Villanueva-Bonilla GA, Mesas YF, de Oliveira Gonzaga M
… +4 more, da Silva Souza H, Brescovit AD, Sobczak JF, Neto JV
Naturwissenschaften
· 2024 Oct · PMID 39476258
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Habitat selection by spiders is strongly influenced by biotic factors such as the availability and diversity of prey and abiotic factors such as temperature, humidity, and the structural complexity of the habitat. Struct...Habitat selection by spiders is strongly influenced by biotic factors such as the availability and diversity of prey and abiotic factors such as temperature, humidity, and the structural complexity of the habitat. Structural complexity is an aspect that intensely affects species persistence, population stability, and the coexistence of interacting species. Trees comprise a complex set of microhabitats due to their large biomass and heterogeneity of the architectural components of their trunk surface and branches. Spider species that live on trunks have diversified physiological or morphological adaptations that confer advantages in this environment. In this study, we experimentally examined the habitat choice by the tree-dwelling spiders Selenops cocheleti (Selenopidae), Corinna rubripes (Corinnidae), and Loxosceles gaucho (Sicariidae). We found that microhabitat specialization was restricted to trunk architectural characteristics rather than plant taxonomy. Selenops cocheleti and C. rubripes significantly preferred loose barks and holes in the trunks, respectively, showing that both spider species can evaluate the physical structure of the microhabitat on a fine scale. On the other hand, L. gaucho selected crevices and holes near the base of the trunk without giving much importance to the physical characteristics of the microhabitat per se (e.g., depth, height, length). Our findings indicate that for generalist predators like spiders, coexistence relies heavily on spatial segregation driven by distinct habitat preferences, irrespective of their method for capturing prey.
Naturwissenschaften
· 2024 Oct · PMID 39446166
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Wildlife forensics plays a pivotal role in the combating illegal trafficking, supporting biodiversity conservation, and aiding in the identification of animals in wildlife. Animal hair, often found in trafficking crimes,...Wildlife forensics plays a pivotal role in the combating illegal trafficking, supporting biodiversity conservation, and aiding in the identification of animals in wildlife. Animal hair, often found in trafficking crimes, serves as vital biological evidence that can provide significant information for animal identification. This study proposes a novel method integrating machine learning classifiers with Fourier transform infrared (FTIR) spectroscopy in attenuated total reflectance (ATR) mode to enhance the effectiveness of animal identification in wildlife forensic casework. Additionally, compound microscopy has also been utilized as a preliminary tool to perform morphological analysis of hair samples from four animal families, including Bovidae, Cervidae, Elephantidae, and Felidae. Further, chemical profiling through spectral data revealed significant overlapping peaks between family Bovidae and Cervidae. The classification experiment provides the random forest (RF) classifier as the most effective for family discrimination model. This research offers valuable insights for wildlife forensics by improving the identification accuracy of unknown hair samples, thus enhancing the overall effectiveness in forensic investigations.
Naturwissenschaften
· 2024 Oct · PMID 39412668
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Investigating the conspicuousness of animal color patterns to different observers is crucial for understanding their function. This study examines the peculiar case of a jumping spider (Saitis barbipes) whose males displ...Investigating the conspicuousness of animal color patterns to different observers is crucial for understanding their function. This study examines the peculiar case of a jumping spider (Saitis barbipes) whose males display red and black ornaments during courtship despite an apparent inability to distinguish these colors. We propose that, through predator eyes, red may actually be a better match than black to the spiders' leaf litter background, and that the black fringe of hairs surrounding red ornaments may blur with red at natural predator acuities and viewing distances to produce a background-matching desaturated red. In a field experiment, we test whether red ornaments reduce predation relative to red ornaments painted black, and find that, unexpectedly, spiders with red ornaments are more heavily predated upon. Having established birds as the spiders' primary predators, we image the spiders in their natural habitat using an avian-vision camera. We find their red coloration to have similar color contrast, but lower achromatic contrast, with the background than black coloration. We also find that red and black elements blur together at typical avian acuities and viewing distances to produce lower chromatic and achromatic contrasts with the background than would be seen by animals with higher acuities and/or closer viewing distances. Interestingly, red ornaments appear orange or yellow when viewed obliquely, which reduces their achromatic, but not chromatic, contrast with the background. Our imaging results provide support for our hypothesis that red is camouflaging, whereas the results of our predation experiment do not. Any functional significance of the spiders' red coloration therefore remains unresolved.
