First records of albino Aesculapian snakes (Zamenis longissimus) in Hungary

Albinism is a genetic condition that results in total hypopigmentation of the eyes, fur, skin, hair, scales, and feathers of an organism. Albinism might result in a selective disadvantage for affected animals. Cases of albinism have been previously recorded in Neotropical vertebrates, such as reptiles, mammals, birds, and fish. However, observing albinism in a wild population is still considered to be a rare event. This paper reports a unique case of complete albinism in a red-brocket deer (Mazama americana) living in the Brazilian Amazon rainforest. The individual was observed within the Biological Reserve of Pará State, one of the most deforested regions of the Brazilian Amazon. The survival of the albino red-brocket deer in the wild can be related to mechanisms of apostatic selection, which theorize the survival of individual prey animals whose mutations make them less likely to be attacked by predators. In other words, the more different a prey animal is from others, the less likely it will be targeted by predators. The high abundance prey animals within the Biological Reserve of Tapirapé seems to support this prediction. This report exemplifies the importance of monitoring the biodiversity and promoting the conservation of favorable habitats to support species multiplicity in highly fragmented regions, as in the Brazilian Amazon.

Anomalous pigmentations have been reported in several groups of reptiles. Among these, albinism is one of the most striking aberrations of body coloration. This pigmentary anomaly is caused by the absence of melanin in the integument. Many cases of albinism have been reported in snakes, primarily in species with cryptozoic habits, and several reports are available for the Dipsadidae family from South America. Geophis is one of the most diverse genera in this family, with 50 species distributed mainly in Mesoamerica. The Yellow-bellied Earth Snake (Geophis godmani) is known only from the mountain ranges of Costa Rica and western Panama. In September, 2020 we encountered an albino individual of the Yellow-bellied Earth Snake at Palmira de Zarcero, Alajuela province, Costa Rica. Here we report on this finding and discuss possible consequences of albinism in snakes. Snakes affected by albinism have red eyes and a yellow or pink coloration due to the presence of xanthophores and erythrophores. As a result, aspects such as thermoregulation can be affected, and jeopardize the snake's survival. However, some individuals can have traits that potentially preclude the negative effects of albinism. These characteristics would allow for the survival of individual snakes to the adult stage, such as the albino individual of Geophis godmani we found in central Costa Rica.

Temperature influences ectotherm fitness by affecting physiological performance. Terrestrial reptiles behaviourally regulate their body temperature by selecting particular microhabitats or activity periods. In temperate climates, thermal constraints make precise thermoregulation costly. Theoretical models of thermoregulation predict that species in cool environments should exhibit lower optimal temperature for performance and lower thermal preferences to minimize thermoregulatory costs. Empirical data in support of this prediction remain equivocal because several species maintain high and constant body temperatures, even in cool environments. We studied two largely sympatric colubrid snakes, Hierophis viridiflavus and Zamenis longissimus that share numerous morphological and ecological similarities, but differ markedly in thermal preference. Our objective was to quantify their thermoregulatory strategies in the field to determine how thermal preferences translate in habitat use and performance gain. The thermophilic species, H. viridiflavus, selected open microhabitats, whereas Z. longissimus, which prefers cooler temperatures, used a greater diversity of microhabitats. The two species differed markedly in their exposure levels. Hierophis viridiflavus was constrained to shuttle between sun and shade to maintain preferred body temperatures rendering it very exposed, while covered microhabitats were usually thermally compatible with the requirements of Z. longissimus. High exposure was apparently counterbalanced by higher locomotor performances in H. viridiflavus. The divergence in thermal ecology between Z. longissimus and H. viridiflavus likely reflects different trade-offs between energy gain and predator avoidance.

