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Selecting a good mate is a decision with important fitness consequences. For this reason, mate choice has promoted the evolution of sexual ornaments signaling the quality of an individual. In fossorial animals, inhabiting visually restricted underground environments, chemical senses should be very important for mate choice. We examined whether sexual chemical signals (substrate scent marks) produced by males of the Iberian worm lizard, Blanus cinereus, a strictly fossorial blind amphisbaenian, provide information to females on morphological traits and health state. We administered corticosterone (CORT) to males simulating a continuous stressor affecting their health. Females preferred settling at sites scent‐marked by males in comparison with similar sites with female scent or unmarked sites, but the attractiveness of males' scent differed between individuals. Females preferred scent marks of larger/older males and with a higher immune response, while their body condition and CORT treatment were unrelated to female preferences. Chemical analyses showed that proportions of some compounds in precloacal secretions of males (used to produce scent marks) were correlated with the morphological (body size) and health state (immune response and body condition, but not CORT treatment) of these males. These results suggest that females may make site‐selection decisions based on assessing the chemical characteristics of males' scent marks, which were reliably related to some of the traits of the male that produced the scent. Therefore, females might use chemical senses to increase the opportunities to find and mate with males of high quality, coping with the restrictions of the subterranean environment. [ABSTRACT FROM AUTHOR]

Talpid moles (Talpidae, Eulipotyphla) are mammals highly specialised in burrowing using their forelimbs. Fossoriality has allowed moles to expand their ecological niche by enabling access to subterranean resources and spaces. This specialisation in burrowing has led to adaptations in the forelimb bones of moles for humeral rotation digging, a distinctive strategy unparalleled among other diggers. While bone robustness has been examined in moles through external morphology, the adaptation of bone microstructure to digging strategy remains unclear. Based on two assumptions, (1) the humerus of moles is subjected to a torsional load due to humeral rotation digging, and (2) the magnitude of torsional load correlates with the compactness of the substrate in which the individuals can dig, we hypothesised that humeral rotation digging influences bone microstructure. Comparative analyses of transverse sections from the humeri and femora of three mole species (Mogera imaizumii, Mogera wogura and Urotrichus talpoides; Talpidae) and an outgroup eulipotyphlan (Suncus murinus; Soricidae) revealed that (1) vascular canals distributed in the humeri of moles align more predominantly circumferential along the bone walls, indicating an adaptation to the torsion generated by humeral rotation digging, and (2) the laminarity of vascular canals, particularly in Mogera species compared with Urotrichus, potentially reflects differences in the magnitude of load due to substrate compactness during digging. The aligned vascular canals are distinctive traits not observed in mammals employing other digging strategies. This suggests that vascular canal laminarity can be an indicator of not only humeral rotation digging in fossorial animals, but also the variation of eco‐spaces in talpid species. [ABSTRACT FROM AUTHOR]

Plant traits and connectivity influence habitat usage, but fine‐scale ecological characteristics that determine fossorial animal movement patterns remain unclear. To understand the influence of landscape connectivity on movement behaviour, we examined vegetation characteristics relative to tracks between vegetation hummocks left by the short blind dart skink, Typhlacontias brevipes, a fossorial lizard inhabiting dunes of the Namib Desert. We measured characteristics of >700 plant hummocks and 293 T. brevipes tracks. Tracks were relatively direct from hummock to hummock (median straightness = 0.94). Vegetation hummocks with tracks were significantly larger than hummocks without tracks, indicating that vegetation size was the most important factor we measured in predicting track occurrence and was more important to skinks than the distances between hummocks, with only 24% of tracks occurring between nearest neighbouring vegetation hummocks. Network clusters consisting of as many as 15 vegetation hummocks were connected by tracks. Skink tracks had a median length of 815 cm and were oriented primarily from 0° to 30°. Our study highlights the importance of vegetation size to fossorial skinks and raises questions regarding other vegetation features that might influence the movement and ecology of fossorial lizards. [ABSTRACT FROM AUTHOR]

Access to subterranean refugia, such as animal burrows, can affect the ecology and life history of wildlife in an array of habitat types. Subterranean refugia are commonly used for thermal refuge, for shelter from predators, or as suitable locations for nesting and/or brooding offspring; because of this, refugia can potentially impact rates of survivorship and recruitment. In southwestern Florida, Burmese pythons (Python bivittatus), an established and highly impactful invasive species, have been observed using subterranean refugia on numerous occasions. Because python management is an utmost priority in Florida, understanding the potential implications of this behavior is key to mitigating python impacts on native wildlife. We used 29 radio-telemetered Burmese pythons to investigate the extent to which pythons used subterranean refugia in the southwestern portion of their Florida range. We explored spatiotemporal patterns of refuge use and quantitatively assessed how python sex, reproductive season, and habitat type affected the probability of using different types of refugia. We observed pythons using four types of refugia, including Gopher Tortoise burrows, Nine-banded Armadillo burrows, and natural and anthropogenic ground-based cavities. Pythons used these refugia for seeking thermal refuge, aggregating, breeding, and nest brooding, and they were most likely to use refugia during their breeding and nesting seasons. Nine python nests, representing 71% of those discovered during the study, were oviposited and brooded in Gopher Tortoise or Nine-banded Armadillo burrows. Implications of this behavior warrant further assessment and incorporation into management strategies as they may affect Burmese python recruitment, survival, and dispersal. [ABSTRACT FROM AUTHOR]

