Dynamics of digging in wet soil

Numerous animals live in, and locomote through, subsea soils. To move in a medium dominated by frictional interactions, many of these animals have adopted unique burrowing strategies. This paper presents a burrowing model inspired by the Atlantic razor clam ({\it Ensis directus}), which uses deformations of its body to cyclically loosen and re-pack the surrounding soil in order to locally manipulate burrowing drag. The model reveals how an anisotropic body -- composed of a cylinder and sphere varying sinusoidally in size and relative displacement -- achieves unidirectional motion through a medium with variable frictional properties. This net displacement is attained even though the body kinematics are reciprocal and inertia of both the model organism and the surrounding medium are negligible. Our results indicate that body aspect ratio has a strong effect on burrowing velocity and efficiency, with a well-defined maximum for given kinematics and soil material properties

Anisotropy driven ultrafast nanocluster burrowing

We explore the occurrence of low-energy and low-temperature transient cluster burrowing leading to intact cluster inclusions. In particular, the anomalously fast (ballistic) Pt nanocluster implantation into Al and Ti substrates has been found by molecular dynamics simulations using a tight-binding many-body potential with the 1-5 eV/atom low impact energy. Similar behavior has also been found for many other cluster/substrate couples such as Cu/Al and Ni/Ti, Co/Ti, etc. In particular, in Ni/Ti at already $\sim 0.5$ eV/atom impact energy burrowing takes place. At this few eV/atom low impact energy regime instead of the expected stopping at the surface we find the propagation of the cluster through a thin Al slab as thick as $\sim 50$ $\hbox{\AA}$ with a nearly constant speed ($\propto 1$ eV/atom). Hence the cluster moves far beyond the range of the impact energy which suggests that the mechanism of cluster burrowing can not be explained simply by collisional cascade effects. In the couples with reversed succession (e.g. Ti/Pt, Al/Pt) no burrowing has been found, the clusters remain on the surface (the asymmetry of burrowing). We argue that cluster penetration occurs at few eV/atom impact energy when the cluster/substrate interaction is size-mismatched and mass anisotropic atomically.Comment: 9 pages, 5 figures. submitted to Phys. Rev. B, preprint: http://www.mfa.kfki.hu/~sule/papers/cluster.pd

Burrowing apparatus

A soil burrowing mole is described in which a housing has an auger blade wound around a front portion. This portion is rotatable about a housing longitudinal axis relative to an externally finned housing rear portion upon operation of driving means to cause an advance through soil and the like. The housing carries a sensor sensitive to deviation from a predetermined path and to which is coupled means for steering the housing to maintain the path

An Annotated Checklist of the Crayfishes (Decapoda: Cambaridae) of Arkansas

Prior to the present study, 56 species with 3 additional subspecies for a total of 59 different taxa of crayfishes were recognized from Arkansas. We add a single species (Carmel Crayfish, Fallicambarus schusteri) to that list, subtract a documented synonym (Procambarus ferrugenius = Procambarus liberorum), update the classification to better reflect recent phylogenetic insights, and provide an updated annotated checklist of the 59 crayfish taxa of presently known from the state. There are 8 endemic species in Arkansas, including the Bayou Bodcau Crayfish (Bouchardina robisoni), Boston Mountains Crayfish (Cambarus causeyi), Hell Creek Cave Crayfish (C. zophonastes), Jefferson County Crayfish (Creaserinus gilpini), Ouachita Burrowing Crayfish (Fallicambarus harpi), Slenderwrist Burrowing Crayfish (F. petilicarpus), Saline Burrowing Crayfish (F. strawni), and Redspotted Stream Crayfish (Faxonius acares). There are also 2 federally endangered species, the Benton County Cave Crayfish (Cambarus aculabrum) and the Hell Creek Cave Crayfish (C. zophonastes) that inhabit Arkansas karst habitat. We expect that additional species will be included in the list with further DNA analyses

Nidificación inusual del Loro Barranquero (Cyanoliseus patagonus) en cavidades naturales de árboles

The Burrowing Parrot Cyanoliseus patagonus is known to breed in burrows mostly on cliffs and ravines in arid or semi‐arid regions of Argentina and Chile. However, during a tree cavity monitoring project we confirmed at least two active nests in tree cavities. Cavity entrances were located between 3.1 and 5.3 m above the ground in live caldén (Prosopis caldenia) trees, Parque Luro, province of La Pampa, Argentina. One nest failed while the other one successfully produced three fledglings. The absence of cliffs and scarcity of ravines in the region, and the presence of a nesting colony of the Blue‐crowned Parakeet (Thectocercus acuticaudatus) in the site may have promoted the adop‐ tion of this new nesting substrate for the species.El Loro Barranquero (Cyanoliseus patagonus) nidifica mayoritariamente en cavidades en barrancos y acantilados en regiones áridas y semiáridas de Argentina y Chile. Sin embargo, durante un proyecto de monitoreo de cavidades en árboles, confirmamos al menos dos nidos activos de Loro Barranquero. La entrada de las cavidades estuvo localizada entre 3.1 y 5.3 m de altura en árboles vivos de caldén (Prosopis caldenia), en Parque Luro, provincia de La Pampa, Argentina. Un nido fracasó mientras que el otro tuvo éxito produciendo tres volantones. La escasez de barrancos y la presencia de una colonia de nidificación de Calancate Común (Thectocercus acuticaudatus) en el sitio, podrían haber favorecido la adopción de este nuevo sustrato de nidificación para la especie.Fil: López, Fernando Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencia Exactas y Naturales. Departamento de Recursos Naturales. Centro para el Estudio y Conservación de Aves Rapaces; ArgentinaFil: Grande, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencia Exactas y Naturales. Departamento de Recursos Naturales. Centro para el Estudio y Conservación de Aves Rapaces; ArgentinaFil: Berkunsky, Igor. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto Multidisciplinario de Ecosistemas y Desarrollo Sustentable; ArgentinaFil: Santillán, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo de Historia Natural de La Pampa; ArgentinaFil: Rebollo, María Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencia Exactas y Naturales. Departamento de Recursos Naturales. Centro para el Estudio y Conservación de Aves Rapaces; Argentin

The Return of \u3ci\u3eHexagenia\u3c/i\u3e (Ephemeroptera: Ephemeridae) to the Lower Fox River, Wisconsin

Burrowing mayflies (Hexagenia bilineata) were collected in 1991 in the vicinity of the DePere dam on the Fox River, Brown County, Wisconsin. Because Hexagenia mayflies are indicators of good water quality, their emergence from the Fox River is evidence of improvement in conditions at the sediment-water interface

Basic Research Tools for Earthworm Ecology

Earthworms are responsible for soil development, recycling organic matter and form a vital component within many food webs. For these and other reasons earthworms are worthy of investigation. Many technologically-enhanced approaches have been used within earthworm-focused research. These have their place, may be a development of existing practices or bring techniques from other fields. Nevertheless, let us not overlook the fact that much can still be learned through utilisation of more basic approaches which have been used for some time. New does not always equate to better. Information on community composition within an area and specific population densities can be learned using simple collection techniques, and burrowing behaviour can be determined from pits, resin-insertion or simple mesocosms. Life history studies can be achieved through maintenance of relatively simple cultures. Behavioural observations can be undertaken by direct observation or with low cost webcam usage. Applied aspects of earthworm research can also be achieved through use of simple techniques to enhance population development and even population dynamics can be directly addressed with use of relatively inexpensive, effective marking techniques. This paper seeks to demonstrate that good quality research in this sphere can result from appropriate application of relatively simple research tools