Patterns of Abundance and Human Use of the Vulnerable Understory Palm, Chamaedorea radicalis (Arecaceae), in a Montane Cloud Forest, Tamaulipas, Mexico

Phenological changes have been observed in a variety of systems over the past century. There is concern that, as a consequence, ecological interactions are becoming increasingly mismatched in time, with negative consequences for ecological function. Significant spatial heterogeneity (inter-site) and temporal variability (inter-annual) can make it difficult to separate intrinsic, extrinsic and stochastic drivers of phenological variability. The goal of this study was to understand the timing and variability in breeding phenology of Adélie penguins under fixed environmental conditions and to use those data to identify a "null model" appropriate for disentangling the sources of variation in wild populations. Data on clutch initiation were collected from both wild and captive populations of Adélie penguins. Clutch initiation in the captive population was modelled as a function of year, individual and age to better understand phenological patterns observed in the wild population. Captive populations displayed as much inter-annual variability in breeding phenology as wild populations, suggesting that variability in breeding phenology is the norm and thus may be an unreliable indicator of environmental forcing. The distribution of clutch initiation dates was found to be moderately asymmetric (right skewed) both in the wild and in captivity, consistent with the pattern expected under social facilitation. The role of stochasticity in phenological processes has heretofore been largely ignored. However, these results suggest that inter-annual variability in breeding phenology can arise independent of any environmental or demographic drivers and that synchronous breeding can enhance inherent stochasticity. This complicates efforts to relate phenological variation to environmental variability in the wild. Accordingly, we must be careful to consider random forcing in phenological processes, lest we fit models to data dominated by random noise. This is particularly true for colonial species where breeding synchrony may outweigh each individual's effort to time breeding with optimal environmental conditions. Our study highlights the importance of identifying appropriate null models for studying phenology.

Summary Water clarity can have a profound influence on aquatic ecosystem structure and processes via its effects on physical habitat (e.g., thermal regime, macrophyte density) and behavioural responses of biota (e.g., predator avoidance, reaction distances, foraging efficiency). Changes in foraging efficiencies under varying water clarity conditions are well documented for many freshwater piscivores in laboratory studies, but the influence of visual foraging conditions on interspecific trophic dynamics is poorly understood in wild populations, especially within water clarity ranges that are realistic for north‐temperate boreal lakes. Here, we used stable isotopes of nitrogen (15N/14N) and carbon (13C/12C) in fish muscle tissue to investigate how resource partitioning between two sympatric visual piscivores is related to water clarity and other habitat variables in 28 small (100–200 ha) Boreal Shield lakes. One of the species is adapted for foraging in low subsurface illumination (walleye, Sander vitreus) and the other in high subsurface illumination (smallmouth bass, Micropterus dolomieu). Trophic niche dimensions of the dark‐adapted predator did not respond significantly to differences in water clarity. In contrast, total isotopic niche space of the light‐adapted predator decreased significantly with increasing water clarity through greater use of pelagic resources and a narrower range of trophic levels, although these relationships were weak. Niche overlap ranged from 0 to 65%, but was not significantly related to water clarity. Rather, indices of prey availability appeared to be much stronger predictors of trophic interactions. Both species occupied more similar food‐web positions when yellow perch (Perca flavescens) abundance was higher, and had more similar niche size and trophic evenness with decreasing prey fish species richness. Results indicate that the trophic ecology of predators adapted to foraging in low light conditions is less influenced by water clarity than that of predators adapted to foraging in high light conditions. However, prey availability, rather than the environmental conditions in which foraging occurs, may be a more important driver of resource partitioning among generalists even when light conditions favour one species’ foraging strategy over another.

