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Conflicts between wildlife and agriculture have increased as cultivation has expanded into previously unexploited areas. As frequent consumers of such crops, parrots (Psittaciformes) are often persecuted, despite the lack of measured economic impacts they may cause. This situation has compromised attempts to manage potential damage and endangered parrot populations. Here, we evaluate and measure actual crop damage and characterize the foraging areas used by the burrowing parrot (Cyanoliseus patagonus) in northeastern Patagonia, Argentina. We found that damage to field crops was economically insignificant, affecting 0.1%–0.4% of the sunflower harvest, with no damage detected in other more important crops in the region. The parrots mainly consumed grain left or spilled after harvesting, and unharvested grain from cultivated pastures and road margins. This grain represents a loss attributable to harvest machines, being independent from the presence of parrots. Given the negligible damage measured here, we conclude that there is no need for management of parrots as crop pests in northeastern Patagonia. Our study provides further support to the view that parrot damage has been often exaggerated and overstated. [ABSTRACT FROM AUTHOR]

Bioturbation is the dominant mode of sediment transport in many aquatic environments and strongly influences both sediment biogeochemistry and contaminant fate. Available bioturbation models rely on highly simplified biodiffusion formulations that inadequately capture the behavior of many benthic organisms. We present a novel experimental and modeling approach that uses time-lapse imagery to directly relate burrow formation to resulting sediment mixing. We paired white-light imaging of burrow formation with fluorescence imaging of tracer particle redistribution by the oligochaete Lumbriculus variegatus. We used the observed burrow formation statistics and organism density to parametrize a parsimonious model for sediment mixing based on fundamental random walk theory. Worms burrowed over a range of times and depths, resulting in homogenization of sediments near the sediment-water interface, rapid nonlocal transport of tracer particles to deep sediments, and large areas of unperturbed sediments. Our fundamental, parsimonious random walk model captures the central features of this highly heterogeneous sediment bioturbation, including evolution of the sediment-water interface coupled with rapid near-surface mixing and anomalous late-time mixing resulting from infrequent, deep burrowing events. This approach provides a general, transferable framework for explicitly linking sediment transport to governing biophysical processes. [ABSTRACT FROM AUTHOR]

Mercury (Hg) is a highly toxic metal that has multiple natural and anthropogenic sources. Many studies have explored the effects of Hg on various physiological and biochemical processes in soil animals. However, the effects of Hg on earthworm behavior and respiration are unknown. In this study, earthworms ( Eisenia fetida ) were exposed to Hg-spiked artificial soils prepared to OECD specification. An avoidance test was performed using soils with 0, 1, 2, 4, 8, 16, 32, 64, and 128 mg Hg 2+ kg −1 dry soil,. The avoidance concentration of Hg to earthworms was 128 mg kg −1 , as determined according to ISO guidelines. Soils with 0, 2, 8, 32, and 128 mg Hg 2+ kg −1 dry soil were prepared to investigate the effects of Hg on the burrowing activity and respiration rate of earthworms. The cumulative burrow lengths of earthworms in 2D terraria were significantly shorter in soil containing Hg at concentrations of 8 mg kg −1 or higher, compared with those in the control (no Hg). However, the maximum burrowing depth was significantly decreased only in soil containing the highest concentration of Hg (128 mg kg −1 ). The respiration rates of earthworms were lower in all Hg treatments than in the control after 2 days and 7 days of exposure. This is the first report on the toxic effects of Hg on earthworm behavior and respiration. These results provide useful information for environmental monitoring and for assessment of Hg contamination in soils. [ABSTRACT FROM AUTHOR]

1. In temperate climates, dung is often colonised by several species of endocoprid (dwelling) dung beetles which use pats for feeding, shelter, and reproduction. 2. Endocoprid beetles aggregate even when offered patches (dung pats) of consistent age, size, and origin, suggesting that beetles themselves might influence the attractiveness of patches to members of their own species. Both pheromones, and physical changes to the structure of dung pats caused by colonising beetles have been suggested as mechanisms facilitating intraspecific aggregation, but neither of these hypotheses have been empirically tested. 3. Using a common European dung beetle ( Aphodius fossor L.), we conducted a simple choice experiment designed to test whether (i) earlier colonisation by conspecifics could alter dung attractiveness and (ii) whether attraction was influenced by sex-specific signals. 4. We found that female beetles are repelled by dung colonised by conspecific females and are attracted to dung colonised by conspecific males. Male beetles show no evidence of attraction or repellence for dung colonised by either sex. Neither in females nor males was uncolonised dung found to be significantly more or less attractive than predicted by non-preference. 5. Our results suggest that for A. fossor male-produced signals may support mate finding in patchy environments, and that female-produced signals may serve to discourage subsequent colonisation by additional females. [ABSTRACT FROM AUTHOR]

Summary The turtle shell is a complex structure that currently serves a largely protective function in this iconically slow-moving group [ 1 ]. Developmental [ 2, 3 ] and fossil [ 4–7 ] data indicate that one of the first steps toward the shelled body plan was broadening of the ribs (approximately 50 my before the completed shell [ 5 ]). Broadened ribs alone provide little protection [ 8 ] and confer significant locomotory [ 9, 10 ] and respiratory [ 9, 11 ] costs. They increase thoracic rigidity [ 8 ], which decreases speed of locomotion due to shortened stride length [ 10 ], and they inhibit effective costal ventilation [ 9, 11 ]. New fossil material of the oldest hypothesized stem turtle, Eunotosaurus africanus [ 12 ] (260 mya) [ 13, 14 ] from the Karoo Basin of South Africa, indicates the initiation of rib broadening was an adaptive response to fossoriality. Similar to extant fossorial taxa [ 8 ], the broad ribs of Eunotosaurus provide an intrinsically stable base on which to operate a powerful forelimb digging mechanism. Numerous fossorial correlates [ 15–17 ] are expressed throughout Eunotosaurus ’ skeleton. Most of these features are widely distributed along the turtle stem and into the crown clade, indicating the common ancestor of Eunotosaurus and modern turtles possessed a body plan significantly influenced by digging. The adaptations related to fossoriality likely facilitated movement of stem turtles into aquatic environments early in the groups’ evolutionary history, and this ecology may have played an important role in stem turtles surviving the Permian/Triassic extinction event. [ABSTRACT FROM AUTHOR]