Pansarin ER, Pedro SRM, Pansarin LM
… +2 more, Davies KL, Stpiczyńska M
Naturwissenschaften
· 2024 Oct · PMID 39400704
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Orchids offer a variety of floral rewards to pollinators. In many orchid groups, however, the transfer of pollen is based on food-deception, as in the case of Laelia (including Schomburgkia s.s.), a genus assigned to the...Orchids offer a variety of floral rewards to pollinators. In many orchid groups, however, the transfer of pollen is based on food-deception, as in the case of Laelia (including Schomburgkia s.s.), a genus assigned to the Neotropical subtribe Laeliinae. Here, we report on the reproductive biology of a Brazilian member of this subtribe, namely, Laelia gloriosa, occurring in the forested areas of southeastern Brazil. The study includes analyses of floral morphology, histochemistry, and the chemical analysis of floral rewards and scents. Pollinators and pollination mechanism data were collected in the field by means of focal observations. Analyses of breeding systems and the percentage of potentially viable seed were also recorded. The floral morphology of Laelia gloriosa indicates that this species is melittophilous. The flowers release a citrus-like fragrance that attracts many species of bee. The flowers offer waxy material as a reward, and this is collected exclusively by Meliponini bees. Several bee species visit the flowers. However, those of L. gloriosa are pollinated exclusively by Trigona spinipes. Pollinaria are deposited on the bee's scutellum. Plants of the studied population were entirely self-compatible, but pollinator-dependent. The frequency of visits to these flowers was greater than in rewardless Laeliinae. Our study provides the first evidence of lipoidal substances as a resource in Laeliinae. The discovery that an orchid species (Laelia gloriosa) of this subtribe, hitherto considered to be entirely pollinated by nectar-seeking pollinators, offers a floral waxy material and provides new insights into the evolution of this important subtribe.
Rolando AMA, Motta MJ, Agnolín FL
… +4 more, Tsuihiji T, Miner S, Brissón-Egli F, Novas FE
Naturwissenschaften
· 2024 Oct · PMID 39382666
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Carcharodontosaurids were gigantic terrestrial dinosaurs and top predators of dinosaur faunas in Gondwanan landmasses during the "Mid"-Cretaceous Period. Despite their wide geographical and stratigraphical distribution,...Carcharodontosaurids were gigantic terrestrial dinosaurs and top predators of dinosaur faunas in Gondwanan landmasses during the "Mid"-Cretaceous Period. Despite their wide geographical and stratigraphical distribution, essential parts of their anatomy are still poorly known. The present contribution aims to describe a new partial skeleton of the carcharodontosaurid Taurovenator violantei, which was previously known only by an isolated postorbital bone coming from Cenomanian-Turonian beds of northern Patagonia, Argentina. The neck of Taurovenator is composed of notably high anterior cervicals, bearing neural spines with expanded, flange-like dorsal tips which are successively imbricated. This condition has been reported previously in the carcharodontosaurid Acrocanthosaurus, but its occurrence in Taurovenator and other members of the clade suggests it may represent a synapomorphy of this theropod family. This unique neck morphology was probably related to strong modifications in musculature and restriction in the range of movements within the neck, but not with the head. The new specimen also affords valuable anatomical information on the forelimb of Patagonian carcharodontosaurids. As in other giganotosaurines, Taurovenator shows strongly reduced forelimbs, particularly the forearm, showing hand elements with elongated non-ungual phalanges, and well-marked articular surfaces and muscular insertions, suggesting highly movable digits. This new specimen of Taurovenator allows us to expand anatomical and morpho-functional discussions about the carcharodontosaurid clade.