The extended phenotype of helical burrowing behavior in animals has evolved independently many times since the Cambrian explosion (~540 million years ago [MYA]). A number of hypotheses have been proposed to explain the evolution of helical burrowing in certain taxa, but no study has searched for a general explanation encompassing all taxa. We reviewed helical burrowing in both extant and extinct animals and from the trace fossil record and compiled 10 hypotheses for why animals construct helical burrows, including our own ideas. Of these, six are post‐construction hypotheses—benefits to the creator or offspring, realized after burrow construction—and four are construction hypotheses reflecting direct benefits to the creator during construction. We examine the fit of these hypotheses to a total of 21 extant taxa and ichnotaxa representing 59–184 possible species. Only two hypotheses, antipredator and biomechanical advantage, cannot be rejected for any species (possible in 100% of taxa), but six of the hypotheses cannot be rejected for most species (possible in 86%–100% of taxa): microclimate buffer, reduced falling sediment (soil), anticrowding, and vertical patch. Four of these six are construction hypotheses, raising the possibility that helical burrowing may have evolved without providing post‐construction benefits. Our analysis shows that increased drainage, deposit feeding, microbial farming, and offspring escape cannot explain helical burrowing behavior in the majority of taxa (5%–48%). Overall, the evidence does not support a general explanation for the evolution of helical burrowing in animals. The function and evolution of the helix as an extended phenotype seems to provide different advantages for different taxa in different environments under different physicochemical controls (some traces/tracemakers are discussed in more detail due to their association with body fossils and well‐constrained physicochemical parameters). Although direct tests of many of the hypotheses would be difficult, we nevertheless offer ways to test some of the hypotheses for selected taxa. [ABSTRACT FROM AUTHOR]

Morphological patterns may vary spatially in response to adaptations to regional environmental conditions. In fossorial animals, edaphic gradients potentially predict intra and interspecific morphological variation because they can limit dispersal and select morphotypes. We measured morphological traits of South American worm lizards, including three Amphisbaena and two Leposternon species, to test whether inter- and intraspecific morphological variation and morphotype distribution are predicted by edaphic gradients measured at different soil profiles. Interspecifically, we found that the variation in head length is mainly predicted by the chemical edaphic structure, which can be explained by spatial variation in prey availability. The variation in the width of the prefrontal and frontal shields was mainly predicted by clay and sand-soil contents, which can be explained by relationships of force and friction associated with digging. Intraspecifically, we found that the effects of edaphic gradients on morphological variation reflects the level of specialization to dig, since the most adapted species were mainly affected by variables measured in deeper soil profiles. We also show that soil-mediated intraspecific morphological variation shape morphotype distribution across different biomes that form the South American dry diagonal, which are discussed in light of biological, ecological, and biogeographic premises. [ABSTRACT FROM AUTHOR]

The relationship between pangolin-CoV and SARS-CoV-2 has been a subject of debate. Further evidence of a special relationship between the two viruses can be found by the fact that all known COVID-19 viruses have an abnormally hard outer shell (low M disorder, i.e., low content of intrinsically disordered residues in the membrane (M) protein) that so far has been found in CoVs associated with burrowing animals, such as rabbits and pangolins, in which transmission involves virus remaining in buried feces for a long time. While a hard outer shell is necessary for viral survival, a harder inner shell could also help. For this reason, the N disorder range of pangolin-CoVs, not bat-CoVs, more closely matches that of SARS-CoV-2, especially when Omicron is included. The low N disorder (i.e., low content of intrinsically disordered residues in the nucleocapsid (N) protein), first observed in pangolin-CoV-2017 and later in Omicron, is associated with attenuation according to the Shell-Disorder Model. Our experimental study revealed that pangolin-CoV-2017 and SARS-CoV-2 Omicron (XBB.1.16 subvariant) show similar attenuations with respect to viral growth and plaque formation. Subtle differences have been observed that are consistent with disorder-centric computational analysis. [ABSTRACT FROM AUTHOR]

Fossorial rodents are ecosystem engineers who significantly alter soil properties and vegetation. We review the impacts of fossorial rodents on soil and vegetation in North and South America based on a comprehensive review of the scientific literature from 1980 to 2021, recording the number of publications. Also, we recorded the number of publications classified by habitat. We classified the variables associated with soil and vegetation impacts to identify research gaps and trends. Additionally, after filtering publications that compared undisturbed and rodent-disturbed areas, we compared these areas to quantify the impact caused by rodents. We found 203 research publications, with a higher number in North America, although South American research has increased in recent decades. Pocket gophers (Geomyidae) were the most studied group in North America of fossorial rodents, while tuco-tucos (Ctenomys) were in South America. Soil variables such as mound and burrow volume, excavation rate, mound area and density, moisture content, and nitrogen content were the most studied, along with vegetation variables such as biomass, cover, diversity, and richness. Variability in soil removal and the surface of the soil removed was observed across different rodent species. Rodent-disturbed areas exhibited lower soil compaction, bulk density, moisture content, and native plant cover, while soil temperature and exotic plant cover were higher. This review enhances understanding of fossorial rodent impacts on soil and vegetation in North and South America and underscores areas in need of further research. [ABSTRACT FROM AUTHOR]

The efficacy of sexual signals in communication is often maximized under specific environmental conditions. Anthropic alterations of these conditions might, thus, negatively affect communication during reproductive behavior. In fossorial animals, inhabiting visually restricted environments, chemical senses are very important. We examined whether climatic episodes of heat-waves with unusual high temperatures may affect the information provided to females by the sexual chemical signals of males of a fossorial reptile, the amphisbaenian Blanus cinereus. The results showed that experimentally heat-altered substrate scent marks of males can still provide information to females about the presence of a male. Females spent more time on males' scent marks, irrespective of the temperature treatment, than on control clean ones. However, heat-altered scent marks did not seem to convey information about the health state (immune response) of the producer. Females spent more time on unaltered scent marks of healthier males (probably indicating mating preferences for these males), while female preferences for some heat-altered scent marks were not related to size or immune response of the same individual males. Chemical analyses indicated that the overall chemical profile of precloacal secretions (used for scent marking) did not change with increased temperatures. However, the relationship between proportions of some compounds in secretions and males' immune response found in unaltered secretions was lost in heat-altered ones. We conclude that unusual increased environmental temperatures may decrease the efficacy of underground sexual chemical signals in this amphisbaenian (i.e., a loss of information on male quality), and consequently, may negatively affect sexual selection and reproduction. Significance statement: It's crucial to be as successful as possible when you show off to attract a mate. This may depend on how the surroundings affect the effectiveness of your exhibition. So, animals have evolved sexual signals tuned up to their local environmental conditions. A blind fossorial reptile uses substrate scent marks to transmit information to conspecifics. The projected rise in soil temperatures due to climate change could alter this communication. Although brief exposures to high temperatures still allows scent marks to inform females that a male is around, the information related to that male quality is disrupted. This could have detrimental effects on female reproductive success by drastically decreasing their capacity to select a suitable partner. It is unknown if animals could change their sexual signals in order to re-adjust to the rapidly shifting new climatic conditions. [ABSTRACT FROM AUTHOR]