In this study, we provide an extended multilocus phylogenetic analysis combining mitochondrial and nuclear DNA of a group of fossorial and miniaturized legless lizards (genus Paracontias) from Madagascar , including the description of two species new to science, P. ampijoroensis sp. nov. and P. mahamavo sp. nov. Our analyses revealed the existence of two distinct, parapatric and diagnosable clades within the genus: (i) the 'kankana clade' (including P. kankana and the two newly described species), located in the north (but absent from the extreme northern tip) of the island and characterized by a pattern of cephalic scales very unusual for Malagasy Scincinae, with large loreal scales extending to and meeting each other at dorsal midline, and (ii) the 'brocchii clade' (including all other studied species), endemic to the north of Madagascar and characterized by small loreal scales separated from each other by the rostral and the frontonasal scale. By combining phylogenetic results with morphological traits observed among species, we develop novel hypotheses on the simplification of the cephalic scalation pattern within this genus, a trend frequently encountered among various lineages of legless squamates that convergently adapted to a burrowing lifestyle. Additionally, a user-friendly graphical identification key for species of Paracontias is provided and made available as supplementary information. [ABSTRACT FROM AUTHOR]

Here, we describe cDNA cloning and purification of the ghrelin gene sequences and ghrelin peptides from the Japanese true mole, Mogera imaizumii . The gene spans >2.9 kbp, has four exons and three introns, and shares structural similarity with those of terrestrial animals. Mature mole ghrelin peptide was predicted to be 28 amino acids long (GSSFLSPEHQKVQQRKESKKPPSKPQPR) and processed from a prepropeptide of 116 amino acids. To further elucidate molecular characteristics, we purified ghrelin peptides from mole stomach. By mass spectrometry, we found that the mole ghrelin peptides had higher ratios of the odd-number fatty acids (C9 and C11 as much as C8) attached to the third serine residue than other vertebrate ghrelin. Truncated forms of ghrelins such as [1–27], [1–19], [1–16] and [1–15], and that lacked the 14th glutamine residue (des-Gln14 ghrelin) were produced in the stomach. Marked expression of ghrelin mRNA in lung was observed as in stomach and brain. Phylogenetic analysis indicated that the branch of M. imaizumii has slightly higher d N / d S ratios (the nucleotide substitution rates at non-synonymous and synonymous sites) than did other eulipotyphlans. Peptide length was positively correlated with human ghrelin receptor activation, whereas the length of fatty-acyl chains showed no obvious functional correlation. The basal higher luciferase activities of the 5′-proximal promoter region of mole ghrelin were detected in ghrelin -negative C2C12 cells and hypoxic culture conditions impaired transcriptional activity. These results indicated that moles have acquired diverse species of ghrelin probably through distinctive fatty acid metabolism because of their food preferences. The results provide a gateway to understanding ghrelin metabolism in fossorial animals. [ABSTRACT FROM AUTHOR]

Small-scale environmental characteristics associated with nesting burrows of the Newell's Shearwater (Puffinus newellii) and Hawaiian Petrel (Pterodroma sandwichensis) were documented in mesic and wet montane forest on the island of Kauai, Hawaii, USA. Most plots containing burrows were located on steep slopes, ranging from 28° to 48° (median = 39°) for tire Newell's Shearwater and 0° to 67° (median = 34.5°) for the Hawaiian Petrel. Plots generally contained > 20% to 40% up to > 80% to 100% estimated vegetation cover 0-1 m above ground and > 0% to 20% up to > 60% to 80% cover 1-2 m above ground. Plots were also associated with estimated canopy cover from > 0% to 10% up to > 80% to 90% for the Newell's Shearwater and 0% up to > 70% to 80% for the Hawaiian Petrel. Soil in Newell's Shearwater plots tended to be harder 7.62-22.86 cm below ground, which might provide increased burrow stability. Additionally, maximum vegetation height tended to be greater above Newell's Shearwater plots (median = 6.00 m) than Hawaiian Petrel plots (median = 3.25 m). Taller trees may serve as climbing structures helping Newell's Shearwaters become airborne in thickly vegetated regions that are farther from ridgelines and associated with lighter wind speeds aloft. Received 7July 2015, accepted 13 December 2015. [ABSTRACT FROM AUTHOR]

Establishment and validation of ethologically-relevant, non-evoked behavioral end-points as surrogate measures of spontaneous pain in rodent pain models has been proposed as a means to improve preclinical to clinical research translation in the pain field. Here, we compared the utility of burrowing behavior with hypersensitivity to applied mechanical stimuli for pain assessment in rat models of chronic inflammatory and peripheral neuropathic pain. Briefly, groups of male Sprague-Dawley rats were habituated to the burrowing environment and trained over a 5-day period. Rats that burrowed =450 g of gravel on any 2 days of the individual training phase were excluded from the study. The remaining rats received either a unilateral intraplantar injection of Freund's complete adjuvant (FCA) or saline, or underwent unilateral chronic constriction injury (CCI) of the sciatic nerve- or sham-surgery. Baseline burrowing behavior and evoked pain behaviors were assessed prior to model induction, and twice-weekly until study completion on day 14. For FCA- and CCI-rats, but not the corresponding groups of sham-rats, evoked mechanical hypersensitivity developed in a temporal manner in the ipsilateral hindpaws. Although burrowing behavior also decreased in a temporal manner for both FCA-and CCI- rats, there was considerable inter-animal variability. By contrast, mechanical hyperalgesia and mechanical allodynia in the ipsilateral hindpaws of FCA- and CCI-rats respectively, exhibited minimal inter-animal variability. Our data collectively show that burrowing behavior is altered in rodent models of chronic inflammatory pain and peripheral neuropathic pain. However, large group sizes are needed to ensure studies are adequately powered due to considerable inter-animal variability. [ABSTRACT FROM AUTHOR]

