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Hüttelmaier, Stefan, Susanne Illenberger, Irina Grosheva, Manfred Rüdiger, Robert H. Singer, and Brigitte M. Jockusch. "Raver1, a dual compartment protein, is a ligand for PTB/hnRNPI and microfilament attachment proteins." Journal of Cell Biology 155, no. 5 (November 26, 2001): 775–86. http://dx.doi.org/10.1083/jcb.200105044.
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By screening a yeast two-hybrid library with COOH-terminal fragments of vinculin/metavinculin as the bait, we identified a new protein termed raver1. Raver1 is an 80-kD multidomain protein and widely expressed but to varying amounts in different cell lines. In situ and in vitro, raver1 forms complexes with the microfilament-associated proteins vinculin, metavinculin, and α-actinin and colocalizes with vinculin/metavinculin and α-actinin at microfilament attachment sites, such as cell–cell and cell matrix contacts of epithelial cells and fibroblasts, respectively, and in costameres of skeletal muscle. The NH2-terminal part of raver1 contains three RNA recognition motifs with homology to members of the heterogeneous nuclear RNP (hnRNP) family. Raver1 colocalizes with polypyrimidine tract binding protein (PTB)/hnRNPI, a protein involved in RNA splicing of microfilament proteins, in the perinucleolar compartment and forms complexes with PTB/hnRNPI. Hence, raver1 is a dual compartment protein, which is consistent with the presence of nuclear location signal and nuclear export sequence motifs in its sequence. During muscle differentiation, raver1 migrates from the nucleus to the costamere. We propose that raver1 may coordinate RNA processing and targeting as required for microfilament anchoring in specific adhesion sites.
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Rangarajan, Erumbi S., Jun Hyuck Lee, and Tina Izard. "Apo raver1 structure reveals distinct RRM domain orientations." Protein Science 20, no. 8 (June 17, 2011): 1464–70. http://dx.doi.org/10.1002/pro.664.
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Gromak, N. "The PTB interacting protein raver1 regulates -tropomyosin alternative splicing." EMBO Journal 22, no. 23 (December 1, 2003): 6356–64. http://dx.doi.org/10.1093/emboj/cdg609.
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Zieseniss, Anke, Ulrich Schroeder, Sabine Buchmeier, Cora-Ann Schoenenberger, Joop van den Heuvel, Brigitte M. Jockusch, and Susanne Illenberger. "Raver1 is an integral component of muscle contractile elements." Cell and Tissue Research 327, no. 3 (November 10, 2006): 583–94. http://dx.doi.org/10.1007/s00441-006-0322-1.
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Fink-Baldauf, Iris M., William D. Stuart, John J. Brewington, Minzhe Guo, and Yutaka Maeda. "CRISPRi links COVID-19 GWAS loci to LZTFL1 and RAVER1." eBioMedicine 75 (January 2022): 103806. http://dx.doi.org/10.1016/j.ebiom.2021.103806.
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Lahmann, Ines, Manuela Fabienke, Berenike Henneberg, Oliver Pabst, Franz Vauti, Daniel Minge, Susanne Illenberger, Brigitte M. Jockusch, Martin Korte, and Hans-Henning Arnold. "The hnRNP and cytoskeletal protein raver1 contributes to synaptic plasticity." Experimental Cell Research 314, no. 5 (March 2008): 1048–60. http://dx.doi.org/10.1016/j.yexcr.2007.10.022.
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Chen, He, Ying Li, Jing Zhang, Yong Ran, Jin Wei, Yan Yang, and Hong-Bing Shu. "RAVER1 is a coactivator of MDA5-mediated cellular antiviral response." Journal of Molecular Cell Biology 5, no. 2 (February 5, 2013): 111–19. http://dx.doi.org/10.1093/jmcb/mjt006.
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Jockusch, Brigitte M., Stefan Hüttelmaier, and Susanne Illenberger. "From the Nucleus Toward the Cell Periphery: a Guided Tour for mRNAs." Physiology 18, no. 1 (February 2003): 7–11. http://dx.doi.org/10.1152/nips.01413.2002.
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RNA processing, directed transport along cytoskeletal tracks, and site-specific translation of mRNA at the cell periphery are considered discrete steps in the generation of microfilament-membrane adhesion complexes. A recently identified member of the heterogeneous nuclear ribonucleoprotein family, raver1, may couple these steps and contribute to the assembly and maintenance of these structures.
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Romanelli, Maria Grazia, Pamela Lorenzi, Francesca Avesani, and Carlo Morandi. "Functional characterization of the ribonucleoprotein, PTB-binding 1/Raver1 promoter region." Gene 405, no. 1-2 (December 2007): 79–87. http://dx.doi.org/10.1016/j.gene.2007.09.004.
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Lee, Jun Hyuck, Erumbi S. Rangarajan, Clemens Vonrhein, Gerard Bricogne, and Tina Izard. "The Metavinculin Tail Domain Directs Constitutive Interactions with Raver1 and vinculin RNA." Journal of Molecular Biology 422, no. 5 (October 2012): 697–704. http://dx.doi.org/10.1016/j.jmb.2012.06.015.
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Adamia, Sophia, Zuzana Chyra, Morgan O'Keefe, Shruti Bhatt, Kenneth Wen, Geoffrey G. Fell, Yu-Tzu Tai, et al. "Identification of Novel Targets Based on Splicing Alterations for Undruggable RAS/CDK Signaling Cascade in Multiple Myeloma." Blood 138, Supplement 1 (November 5, 2021): 2688. http://dx.doi.org/10.1182/blood-2021-152986.