Burrowing animals are a critical driver of terrestrial ecosystem functioning, but we know little about their effects on soil microbiomes. Here, we evaluated the effect of burrowing animals on microbial assembly processes and co-occurrence patterns using soil microbiota from a group of habitats disturbed by Plateau pikas (Ochtona curzoniae). Pika disturbance had different impacts on bacterial and fungal communities. Fungal diversity generally increased with patch area, whereas bacterial diversity decreased. These strikingly different species–area relationships were closely associated with their community assembly mechanisms. The loss of bacterial diversity on larger patches was largely driven by deterministic processes, mainly due to the decline of nutrient supply (e.g., organic C, inorganic N). In contrast, fungal distribution was driven primarily by stochastic processes that dispersal limitation contributed to their higher fungal diversity on lager patches. A bacterial co-occurrence network exhibited a positive relationship of nodes and linkage numbers with patch area, and the fungal network presented a positive modularity–area relationship, suggesting that bacteria tended to form a closer association community under pika disturbance, while fungi tended to construct a higher modularity network. Our results suggest that pikas affects the microbial assembly process and co-occurrence patterns in alpine environments, thereby enhancing the current understanding of microbial biogeography under natural disturbances. [ABSTRACT FROM AUTHOR]

Many mesocarnivores are fossorial and use burrow systems to avoid predators. But fossorial animals cannot stay safely underground forever; they must also risk emerging overground to forage and find mates. To make this trade‐off effectively and maximise their own fitness, it is imperative they assess how risk varies in space and time and adapt their denning behaviour accordingly. We used the badger in Białowieża Forest, Poland, as a model for investigating how the denning behaviour of a fossorial mesocarnivore varies in response to short‐term large carnivore risk. To this end, we experimentally simulated perceived wolf presence outside 10 badger setts using audio playbacks of wolves (their howls). We assayed two behavioural measures of fear: badger emergence time from setts on the day playbacks were broadcast and their presence in setts on the day after. We found that neither badger emergence time nor next‐day sett use varied in response to wolf playbacks. The results of the present study contrast with a previous study of ours that found badgers used setts in areas with high landscape level perceived wolf risk less often than those in lower‐risk areas. Together, these papers' findings suggest that different spatiotemporal scales of perceived risk can have differential effects on badger behaviour. We conclude that rather than take risk avoidance measures at all risky times and places, badgers likely display a diversity of reactions to large carnivore presence that depend on the context and spatiotemporal scale of the risk being perceived. [ABSTRACT FROM AUTHOR]

Context. The decline and extinction of native burrowing mammals across much of Australia has resulted in a loss of underground refugia constructed by native fauna in the environment. The introduced European rabbit (Oryctolagus cuniculus) is now the most widespread mammalian burrower across Australia. Rabbits are an invasive species in Australia, and the destruction of rabbit warrens for pest management is common practice. This destruction of warrens removes a potential refuge for both rabbits and other species in the environment. In landscapes where critical weight range burrowing mammals have declined, the widespread destruction of rabbit warrens removes many underground refuges for several commensal animal species. Aims. To identify the use of rabbit warrens by fauna in the seasonally hot, semi-arid Ikara-Flinders Ranges National Park (IFRNP) in South Australia. Methods. We used camera traps placed at burrow entrances of warrens and nearby structure to identify the vertebrate species that interact with rabbit warrens in the IFRNP. Key results. We recorded 11 bird, nine mammal and eight reptile species present at the entrances of rabbit warrens. Only four of the taxa recorded on cameras in our study showed a preference for warrens over adjacent above-ground structure, three of them introduced species. The alien commensal species recorded using the burrows were rabbits, house mice (Mus musculus) and feral cats (Felis catus). Conclusions. Rabbit warrens in the IFRNP are an important resource for a range of native and alien commensal species. In our study, they seem to be of special importance for introduced species. Implications. Warren removal in the IFRNP may negatively impact native commensal species in treated areas but is likely to be of long-term net benefit for a wider range of native animals. [ABSTRACT FROM AUTHOR]

Animal activities threaten levee stability, especially during flood events, increasing levee failure risk. Indeed, while dens alter hydraulically‐induced failure mechanisms, it is difficult to locate them and to know in advance if critical conditions may be reached. This paper demonstrates that it is possible to perform nondestructive surveys to assess the risk of burrow animal activities in levee systems using a ground penetrating radar (GPR) for effective levee structure control, being GPR a nondestructive, expeditious, and cost‐effective geophysical technique. Here, a flood‐prone area in Sicily, where traditional hydraulic phenomena did not justify past levee failure events, is considered a case study. Through a visual inspection survey, several animal holes were recovered. GPR measurements allowed us to explore the levee interior and to detect the presence, distribution, and configuration of dens inside them. It was found that a complex burrow system crosses the entire embankment. Porcupine was recognized as a builder of such cavities. Although, previous studies established the porcupine presence in semi‐humid environments, for the first time, here we provide evidence of the development, articulation, and extension of porcupine burrows inside the levee system. [ABSTRACT FROM AUTHOR]