Raiary B, Ribeiro C, Lima D
… +8 more, Afeitos A, Mendonça T, Cárdenas V, Magalhães A, de Azevedo CS, Cassino R, Antonini Y, Cardoso JCF
Naturwissenschaften
· 2024 Oct · PMID 39373872
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Water-filled tree hollows constitute phytotelmata that harbor specialized organisms. One striking example of extreme adaptation to these microhabitats is the case of the microcrustacean Micromoina arboricola, which has b...Water-filled tree hollows constitute phytotelmata that harbor specialized organisms. One striking example of extreme adaptation to these microhabitats is the case of the microcrustacean Micromoina arboricola, which has been found inhabiting the hollow of a single tree individual in the Atlantic Forest. We investigated the spatial distribution and influence of microhabitat characteristics such as hollow volume and height from the ground in the occurrence of M. arboricola. We surveyed all the trunks present in ca. 5000 m of an Atlantic old-growth forest area. We found M. arboricola individuals in 75% of the hollows, thus expanding the known distribution of the species. Spatial analysis suggested a clustered pattern of population densities across hollows, indicating that the dispersal capacity to new microhabitat patches may vary in space. Although we did not find an effect of hollow volume, population density was negatively related to hollow height. This suggests that more restrictive abiotic conditions at greater heights limit the occurrence of the species, emphasizing its vulnerability to environmental changes. Hollow-mediated ecosystem engineering depends on the occasional formation of cavities that require time and ancient trees. Preserving old forests with hollows under varying conditions tends to maintain ecosystem functionality and the conservation of this unique microendemic species.
Nishimura T, Nakatani E, Lin MC
… +3 more, Yamauchi H, Fukushima M, Hsu CY
Naturwissenschaften
· 2024 Oct · PMID 39373747
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Prior research has indicated a correlation between the birth season and life expectancy; however, many of these studies did not sufficiently account for comorbidities. In this comprehensive investigation, we aimed to met...Prior research has indicated a correlation between the birth season and life expectancy; however, many of these studies did not sufficiently account for comorbidities. In this comprehensive investigation, we aimed to meticulously explore the association between the birth month and life expectancy, giving due consideration to comorbidities. We used a robust dataset derived from Taiwan's National Health Insurance Research Database (2000-2013), which allowed us to conduct a thorough examination. We divided our participants into four groups based on their season of birth: spring, summer, autumn, and winter. Propensity score matching was used to ensure an equitable distribution of demographic and clinical characteristics across the groups. Propensity scores were computed using logistic regression. Our model incorporated a broad range of demographic factors and comorbidities, providing rigorous adjustment for potential confounders. Our findings revealed a significantly increased risk of all-cause mortality among individuals born in spring, even after stringent adjustment for demographic factors and comorbidities. People born in spring demonstrated a 1.05-fold increase in the risk of all-cause mortality, with a hazard ratio of 1.05 and a 95% confidence interval of 1.01-1.09. Our study provides compelling evidence that helps understand the potential long-term impacts of a person's birth season, which acts as a proxy for pregnancy / early-life environmental exposure, on life expectancy. These findings underscore the crucial need for additional research to illuminate the underlying biological and environmental mechanisms linking the birth season and lifespan of a person. The elucidation of these links could guide the development of innovative health promotion and disease prevention strategies that are tailored to an individual's birth season.