Tadpoles of the monotypic Indian dancing frog family Micrixalidae have remained obscure for over 125 years. Here we report the discovery of the elusive tadpoles of Micrixalus herrei from the sand beds of a forested stream in southern Western Ghats, and confirm their identity through DNA barcoding. These actively burrowing tadpoles lead an entirely fossorial life from eggs to late metamorphic stages. We describe their internal and external morphological characters while highlighting the following features: eel-like appearance, extensively muscularized body and tail, reduced tail fins, skin-covered eyes, delayed development of eye pigmentation in early pre-metamorphic stages (Gosner stages 25–29), prominent tubular sinistral spiracle, large transverse processes on vertebrae II and III, ankylosed ribs on transverse processes of vertebra II, notochord terminating before the atlantal cotyle-occipital condyle junction, absence of keratodonts, serrated well-formed jaw sheaths, and extensive calcified endolymphatic sacs reaching sacrum posteriorly. The tadpole gut contains mostly fine sediments and sand. We discuss the eel-like morphology and feeding habits of M. herrei in the context of convergence with other well-known fossorial tadpoles. This discovery builds the knowledge base for further comparative analyses and conservation of Micrixalus, an ancient and endemic lineage of Indian frogs. [ABSTRACT FROM AUTHOR]

The ecology of West African arid savannah snakes is still poorly known, especially in regard to the fossorial species. Here, field data on distribution, morphometrics, habitat use and diet are reported for the sand boaEryx muelleri(Erycidae) from three different countries, i.e. Burkina Faso, Togo and Nigeria. This snake was observed in 21 distinct localities, and a total of 39 individuals was recorded. The species is likely fairly common and locally abundant. Mean body length of snakes was similar among countries and between sexes, but males had proportionately longer tails than females. Body length was significantly positively correlated with both tail length and head length. Adult sex ratio was close to parity. Most of the specimens were found in well-vegetated spots with low percentage of bare soil. There were apparently both ontogenetic and intersexual dietary variations: (1) a single analysed juvenile fed upon a small-sized lizard, whereas adults fed considerably upon young rodents; and (2) females fed exclusively upon young rodents and males upon both lizards and young rodents. In conservation terms, the species is actively exported from Togo for the pet trade, and additional individuals may also be illegally collected in other countries. [ABSTRACT FROM AUTHOR]

Burrowing and foraging of semi-fossorial rodents can affect species distribution and composition. Ground squirrels dig large burrow systems for refuge from predators and temperature extremes. Burrowing and foraging around burrows by squirrels may affect habitat and resource distributions for other organisms. We examined the impact of Cape ground squirrels ( Xerus inauris) on vegetation, small mammals and beetles during winter and summer in grasslands on the edge of the Namib Desert. At each burrow system and paired control site without burrows, we estimated plant cover and height using quadrats (N = 8 paired sites), small mammal abundance and species richness using mark-recapture techniques (N = 8 paired sites) and beetle abundance and species richness using pitfall traps (N = 6 paired sites, winter only). Squirrel burrowing and foraging activities resulted in lower plant cover and height, higher small mammal abundance and lower beetle abundance and species richness. Squirrels also reduced more plant cover in winter compared to summer, but had no effect on small mammal species richness. Furthermore, plant cover and height were higher in summer, whereas small mammal abundance and species richness were higher in winter. Our results suggest that Cape ground squirrels are important ecosystem engineers that influence plant and animal communities in the Namib Desert grasslands. [ABSTRACT FROM AUTHOR]

The middle Cambrian taxon Waptia fieldensis offers insights into early evolution of sensory arrangements that may have supported a range of actions such as exploratory behavior, burrowing, scavenging, swimming, and escape, amongst others. Less elaborate than many modern pancrustaceans, specific features of Waptia that suggest a possible association with the pancrustacean evolutionary trajectory, include mandibulate mouthparts, a single pair of antennae, reflective triplets on the head comparable to ocelli, and traces of brain and optic lobes that conform to the pancrustacean ground pattern. This account revisits an earlier description of Waptia to further interpret the distribution of its overall morphology and receptor arrangements in the context of plausible behavioral repertoires. [ABSTRACT FROM AUTHOR]

ABSTRACT Burrow-nesting petrels (order Procellariiformes) are keystone species in island ecosystems, where they modify habitat through guano deposition and burrow digging. Burrowing petrels are among the most threatened groups of birds, yet robust long-term monitoring data remain scarce because of the financial and logistical constraints of working on offshore breeding islands, the variety of surveying strategies used, and the birds' below-ground breeding behavior. We examined the sampling requirements of monitoring programs to detect changes in the number of breeding pairs of gray-faced petrels ( Pterodroma gouldi), a common species in northern New Zealand. We first examined the relationship between burrow entrance density and breeding pair density using 4 years of data from 3 large colonies. We then conducted a simulation-based power analysis to assess the ability of different burrow-occupancy sampling regimes to detect changes in breeding bird abundance. Power to detect change was influenced by population growth rates, initial bird density, inter-annual variation in abundance, plot size, number of plots, intervals between surveys, time of year surveys are undertaken, and duration of the monitoring program. Our analyses suggest that, under the most suboptimal monitoring conditions, at least 45 randomly assigned 5-m-radius plots surveyed annually during the incubation period for ≥20 years will be required to detect a 1% annual change in breeding bird abundance. Because power will vary depending on project specifications, local conditions, and potential change, we created an online application with over 50,000 combinations of starting parameters (). This allows managers to determine the power of different combinations of survey intensities while maintaining consistency and maximizing efficiency. © 2015 The Wildlife Society. [ABSTRACT FROM AUTHOR]