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Abstract Background: RAS/CDK-dependent pathways play essential roles in multiple myeloma (MM) pathogenesis. Targeting these pathways represents a novel therapeutic strategy in MM. Our ongoing studies (>420 patients) demonstrate that aberrantly spliced transcript expressions can predict MM patient survival outcomes better than gene expression alone, indicating a significant role of splicing mechanism in MM pathophysiology. These studies also identified intron retentions as the predominant recurrent alterations (~32% of spliced genes were retained introns) in MM. We evaluated splicing alterations associated with pathway-level responses after RAS/CDK inhibition in order to identify and validate novel molecular targets. Methods/results: MM cells were treated with selected Erk1/2 and CDK4/6 inhibitors (Ei, Ci) to inhibit RAS and CDK pathways. Our studies demonstrated strong synergistic (IC<0.5) MM cytotoxicity triggered by this combination treatment, which triggered dose-dependent manner G0/G1 phase growth arrest. We assessed early death cascade in MM cells after Ei+Ci treatment, and demonstrated significant priming to selective peptides BIM, BAD, and MS1 or HRK, suggesting dependency on BCL2 and MCL1 or on BCL-XL proteins. Our studies showed that Ei+Ci treatment induced inhibition of key target molecules in Erk1/2 and CDK4/6 signaling including c-myc, p-RSK, p-S6, p-RB, and E2F1, suggesting on-target activity of Ei and Ci. Patient MM cells co-cultured with or without autologous BM stromal cells remain equally sensitive to Ei+Ci, suggesting that this combination can overcome the protective effects of the MM BM milieu. Moreover, our in vivo study demonstrated a significant (P=0.0004) MM burden decrease in Ei+Ci-treated mice. We evaluated the effect of Ei+Ci treatment on target gene expression in BM cells isolated from flushed femurs of treated animals with Ei, Ci or Ei+Ci, and observed downregulation of Erk1/2-CDK4/6-dependent gene signature. Therefore, we suggest that these inhibitors selectively target Erk1/2, CDK4/6 and their downstream substrates both in vitro/vivo. We next evaluated aberrantly spliced transcript expression in MM cells, with/without Erk1/2 knockdown (KD) or with Ei+Ci treatment. Unsupervised clustering of deregulated genes showed dose-dependent treatment effects. This observation was further supported by principal component analyses: upregulation in response to Erk1/2 KD and downregulation due to treatment with Ei+Ci were considered spliced gene-signatures linked to RAS/CDK modulation. Gene/pathway enrichment analyses of these genes showed their involvement in cell proliferation and regulation of epigenetic networks in MM. Importantly, these analyses suggest that overexpression of RAVER1/SNRPB core splicing regulator genes are associated with RAS/CDK pathway regulation. These genes encode subunits of U1/2/4/5 spliceosome complex and are involved in intron retention processes, a marker of malignant transformation. We compared signature-gene expressions from 558 MM patient samples to the signature-genes in plasma cells from normal donors and observed significant (p<2e-11) upregulation of genes with progression from MGUS to sMM, and, also to overt MM . SNRPB overexpression is associated with shorter overall patient survival (p<0.01), while RAVER1 is linked with poor outcomes. SNRPB proteins are also overexpressed in MM cells. Our studies evaluating SNRPB effects on RNA splicing showed both upregulation of transcripts with full intron retention and transcripts with cryptic stop codons utilizing intronic sequences causing their partial retention. We evaluated RAVER1 and SNRPB expression in BM cells from animals treated with Ei and Ci alone or in combination. We observed significant downregulation of RAVER1/SNRPB (p=0.001) in BM samples obtained from animals treated with Ei+Ci. We observed decreased intron retention events in genes in treated samples, consistent with our in vitro analyses in MM cell lines and patient samples. Thus, RAVER1/SNRPB overexpression contributes to the aberrant transcriptome splicing associated with RAS/CDK cascade in MM. Conclusions: Our studies 1) show an association between RNA processing and RAS-CDK pathways in MM, 2) identify a core splicing protein, SNRPB/RAVER1, as a novel target for modulating this cascade, and 3) suggest that targeting spliceosome complexes represents a promising therapy in MM. Disclosures Letai: Zentalis Pharmaceuticals: Other: equity holding member of the scientific advisory board; Dialectic Therapeutics: Other: equity holding member of the scientific advisory board; Flash Therapeutics: Other: equity holding member of the scientific advisory board. Anderson: Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Millenium-Takeda: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Sanofi-Aventis: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Scientific Founder of Oncopep and C4 Therapeutics: Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Mana Therapeutics: Membership on an entity's Board of Directors or advisory committees.
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Spellman, R., A. Rideau, A. Matlin, C. Gooding, F. Robinson, N. McGlincy, S. N. Grellscheid, J. Southby, M. Wollerton, and C. W. J. Smith. "Regulation of alternative splicing by PTB and associated factors." Biochemical Society Transactions 33, no. 3 (June 1, 2005): 457–60. http://dx.doi.org/10.1042/bst0330457.
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PTB (polypyrimidine tract-binding protein) is a repressive regulator of alternative splicing. We have investigated the role of PTB in three model alternative splicing systems. In the α-actinin gene, PTB represses the SM (smooth muscle) exon by binding to key sites in the polypyrimidine tract. Repressive binding to these sites is assisted by co-operative binding to additional downstream sites. SM exon splicing can be activated by CELF proteins, which also bind co-operatively to interspersed sites and displace PTB from the pyrimidine tract. Exon 11 of PTB pre-mRNA is repressed by PTB in an autoregulatory feedback loop. Exon 11-skipped RNA gets degraded through nonsense-mediated decay. Less than 1% of steady-state PTB mRNA is represented by this isoform, but inhibition of nonsense-mediated decay by RNA interference against Upf1 shows that at least 20% of PTB RNA is consumed by this pathway. This represents a widespread but under-appreciated role of alternative splicing in the quantitative regulation of gene expression, an important addition to its role as a generator of protein isoform diversity. Repression of α-tropomyosin exon 3 is an exceptional example of PTB regulation, because repression only occurs at high levels in SM cells, despite the fact that PTB is widely expressed. In this case, a PTB-interacting cofactor, raver1, appears to play an important role. By the use of ‘tethering’ assays, we have identified discrete domains within both PTB and raver1 that mediate their repressive activities on this splicing event.
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Coelho, Miguel B., David B. Ascher, Clare Gooding, Emma Lang, Hannah Maude, David Turner, Miriam Llorian, Douglas E. V. Pires, Jan Attig, and Christopher W. J. Smith. "Functional interactions between polypyrimidine tract binding protein and PRI peptide ligand containing proteins." Biochemical Society Transactions 44, no. 4 (August 15, 2016): 1058–65. http://dx.doi.org/10.1042/bst20160080.
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Polypyrimidine tract binding protein (PTBP1) is a heterogeneous nuclear ribonucleoprotein (hnRNP) that plays roles in most stages of the life-cycle of pre-mRNA and mRNAs in the nucleus and cytoplasm. PTBP1 has four RNA binding domains of the RNA recognition motif (RRM) family, each of which can bind to pyrimidine motifs. In addition, RRM2 can interact via its dorsal surface with proteins containing short peptide ligands known as PTB RRM2 interacting (PRI) motifs, originally found in the protein Raver1. Here we review our recent progress in understanding the interactions of PTB with RNA and with various proteins containing PRI ligands.