By living underground, fossorial animals may be challenged by limited gas exchange due to prolonged exposure to low oxygen levels (hypoxia) and carbon dioxide buildup (hypercarbia) in their burrows. The negative effects of hypoxia and hypercarbia generally relate to changes in breathing and energy metabolism. In mammals, reduced metabolic rates are a common adaptation to a fossorial lifestyle. It is unclear, however, whether fossoriality exerted a similar selection pressure over the metabolism of fossorial ectotherms. In this study, we tested whether fossorial amphibians showed reduced metabolic rates compared to non-fossorial and aquatic ones in a phylogenetic framework. We found that whole-organism resting metabolic rates varied according to body mass and temperature. However, our analyses did not support the hypothesis of lowered energy expenditure in fossorial species. We suggest that the intrinsically low energetic requirements of amphibians, coupled with their relatively small body sizes, and ability to breathe through both lungs and skin, potentially circumvented the energetic and respiratory challenges imposed by fossoriality. Our analyses further suggest that species from higher latitudes have higher metabolic rates than those from lower latitudes regardless of lifestyle. This finding supports a mechanism of negative compensation in metabolic responses, whereby species from cooler habitats would be able to sustain relatively high activity levels despite thermal constraints. This view of energetics in the context of fossoriality integrates central tenets of eco-physiological theory (metabolic scaling, metabolic variation along environmental gradients) and comparative physiology (control of bimodal breathing). Ultimately, our work contributes to a broader understanding of the metabolic correlates in vertebrate ectotherms. [ABSTRACT FROM AUTHOR]

Increased predation where ground cover is reduced after severe wildfire is increasingly implicated as a factor causing decline of vulnerable prey populations. In arid central Australia, one species detrimentally affected by repeated wildfire is the great desert skink or tjakura (Liopholis kintorei), a distinctive lizard of the central Australian arid zone that constructs and inhabits multi‐entranced communal burrows. We aimed to test whether tjakura or predator activity at burrow entrances varied with cover and how tjakura respond to predator presence. Using time‐lapse photography, we monitored tjakura and predator activity at the largest entrance of 12 burrows ranging from high (>70%) to low (<50%) cover and at multiple entrances of two other burrows. Overall activity did not vary between burrows with high and low cover. Within burrow systems tjakura were more active at sparsely vegetated entrances, often sitting wholly or partly inside the burrow. However, consistent between and within burrow systems, skinks spent proportionally more time fully outside where cover was higher. Predators—mostly native—were detected at most burrows, with no apparent relationship between predator activity and cover. Skinks also did not appear to modify their activity in response to predator visits. Our results indicate that tjakura may spend more time outside burrow entrances when cover is higher but there was no direct evidence that this related to perceived or real predation risk. Differences in food availability, thermoregulatory opportunities and opportunities for ambush foraging associated with differences in vegetation cover or composition are other factors likely to be important in determining the activity of tjakura at burrows. Our research demonstrates the usefulness of camera traps for behavioural studies of ectothermic burrowing animals. The complex relationships between tjakura activity and vegetation cover thereby revealed, suggest outcomes of fire‐mediated habitat change on predator–prey interactions are not easily predictable. [ABSTRACT FROM AUTHOR]

The adoption of flowable mixtures of treated soils is suggested as a sustainable solution for repairing the damage caused by burrowing animals in the Po River embankments. Soil from damaged sites is proposed to be mixed with lime or cement, other additives, and water in order to obtain mixtures with an adequate compromise between viscosity—which is crucial for flowing the mixture into the hole with site machines—and shrinkage that might occur over time according to the hole boundary conditions. Injections of soil-treated mixtures must guarantee hydraulic and mechanical continuity with the existing embankment and reduce shrinkage phenomena that frequently occur with cement–bentonite grout, which is commonly used for this purpose. This study presents an interdisciplinary experimental programme in the search for the best formulation among several recipes of mixtures of soils, collected from four embankments of Po River or its tributaries and treated with lime or cement, different percentages of water, and other additives. The mixtures, after soil classification and viscosity determinations, were then used to create samples for which shrinkage and erosion susceptibility were estimated, respectively, through a non-standard volume measurement procedure and crumb tests. An abacus will be then proposed in order to give, as a first estimation, applicative indications on the best recipe among the investigated mixtures. [ABSTRACT FROM AUTHOR]

This article examines the portrayal of animals in Franz Kafka's fiction, particularly the lack of specificity in their categorization. Unlike other modern writers, Kafka rarely names specific animal species in his works, instead opting for ambiguous descriptions. The author argues that this approach challenges traditional categorizations and emphasizes the individuality and subjectivity of the characters. The article also suggests that traditional methods of analysis may not fully capture the innovative nature of Kafka's animal stories. [Extracted from the article]

We observed the Cape fox and polecat following each other until a burrow system was found, at which point the polecat entered the burrow system and the Cape fox trailed closely behind but remained above ground (a). Keywords: Cape fox; Ictonyx striatus; interspecific association; Kalahari; striped polecat; Vulpes chama EN Cape fox Ictonyx striatus interspecific association Kalahari striped polecat Vulpes chama 217 220 4 02/21/23 20230301 NES 230301 INTRODUCTION Interspecific associations, defined as individuals of two species (or more) behaving as members of the same group, occur across a wide range of taxa including birds, fishes and mammals. We hypothesise that, like the American badger-coyote association, the Cape fox-polecat association is a form of mutualism. [Extracted from the article]