A major obstacle to understanding feeding and burrowing behaviour of earthworms and their impact on soil structure in natural field conditions is that it remains impossible to identify the origins of burrows in the soil matrix. This gap in our knowledge makes it difficult to understand the roles of different earthworm species in creating the burrow network in soils. We tested the utility of near infrared spectroscopy (NIRS) as a new tool to overcome this obstacle. For the first time, we studied the ability of NIRS to detect specific chemical footprints left by different earthworms during the production of burrows, and thereby to identify the origins of burrows produced in the same soil matrix in the field, in terms of the earthworm species that produced them. The method was tested in three study sites (in sandstone, schist and marl geologies), differing in soil mineralogical composition and texture, with well-characterized and partially overlapping earthworm faunas. Burrows collected in the field were identified by comparing their NIR spectral signatures to the signatures of macroaggregates produced by the same earthworm species living in the same soil in laboratory conditions. We showed clearly that burrows of anecic and epi-endogeic earthworm species were characterized by specific NIR spectral signatures, resulting from quantitative and qualitative differences of OM in burrows among species. PLS-DA models conducted on NIR spectral data showed that NIRS technique allowed identification of a mean of 57.1% (±7.4) of burrows in soil monoliths at the sandstone site, 51.6% (±10.2) at the schist site and 46.5% (±8.1) at the marl site. Our study reveals some clear limitations in this method: low predictive abilities in surface soils, inability to discriminate among endogeic species and the requirement for a calibration procedure through the establishment of a site-dependent reference database. [ABSTRACT FROM AUTHOR]

This note describes five observations during 2014 and 2015 of predation by Eastern Yellow Robins Eopsaltria australis, on a burrowing crayfish Engaeus sp. and small skinks. This species feeds predominantly on terrestrial invertebrates and insects but these recent observations suggest that it is an opportunistic feeder. [ABSTRACT FROM AUTHOR]

By living in permanent burrows and incorporating organic detritus from the soil surface, anecic earthworms contribute to soil heterogeneity, but their impact is still under-studied in natural field conditions. We investigated the effects of the anecic earthworm Lumbricus centralis on fresh carbon (C) incorporation, soil organic matter composition, protists, and nematodes of a Cambisol under grassland. We used plant material labelled with stable isotope tracers to detect fresh C input around earthworm-occupied burrows or around burrows from which the earthworm had been removed. After 50 days, we sampled soil (0-10 cm depth) in concentric layers around the burrows, distinguishing between drilosphere (0-8 mm) and bulk soil (50-75 mm). L. centralis effectively incorporated fresh C into the drilosphere, and this shifted soil organic matter amount and chemistry: total soil sugar content was increased compared to unoccupied drilosphere and bulk soil, and the contribution of plant-derived sugars to soil organic matter was enhanced. Earthworms also shifted the spatial distribution of soil C towards the drilosphere. The total abundance of protists and nematodes was only slightly higher in earthworm-occupied drilosphere, but strong positive effects were found for some protist clades (e.g. Stenamoeba spp.). Additional data for the co-occurring anecic earthworm species Aporrectodea longa showed that it incorporated fresh C less than L. centralis, suggesting that the two species may have different effects on soil C distribution and organic matter quality. [ABSTRACT FROM AUTHOR]

Vertebrate consumers can be important drivers of the structure and functioning of ecosystems, including the soil and litter invertebrate communities that drive many ecosystem processes. Burrowing seabirds, as prevalent vertebrate consumers, have the potential to impact consumptive effects via adding marine nutrients to soil (i.e. resource subsidies) and non-consumptive effects via soil disturbance associated with excavating burrows (i.e. ecosystem engineering). However, the exact mechanisms by which they influence invertebrates are poorly understood. We examined how soil chemistry and plant and invertebrate communities changed across a gradient of seabird burrow density on two islands in northern New Zealand. Increasing seabird burrow density was associated with increased soil nutrient availability and changes in plant community structure and the abundance of nearly all the measured invertebrate groups. Increasing seabird densities had a negative effect on invertebrates that were strongly influenced by soil-surface litter, a positive effect on fungal-feeding invertebrates, and variable effects on invertebrate groups with diverse feeding strategies. Gastropoda and Araneae species richness and composition were also influenced by seabird activity. Generalized multilevel path analysis revealed that invertebrate responses were strongly driven by seabird engineering effects, via increased soil disturbance, reduced soil-surface litter, and changes in trophic interactions. Almost no significant effects of resource subsidies were detected. Our results show that seabirds, and in particular their non-consumptive effects, were significant drivers of invertebrate food web structure. Reductions in seabird populations, due to predation and human activity, may therefore have far-reaching consequences for the functioning of these ecosystems. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of CO2-induced seawater acidification (pH 8.1; control pH 7.0 and 6.0) on the survival, behaviour and metabolic rate of the Baltic clam Macoma balthica during short- (36 hours) and long-term (14 days) exposures. Total metabolic rate and gaping behaviour (shell opening and closing) were determined based on heat dissipation measurements using an isothermal twin calorimeter of the Calvet type. The survival and burrowing behaviour during long-term exposure were observed every day. Short-term exposure to reduced pH did not significantly affect the resting or active metabolic rate. Neither were there any significant changes in gaping behaviour. However, long-term exposure significantly affected burrowing behaviour. In the lowest-pH treatment, both resting and active metabolic rates were also significantly higher than in the control. [ABSTRACT FROM AUTHOR]