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Rideau, Alexis P., Clare Gooding, Peter J. Simpson, Tom P. Monie, Mike Lorenz, Stefan Hüttelmaier, Robert H. Singer, Stephen Matthews, Stephen Curry, and Christopher W. J. Smith. "A peptide motif in Raver1 mediates splicing repression by interaction with the PTB RRM2 domain." Nature Structural & Molecular Biology 13, no. 9 (August 27, 2006): 839–48. http://dx.doi.org/10.1038/nsmb1137.
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Joshi, Amar, Miguel B. Coelho, Olga Kotik-Kogan, Peter J. Simpson, Stephen J. Matthews, Christopher W. J. Smith, and Stephen Curry. "Crystallographic Analysis of Polypyrimidine Tract-Binding Protein-Raver1 Interactions Involved in Regulation of Alternative Splicing." Structure 19, no. 12 (December 2011): 1816–25. http://dx.doi.org/10.1016/j.str.2011.09.020.
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Lee, Jun Hyuck, Erumbi S. Rangarajan, S. D. Yogesha, and Tina Izard. "Raver1 Interactions with Vinculin and RNA Suggest a Feed-Forward Pathway in Directing mRNA to Focal Adhesions." Structure 17, no. 6 (June 2009): 833–42. http://dx.doi.org/10.1016/j.str.2009.04.010.
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Sayan, Erdinç. "A MORE DEVASTATING VERSION OF THE RAVEN PARADOX." Think 19, no. 54 (December 11, 2019): 21–24. http://dx.doi.org/10.1017/s1477175619000356.
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Hempel's famous Raven Paradox derives from Nicod's criteria for confirmation and the Equivalence Condition, the unintuitive conclusion that things like white roses, green T-shirts and ice cubes confirm the raven hypothesis ‘All ravens are black.’ By a small rearrangement of the Equivalence Condition, I show that we can also derive the conclusion, which sounds even more intuitively intolerable, that observation of black ravens fails to confirm the raven hypothesis. We are left with the contradictory result that black ravens both confirm and do not confirm the raven hypothesis.
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Kafasla, Panagiota, Ian Mickleburgh, Miriam Llorian, Miguel Coelho, Clare Gooding, Dmitry Cherny, Amar Joshi, et al. "Defining the roles and interactions of PTB." Biochemical Society Transactions 40, no. 4 (July 20, 2012): 815–20. http://dx.doi.org/10.1042/bst20120044.
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PTB (polypyrimidine tract-binding protein) is an abundant and widely expressed RNA-binding protein with four RRM (RNA recognition motif) domains. PTB is involved in numerous post-transcriptional steps in gene expression in both the nucleus and cytoplasm, but has been best characterized as a regulatory repressor of some ASEs (alternative splicing events), and as an activator of translation driven by IRESs (internal ribosome entry segments). We have used a variety of approaches to characterize the activities of PTB and its molecular interactions with RNA substrates and protein partners. Using splice-sensitive microarrays we found that PTB acts not only as a splicing repressor but also as an activator, and that these two activities are determined by the location at which PTB binds relative to target exons. We have identified minimal splicing repressor and activator domains, and have determined high resolution structures of the second RRM domain of PTB binding to peptide motifs from the co-repressor protein Raver1. Using single-molecule techniques we have determined the stoichiometry of PTB binding to a regulated splicing substrate in whole nuclear extracts. Finally, we have used tethered hydroxyl radical probing to determine the locations on viral IRESs at which each of the four RRM domains bind. We are now combining tethered probing with single molecule analyses to gain a detailed understanding of how PTB interacts with pre-mRNA substrates to effect either repression or activation of splicing.
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Zawadzka, Dorota, and Grzegorz Zawadzki. "Synanthropisation And Synurbisation Of Raven Corvus Corax In Poland: A Review." International Studies on Sparrows 38, no. 1 (December 1, 2014): 11–16. http://dx.doi.org/10.1515/isspar-2015-0025.
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Abstract The Raven Corvus corax is one of the oldest synanthropic bird species. Historical development of human settlements and cities was the reason of occupancy by ravens neighborhood of villages and town. Nowadays, suburban areas are, among forest and rural areas, habitats used by Ravens. Since end of middle ages Ravens began breeding in interior of towns in the Great Britain. During 20th century Raven occupied several big cities of Europe and North America. In Poland, the first attempts of colonization of cities took place in the 1950s in Warsaw and Kraków. During next decades Raven came back from centrum of cities and began colonized suburban zone, mainly big forests within the border of towns. Untilnow, Raven in Poland nest only in suburban zones. Observations of non-breeding pairs inside of cities are still rare. The biggest population in cities do not exceed 20 breeding pairs.
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Howe, Kristy B., and Peter S. Coates. "Observations of Territorial Breeding Common Ravens Caching Eggs of Greater Sage-Grouse." Journal of Fish and Wildlife Management 6, no. 1 (June 1, 2015): 187–90. http://dx.doi.org/10.3996/042014-jfwm-030.
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AbstractPrevious investigations using continuous video monitoring of greater sage-grouse Centrocercus urophasianus nests have unambiguously identified common ravens Corvus corax as an important egg predator within the western United States. The quantity of greater sage-grouse eggs an individual common raven consumes during the nesting period and the extent to which common ravens actively hunt greater sage-grouse nests are largely unknown. However, some evidence suggests that territorial breeding common ravens, rather than nonbreeding transients, are most likely responsible for nest depredations. We describe greater sage-grouse egg depredation observations obtained opportunistically from three common raven nests located in Idaho and Nevada where depredated greater sage-grouse eggs were found at or in the immediate vicinity of the nest site, including the caching of eggs in nearby rock crevices. We opportunistically monitored these nests by counting and removing depredated eggs and shell fragments from the nest sites during each visit to determine the extent to which the common raven pairs preyed on greater sage-grouse eggs. To our knowledge, our observations represent the first evidence that breeding, territorial pairs of common ravens cache greater sage-grouse eggs and are capable of depredating multiple greater sage-grouse nests.
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Chlumsky, Robert, James R. Craig, Simon G. M. Lin, Sarah Grass, Leland Scantlebury, Genevieve Brown, and Rezgar Arabzadeh. "RavenR v2.1.4: an open-source R package to support flexible hydrologic modelling." Geoscientific Model Development 15, no. 18 (September 16, 2022): 7017–30. http://dx.doi.org/10.5194/gmd-15-7017-2022.