Population dynamics of terrestrial vertebrates are affected by climatic fluctuations, notably in ectotherms. An understanding of the interaction between physiology and demographic processes is necessary to predict the impacts of climate change. Reptiles are particularly sensitive to temperature, but only a few studies have explored the relationship between thermoregulatory strategy and demography in these animals. Using 12 years of mark‐recapture data on two sympatric colubrid snakes ( Hierophis viridiflavus and Zamenis longissimus ), we tested whether demographic parameters are influenced by contrasted thermoregulatory strategies. The thermophilic and conspicuous species ( H. viridiflavus ) grew faster than the thermoconforming and secretive species ( Z. longissimus ), and this difference was most pronounced in open habitats, suggesting that the metabolic benefits associated with high thermal preferences depend on environmental factors at small spatial scales. Survival varied annually in both species, but was not lower in H. viridiflavus despite a higher degree of exposure. In Z. longissimus , survival was negatively affected by low temperatures during the active season, possibly underlying an exposure trade‐off.

Human-caused environmental change will have significant non-lethal and indirect impacts on organisms due to altered sensory pathways, with consequences for ecological interactions. While a growing body of work addresses how global ocean change can impair the way organisms obtain and use information to direct their behavior, these efforts have typically focused on one step of the pathway (e.g., reception of a cue/signal), one sensory modality (e.g., visual), or one environmental factor (e.g., temperature). An integrated view of how aspects of environmental change will impact multiple sensory pathways and related ecological processes is needed to better anticipate broader consequences for marine ecosystems. Here, we present a conceptual synthesis of effects of global change on marine sensory ecology, based on a literature review. Our review supports several predictions for how particular sensory pathway steps – production, transmission, and reception/processing of cues/signals – are affected by environmental change. First, the production and reception/processing of multiple modalities of cues/signals are vulnerable to multiple global change stressors, indicating that there are generalizable mechanisms by which environmental change impairs these pathways steps, leading to altered sensory pathway outcomes. Factors that enhance organismal stress as a whole may amplify impacts to these sensory pathways. Second, global change factors tend to affect specific modalities of cue/signal transmission. Consequently, local impacts on ecological processes linked with cue/signal transmission will vary depending on environmental stressor(s) present and the corresponding sensory modality. Finally, because many ecological and evolutionary interactions rely on sensory processing, impairment of sensory pathways may frequently underpin impacts of global ocean change on marine ecosystems. Effects on individual sensory processes will integrate to shape processes like mating, predation, and habitat selection, and we highlight new insights on impacts to ecological interactions by employing our mechanistic conceptual framework.

Cultured Atlantic salmon Salmo salar are of international socioeconomic value, and the process of domestication has resulted in significant behavioural, morphological, and allelic differences from wild populations. Substantial evidence indicates that direct genetic interactions or interbreeding between wild and escaped farmed Atlantic salmon occurs, genetically altering wild salmon and reducing population viability. However, genetic interactions may also occur through ecological mechanisms (e.g. disease, parasites, predation, competition), both in conjunction with and in the absence of interbreeding. Here we examine existing evidence for ecological and non-reproductive genetic interactions between domestic Atlantic salmon and wild populations and the potential use of genetic and genomic tools to resolve these impacts. Our review identified examples of genetic changes resulting from ecological processes, predominately through pathogen or parasite transmission. In addition, many examples were identified where aquaculture activities have either altered the selective landscape experienced by wild populations or resulted in reductions in population abundance, both of which are consistent with the widespread occurrence of indirect genetic changes. We further identify opportunities for genetic or genomic methods to quantify these impacts, though careful experimental design and pre-impact comparisons are often needed to accurately attribute genetic change to aquaculture activities. Our review indicates that ecological and non-reproductive genetic interactions are important, and further study is urgently needed to support an integrated understanding of aquaculture-ecosystem interactions, their implications for ecosystem stability, and the development of potential mitigation and management strategies.