The foraging and burrowing activities of small mammalian herbivores may have either detrimental or beneficial effects on grassland ecosystems; the direction of the effect is determined by the species, population abundances and fluctuations. Twelve survey sites with active burrow of plateau pika were classified into four degrees of density: approximately zero-density, low-density, mediumdensity and high-density, to evaluate the impact of different pika densities on vegetation, plant biomass, soil organic carbon and nutrients in a whole growing season. We show that pika as a main supplement to livestock activities contributed to a decrease in the number of plant species, vegetation cover, plant height and seasonal mean biomass, while values at medium-density site except above-ground biomass were the lowest. With the exception of available potassium, soil organic carbon, nitrogen, total phosphorus and soil water content, zero-density areas were significantly higher than those of pika occupied areas. However, there were slight or no differences in vegetation characteristics and soil properties between medium-and high-density sites. Our study suggests pika activities with high-density made palatable forage less and soil carbon and nitrogen more than low-density, moreover, plateau pika had greater impacts on above-ground vegetation than on root system. [ABSTRACT FROM AUTHOR]

Since 2004 there has been mounting evidence of the severe impact of introduced house mice (Mus musculus L.) killing chicks of burrow-nesting petrels at Gough Island. We monitored seven species of burrow-nesting petrels in 2014 using a combination of infra-red video cameras augmented by burrowscope nest inspections. All seven camera-monitored Atlantic petrel (Pterodroma incerta Schlegel) chicks were killed by mice within hours of hatching (average 7.2±4.0 hours) with an 87% chick failure rate (n=83 hatchlings). Several grey petrel (Procellaria cinerea Gmelin) chicks were found with mouse wounds and 60% of chicks failed (n=35 hatchlings). Video surveillance revealed one (of seven nests filmed) fatal attack on a great shearwater (Puffinus gravis O’Reilly) chick and two (of nine) on soft-plumaged petrel (Pterodroma mollis Gould) chicks. Mice killed the chicks of the recently discovered summer-breeding MacGillivray’s prion (Pachyptila macgillivrayi Mathews), with a chick mortality rate of 82% in 2013/14 and 100% in 2014/15. The closely-related broad-billed prion (P. vittata Forster) breeds in late winter and also had a chick mortality rate of 100% in 2014. The results provide further evidence of the dire situation for seabirds nesting on Gough Island and the urgent need for mouse eradication. [ABSTRACT FROM AUTHOR]

Abstract Calathotarsus simoni Schiapelli & Gerschman, 1975 is an endemic and rare trapdoor spider that lives exclusively in the mountainous systems of southern Buenos Aires province, central Argentina. In previous studies, authors suggested the preference of this species to a particular soil surface type. Thus, we hypothesized that this species differs in its responses to the soil surface type for burrow construction. To test this, we placed 26 adult females in chambers providing two choices (soil with moss and without moss) and compared the proportions of observations in each to evaluate species preference. Calathotarsus simoni significantly preferred the soil with moss. We observed a remarkable behaviour before the construction of the burrow when spiders were at the soil with moss. Finally, we discuss the possible ecological significances of this preference. [ABSTRACT FROM AUTHOR]

The article discusses burrows of the species Gopherus Agassizii. It mentions that tortoise burrows provide a unique environment that is both cooler and more humid than surface conditions. It states that ground squirrels excavate their own burrows, it seems unlikely that the use of the burrow was as a refugia, particularly at this time of year.

The article discusses reproduction in the species Chitra Indica and mentions that it was observed nesting on higher loamy beaches. It highlights the factors influencing the nesting event as post-winter climatic conditions are much different than those during the monsoon season. It states that n post-winter cases, incubation duration could be shorter due to higher substrate temperature.

The genus Virilastacus was created in 1991 to accommodate Parastacus araucanius Faxon, 1914. At present, Virilastacus comprises four burrowing species, three of which were described at the beginning of the XXI century, and biological knowledge about these species is mainly limited to taxonomic and distributional aspects. This review compiles published information about these species, together with other data available to the author in order to update the current state of biological knowledge and, in turn, to promote the conservation of these species. An upgraded diagnosis of the genus Virilastacus is provided, together with information related to each species with regard to: distinctive morphological traits, geographic distribution, habitat, burrow morphology, burrowing behavior, body size, sexual system, and state of conservation. Some aspects related to morphological adaptations to their burrowing life style, phylogenetic affinities and main threats to conservation are also discussed. It is concluded that biological knowledge about these four species is scarce and fragmentary; furthermore, they are currently under threat as a result of anthropogenic activities that are degrading and fragmenting their habitat. [ABSTRACT FROM AUTHOR]

Theory and experiments show that the nature of 'green' trophic cascades, between predators, herbivores and plants, varies with several key species traits: predator hunting mode and predator and prey habitat domains. Meanwhile, 'brown' cascades between predators, environment-modifying detritivores and plants have been largely overlooked and the roles of species traits, particularly prey traits, in determining the nature of these cascades remains unclear., We hypothesize that, in predator-detritivore-plant interaction chains, the burrowing ability of plant-facilitating detritivores determines their response to predators and thus the sign of indirect effect transmitted. In the dung-decomposer food web of an alpine meadow, we predicted that in the presence of above-ground predacious beetles: (i) non-burrowing detritivores will suffer mortality due to predation and transmit negative indirect effects to plants, whereas (ii) burrowing detritivores will escape predation by retreating deeper into the soil, transmitting positive indirect effects to plants., In support of predictions, experiments showed that a single species of predacious beetle (i) reduced the density of the non-burrowing species and indirectly reduced dung loss rate, soil nutrient concentrations and plant biomass, but (ii) drove the burrowing species deeper, indirectly improved soil conditions and increased plant biomass., These results show that the burrowing ability of a detritivore can determine whether it transmits a negative indirect effect mediated by a reduction in its density, or a positive indirect effect mediated by its behavioural response to predation risk., We call for further tests of our detritivore-trait hypothesis in different regions and ecosystems to further develop a general trait-based framework for trophic cascades in detrital food webs. We further advance the general hypothesis that the locomotion traits of prey species (e.g. burrowing/flying ability) may help explain their behavioural response to predation risk and the nature of indirect effect they transmit from predators to plants. [ABSTRACT FROM AUTHOR]