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Abstract. In recent decades, advances in the flexibility and complexity of hydrologic models have enhanced their utility in scientific studies and practice alike. However, the increasing complexity of these tools leads to a number of challenges, including steep learning curves for new users and issues regarding the reproducibility of modelling studies. Here, we present the RavenR package, an R package that leverages the power of scripting to both enhance the usability of the Raven hydrologic modelling framework and provide complementary analyses that are useful for modellers. The RavenR package contains functions that may be useful in each step of the model-building process, particularly for preparing input files and analyzing model outputs. The utility of the RavenR package is demonstrated with the presentation of six use cases for a model of the Liard River basin in Canada. These use cases provide examples of visually reviewing the model configuration, preparing input files for observation and forcing data, simplifying the model discretization, performing realism checks on the model output, and evaluating the performance of the model. All of the use cases are fully reproducible, with additional reproducible examples of RavenR functions included with the package distribution itself. It is anticipated that the RavenR package will continue to evolve with the Raven project and will provide a useful tool to new and experienced users of Raven alike.
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Vancatova, M. A., and T. Klima. "The spontaneous tool use by raven in a zoo." Experimental Psychology (Russia) 12, no. 3 (2019): 135–41. http://dx.doi.org/10.17759/exppsy.2019120310.
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Ravens are known for their ability to use tools, both in captivity and in natural conditions. This activity is connected mainly to nourishment-related or aggressive behaviour. At Košice Zoo, we carried out an observation of raven tool use behaviour, with the observation focused on contact with a human, that can be interpreted as social behaviour within the context of interspecies communication. In all observed cases (54) of raven tool use, this type of behaviour only manifested itself in an adult male. The raven was inclined to mostly choose longer tools for an attack. In roughly the same measure, the raven uses a new tool, or uses the same tool repeatedly. Concerning the working of the tool, a tool that has not been worked on predominates significantly in this case. In the case of working the tool, the male raven nibbles or shortens the sticks with his beak. A human in and of himself does not represent danger to ravens in a zoo, because the birds are in daily contact with zookeepers. In the given situation, it seems that male raven was aiming to establish contact with a visitor. The entire situation is more reminiscent of a game, rather than the protection of the nest. The whole situation of using the tool was spontaneous and in no case was prepared in advance or otherwise induced experimentally.
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Segura, Amalia, and Pelayo Acevedo. "Influence of Habitat and Food Resource Availability on Common Raven Nest Site Selection and Reproductive Success in Mediterranean Forests." Birds 2, no. 3 (September 9, 2021): 302–13. http://dx.doi.org/10.3390/birds2030022.
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Bird nest selection in forests can be influenced by the composition of key structural elements and resources. This has important consequences in terms of species population dynamics since it can determine reproduction success. Here, we assessed Common raven nest-site selection and reproductive success, and how these might be determined by foraging behavior and habitat structure. A previously documented breeding raven population that exerts high predation pressure on young Spur-thighed tortoises (Testudo graeca) in a Mediterranean forest was monitored. Generalized linear mixed models were performed to determine the singularities of the trees with nests and the drivers of reproductive success of breeding pairs of ravens. The results showed a high density of breeding pairs in the study area (0.8 pairs/km2), which selected taller trees in areas with higher bare ground cover and a high density of tortoises for nesting. Nests were spatially aggregated; breeding pairs occupied smaller territories and intraspecific competition seemed relaxed, reflecting the abundance of food resources. Most breeding pairs occasionally predated on young tortoises. Tortoises seem to play a part in raven reproductive success in our study area, which might be associated with the availability/catchability of young tortoises. The study illustrates that Spur-thighed tortoise distribution and abundance plays a role in the breeding behavior of ravens and is mediated by habitat structure. Understanding the drivers of nest-site selection and the breeding behavior of ravens is pivotal to implementing appropriate habitat management and conservation strategies across their distribution range, particularly in areas where ravens potentially affect threatened species.
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Lill, Alan, and Emma Hales. "Behavioural and Ecological Keys to Urban Colonization by Little Ravens ()." Open Ornithology Journal 8, no. 1 (May 29, 2015): 22–31. http://dx.doi.org/10.2174/1874453201508010022.
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Avian urban colonization is thought to be facilitated by a capacity for innovative feeding, ecological generalism and social foraging. However, the relative importance in exploiting urban resources and avoiding urban predators of being inherently ‘pre-adapted’ to the urban environment or adjusting to it through phenotypic plasticity requires more examination. These issues were explored in a native ‘urban adapter’, the Little raven Corvus mellori, by comparing its foraging ecology, group size and nest site use in Melbourne, Australia, and the surrounding exurban environment. Urban individuals manipulated human food waste and gleaned from sealed surfaces more than exurban conspecifics (suggesting behavioural flexibility), but foraging behaviour and substrate use were broadly similar in both environments (suggesting ‘preadaptation’). Little ravens foraged close to conspecifics and heterospecifics more frequently in the urban than the exurban environment, but some potential dietary competitors rarely foraged near urban Little ravens, possibly indicating some niche partitioning. Mean urban rate of agonistic interaction with other bird species was low (0.023 interactions per foraging raven observed). Although displacement of a raven >10 m occurred in 61-70% of such interactions, the displaced individual usually rapidly resumed foraging nearby. Thus aggressive, interspecific interference competition for food appeared limited. Large groups of Little ravens were twice as common in the exurban as the urban environment, which was inconsistent with the hypothesis that social foraging facilitated urban colonization. Nest tree type (predominantly eucalypts), size and isolation were similar in urban and exurban environments, but urban nests were significantly more concealed. We suggest that ‘preadaptation’, behavioural innovation and a relative lack of significant, interspecific food competition have contributed to urban colonization by Little ravens.
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Restani, Marco, John M. Marzluff, and Richard E. Yates. "Effects of Anthropogenic Food Sources on Movements, Survivorship, and Sociality of Common Ravens in the Arctic." Condor 103, no. 2 (May 1, 2001): 399–404. http://dx.doi.org/10.1093/condor/103.2.399.
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Abstract We investigated survivorship, movements, and sociality of Common Ravens (Corvus corax) exploiting concentrated food resources at a landfill in Greenland. From 1992–1995 we banded 383 ravens: 365 were captured at the landfill and 18 were banded in nearby nests. Thirty-nine ravens were recovered, most by shooting (87%). Mean number of days survived post-banding (494 ± 97) did not differ among age groups, but a higher proportion of juveniles was recovered. Ravens migrated west and south to the coast during winter. No difference existed among age groups in mean distance between locations of banding and recovery (151 ± 31 km). Number of ravens congregating at the landfill declined during the study, coinciding with a decrease in the local human population. Harsh winter climate, limited ice-free land, and abundant human refuse influenced raven use of the wilderness landscape by facilitating the formation of large, nomadic foraging groups.
