Are Purple Hermit Crabs (Coenobita brevimanus) Seed Dispersers or Predators?

Vertebrate frugivores play an important role in forests by dispersing seeds and helping improve germination through gut passage. Some frugivores may also be seed predators, where the seed is destroyed through gut passage. On the island of Saipan, the native frugivores are birds, bats, and crabs. This experiment focused on purple hermit crabs, Coenobita brevimanus, which are known to consume fruits, but it is unknown whether purple hermit crabs disperse or predate the seeds they consume. A maximum of ten purple hermit crabs, ranging in size from medium to large individuals, were captured from the forest and kept in captivity. In captivity, they were fed native fruits including Premna (Premna mariannarum or Premna paulobarbata), Ficus (Ficus prolixa), Aglaia (Lansium parasiticum), and Guamia (Guamia mariannae) and non-native fruits including papaya (Carica papaya) collected in the wild. The cage was inspected to see if fruits were consumed but the seeds were not ingested, and the fecal matter was searched for damaged seeds (crushed or in pieces) or undamaged seeds (whole or intact). Analysis of predation or dispersal was done using logistic regression. It was hypothesized that purple hermit crabs are beneficial seed dispersers, passing most seeds unharmed for both native and non-native fruiting tree species. As beneficial frugivores, purple hermit crabs could play a significant role in dispersing seeds in the forests of Saipan

Countersong: Rising or Falling

A recording, analysis and poetic translation of countersong between two Hermit thrushes (Catharus guttatis) recorded in the mountains of Northern New Mexico (United States) on 19 July 2015

A Hermit in Suburbia

Solo exhibition. This exhibition included paintings, animations and drawings and was part of a long-term enquiry into the ways in the largely Western and urban-based population perceive and encounter the natural world. This show focused on the ornamental hermit, a curious invention of the English Landscape Garden tradition. These were not real hermits, but were employed to live within large estates to provide human subjects for their picturesque grounds, for the amusement of the owner and guests alike. The hermits in this exhibition have been redeployed to the contemporary British suburbs asking the viewer to think anew about our relationship with nature in these ‘hybridised spaces’ whilst considering ideas about the wilderness, retreat and solitude

Towards Understanding Reasoning Complexity in Practice

Although the computational complexity of the logic underlying the standard OWL 2 for the Web Ontology Language (OWL) appears discouraging for real applications, several contributions have shown that reasoning with OWL ontologies is feasible in practice. It turns out that reasoning in practice is often far less complex than is suggested by the established theoretical complexity bound, which reflects the worstcase scenario. State-of-the reasoners like FACT++, HERMIT, PELLET and RACER have demonstrated that, even with fairly expressive fragments of OWL 2, acceptable performances can be achieved. However, it is still not well understood why reasoning is feasible in practice and it is rather unclear how to study this problem. In this paper, we suggest first steps that in our opinion could lead to a better understanding of practical complexity. We also provide and discuss some initial empirical results with HERMIT on prominent ontologie

Feeding behaviour of fifteen species of hermit crabs (Crustacea : Decapoda : Anomura) from the Otago region, southeastern New Zealand