The activities of 2 species of burrowing shrimp have a negative impact on the growth and survival of oysters reared on intertidal mudflats in Willapa Bay and Grays Harbor, Washington (USA). To maintain viable harvests, oyster growers proposed the application of the neonicotinoid insecticide imidacloprid onto harvested beds for the control of burrowing shrimp. In test applications, water column concentrations of imidacloprid were relatively low and dissipated rapidly. The foraging activities of the green sturgeon (listed in the US Endangered Species Act) could result in exposure to higher, more sustained imidacloprid concentrations within sediment porewater and from the consumption of contaminated shrimp. Controlled experiments were conducted using surrogate white sturgeon to determine acute and chronic effect concentrations, to examine overt effects at more environmentally realistic concentrations and durations of exposure, and to assess chemical depuration. The 96-h median lethal concentration was 124 mg L-1, and the predicted 35-d no-observed-adverse-effect concentration was 0.7 mg L-1. No overt effects were observed following environmentally relevant exposures. Imidacloprid half-life in plasma was greater than 32 h. Measured concentrations of imidacloprid in porewater were significantly lower than the derived acute and chronic effect concentrations for white sturgeon. Exposure risk quotients were calculated using the effect concentrations and estimated environmental exposure. The resulting values were considerably below the level of concern for direct effects from either acute or chronic exposure to an endangered species. Environ Toxicol Chem 2015;34:2542-2548. © 2015 SETAC [ABSTRACT FROM AUTHOR]

Willapa Bay and Grays Harbor (WA, USA) comprise the largest region of commercial oyster cultivation on the Pacific Coast. The activities of 2 species of burrowing shrimp impair growth and survival of oysters reared on the intertidal mudflats. To maintain viable harvests, the oyster growers have proposed controlling the shrimp by applying the insecticide imidacloprid onto harvested beds. Green sturgeon (listed in the Endangered Species Act) forage on burrowing shrimp and could be exposed to imidacloprid in the sediment porewater and through consumed prey. Studies were conducted to evaluate the likelihood that green sturgeon would be exposed to imidacloprid and to characterize the subsequent environmental exposure. Comparisons between treated and untreated control beds following test application of the insecticide suggested that green sturgeon fed opportunistically on imidacloprid-impaired shrimp. The highest interpolated imidacloprid residue concentrations in field samples following chemical application were 27.8 µg kg-1 and 31.4 µg kg-1 in porewater and shrimp, respectively. Results from modeled branchial and dietary uptake, based on conservative assumptions, indicated that the porewater exposure route had the greatest contribution to systemic absorption of imidacloprid. The highest average daily uptake from porewater (177.9 µg kg-1 body wt) was 9.5-fold greater than total dietary uptake (18.8 µg kg-1 body wt). Concentrations and durations of exposure would be lower than the levels expected to elicit direct acute or chronic toxic effects. Environ Toxicol Chem 2015;34:2533-2541. © 2015 SETAC [ABSTRACT FROM AUTHOR]

Limbless lizards of the genus Anniella are found in the western United States and Mexico. Until recently only two species were known, but four new species have since been described. Since these lizards are fossorial, not much is known about the nature of gene flow within species, or if gene flow occurs across species boundaries in regions of overlap. Since these lizards are of conservation interest, we isolated and developed nine tetranucleotide microsatellite loci for the recently described species Anniella alexanderae . We characterized the polymorphism of each locus in A. alexanderae , and then cross-amplified these loci in five other Anniella species. These nine loci have high observed levels of heterozygosity and polymorphism information content, and were in Hardy–Weinberg equilibrium within the A. alexanderae samples we tested, indicating that they will have high utility in assessing population genetic and demographic patterns within Anniella . [ABSTRACT FROM AUTHOR]

Earthworm burrow systems are generally described based on postulated behaviours associated with the three ecological types. In this study, we used X-ray tomography to obtain 3D information on the burrowing behaviour of six very common anecic ( Aporrectodea nocturna and Lumbricus terrestris) and endogeic ( Aporrectodea rosea, Allolobophora chlorotica, Aporrectodea caliginosa, Aporrectodea icterica) earthworm species, introduced into repacked soil cores for 6 weeks. A simple water infiltration test, the Beerkan method, was also used to assess some functional properties of these burrow systems. Endogeic worms make larger burrow systems, which are more highly branched, less continuous and of smaller diameter, than those of anecic worms. Among the anecic species, L. terrestris burrow systems are shorter (9.2 vs 21.2 m) with a higher number (14.5 vs 23.5) of less branched burrows (12.2 vs 20.2 branches m), which are also wider (7.78 vs 5.16 mm) than those of A. nocturna. In comparison, the burrow systems made by endogeic species appeared similar to each other. However, A. rosea burrows were short and narrow, whereas A. icterica had a longer burrow system (15.7 m), more intense bioturbation intensity (refilled macropores or soil lateral compaction around them) and thus a greater number of burrows. Regarding water infiltration, anecic burrow systems were far more efficient due to open burrows linking the top and bottom of the cores. For endogeic species, we observed a linear relationship between burrow length and the water infiltration rate ( R = 0.49, p < 0.01). Overall, the three main characteristics significantly influencing water infiltration were burrow length, burrow number and bioturbation volume. This last characteristic highlighted the effect of burrow refilling by casts. [ABSTRACT FROM AUTHOR]