The escape of Atlantic salmon (Salmo salar) from aquaculture facilities can result in both negative genetic and ecological interactions with wild populations, yet the ability to predict the associated risk to wild populations has remained elusive. Here we assess the potential of a spatiotemporal database of aquaculture facility locations, production estimates, and escape events to predict the distribution of escaped farmed salmon and genetic impacts on wild populations in the Northwest Atlantic. Industry production data, reported escape events, and in-river detections of escaped farmed salmon were collected from across the Northwest Atlantic. Genetic estimates of impact were obtained using single nucleotide polymorphisms (95 loci) representing aquaculture and wild salmon throughout the region (30 populations, 3048 individuals). Both the number of escaped farmed salmon detected at counting facilities and the magnitude of genetic impacts were positively correlated with a cumulative spatial measure of aquaculture production. Our results suggest that the risk of escapees and genetic introgression from wild–farmed salmon interactions can be assessed using information on farm production characteristics. This represents a first step in predicting the impact of existing cage-based farms on wild Atlantic salmon.

Marine aquaculture of Atlantic salmon (Salmo salar) is a relatively new industry where breeding programs have led to rapid genetic change in the captive populations that were built up alongside conspecific wild individuals. Throughout its 50-years history, marine aquaculture of Atlantic salmon has been associated with escapes, and studies have shown that escapees may enter rivers, spawn successfully, and this may lead to farmed-to-wild genetic introgression and maladaptation in wild populations. Yet, an open question is what factors can best explain the variability in the proportion of farmed escapees in wild populations, and when present, which additional factors lead to introgression. Here, we combine two large-scale data sets from monitoring escaped farmed salmon and introgression in Norwegian rivers between 2006 and 2018 to model how anthropogenic, environmental, and population factors influence proportion of escapees and level of introgression. We found that increasing farming intensity and river discharge increase the expected proportions of escaped farmed salmon in rivers, whereas a larger wild salmon population size reduces the expected proportion of escapees despite increasing the expected absolute numbers of escaped farmed salmon. On a large scale, introgression is primarily a function of proportions of escaped farmed salmon, and only to a minor extent a function of local environmental factors or salmon population characteristics. This suggests that as long as salmon aquaculture is based on technologies where non-sterile fish can escape, all anadromous wild Atlantic salmon populations are at risk. Large marine protected areas without salmon aquaculture may slow down the rate of intrusion and introgression by increasing the distance between intensive aquaculture and wild populations.

Only a few records of pigmentation anomalies, particularly hypopigmentation conditions such as albinism, have been reported among Neotropical non-human primates. In Brazil, there are only 14 documented cases of pigmentation anomalies, with just two instances of albinism recorded within the Cebidae family. To our knowledge, no pigmentation polymorphisms have been documented in the Pitheciidae family to date. In this study, we report the first documented case of albinism in Callicebus nigrifrons (the black-fronted titi monkey) within the largest remnant of the Atlantic Forest in the State of Minas Gerais, Brazil. This observation was made using a drone equipped with 4K cameras and thermal infrared sensors. This primate exhibited characteristics such as the absence of pigmentation in its fur, as well as in its palms of its hands and feet, and dark red eyes. It was observed in a group composed of two other individuals displaying typical coloration. The group's behavior was normal, showing no signs of exclusion toward the albino individual. Potential causes of albinism in C. nigrifrons may include genetic or environmental factors, or combined pressures, though these remain speculative. This is the first confirmed case of albinism in the Pitheciidae family and the first record of such a phenomenon using drone technology in the wild. Our findings underscore the potential of drones for detecting low-frequency phenotypic traits in elusive species and reinforce the role of protected areas such as the Rio Doce State Park in safeguarding threatened and genetically distinct individuals.

For most pond-breeding anurans, movement is fundamental for foraging, reproduction, avoidance of adverse environmental conditions, and predator avoidance and escape. Although the influence of environmental factors such as temperature and rainfall on anuran activity other than movement is well documented, the effect of these factors on anuran movement is less clear. In this study, we examined the influence of environmental factors on distances moved by 11 adult male Butter Frogs (Leptodactylus latrans) during their breeding season. We fitted movement data as the response variable and environmental factors as fixed effects in generalized linear models and performed model selection and model averaging to understand the contribution of each variable to movement. We were not able to identify any environmental factors that trigger movement in Leptodactylus latrans, but distance moved was positively related to darker phases of the moon, higher temperatures, and greater rainfall. Behavioral response to the lunar cycle is believed to be associated with predator avoidance and reproduction synchronization, whereas responses to temperature and rainfall are most associated with water balance and metabolic regulation.