Background: Many animals rely on chemical cues for intraspecific communication. This is especially important in fossorial animals because visual restrictions of the underground environment limit the opportunities for visual communication. Previous experiments showed the ability of the amphisbaenian Trogonophis wiegmanni to discriminate between several categories of conspecifics based on chemical cues alone. However, in contrast with many other reptile species, T. wiegmanni does not have external secretory glands, but uses uncharacterized secretions from the cloaca in intraspecific chemosensory communication. Methods: Using gas chromatography-mass spectrometry (GC-MS), we analyzed the lipophilic compounds from feces and cloacal products freshly extracted from the cloaca of male and female T. wiegmanni. We identified and estimated relative proportions of the compounds found, and tested for intersexual and body-size related differences. Results: We found a total of 103 compounds, being some steroids (mainly cholesterol and cholestanol), some alkanes and squalene the most abundant and frequent. Further, we found intersexual differences, with males, especially larger ones, having higher proportions of several alkanes between C13 and C24 and of squalene than females, which had higher proportions of several steroids and also of nonacosane and methylnonacosane than males. We compared these findings with secretions of other animals and discuss the potential role of these compounds and their variations in intraspecific communication of amphisbaenians. [ABSTRACT FROM AUTHOR]

Conspecific cues often provide social information on habitat quality that is considered when deciding to settle at a specific site. The type of sensory cues useful for this will depend on the environment. For amphisbaenians, reptiles adapted to an underground life with highly reduced sight, chemoreception is especially useful to recognize conspecifics. Here, we first analyzed the lipophilic compounds from precloacal gland secretions of the amphisbaenian Blanus cinereus, showing that there were sex- and size-related variations in the proportions of the three major compounds. Then, we tested in the laboratory whether there was an underground site selection based on conspecific chemical cues (substrate scent marks) in two different contexts. In loose substrates, both male and female amphisbaenians tended to choose first the scent-marked substrates more often when the individual that produced the scent, independently of its sex, was relatively larger than the focal individual. In contrast, inside semi-permanent galleries, males, but not females, chose the scent-marked gallery more often when the scent donor, independently of its sex, was relatively smaller. These results suggest that the proportions of compounds in scent marks may allow amphisbaenians to estimate the body size of the producer and that this information affects their site selection decisions. However, the different substrate-dependent responses suggest a different meaning and usefulness of scent marks depending on the context. Significance statement: The presence of your conspecific in a site may indicate that this is a "quality" site to live in. If you are blind and live underground, smell is one of the best options for detecting conspecifics and assessing how good are your surroundings. Here, we test whether a blind amphisbaenian reptile that spends its life buried in sandy substrates uses conspecific chemical stimuli to choose where to settle. We found that this decision is influenced by the microhabitat type, sex, and the size difference between the individual that sniffs and the producer of the scent. Amphisbaenians seem to detect and assess conspecific traits based on the differences in compounds in their odors. Therefore, using conspecific scent to assess habitat quality may help fossorial animals to live underground. [ABSTRACT FROM AUTHOR]

Deep application of liquid fertilizer is a technique that applies liquid fertilizer deep near the root system of crops, which has many advantages such as high fertilizer utilization rate and low environmental pollution. However, high power and high specific energy consumption caused by soil-engaging components in liquid fertilizer deep application make it difficult to popularize in northeast China. The claw-toe structure of burrowing animals has the characteristics of low resistance and low friction, which has been the focus of many scholars' research on soil-engaging components. The claw-toe structure of the badger, a widely distributed burrowing animal in northeast China, has good characteristics of low power and low specific energy consumption. Therefore, in this research, a bionic liquid fertilizer deep application spray needle was designed, based on the claw-toe structure of the badger, to improve the operating performance of liquid fertilizer deep application. In this research, the discrete element method (DEM) was used for a computer simulation test, and the indoor soil bin verification test was carried out. The results showed that the operating angle, operating speed and fertilization depth of bionic liquid fertilizer deep application spray needle had significant effects on the power and specific energy consumption, and the optimal operating performance combination of bionic liquid fertilizer deep application spray needle was obtained as follows: The fertilization depth is 60 mm; the operating speed is 6 km h−1; the operating angle is 24.8°; the power consumption is 0.066 kW; and the specific energy consumption is 4.257 kJ m−3 under this operating condition. Through the comparison of operating performance, the operating performance of the bionic liquid fertilizer deep application spray needle is significantly better than that of other types of liquid fertilizer deep application furrow opener, with the power reduced by 9.52~40.5% and the specific energy consumption reduced by 93.9~208.6%. This research clarified the internal mechanism affecting the operating performance. Finally, based on the above findings, this research suggests that more attention should be paid to finding suitable bionic prototype and design scheme in the future design and research of soil-engaging components of liquid fertilizer deep application. [ABSTRACT FROM AUTHOR]

Burrowing animals can profoundly affect the biological structure and ecosystem functions of their environments. For instance, burrowing crabs increase sediment deposition and facilitate sediment homogenization and turnover, with potential impacts to sediment biogeochemistry. However, the relative importance of burrowing crabs on sediment dynamics can vary considerably between, and within, habitats. Sediment properties influence how burrowing crabs will affect edaphic conditions, but these studies often assume homogenous sediment conditions and fail to consider how sediment properties change with depth. Thus, understanding how burrowing crab effects on sediment properties are influenced by the vertical sediment profile should inform where burrowing crabs structure edaphic conditions. Here, we conducted an intensive field survey across three tidal salt marshes with variable sediment properties to understand if marsh vertical sediment profiles can help predict the nature of burrowing crab–sediment relationships. We found that burrowing crabs homogenize sediments in all marshes, but their effects on sediment homogenization and edaphic conditions were greater in marshes with highly stratified vertical sediment profiles. Our study suggests that understanding the vertical sediment profile of a salt marsh may provide critical insights into how crab burrowing may influence the edaphic conditions and physical characteristics of marsh surface sediments—especially in restored, created, and managed salt marshes. [ABSTRACT FROM AUTHOR]