Burrowing animals such as warthog (Phacochoerus africanus), Cape porcupine (Hystrix africaeaustralis) and aardvark (Orycteropus afer) are able to compromise the integrity of fenced-in farmlands by digging holes under game fences. These holes provide access for predators to enter the farm where they can kill livestock or captive game animals. Data collected from the use of swing gates (n = 263) installed along a 23.93 km game fence in the Otjozondjupa region of Namibia was analysed to determine the factors that influenced their efficacy at reducing hole creation along the fence by digging animals. Statistical analyses revealed that soil substrate, grass height, vegetation density, distance to the nearest permanent water source and season influenced digging activity along the fence line. The number of holes created and reopened decreased over time from the start of the study period, probably demonstrating that burrowing animals had learnt to use the swing gates rather than dig holes under the fence. These factors can inform the correct future usage of swing gates as a large predator exclusion method to ensure that they do not enter game farms, which will reduce the need to lethally control carnivores and burrowing animals. [ABSTRACT FROM AUTHOR]

Concordant phylogeographic patterns among species indicate similar ecological and/or evolutionary histories. A concordant phylogeographic pattern exists among two fossorial skinks inhabiting Florida scrub habitat on the Lake Wales Ridge in central Florida. We evaluate whether the Peninsula Crowned Snake ( Tantilla relicta relicta), a fossorial species similarly adapted to xeric upland habitats in central Florida, follows the same phylogeographic pattern. We collected 51 Peninsula Crowned Snakes from 13 sites on the Lake Wales Ridge. The sites spanned Josephine Creek, a location identified as a potential phylogeographic break-point for the species studied previously. We screened the genetic variation of a portion of the mitochondrial cytochrome-b gene and the mitochondrial control region. Phylogenetic analysis indicated that the Peninsula Crowned Snake has central and southern groups, which is similar, yet not identical, to other reptiles on the Lake Wales Ridge. Tests of differentiation detected population structure among three Peninsula Crowned Snake populations within 10 km of Archbold Biological Station. Our results support the presence of at least two major phylogeographic segments for scrub reptiles on the Lake Wales Ridge and suggest that the Peninsula Crowned Snake may have a genetic population structure, even in connected habitats. [ABSTRACT FROM AUTHOR]

Whereas there are many studies of the time allocated to antipredator vigilance while animals forage, the vast majority of these studies remain correlative. This is potentially problematic because a variety of factors other than variation in perceived risk might influence putative antipredator behaviors such as time allocated to vigilance and foraging. We conducted an experimental study of yellow-bellied marmot ( Marmota flaviventris) antipredator behavior while marmots foraged at a replicated set of feeding stations established 1, 5, 10, and 20 m from their main burrows. Marmots appeared to perceive a reduced risk of predation when they foraged in the presence of other marmots; they allocated more time to foraging and decreased the time allocated to vigilance. When they foraged farther from their burrows, marmots initiated foraging after a substantially greater amount of time, tended to increase the frequency of their bouts of vigilance, and decreased the duration of each bout. Yearling marmots took less time to begin foraging than adults. Marmot flight initiation distance at our feeding trays was independent of the distance they foraged away from the burrow. Taken together, these experimental results demonstrate that marmots' perceptions of risk increased with distance to the burrow and decreased when other individuals were within 10 m of them while they foraged. [ABSTRACT FROM AUTHOR]

Animal ecologists often use animal sign as a surrogate for direct observation of organisms, especially when species are secretive or difficult to observe. Spatial heterogeneity in arid environments makes it challenging to consistently detect and precisely characterize animal sign, which can bias estimates of animal abundance or habitat use. Piute ground squirrels ( Urocitellus mollis ) and Owyhee harvester ants ( Pogonomyrmex salinus ) live in arid environments and are fossorial, which can make them difficult to observe directly. Their relative abundance can be assessed using sign (i.e., burrows and nests). We implemented an over-sampling framework (i.e., recorded an excessive amount of information) with two observers to 1) identify a sampling intensity that balanced precision with our resource constraints, and 2) assess classification and detection of squirrel burrows and ant nests across vegetation conditions. We sampled 20 1-ha plots for ground squirrel burrows and ant nests using six 4 m × 100 m belt transects. Analyses of precision and sampling effort indicated that three belt transects covering 1200 m 2 per ha provided sufficient precision, while minimizing effort. Regardless of vegetation conditions, counts by two observers were strongly correlated for ground squirrel burrows ( r = 0.99, P < 0.001, df = 18; slope = 0.92) and harvester ant nests ( r = 0.99, P < 0.001, df = 18; slope = 1.01) indicating observer consistency and perhaps high detection probability. These findings illustrate an approach for evaluating sampling designs in many ecological contexts. [ABSTRACT FROM AUTHOR]

Recent studies show Xenarthra to be even more isolated systematically from other placental mammals than traditionally thought. The group not only represents 1 of 4 primary placental clades, but proposed links to other fossorial mammal taxa (e.g., Pholidota, Palaeanodonta) have been contradicted. No unambiguous Paleocene fossil xenarthran remains are known, and Eocene remains consist almost exclusively of isolated cingulate osteoderms and isolated postcrania of uncertain systematic provenance. Cingulate skulls are unknown until the late middle Eocene, and the oldest sloth and anteater skulls are early Oligocene and early Miocene age, respectively; there are no nearly complete xenarthran skeletons until the early Miocene. Ecological reconstructions of early xenarthrans based on extant species and the paleobiology of extinct Neogene taxa suggest the group's progenitors were myrmecophagous with digging and perhaps some climbing adaptations. The earliest cingulates were terrestrial diggers and likely myrmecophagous but soon diverged into numerous omnivorous lineages. Early sloths were herbivores with a preference for forested habitats, exhibiting both digging and climbing adaptations. We attribute the rarity of early xenarthran remains to low population densities associated with myrmecophagy, lack of durable, enamel-covered teeth, and general scarcity of fossil localities from tropical latitudes of South America. The derivation of numerous omnivorous and herbivorous lineages from a myrmecophagous ancestor is a curious and unique feature of xenarthran history and may be due to the peculiar ecology of the native South American mammal fauna. Further progress in understanding early xenarthran evolution may depend on locating new Paleogene fossil sites in northern South America. [ABSTRACT FROM AUTHOR]