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Whisson, Desley A., Michael A. Weston, and Kelly Shannon. "Home range, habitat use and movements by the little raven (Corvus mellori) in a coastal peri-urban landscape." Wildlife Research 42, no. 6 (2015): 500. http://dx.doi.org/10.1071/wr15039.
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Context In peri-urban environments, high availability of anthropogenic resources may result in relatively high abundances of some species, with potentially negative implications for other native biota. Effective management of such impacts requires understanding of the spatial ecology of problem species. However, home range and habitat use have not been described for the little raven (Corvus mellori), a superabundant native predator that occurs in urban and natural habitats, including those where threatened shorebirds breed. Aims The aim of this study was to provide basic information on little raven home range, habitat use and movements in a coastal peri-urban landscape. Methods Between October 2011 and January 2012 we radio-tracked 20 little ravens captured in a coastal wetland (near Melbourne, Australia). Key results Little ravens were highly mobile, moving up to 9.9 km in an hour (median = 2 km), and had large ranges: Minimum Convex Polygons were 1664–9989 ha (median = 3362 ha). Although most birds used both anthropogenic and natural habitats, some birds strongly selected for coastal wetland habitat. Birds used multiple roosts during the study period, most of which occurred in grassland (58.7%) or urban (22.3%) areas. Movement of up to 8.3 km (median = 2.2 km) between roosts during the night was also detected. Conclusions Ravens were highly mobile and used large home ranges and a variety of habitats, with habitat preferences varying between birds. Implications Considering the large home ranges and inter-individual variation in habitat preferences of little raven populations, localised management to reduce their impacts on breeding shorebirds is unlikely to be successful.
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Król, Karol, and Józef Hernik. "Crows and Ravens as Indicators of Socioeconomic and Cultural Changes in Urban Areas." Sustainability 12, no. 24 (December 8, 2020): 10231. http://dx.doi.org/10.3390/su122410231.
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Crows and ravens are deeply symbolic. They have featured in myriads of myths and legends. They have been perceived as ominous, totemic, but also smart and intelligent birds by various peoples around the world. They have heralded bad luck and evoked negative associations. How are they perceived today, in the time of the Internet, mobile devices, and popular culture? Is the young generation familiar with the legends, tales, or beliefs related to these birds? The purpose of this paper was to determine the place of the crow and raven in the consciousness of young generations, referred to as Generation Y and Generation Z. The authors proposed that young people, Generations Y and Z, were not familiar with the symbolism of crows and ravens, attached no weight to them, and failed to appreciate their past cultural roles. The survey involved respondents aged 60 and over as well. Both online surveys and direct, in-depth, structured interviews were employed. It was demonstrated that the crow and raven are ominous birds that herald bad luck and evoke negative associations and feelings in the consciousness of young generations. The perception of crows and ravens by the younger generation stems mostly from popular culture and the appearance and behavior of the birds. The ways in which crows and ravens are represented in popular culture and perceived by the public may directly affect their fate in areas with human presence.
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Ciach, Michał, Dominik Wikar, and Małgorzata Bylicka. "Density and Flock Size of the Raven (Corvus corax) In the Orawa - Nowy Targ Basin During Non-Breeding Season." Ring 28, no. 2 (January 1, 2006): 119–25. http://dx.doi.org/10.2478/v10050-008-0033-y.
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Density and Flock Size of the Raven (Corvus corax) In the Orawa - Nowy Targ Basin During Non-Breeding Season During the 2002/2003-2004/2005 non-breeding seasons the density of the Raven in the open habitats of the Orawa - Nowy Targ Basin was studied by line transect method. The results were analysed in four periods (autumn, early winter, winter and early spring). The median density of Ravens did not differ significantly between individual periods and was respectively: 3.5, 3.8, 4.8 and 3.8 indiv. / 10 km. Number of birds during particular controls varied from 1.0 to 24.8 indiv. / 10 km. However, while excluding flocks, the median density of single individuals and pairs of the Raven was considerably lower and in subsequent periods reached respectively: 2.2, 2.4, 2.2 and 1.7 indiv. / 10 km. Flock size did not differ significantly between individual periods. Single individuals and, less often, groups of two birds were recorded mostly. Small (3-5 indiv.) and medium (6-15 indiv.) flocks were recorded rarely and large flocks (16 indiv. and above) - only exceptionally. The high density and strong fluctuations of abundance of Ravens were determined by flocks presence, which was probably linked to irregular occurrence of food resources.
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Gėgžnienė, D. "RAVENO PROGRESYVINIŲ MATRICŲ METODIKOS TAIKYMAS ABITURIENTŲ MĄSTYMO SUGEBĖJIMAMS TIRTI." Psichologija 4 (December 23, 2015): 29–40. http://dx.doi.org/10.15388/psichol.1983.4.9136.
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Šiame straipsnyje apžvelgiami Lietuvos TSR abiturientų intelektualiniai gebėjimai, naudojant Raveno metodiką ir sudarant standartines normas. Buvo ištirti 576 17-20 metų amžiaus abiturientai ir skirtingų Lietuvos miestų ir rajonų centrų ir kaimų. Gautos normos ir kiti rezultatai buvo palyginti su gautaisiais J. C. Raven, A. Toim ir A. Lunge.
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Kelly, John P., Katherine L. Etienne, and Jennifer E. Roth. "Factors Influencing the Nest Predatory Behaviors of Common Ravens in Heronries." Condor 107, no. 2 (May 1, 2005): 402–15. http://dx.doi.org/10.1093/condor/107.2.402.