Burrowers are the main creators, converters, and keepers of landscapes and soils of steppe ecosystems. The northern mole vole Ellobius talpinus (Pallas, 1770) is a rather widespread species of burrowing animals, an indicator species of various types of steppes, with a pronounced environment-forming activity. Fourteen large colonies of E. talpinus were studied in the Middle Volga region during the field seasons of 2006–2021. The agrochemical indicators of the soil characterise the possibility of developing certain steppe microstations, in which specific plant associations are formed. The parameters of soil samples and their combinations show the suitability of the formation of those plant associations that will correspond to the conditions of existence, reproduction, and feeding of burrowing rodents, in this case, the northern mole vole. The agrochemical features of steppe landscapes and habitats of the northern mole vole E. talpinus in the Middle Volga region are considered as stable trends in the formation of steppe communities. The northern mole vole E. talpinus prefers soils with a neutral or slightly alkaline pH, moderate phosphorus and calcium content, high copper and manganese content, moderate zinc content, uncontaminated by heavy metals (sometimes with an excess of cadmium content in the ancient layers of the parent rock) and rather loose (from loose sand and sandy loam to light and medium loam), which is easily carried out when digging the burrow, easily digs and deepens, for arranging chambers and passages, when extracting rhizomes, tubers, and bulbs of fodder plants. In the studied region, the steppe mole vole is generally attached to steppe and steppe landscapes, forb-feather grass-fescue steppes on parent sand and sandstone, chalk rocks; it chooses burrowing sites with steppe vegetation of various options, preferring calciphilic and psammophilic associations. The mole vole, as well as other burrowing rodents, are indicators of steppe landscapes and the preservation of soil in their biotopes, which, in turn, are indicators of the preservation of steppe habitats. The type of soil, its main features, as well as landscape characteristics of the habitat are important regional diagnostic characters of E. talpinus colonies.

The existing methods for determining the species identity of shelter hosts and taking censuses of the natural hosts of the rabies virus (foxes, corsacs, two badger species, raccoon dogs, and wolves) have been improved during a spring–summer inspection of burrows of these predators. The field work was carried out in the years 1976–2011 at 42 census sites with a total area of 3582 km2 in natural foci of rabies within 14 administrative territories of the Russian Federation: Amur, Astrakhan, Bryansk, Volgograd, Voronezh, Novosibirsk, Omsk, Saratov, and Tula oblasts, Altai krai, Transbaikal region, and Khabarovsk krai, and the republics of Tyva and Altai. In total, 111 censuses were conducted and 3920 burrows of these animals were inspected. Burrows built by individuals of the same species could later be used or reconstructed and used by other species. Therefore, it was impossible to compile a dichotomous key to differences in the characters of the actual use of a specific shelter by a certain species in a given year during the research. The exception is the size of side holes of the fox and corsac that were dug by these predators in the first year of their settlement. Clear differences were observed only between the burrows of foxes, corsacs, and wolves in the presence of excrement and food debris near their shelters, in contrast to the unpolluted burrows of badgers and raccoon dogs. Burrows of foxes, corsacs, and wolves could alternately be occupied by different host species in subsequent years. It was possible to identify reliably the carnivorous species that occupied the shelter only in May to early June by the size of excrement of young and adult individuals. Shelters of badgers and raccoon dogs significantly differed only in paw prints and the color of fallen hair during the replacement of one species by the other in a burrow. It is necessary to use a set of key characters for the species identification of shelter hosts in each particular case. During primary censuses, it is extremely laborious to identify and map the territorial distribution of burrows. However, a high-quality registration of burrow hosts in the first year of the study made it possible to reproduce registrations in many subsequent years with low material and time costs. It is recommended to use this corrected methodology both for the real-time counting of the relative and absolute numbers of the main natural distributors of the rabies virus and for analysis of their intra- and interspecific biotic relationships. In the natural foci of rabies, this technique makes it possible to record not only the abundance of predators but also their territorial distribution and concentrations near burrow shelters, which is important during oral vaccinations of predators against rabies. [ABSTRACT FROM AUTHOR]

This article discusses the survival strategies of amphibians in Yellowstone National Park during the winter. It focuses on the boreal chorus frog, Columbia spotted frog, western toad, and western tiger salamander, highlighting their ability to burrow underground, live in ponds, and tolerate freezing water in their bodies. The information gathered from studying these strategies helps scientists in recommending ways to protect amphibian habitats and ensure their long-term survival. The article also features the work of Peterson, a nature photographer dedicated to raising awareness about the importance of amphibians and reptiles and promoting conservation efforts through his photography. [Extracted from the article]

Burrowing animals influence surface microtopography and hillslope sediment redistribution, but changes often remain undetected due to a lack of automated high-resolution field monitoring techniques. In this study, we present a new approach to quantify microtopographic variations and surface changes caused by burrowing animals and rainfall-driven erosional processes applied to remote field plots in arid and Mediterranean climate regions in Chile. We compared the mass balance of redistributed sediment between burrow and burrow-embedded area, quantified the cumulative sediment redistribution caused by animals and rainfall, and upscaled the results to a hillslope scale. The newly developed instrument, a time-of-flight camera, showed a very good detection accuracy. The animal-caused cumulative sediment excavation was 14.6 cm 3 cm -2 yr -1 in the Mediterranean climate zone and 16.4 cm 3 cm -2 yr -1 in the arid climate zone. The rainfall-related cumulative sediment erosion within burrows was higher (10.4 cm 3 cm -2 yr -1) in the Mediterranean climate zone than the arid climate zone (1.4 cm 3 cm -2 yr -1). Daily sediment redistribution during rainfall within burrow areas was up to 350 % (40 %) higher in the Mediterranean (arid) zone compared to burrow-embedded areas and much higher than previously reported in studies that were not based on continuous microtopographic monitoring. A total of 38 % of the sediment eroding from burrows accumulated within the burrow entrance, while 62 % was incorporated into hillslope sediment flux, which exceeds previous estimations 2-fold. On average, animals burrowed between 1.2–2.3 times a month, and the burrowing intensity increased after rainfall. This revealed a newly detected feedback mechanism between rainfall, erosion, and animal burrowing activity, likely leading to an underestimation of animal-triggered hillslope sediment flux in wetter climates. Our findings hence show that the rate of sediment redistribution due to animal burrowing is dependent on climate and that animal burrowing plays a larger than previously expected role in hillslope sediment redistribution. Subsequently, animal burrowing activity should be incorporated into soil erosion and landscape evolution models that rely on soil processes but do not yet include animal-induced surface processes on microtopographical scales in their algorithms. [ABSTRACT FROM AUTHOR]

