferences reveals that creators successfully captured human attention toward less popular animal taxa, highlighting potential indirect benefits. Future research should integrate audience enjoyment of frightening content with conservation intentions. Full article