Naturwissenschaften
· 2024 Oct · PMID 39352565
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Colonization of new habitats is a key event in forming current distributions in organisms. It has been speculated that freshwater fish eggs can be dispersed passively by attaching to or egestion from waterbirds that arri...Colonization of new habitats is a key event in forming current distributions in organisms. It has been speculated that freshwater fish eggs can be dispersed passively by attaching to or egestion from waterbirds that arrive in wetland habitats. Recent research showed that some freshwater fish eggs could be excreted alive from birds and then successfully hatch, but scientific evidence of bird-mediated fish dispersal is still limited to endozoochory (internal transport through a bird's digestive tract). Here, we experimentally suggest the dispersal potential in another way or epizoochory (external dispersal by attaching to waterbirds), using medaka Oryzias latipes, which spawns on aquatic plants. Our field experiment showed that waterbirds could carry artificial aquatic plants among waterbodies. Medaka eggs attached to aquatic plants could survive in the air for up to 18 h with a median lethal period of 16.3 h. Those two findings raise the possibility of the epizoochory of medaka in nature.
Biophotovoltaics (BPV) is a clean and sustainable solar energy generation technology that operates by utilizing photosynthetic autotrophic microorganisms to capture light energy and generate electricity. However, a major...Biophotovoltaics (BPV) is a clean and sustainable solar energy generation technology that operates by utilizing photosynthetic autotrophic microorganisms to capture light energy and generate electricity. However, a major challenge faced by BPV systems is the relatively low electron transfer efficiency from the photosystem to the extracellular electrode, which limits its electrical output. Additionally, the transfer mechanisms of photosynthetic microorganism metabolites in the entire system are still not fully clear. In response to this, this article briefly introduces the basic BPV principles, reviews its development history, and summarizes measures to optimize its electrogenic efficiency. Furthermore, recent studies have found that constructing photosynthetic-electrogenic microbial consortia can achieve high power density and stability in BPV systems. Therefore, the article discusses the potential application of constructing photosynthetic-electrogenic microbial aggregates in BPV systems. Since photosynthetic-electrogenic microbial communities can also exist in natural ecosystems, their potential contribution to the carbon cycle is worth further attention.
Lopez VM, Guillermo-Ferreira R, Seip L
… +1 more, Gorb S
Naturwissenschaften
· 2024 Sep · PMID 39325197
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Sexual conflict theory predicts that males that adopt coercive mating strategies impose costs to females during copulation. Nevertheless, conflicting mating strategies may also affect males, although such effects on male...Sexual conflict theory predicts that males that adopt coercive mating strategies impose costs to females during copulation. Nevertheless, conflicting mating strategies may also affect males, although such effects on males are often neglected in the literature. Here, we seek to understand whether male water striders (Gerris lacustris) experience higher body temperatures than females during coercive mating behavior. We we explored whether the water temperature affected male and female body temperature differently, considering that water contact by females might serve as a thermal regulator. We built generalized linear mixed models considering the male and female temperature as the dependent variables. Air temperature (as a proxy for solar radiation), water temperature, and sex were used as predictor variables. Our results suggest that males are warmer than females, and despite females coming into contact with water during skimming, this contact does not significantly contribute to lowering their body temperature or improving thermoregulation under the observed conditions. These findings provide novel insights into the thermal biology of water striders. Future studies should focus on addressing whether warmer temperatures confer some advantages to males, such as increased mobility and better ability to hold onto females or impose physiological constraints and fitness costs.
Genitalia are known to evolve rapidly and are among the most variable structures in insect morphology, making them a target of active research. However, function and evolutionary significance of internal genital structur...Genitalia are known to evolve rapidly and are among the most variable structures in insect morphology, making them a target of active research. However, function and evolutionary significance of internal genital structures remain less well understood. Here, we report the morphology and mechanism of a novel ejaculatory system that has evolved in the dancefly genus Rhamphomyia (Insecta: Diptera: Empididae). Using synchrotron µCT technology, we examined the male genitalia of five dancefly species and identified an ejaculatory system resembling a leverage hydraulic jack, which is thought to have derived from a plunger-like pumping system. This jacking system amplifies the applied muscle power by up to 4.2 times, allowing the system to produce the same pumping power with much smaller muscles. However, the volume of the pumping muscle in the jacking system is comparable to that of the plunger system, indicating a significant increase in ejaculation power in this genus. We hypothesize that the greater pumping power evolved through sexual selection favoring strong ejaculation to rapidly pass semen through a thin and elongated phallus and spermathecal duct.