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AbstractAn investigation of nest predation and associated foraging behaviors by resident Common Ravens (Corvus corax) indicated that occupation of heronries, predation of Great Egret (Ardea alba) nests, duration of patrol flights, landing rates, and number of interactions with ardeids varied with the productivity of resident ravens. Annual increases in raven predatory behaviors were consistent with increases in foraging experience for a few to several years after ravens became resident at colony sites. However, overall nest predation did not increase at three sites from 1999–2004, and at one of these sites, predation did not differ from levels measured before ravens were resident, suggesting that ravens may have interfered with the nest predatory activities of other species. Ravens at one colony site obtained most or all of their energy needs from the heronry. Predation of Great Egret nestlings was most likely 14–29 days after first hatch, when parental attendance begins to decline. Regional monitoring of heronries in the San Francisco Bay area, California, indicated highly variable rates of nest predation by Common Ravens and a low overall presence of ravens, even though ravens occurred throughout the region. Implications for conservation include the potential value of manipulating raven reproduction to limit nest predation, exclusion of other nest predators by resident ravens, annual increases in nest predatory behaviors, and the importance of regional monitoring to substantiate concerns about raven predation.Factores que Influencian las Conductas de Corvus corax como Depredadores de Nidos en Colonias de GarzasResumen. Una investigación de la depredación de nidos y de las conductas asociadas de cuervos de la especie Corvus corax indicaron que la ocupación de colonias de garzas, la depredación de los nidos de Ardea alba, la duración de los vuelos de patrullaje, las tasas de aterrizaje y el número de interacciones con ardeidos varió con la productividad de los cuervos residentes. Los incrementos anuales de las conductas depredadoras de los cuervos fueron consistentes con los aumentos en la experiencia de forrajeo de unos pocos a varios años, a partir de que los cuervos se incorporaron como residentes en las colonias. Sin embargo, la depredación global de nidos no incrementó en los tres sitios entre 1999 y 2004, y en uno de los sitios la depredación no varió con relación a los niveles medidos antes de que los cuervos fueran residentes, lo que sugiere que los cuervos pueden haber interferido con las actividades de depredación de nidos de otras especies. Los cuervos de una colonia obtuvieron la mayoría o todas sus necesidades energéticas de las colonias de garzas. La depredación de los pichones fue más probable entre los 14 y los 29 días luego de la primera eclosión, cuando la asistencia de los padres comienza a disminuir. El monitoreo regional de las garzas en el área de la bahía de San Francisco, California, indicó la existencia de tasas de depredación de nidos por parte de C. corax altamente variables y una presencia general baja de cuervos, aunque estas aves estuvieron presentes en toda la región. Las implicancias para la conservación incluyen el valor potencial de manipular la reproducción de C. corax para limitar la depredación de nidos, la exclusión de otros depredadores de nidos por parte de cuervos residentes, incrementos anuales en comportamientos de depredación de nidos y la importancia del monitoreo regional para verificar las preocupaciones sobre la depredación de nidos.
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Driver, Jonathan C. "Raven Skeletons from Paleoindian Contexts, Charlie Lake Cave, British Columbia." American Antiquity 64, no. 2 (April 1999): 289–98. http://dx.doi.org/10.2307/2694279.
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Two raven skeletons were excavated from Charlie Lake Cave, British Columbia, in association with Paleoindian occupations dated at about 10,500 and 9500 B.P. The distribution and condition of the bones, the association with artifacts, the configuration and location of the site, and data from ethnographic and historic sources contribute to the argument that the two ravens were deposited deliberately by people.
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Policht, Richard, Vlastimil Hart, Denis Goncharov, Peter Surový, Vladimír Hanzal, Jaroslav Červený, and Hynek Burda. "Vocal recognition of a nest-predator in black grouse." PeerJ 7 (March 15, 2019): e6533. http://dx.doi.org/10.7717/peerj.6533.
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Corvids count among the important predators of bird nests. They are vocal animals and one can expect that birds threatened by their predation, such as black grouse, are sensitive to and recognize their calls. Within the framework of field studies, we noticed that adult black grouse were alerted by raven calls during periods outside the breeding season. Since black grouse are large, extremely precocial birds, this reaction can hardly be explained by sensitization specifically to the threat of nest predation by ravens. This surprising observation prompted us to study the phenomenon more systematically. According to our knowledge, the response of birds to corvid vocalization has been studied in altricial birds only. We tested whether the black grouse distinguishes and responds specifically to playback calls of the common raven. Black grouse recognized raven calls and were alerted, displaying typical neck stretching, followed by head scanning, and eventual escape. Surprisingly, males tended to react faster and exhibited a longer duration of vigilance behavior compared to females. Although raven calls are recognized by adult black grouse out of the nesting period, they are not directly endangered by the raven. We speculate that the responsiveness of adult grouse to raven calls might be explained as a learned response in juveniles from nesting hens that is then preserved in adults, or by a known association between the raven and the red fox. In that case, calls of the raven would be rather interpreted as a warning signal of probable proximity of the red fox.
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Kulahci, Ipek G., Daniel I. Rubenstein, Thomas Bugnyar, William Hoppitt, Nace Mikus, and Christine Schwab. "Social networks predict selective observation and information spread in ravens." Royal Society Open Science 3, no. 7 (July 2016): 160256. http://dx.doi.org/10.1098/rsos.160256.
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Animals are predicted to selectively observe and learn from the conspecifics with whom they share social connections. Yet, hardly anything is known about the role of different connections in observation and learning. To address the relationships between social connections, observation and learning, we investigated transmission of information in two raven ( Corvus corax ) groups. First, we quantified social connections in each group by constructing networks on affiliative interactions, aggressive interactions and proximity. We then seeded novel information by training one group member on a novel task and allowing others to observe. In each group, an observation network based on who observed whose task-solving behaviour was strongly correlated with networks based on affiliative interactions and proximity. Ravens with high social centrality (strength, eigenvector, information centrality) in the affiliative interaction network were also central in the observation network, possibly as a result of solving the task sooner. Network-based diffusion analysis revealed that the order that ravens first solved the task was best predicted by connections in the affiliative interaction network in a group of subadult ravens, and by social rank and kinship (which influenced affiliative interactions) in a group of juvenile ravens. Our results demonstrate that not all social connections are equally effective at predicting the patterns of selective observation and information transmission.
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MANHÃES, MARCELO. "IMAGEM E PROCESSO CRIATIVO: A DEFORMAÇÃO DO REAL EM THE RAVEN DE EDGAR ALLAN POE." IPOTESI – REVISTA DE ESTUDOS LITERÁRIOS 25, no. 2 (December 31, 2021): 53–63. http://dx.doi.org/10.34019/1982-0836.2021.v25.35693.