Hermit crabs are common and conspicuous; members of intertidal and subtidal habitats. Although there exists an extensive literature on their behaviour, in the main this deals with :shell related behaviour :such as shell selection and shell fighting, and with behaviour patterns associated with the various symbiotic relationships of which hermit crabs form part (see the extensive bibliography in the recent review of hermit crab behavioural ecoloKv by Hazlett 1981). Other aspects of their behaviour have received much less attention . A number of studies on hermit. crab tee(ling behaviour have been made. However, relative to the number of living species (estimated at '" 700, Alcock 1905, Gordan 1956) very few have been investigated. Moreover, those species which have been studied to date all belong to genera of only two out of six families of marine hermit crabs (the Diogenidae and the Paguridae), and are intertidal or shallow water species. The feeding behadour of hermit crabs belonging to less well known families or genera or from less accessible habitats has not been studied. Nonetheless the available'data are sufficient to show that these animals have a wide range of feeding mechanisms including deposit-feeding, suspension-feeding, predation and scavenging. Often a species is able to feed in different ways depending on what food is available at the time (Kunze and Anderwn 1979, Schembri, 1982). Given such complexity of behaviour: (1 larger cross-section of species from a wider taxonomic range and from more diverse habitats needs to be investigated before evolutionary trends and adaptive radiation within the group can be studied. Sixteen species of hermit crabs belonging to four families are known to occur in the Otago region (table I; the late E. J. Batham unpublished data, C. L. ;McLay), personal communication) in habitats ranging from rocky intertidal through relatively coarse sediments of various sorts on the continental shelf to finer sediment:; on the continental shelf edge and slope. This rich fauna presented an ideal opportunity to study feeding in hermit crabs from a variety of taxonomic grouping and habitat types. Here the feeding behaviour and feeding mechanisms of 15 species of Otago hermit crabs are described and discussed in relation to their morphology habitat and previous work on feeding in hermit crabs.peer-reviewe

How Stochastic is the Relative Bias Between Galaxy Types?

Examining the nature of the relative clustering of different galaxy types can help tell us how galaxies formed. To measure this relative clustering, I perform a joint counts-in-cells analysis of galaxies of different spectral types in the Las Campanas Redshift Survey (LCRS). I develop a maximum-likelihood technique to fit for the relationship between the density fields of early- and late-type galaxies. This technique can directly measure nonlinearity and stochasticity in the biasing relation. At high significance, a small amount of stochasticity is measured, corresponding to a correlation coefficient of about 0.87 on scales corresponding to 15 Mpc/h spheres. A large proportion of this signal appears to derive from errors in the selection function, and a more realistic estimate finds a correlation coefficient of about 0.95. These selection function errors probably account for the large stochasticity measured by Tegmark & Bromley (1999), and may have affected measurements of very large-scale structure in the LCRS. Analysis of the data and of mock catalogs shows that the peculiar geometry, variable flux limits, and central surface-brightness selection effects of the LCRS do not seem to cause the effect.Comment: 38 pages, 14 figures. Submitted to Apj. Modified from a chapter of my Ph.D. Thesis at Princeton University, available at http://www-astro-theory.fnal.gov/Personal/blanton/thesis/index.htm

Distribution Pattern and Abundance of the Marine Hermit Crabs Population in Sindangkerta Beach of Cipatujah District, Tasikmalaya Regency

The research has been conducted on April 2016. It aims to obtain the quantitative information concerning the distribution pattern and abundance of the Marine Hermit Crabs population. The applied research method is the descriptive method with the research design of belt transect and the hand sorting as the applied sampling technique. Sampling was carried out at the Littoral Zone at 6 stations with 5 plot squared for each station. The applied area of plot squared is 1 x 1 m. The taken data are the data of hermit crabs and the supporting data of environment. Data analysis includes the distribution pattern and abundance of the Marine Hermit Crabs population. Marine Hermit Crabs determination is carried out in the Research Center Laboratory of the Oceanography Indonesian Institute of Science Jakarta. Determination result obtains the 50 individuals of Marine Hermit Crabs consist of one family and 9 species, namely Aniculus erythraeus, Calcinus morgani, Calcinus laevimanus, Clibanarius corallinus, Clibanarius humilis, Clibanarius mergueinisis, Clibanarius striolatus, Clibanarius virescens, and Dardanus megistos. Research result shows that the abundance of the Marine Hermit Crabs population ranges of 1 ind/m2 – 2 ind/m2. In general the abundance analysis shows the low level of abundance. Morishita index shows the distribution pattern of Marine Hermit Crabs in Sindangkerta Beach includes the category of clustering (Id > 1) and uniform (Id < 1)