Deformed wing virus (DWV) has long been identified as a critical pathogen affecting honeybees, contributing to colony losses through wing deformities, neurological impairments, and reduced lifespan. Since DWV also affect...Deformed wing virus (DWV) has long been identified as a critical pathogen affecting honeybees, contributing to colony losses through wing deformities, neurological impairments, and reduced lifespan. Since DWV also affects other pollinators, it poses a significant threat to global pollination networks. While honeybees have been the focal point of DWV studies, emerging research indicates that this RNA virus is not host-specific but rather a generalist pathogen capable of infecting a wide range of insect species, including other bee species such as bumblebees and solitary bees, as well as wasps and ants. This expands the potential impact of DWV beyond honeybees to broader ecological communities. The black imported fire ant, Solenopsis richteri, is an economically important invasive ant species. In this study, we describe deformed wing (DW) symptoms in S. richteri. DW alates were found in three of nine (33%) laboratory colonies. The symptoms ranged from severely twisted wings to a single crumpled wing tip. Additionally, numerous symptomatic alates also displayed altered mobility, ranging from an ataxic gait to an inability to walk. Viral replication of DWV was confirmed using a modified strand-specific RT-PCR. Our results suggest that S. richteri can be an alternative host for DWV, expanding our understanding of DWV as a generalist pathogen in insects. However, additional research is required to determine whether DWV is the etiological agent responsible for DW syndrome in S. richteri.
Megaloptera larvae are important bioindicator species and potential resource insects. To further cultivate their economic role, their living environment must be examined in more detail. In this study, we analyzed the phy...Megaloptera larvae are important bioindicator species and potential resource insects. To further cultivate their economic role, their living environment must be examined in more detail. In this study, we analyzed the physiological and biochemical effects of a sublethal dose of imidacloprid, a widely used neonicotinoid insecticide, on the larvae of Protohermes xanthodes. After treatment with imidacloprid, P. xanthodes larvae exhibited clear symptoms of poisoning, including the head curling up toward the ventral surface. Additionally, the activity of acetylcholinesterase was significantly inhibited following exposure. The activities of glutathione S-transferases initially continuously increased but showed a slight decrease after 8 days. Catalase activity initially increased and then decreased following imidacloprid treatment; superoxide dismutase activity fluctuated over time, and peroxidase activity continuously increased. The expression levels of HSP70s genes were evaluated using qRT-PCR. These results indicate that P. xanthodes larvae exhibit a toxic response to imidacloprid exposure, manifested as oxidative stress, as observed through behavioral and physiological indicators.
Naturwissenschaften
· 2024 Aug · PMID 39141101
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6-methoxybenzoxazolinone (6-MBOA) is a secondary plant metabolite predominantly found in monocotyledonous plants, especially Gramineae. In damaged tissue, 2-β-D-glucopyranosyloxy-4-hydroxy-7-methoxy-1,4-benzoxazin-3-one...6-methoxybenzoxazolinone (6-MBOA) is a secondary plant metabolite predominantly found in monocotyledonous plants, especially Gramineae. In damaged tissue, 2-β-D-glucopyranosyloxy-4-hydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA-Glc) is hydrolyzed to DIMBOA, which spontaneously decomposes into 6-MBOA. It is commonly detected in plants consumed by voles and livestock and can also be present in cereal-based products. Discovered in 1955, this compound is renowned for its ability to trigger animal reproduction. However, there is a lack of research on its functional and mechanistic properties, leaving much of their potential unexplored. This review aimed to comprehensively summarize the effects of 6-MBOA on animal reproduction and human health, as well as its defensive role against herbivores. Studies have shown that 6-MBOA effectively inhibits the digestion, development, growth, and reproduction of insects. 6-MBOA may act as a partial agonist of melatonin and exert a regulatory role in mammalian reproduction, resulting in either promoting or inhibiting effects. 6-MBOA has been theorized to possess anti-tumor, anti-AIDS, anti-anxiety, and weight-loss effects in humans. However, insufficient attention has been paid to its defense properties against mammalian herbivores, and the mechanisms underlying its effects on mammalian reproduction remain unclear. In addition, research on its impact on human health is still in its preliminary stages. The review emphasizes the need for further systematic and comprehensive research on 6-MBOA to fully understand its diverse functions. Elucidating the effects of 6-MBOA on animal reproduction, adaptation, and human health would advance our understanding of plant-herbivore coevolution and the influence of environmental factors on animal population dynamics. Furthermore, this knowledge could potentially promote its application in human health and animal husbandry.