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Discute-se aqui a deformação do real na produção de The Raven de Edgar Allan Poe, tomando-se por base seu texto Filosofia da Composição em que apresenta seus critérios para a construção do poema, dentre os quais, prima por estabelecer conexões com o mundo real, mantendo a lógica, o racional, o plausível. Entretanto, levanta-se a discussão se a escolha do termo “raven” ao invés de “crow” na língua inglesa teria sido um equívoco de Poe. REFERÊNCIAS BÍBLIA. Português. Bíblia sagrada. Tradução: João Ferreira de Almeida. Brasília-DF: Sociedade Bíblica do Brasil, 1969. CÂNDIDO, Antônio. Literatura e sociedade: estudos de teoria e história literária. 7ª ed. São Paulo: Nacional, 1985. CORVIDRESEARCH. BLOG. O guia definitivo para distinguir corvos americanos e corvos comuns. Disponível em: https://corvidresearch.blog/2020/04/16/the-definitive-guide-for-distinguishing-american-crows-common-ravens/. Acesso em 18 ago. 2021. HAUSER, Arnold. Historia social de la literatura y el arte. Madrid: Guadarrama, 1969. JONSSON. FABRE. IRESTEDT. Cérebros, inovações de ferramentas e biogeografia em corvos e corvos. BCM Evolutionary Biology. Disponível em: Brains, tools, innovation and biogeography in crows and ravens - BMC Ecology and Evolution. Acesso em 18 ago. 2021. LEITÃO, Nuno. O mítico Corvo. Disponível em: https://www.geralforum.com/board/showthread.php/429980-o-mitico-corvo. Acesso em 10 ago. 2021. MAFRA. SCHRULL. Análise de quatro traduções do poema The Raven de Edgar Allan Poe. Revista Translatio. 2011. Disponível em: https://seer.ufrgs.br/translatio/article/view/36692/23759. Acesso em 14 ago. 2021. NETMUNDI.ORG, O Corvo de Edgar Allan Poe. Tradução de Milton Amado. Disponível em: https://www.netmundi.org/home/2017/o-corvo-de-edgar-allan-poe-milton-amado/. Acesso em 14 ago. 2021. KUMAR, Manisha. Difference Between Crow and Raven. Disponível em: http://www.differencebetween.net/science/nature/difference-between-crow-and-raven/. Acesso em 02 abril 2014. OSTROWER, Fayga. A sensibilidade do intelecto. Rio de Janeiro: Campus, 1998. POE, Edgar Allan . A filosofia da composição. Disponível em: https://edisciplinas.usp.br/pluginfile.php/2544953/mod_resource/content/1/Poe.pdf. Acesso em 14 ago. 2021. POE, Edgar Allan. Poemas e Ensaios. Trad. Oscar Mendes e Milton Amado. São Paulo: Globo, 1999. 3. ed. Revista. Disponível em: www.ufrgs.br/proin/versao_2/textos/filosofia.doc. Acesso em: 02 abr. 2014. POE, Edgar Allan. The Raven. Disponível em: www.blocosonline.com.br/literatura/poesia/pidp/pidp.htm. Acesso em 02 abr. 2014. SCHOLLHAMMER, Karl Erik. O olhar da literatura. 2. ed. Rio de Janeiro: 7 Letras, 2016. SONTAG, S. Contra a interpretação. Trad.Ana Maria Capovilla. Porto Alegre: L&PM, 1987. WIKISOURCE.ORG, O Corvo. Trad. Fernando Pessoa. Disponível em: Acesso em 14 ago. 2021.
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Bollhagen, Andrew. "Hempel’s Raven Revisited." Journal of Philosophy 118, no. 3 (2021): 113–37. http://dx.doi.org/10.5840/jphil2021118310.
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The paper takes a novel approach to a classic problem—Hempel’s Raven Paradox. A standard approach to it supposes the solution to consist in bringing our inductive logic into “reflective equilibrium” with our intuitive judgements about which inductive inferences we should license. This approach leaves the intuitions as a kind of black box and takes it on faith that, whatever the structure of the intuitions inside that box might be, it is one for which we can construct an isomorphic formal edifice, a system of inductive logic. By popping open the box we can see whether that faith is misplaced. I aim, therefore, to characterize our pre-theoretical, intuitive understanding of generalizations like “ravens are black” and argue that, intuitively, we take them to mean, for instance: “ravens are black by some indeterminate yet characteristic means.” I motivate and explicate this formulation and bring it to bear on Hempel’s Problem.
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MARSH, CHARITY. "‘Understand us before you end us’: regulation, governmentality, and the confessional practices of raving bodies." Popular Music 25, no. 3 (September 11, 2006): 415–30. http://dx.doi.org/10.1017/s0261143006001000.
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In this article I investigate how power is (re)produced on and through the body, specifically on Toronto's raving bodies during the summer of 2000. Toward the end of 1999 and throughout 2000, Toronto's rave culture came under intense surveillance by institutional and discursive authorities such as city councillors, police, parents, community health organisations, public intellectuals, and the mass media. What ensued was a temporary ban of raves in Toronto on city-owned property. In response to this ban, Toronto ravers relied on liberal approaches such as educational programmes and state lobbying as a way to protect their ‘freedom to dance’. In light of these reactions, one of my primary questions is: As rave becomes more normative, what are its own disciplinary mechanisms or techniques of control that are asserted at the site of the raving body?
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Ekanayake, Kasun B., Duncan R. Sutherland, Peter Dann, and Michael A. Weston. "Out of sight but not out of mind: corvids prey extensively on eggs of burrow-nesting penguins." Wildlife Research 42, no. 6 (2015): 509. http://dx.doi.org/10.1071/wr15108.
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Context Egg depredation is a major cause of reproductive failure among birds and can drive population declines. In this study we investigate predatory behaviour of a corvid (little raven; Corvus mellori) that has only recently emerged, leading to widespread and intense depredation of eggs of a burrow-nesting seabird (little penguin; Eudyptula minor). Aims The main objective of this study was to measure the rate of penguin egg depredation by ravens to determine potential threat severity. We also examined whether penguin burrow characteristics were associated with the risk of egg depredation. Ravens generally employ two modes of predatory behaviour when attacking penguin nests; thus we examined whether burrow characteristics were associated with these modes of attack. Methods Remote-sensing cameras were deployed on penguin burrows to determine egg predation rates. Burrow measurements, including burrow entrance and tunnel characteristics, were measured at the time of camera deployment. Key results Overall, clutches in 61% of monitored burrows (n = 203) were depredated by ravens, the only predator detected by camera traps. Analysis of burrow characteristics revealed two distinct types of burrows, only one of which was associated with egg depredation by ravens. Clutches depredated by ravens had burrows with wider and higher entrances, thinner soil or vegetation layer above the egg chamber, shorter and curved tunnels and greater areas of bare ground and whitewash near entrances. In addition, 86% were covered by bower spinach (Tetragonia implexicoma), through which ravens could excavate. Ravens used two modes to access the eggs: they attacked through the entrance (25% of burrow attacks, n = 124); or dug a hole through the burrow roof (75% of attacks, n = 124). Burrows that were subject to attack through the entrance had significantly shorter tunnels than burrows accessed through the roof. Conclusions The high rates of clutch loss recorded here highlight the need for population viability analysis of penguins to assess the effect of egg predation on population growth rates. Implications The subterranean foraging niche of a corvid described here may have implications for burrow-nesting species worldwide because many corvid populations are increasing, and they exhibit great capacity to adopt new foraging strategies to exploit novel prey.