Earth dams and levees often offer an attractive habitat for burrowing animals such as porcupines, nutria, badgers, etc. However, their activity may damage the earth structure, potentially leading to catastrophic failures. If the burrow system connects the waterside and the landside, water flows through the pipe and it can start concentrated erosion. This paper shows that the conditions to trigger concentrated erosion can be generated by a local instability mechanism of the landside slope in which the soil cover between the cavity and the surface is expulsed due to increasing water pressure. A simplified model based on the limit equilibrium method is proposed and compared with bi-dimensional and three-dimensional finite element analyses. This mechanism can better explain real failure cases. The results provide useful suggestions for the assessment of levee vulnerability to animal burrows and for the management of water retaining structures. [ABSTRACT FROM AUTHOR]

The morphological features of fossorial animals have continuously evolved in response to the demands of survival. However, existing methods for animal burrowing mechanics are not capable of addressing the large deformation of substrate. The discrete element method (DEM) is able to overcome this limitation. In this study, we used DEM to develop a general model to simulate the motion of an animal body part and its interaction with the substrate. The DEM also allowed us to easily change the forms of animal body parts to examine how those different forms affected the biomechanical functions. These capabilities of the DEM were presented through a case study of modeling the burrowing process of North American Badger. In the case study, the dynamics (forces, work, and soil displacements) of burrowing were predicted for different forms of badger claw and manus, using the model. Results showed that when extra digits are added to a manus, the work required for a badger to dig increases considerably, while the mass of soil dug only increases gradually. According to the proposed efficiency index (ratio of the amount of soil dug to the work required), the modern manus with 5 digits has indeed biomechanical advantage for their fossorial lifestyle, and the current claw curvature (25.3 mm in radius) is indeed optimal. The DEM is able to predict biomechanical relationships between functions and forms for any fossorial animals. Results can provide biomechanical evidences for explaining how the selective pressures for functions influence the morphological evolution in fossorial animals. [ABSTRACT FROM AUTHOR]

Abstract Burrows provide burrowing animals with a place to hibernate, reproduce, and avoid predators and harsh weather conditions and thus have a vital impact on their survival. However, the general physical characteristics and ecological functions of Marmota himalayana burrows as well as whether there are differences in burrow traits under different terrains (e.g., sunny slopes, shady slopes, and flat areas) are not well understood. From July to August 2019 (warm season), we used unmanned aerial vehicles to fly at low altitudes and slow speeds to locate 131 M. himalayana burrows (45 on shaded slopes, 51 on sunny slopes, and 35 on flat areas) in the northeastern Qinghai‐Tibetan Plateau region. We then measured the physical characteristics (burrow density, entrance size, first tunnel length, volume, orientation, and plant characteristics near the burrow entrance) of these burrows on site. We found that terrain had a substantial influence on burrow density, orientation, and entrance size and on the angle of the burrow entrance; species richness had a substantial impact on path density and tunnel volume. The physical parameters of the M. himalayana burrows showed that they function to protect the marmots from natural enemies and bad weather, provide good drainage, and maintain a stable microclimate around the entrance. We discuss the ability of burrowing animals (e.g., M. himalayana) to adapt to the external environment based on their burrow characteristics.

Before the SARS-CoV-2 Omicron variant emergence, shell disorder models (SDM) suggested that an attenuated precursor from pangolins may have entered humans in 2017 or earlier. This was based on a shell disorder analysis of SARS-CoV-1/2 and pangolin-Cov-2017. The SDM suggests that Omicron is attenuated with almost identical N (inner shell) disorder as pangolin-CoV-2017 (N-PID (percentage of intrinsic disorder): 44.8% vs. 44.9%—lower than other variants). The outer shell disorder (M-PID) of Omicron is lower than that of other variants and pangolin-CoV-2017 (5.4% vs. 5.9%). COVID-19-related CoVs have the lowest M-PIDs (hardest outer shell) among all CoVs. This is likely to be responsible for the higher contagiousness of SARS-CoV-2 and Omicron, since hard outer shell protects the virion from salivary/mucosal antimicrobial enzymes. Phylogenetic study using M reveals that Omicron branched off from an ancestor of the Wuhan-Hu-1 strain closely related to pangolin-CoVs. M, being evolutionarily conserved in COVID-19, is most ideal for COVID-19 phylogenetic study. Omicron may have been hiding among burrowing animals (e.g., pangolins) that provide optimal evolutionary environments for attenuation and increase shell hardness, which is essential for fecal–oral–respiratory transmission via buried feces. Incoming data support SDM e.g., the presence of fewer infectious particles in the lungs than in the bronchi upon infection. [ABSTRACT FROM AUTHOR]