Naturwissenschaften
· 2024 Aug · PMID 39136793
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Galls are plant neoformations induced by specialized parasites. Since gall inducers rely on reactive plant sites for gall development, variations in abiotic factors that affect plant phenology are expected to impact the...Galls are plant neoformations induced by specialized parasites. Since gall inducers rely on reactive plant sites for gall development, variations in abiotic factors that affect plant phenology are expected to impact the life cycle of gall inducers. To test the hypothesis that different light conditions affect both host plant and gall inducer life cycles, we studied the system Eugenia uniflora (Myrtaceae) - Clinodiplosis profusa (Cecidomyiidae), comparing plants occurring in sunny and shaded environments. We mapped phenological differences among individuals of E. uniflora occurring in the two environments and related them to the influence of luminosity on the life cycle of the gall inducer. Shade plants showed lower intensity of leaf sprouting throughout the year compared to sun-exposed plants, especially during the rainy season. Young and mature galls are synchronized with the peak of leaf sprouting at the beginning of the rainy season, lasting longer in sun-exposed plants - approximately two months longer compared to shade plants. The greater light intensity positively impacts the formation and growth of leaves and galls, with an extended period available for their induction and growth. Thus, light is an important factor for the development of gallers, considering that variations in luminosity influenced not only the phenology of the host plant, but also determined the life cycle of gall inducers. Furthermore, changes in plant-environment interactions are expected to affect the life cycle and richness of other host plant-gall inducer systems.
Naturwissenschaften
· 2024 Aug · PMID 39115554
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The female locust lays its eggs deep within soft substrate to protect them from predators and provide optimal conditions for successful development and hatching. During oviposition digging, the female's abdomen is pooled...The female locust lays its eggs deep within soft substrate to protect them from predators and provide optimal conditions for successful development and hatching. During oviposition digging, the female's abdomen is pooled and extends into the ground, guided by a dedicated excavation mechanism at its tip, comprising two pairs of specialized digging valves. Little is known about how these active valves negotiate the various obstacles encountered on their path. In this study, female locusts oviposited their eggs in specialized sand-filled tubes with pre-inserted 3D-printed plastic obstacles. The subterranean route taken by the abdomen and digging valves upon encountering the obstacles was investigated, characterized, and compared to that in control tubes without obstacles. Data were obtained by way of visual inspection, by utilizing cone beam computed tomography scans in high-definition mode, and by making paraffin casts of the oviposition burrows (after egg hatching). We demonstrate, for the first time, the subterranean navigation ability of the female locust's excavation mechanism and its ability to circumvent obstacles during oviposition. Finally, we discuss the role of active sensory-motor mechanisms versus the passive embodied function of the valves, central control, and decision-making.