Vermifiltration is a new technology for treating wastewater with a high organic loading, but there is almost no published information on the biochemical and behavioral response of earthworms in a vermifilter environment. This study measured antioxidase enzyme (AOE) activities and reactive oxygen species (ROS) and malondialdehyde (MDA) levels in tissues of earthworms for a period of 56 d after transfer into simulated vermifilters. Three vermifilter media were tested. In general AOE activities, ROS and MDA were elevated for the first 3–5 d after transfer, variable for approximately the next 7 d, and statistically indistinguishable from controls after 15 d. Similarly, earthworm activity as measured by daily burrowing length was initially enhanced but converged with that of controls after 6 d. Removal of chemical oxygen demand (COD) from artificial wastewater was significantly correlated with AOE and ROS in earthworm tissues, and daily burrowing length of earthworms, but none of these parameters was correlated to NH 4 + -N removal rate, suggesting earthworms do not play a direct role in nitrogen removal in vermifilters. The data provide useful information for vermifilter operators about the biochemical adaptive process earthworms undergo when introduced to a vermifilter environment and the lag time between set up and reliable operation of a vermifilter. The results could potentially lead to development of preconditioning treatments to shorten the settling-down time for newly set up vermifilters. Maximum burrow depth was reduced in simulated vermifilters, suggesting an optimal depth for vermifilter substrates. The three vermifilter media tested differed in performance and possible reasons are briefly discussed. [ABSTRACT FROM AUTHOR]

Re-occupation of existing nesting burrows in the European bee-eater Merops apiaster has only rarely - and if so mostly anecdotically - been documented in the literature record, although such behavior would substantially save time and energy. In this study, we quantify burrow re-occupation in a German colony over a period of eleven years and identify ecological variables determining reuse probability. Of 179 recorded broods, 54% took place in a reused burrow and the overall probability that one of 75 individually recognized burrows would be reused in a given subsequent year was estimated as 26.4%. This indicates that between-year burrow reuse is a common behavior in the study colony which contrasts with findings from studies in other colonies. Furthermore, burrow re-occupation probability declined highly significantly with increasing age of the breeding wall. Statistical separation of within- and between-burrow effects of the age of the breeding wall revealed that a decline in re-occupation probability with individual burrow age was responsible for this and not a selective disappearance of burrows with high re-occupation probability over time. Limited duty cycles of individual burrows may be caused by accumulating detritus or decreasing stability with increasing burrow age. Alternatively, burrow fidelity may presuppose pair fidelity which may also explain the observed restricted burrow reuse duty cycles. A consequent next step would be to extend our within-colony approach to other colonies and compare the ecological circumstances under which bee-eaters reuse breeding burrows. [ABSTRACT FROM AUTHOR]

Phenetic and ecological plasticity in Arvicola has caused a long-standing dispute over the number of species within the genus, which is currently thought to consist of two aquatic ( sapidus, amphibius) and one fossorial species ( scherman). We used mitochondrial cytochrome b (cyt b) gene sequences to reconstruct phylogenetic relationships between the fossorial and the aquatic water voles from the various regions of their European and Asiatic range. These two types differed morphologically and exhibited allopatric ranges. Our study provided 50 new haplotypes, generating a total dataset of 70 different water vole cyt b haplotypes. Phylogenetic reconstructions retrieved two major lineages that were in a sister position to A. sapidus: a fossorial Swiss lineage and a widespread cluster, which contained aquatic and fossorial water voles from Europe and western Siberia. The phylogeographic architecture in water voles is explained by Quaternary climatic dynamics. Our results show that A. scherman in its present scope is not a monophyletic taxon. [ABSTRACT FROM AUTHOR]

The dominant hypothesis for the evolutionary origin of snakes from 'lizards' (non-snake squamates) is that stem snakes acquired many snake features while passing through a profound burrowing (fossorial) phase. To investigate this, we examined the visual pigments and their encoding opsin genes in a range of squamate reptiles, focusing on fossorial lizards and snakes. We sequenced opsin transcripts isolated from retinal cDNA and used microspectrophotometry to measure directly the spectral absorbance of the photoreceptor visual pigments in a subset of samples. In snakes, but not lizards, dedicated fossoriality (as in Scolecophidia and the alethinophidian Anilius scytale) corresponds with loss of all visual opsins other than RH1 (kmax 490- 497 nm); all other snakes (including less dedicated burrowers) also have functional sws1 and lws opsin genes. In contrast, the retinas of all lizards sampled, even highly fossorial amphisbaenians with reduced eyes, express functional lws, sws1, sws2 and rh1 genes, and most also express rh2 (i.e. they express all five of the visual opsin genes present in the ancestral vertebrate). Our evidence of visual pigment complements suggests that the visual system of stem snakes was partly reduced, with two (RH2 and SWS2) of the ancestral vertebrate visual pigments being eliminated, but that this did not extend to the extreme additional loss of SWS1 and LWS that subsequently occurred (probably independently) in highly fossorial extant scolecophidians and A. scytale. We therefore consider it unlikely that the ancestral snake was as fossorial as extant scolecophidians, whether or not the latter are para- or monophyletic. [ABSTRACT FROM AUTHOR]

Unusual behavior before earthquakes has been reported for millennia but no plausible mechanism has been identified. One possible way in which animals could be affected by pre-earthquake processes is via stress activated positive holes leading to the formation of hydrogen peroxide at the rock water interface. Aquatic and fossorial animals could be irritated by H2O2 and move down the concentration gradient. Here, we carry out avoidance tests with hydrogen peroxide in two model organisms; Daphnia pulex and earthworms. Daphnia were found to move away from increasing concentrations of H2O2 but earthworms appeared unaffected. It is possible that earthworm swarming behavior, reported frequently before earthquakes, is caused by electric field shifts or another unknown mechanism, whereas zooplankton may be affected by increasing levels of H2O2. [ABSTRACT FROM AUTHOR]