Soil carbon (C) sequestration rates vary widely in abandoned agricultural lands, and factors determining this variation, beyond climate, soil type, and productivity, are poorly understood. One such factor is soil disturbance by burrowing mammals. Despite being ubiquitous in all grasslands, the impact of burrowing mammals on soil C dynamics is not well understood. We quantified the major ecosystem processes that are influenced by one such burrowing mammal, plains pocket gophers (Geomys bursarius), in old field ecosystems located in east‐central Minnesota, USA. We found that pocket gopher abundance varied among old fields and that newly formed gopher mounds covered up to 6% of the soil surface annually. We first measured short‐term C pool and flux changes induced by gopher activities. Soil N mineralization did not differ between the soil in gopher mounds and undisturbed soil. However, for the soil under gopher mounds, N mineralization was 30% lower compared with the undisturbed soil. We developed a process model to simulate the long‐term gopher disturbance impact on old field soil C accumulation. This simulation showed that pocket gophers reduced both the rate of soil C accumulation and the total C pool. This reduction is primarily driven by reduced plant C input due to the time it requires for the vegetation to recolonize gopher mounds. Soil organic matter (SOM) decomposition changes had only a minor impact. The process model showed that the depth from which burrowing mammals redistribute soil to the surface is a key factor in determining the overall impact on SOM. In total, our study indicated that soil disturbance by burrowing animals could significantly reduce C storage in old field ecosystems when the mammals are mostly active at the surface soil and can be a significant factor in decreasing overall C sequestration after land abandonment. However, at our study site, gopher abundance decreased with abandonment age, which was likely to have been cause by successional vegetation changes, therefore the gopher disturbance‐induced reduction in soil C is transient and decreases with abandonment age. [ABSTRACT FROM AUTHOR]

Bioturbators shape their environment with considerable consequences for ecosystem processes. However, both the composition and the impact of bioturbator communities may change along climatic gradients. For burrowing animals, their abundance and composition depend on climatic and other abiotic components, with ants and mammals dominating in arid and semiarid areas, and earthworms in humid areas. Moreover, the activity of burrowing animals is often positively associated with vegetation cover (biotic component). These observations highlight the need to understand the relative contributions of abiotic and biotic components in bioturbation in order to predict soil-shaping processes along broad climatic gradients. In this study, we estimated the activity of animal bioturbation by counting the density of holes and the quantity of bioturbation based on the volume of soil excavated by bioturbators along a gradient ranging from arid to humid in Chile. We distinguished between invertebrates and vertebrates. Overall, hole density (no/ 100 m2) decreased from arid (raw mean and standard deviation for invertebrates: 14 ± 7.8, vertebrates: 2.8 ± 2.9) to humid (invertebrates: 2.8 ± 3.1, vertebrates: 2.2 ± 2.1) environments. However, excavated soil volume did not follow the same clear geographic trend and was 300-fold larger for vertebrates than for invertebrates. The relationship between bioturbating invertebrates and vegetation cover was consistently negative whereas for vertebrates both, positive and negative relationships were determined along the gradient. Our study demonstrates complex relationships between climate, vegetation and the contribution of bioturbating invertebrates and vertebrates, which will be reflected in their impact on ecosystem functions. [ABSTRACT FROM AUTHOR]

Augerinoichnus refers to successions of horseshoe-shaped structures interpreted as sedimentary remains of horizontal helical burrows of worm-like animals. The monospecific trace fossil was hitherto only known from early Permian intertidal to lowland coastal-plain deposits of New Mexico, U.S.A. Recent discoveries of conspecific material in early Permian nearshore lacustrine deposits of southwestern Germany represent the first record of Augerinoichnus outside of New Mexico and extend the paleogeographic and paleoenvironmental distribution of the ichnotaxon. Augerinoichnus evidentally was made in a wide array of nonmarine settings that ranged from tidal flats to inland floodplains where substrate cohesion and stability as well as stable and predictable food resources allowed the tracemaker to forage in open burrows. [ABSTRACT FROM AUTHOR]

Featured Application: In order to repair Po River embankments affected by animal burrowing, the possibility of injections of lime treated soil is proposed as a sustainable compromise proposal between common interventions. Animal burrowing along riverbanks has a negative impact on the hydraulic performance, and can have severe consequences on the structural integrity, of levees. Hence, as soon as burrows are detected during monitoring activities, it is strongly recommended that interventions are taken within the shortest possible time to mitigate disaster risk. The two most common engineering interventions used to repair the embankments (i.e., the excavation of the area with the following backfill or the injection of a low pressure flowable grout) may cause disadvantages and the weakening of the embankment because of the backfill soil lower compaction—which involves also the uncertainty of the complete filling—or piping and interface problems that may be encouraged by discontinuities of mechanical and hydraulic characteristics after injections of the low pressure grout. In this preliminary study, the possibility of injections of lime treated soil was investigated as a sustainable compromise proposal between the two mentioned interventions; oedometer tests on lime treated specimens of soils from the Po River embankment were carried out in order to study the effects of lime on the compressibility of less compacted soil compared to more compacted raw ones. [ABSTRACT FROM AUTHOR]

We describe a new species of microhylid frog of the genus Synapturanus from the lower Putumayo basin in Loreto, Perú. Specimens inhabited the soils of stunted pole forests growing on peat. The new species is distinguished from other species of Synapturanus through morphology, genetics, and acoustic characteristics. This species differs from most nominal congeners by having a head flat in lateral view (vs convex in the rest of species), a characteristic only shared by S. rabus and S. salseri. The new species can be distinguished from S. rabus and S. salseri by a combination of morphological characters and by having an advertisement call with a note length of 0.05-0.06 seconds (vs 0.03 seconds in S. rabus) and a dominant frequency ranging from 1.73 to 1.81 kHz (vs 1.10-1.47 kHz in S. salseri). Principal component analyses of 12 morphological characters and three acoustic variables further support differences between the new species and its described and undescribed congeners. [ABSTRACT FROM AUTHOR]

The relationship between body mass and the respiratory microenvironment of burrowing animals is examined using artificial burrows containing surrogate animals that simulate O2 consumption by removal of air and simultaneous replacement with N2. Allometric relationships between body mass and burrow radius, nest chamber radius, and O2 consumption rate show that published mathematical predictions of diffusion-mediated gas exchange are adequate to describe the respiratory environments of animals in small blind-ending burrows through porous substrata. Diffusion is sufficient to ventilate burrows containing small mammals weighing less than 340 g, or subterranean nest chambers connected to the surface by one or more tunnels containing mammals weighing less than 30 kg. Outside of these limits, convection prevails and prevents the development of hypoxic conditions, particularly in burrows of mammals weighing more than 1300 g. [ABSTRACT FROM AUTHOR]