Wild animals maximize fitness through certain behaviors (e.g., foraging, mating, predator avoidance) that incur metabolic costs and often require high levels of locomotor activity. Consequently, the ability of animals to achieve high fitness often relies on their physiological capacity for exercise (aerobic scope) and/or their ability to acquire and utilize energy judiciously. Here, we explore how environmental factors and physiological limitations influence exercise and metabolism in fish while foraging, migrating to spawning grounds, and providing parental care. We do so with three case studies that use a number of approaches to studying exercise in wild fish using biologging and biotelemetry platforms. Bonefish (Albula vulpes) selectively use shallow water tropical marine environments to forage when temperatures are near optimal for aerobic scope and exercise capacity. Bonefish energy expenditure at upper thermal extremes is maximal while activity levels diminish, likely caused by reduced aerobic scope. Pacific salmon (Oncorhynchus spp.) reproductive migrations frequently involve passage through hydraulically challenging areas, and their ability to successfully pass these regions is constrained by their physiological capacity for exercise. Aerobic scope and swim performance are correlated with migration difficulty among sockeye salmon (O. nerka) populations; however, depletion of endogenous energy stores can also limit migration success. In another example, male smallmouth bass (Micropterus dolomieu) allocate a significant amount of energy to nest-guarding behaviors to protect their developing brood. Smallmouth bass body size, endogenous energy reserves, and physiological state influence nest-guarding behaviors and reproductive success. We suggest that in some scenarios (e.g., bonefish foraging, Pacific salmon dam passage) metabolic capacity for exercise may be the strongest determinant of biological fitness, while in others (e.g., long distance salmon migration, smallmouth bass parental care) energy stores may be more important. Interactions among environmental and ecological factors, fish behavior, and fish physiology offer important avenues of mechanistic inquiry to explain ecological dynamics and demonstrate how exercise is fundamental to the ecology of fish.

BackgroundPopulation growth and management in cervid species is dependent on reproductive ecology and factors influencing juvenile survival. Aspects of the female’s movement behavior likely affect juvenile survival and movement patterns of pregnant and lactating females differ from non-pregnant or non-lactating females. Explanations for these differing movement patterns include change in nutritional demands for the female, isolation during parturition, and predator avoidance. White-tailed deer (Odocoileus virginianus) are an important managed cervid and a better understanding of their reproductive ecology, including the relationships between resources, movement, and juvenile survival, can better inform management.MethodsOur objective was to determine if biological factors, such as female age, fawn age, number of fawns, as well as characteristics of prepartum range affected the female’s postpartum daily movement or overlap of space used pre- and postpartum in Sussex County, Delaware, USA (2,420 km2). We collected GPS locations 2 weeks pre- and postpartum on 22 individual females from 2016 to 2017. In total, we recorded data from 263 days of postpartum movement for an average of 12 days/individual. We used a hierarchical modeling process to test biological factors and prepartum home range characteristics on two aspects of postpartum movement behavior, mean hourly displacements and daily use of prepartum home range.ResultsMean hourly displacement decreased with increased female age and increased with number of known fawns alive and the female’s home range size prior to parturition. We found that as fawns aged the doe increased use of the prepartum home range.ConclusionsOur results indicate that younger females are moving more than older females during lactation potentially to access higher quality habitat. This increased movement increases nutritional demand and may play a role in fawn survival. Females are more likely to use more of their prepartum home range as fawns age, a finding congruent with previous research. This differentiation in metric response (movement rate vs. space use) emphasizes the complexities of movement ecology and the importance of considering multiple dependent variables for complex behavior.