Viviano A, De Meo I, Mori E
… +2 more, Sergiacomi C, Paletto A
Naturwissenschaften
· 2024 Aug · PMID 39093457
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Monitoring and management of alien coypu (Myocastor coypus) is a key issue in Europe since this species has been included in the EU Invasive Alien Species Regulation 1143/2014. Thus, controlling the population of this ro...Monitoring and management of alien coypu (Myocastor coypus) is a key issue in Europe since this species has been included in the EU Invasive Alien Species Regulation 1143/2014. Thus, controlling the population of this rodent is considered as imperative by wildlife managers. Coypu management in urban areas is crucial considering potential conflicts with human activities. The aim of this study is to investigate citizens' knowledge, perceptions and opinions towards the presence and management of coypu in a case study in Central Italy (the Serravalle urban park, Tuscany). The survey was administered to a subset of municipal residents and garnered responses from 281 park visitors. The outcomes showed a high level of knowledge of respondents: 99.3% of total respondents had heard of coypu before this survey, and 93.9% were able to distinguish the coypu from the Eurasian beaver (Castor fiber). Despite the importance of coypu control in invaded countries, our results highlight that most respondents are against the removal of coypu, with the exception of most young, highly-educated and upperclass men, but favouring sterilization over capture and population control. Findings of this study could assist managers in enhancing the efficacy of management efforts via an information initiative involving the general public. Achieving this goal may entail improved communication by wildlife managers, which is imperative for optimizing management strategies regarding alien species.
Waltert M, Klug J, Motombi FN
… +4 more, Cejp B, Bobo KS, Soofi M, Peters MK
Naturwissenschaften
· 2024 Jul · PMID 39080026
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Ant-following behavior is a common phenomenon in birds of Neotropical and Afrotropical rainforests but yet little is known from Central Africa. We here report on the phenomenon in lowland rainforest in Cameroon, quantify...Ant-following behavior is a common phenomenon in birds of Neotropical and Afrotropical rainforests but yet little is known from Central Africa. We here report on the phenomenon in lowland rainforest in Cameroon, quantifying the strength of the interaction of different ant-following bird species with driver ants and test the hypothesis that higher levels of specialization in ant-following behavior are associated with dominance or aggression-dependent plumage and other morphological traits. Flock size varied between 1 and 11 individuals with a mean size of 5.34 ± 2.68 (mean ± SD) individuals occurring at the same time. The maximum number of species present during one raid observed was ten, whereas the minimum number was four with an overall species richness of 6.89 ± 2.1 species. The 21 attending bird species strongly varied in the degree of ant-following behavior. In an interspecific comparison, plumage traits such as the presence of a colored crown, eyespots, and bare skin around the eye, in combination with metatarsus length and weight, were significantly correlated with ant-following behavior. These results suggest that-in size and identity of species-ant-following bird assemblages in Central Africa are similar to those reported from East Africa. They also suggest that ant following favors the selection of traits that signal dominance in interactions between individuals struggling for valuable food resources in the forest understory.
Lucas EA, Martin GR, Rocamora G
… +1 more, Portugal SJ
Naturwissenschaften
· 2024 Jul · PMID 39017742
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The visual field of a bird defines the amount of information that can be extracted from the environment around it, using the eyes. Previous visual field research has left large phylogenetic gaps, where tropical bird spec...The visual field of a bird defines the amount of information that can be extracted from the environment around it, using the eyes. Previous visual field research has left large phylogenetic gaps, where tropical bird species have been comparatively understudied. Using the ophthalmoscopic technique, we measured the visual fields of seven tropical seabird species, to understand what are the primary determinants of their visual fields. The visual field topographies of the seven seabird species were relatively similar, despite the two groups of Terns (Laridae) and Shearwaters (Procellariidae) being phylogenetically distant. We propose this similarity is due to their largely similar foraging ecology. These findings support previous research that foraging ecology rather than relatedness is the key determining factor behind a bird's visual field topography. Some bird species were identified to have more limited binocular fields, such as Brown Noddies (Anous stolidus) where binocularity onsets lower down within the visual field, resulting in a larger blind area about the head.