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Kõiva, Mare. "Loomade ja inimeste suhteid tähistavad loitsud – adresseerimine, eufemismid, düsfemismid." Mäetagused 83 (August 2022): 219–52. http://dx.doi.org/10.7592/mt2022.83.koiva.
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The use of euphemisms is a characteristic of everyday language use today. However, substitute names and euphemisms were widely used in incantations, where euphemisms were tightly interwoven with taboos. In incantations euphemisms are used in various situations: healing the sick, coping with animals and natural phenomena, creating social relationships; coping with core rituals of human life (primarily birth and death); retaliating for theft, murder, and infidelity; promoting one’s work. Euphemisms represent an important pole in the use of verbal magic, and they are different from references to dysphemisms, that is, using vituperation, cursing, profanity or hexing to cut off contact or to achieve one’s goal. This article discusses general principles for the use of euphemisms and examines which euphemisms are used in which functions, using examples of certain belief rituals and values (fishing), symbolic animals (the wolf and the raven) and cockroaches. The results demonstrate that there is no direct appeal in 11% of texts concerned with wolf words, in 10.9% of texts about ravens, and 58% of texts about cockroaches; and euphemisms are used in 66% of texts concerned with the wolf, in 19,5% of texts about the raven, and 32,2% of texts about cockroaches, whereas dysphemisms are used in 32% of texts about the raven and in 3% of texts about cockroaches.
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Matson, Leslie, J. Anthony, and T. J. McElligott. "Alf the Sacred Raver." Books Ireland, no. 111 (1987): 29. http://dx.doi.org/10.2307/20630519.
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Madl, Tobias, and Michael Sattler. "Adhesion Dance with Raver." Structure 17, no. 6 (June 2009): 781–83. http://dx.doi.org/10.1016/j.str.2009.05.004.
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Lu, Chenguang. "Channels’ Confirmation and Predictions’ Confirmation: From the Medical Test to the Raven Paradox." Entropy 22, no. 4 (March 26, 2020): 384. http://dx.doi.org/10.3390/e22040384.
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After long arguments between positivism and falsificationism, the verification of universal hypotheses was replaced with the confirmation of uncertain major premises. Unfortunately, Hemple proposed the Raven Paradox. Then, Carnap used the increment of logical probability as the confirmation measure. So far, many confirmation measures have been proposed. Measure F proposed by Kemeny and Oppenheim among them possesses symmetries and asymmetries proposed by Elles and Fitelson, monotonicity proposed by Greco et al., and normalizing property suggested by many researchers. Based on the semantic information theory, a measure b* similar to F is derived from the medical test. Like the likelihood ratio, measures b* and F can only indicate the quality of channels or the testing means instead of the quality of probability predictions. Furthermore, it is still not easy to use b*, F, or another measure to clarify the Raven Paradox. For this reason, measure c* similar to the correct rate is derived. Measure c* supports the Nicod Criterion and undermines the Equivalence Condition, and hence, can be used to eliminate the Raven Paradox. An example indicates that measures F and b* are helpful for diagnosing the infection of Novel Coronavirus, whereas most popular confirmation measures are not. Another example reveals that all popular confirmation measures cannot be used to explain that a black raven can confirm “Ravens are black” more strongly than a piece of chalk. Measures F, b*, and c* indicate that the existence of fewer counterexamples is more important than more positive examples’ existence, and hence, are compatible with Popper’s falsification thought.
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Ekanayake, Kasun B., Desley A. Whisson, Laura X. L. Tan, and Michael A. Weston. "Intense predation of non-colonial, ground-nesting bird eggs by corvid and mammalian predators." Wildlife Research 42, no. 6 (2015): 518. http://dx.doi.org/10.1071/wr15080.
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Context Loss of eggs to predators is a major cause of reproductive failure among birds. It is especially pronounced among ground-nesting birds because their eggs are accessible to a wide range of predators. Few studies document the main causes of clutch fate of ground-nesting birds. Aims The main objective of the present study was to identify the major egg predator of red-capped plovers (Charadrius ruficapillus). We also investigated the effectiveness of the following two primary strategies available to the plovers to avoid egg predation: (1) the placement of clutches under vegetative cover and (2) avoiding predators by nesting outside the peak season of predator occurrence. Methods Remote-sensing cameras were deployed on plover nests to identify egg predators and nests were monitored over four breeding seasons to document reproductive success and fate. An experiment using false clutches with model eggs investigated the influence of nest cover on the risk of egg predation throughout the year. Line-transect surveys were conducted to estimate the abundance of egg predators in and around the wetlands. Key results The little raven (Corvus mellori) was the major egg predator identified in 78.6% of red-capped plover clutches and in 92.4% of false clutches that were camera-monitored. The hatching success of plover eggs was not influenced by nest cover (P = 0.36), but model egg survival in false clutches improved significantly with the presence of nest cover (P = 0.02). The abundance of little ravens increased during the plover breeding season and was highly negatively correlated with false clutch survival (rpearson = –0.768, P = 0.005). Conclusions Little ravens were the major predator of red-capped plover eggs and their abundance increased significantly during the plover breeding season. Any influence of nest cover on hatching success of eggs may have been masked by the extremely high rate of egg loss associated with the increased little raven abundance during the plover breeding season. Implications The high rate of egg predation is likely to have negative consequences on the local red-capped plover population, suggesting management is warranted. Little raven populations have expanded and, thus, their impact as egg predators needs to be investigated especially on threatened species.
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Jung, Thomas. "Raven (<i>Corvus corax</i>) as a novel food item for lynx (<i>Lynx canadensis</i>)." Canadian Field-Naturalist 136, no. 1 (July 29, 2022): 17–19. http://dx.doi.org/10.22621/cfn.v136i1.2769.
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Canada Lynx (Lynx canadensis) is a specialist predator of Snowshoe Hare (Lepus americanus), which dominates its diet. However, hare populations cycle over 9–11 years, and many lynx disperse or starve during cyclic lows of their prey. Here, I report observations of Canada Lynx scavenging and attempting to prey on Common Raven (Corvus corax). In addition, I provide a brief review of birds as a food item of lynx. These are the first observations of ravens as a food source for lynx and may be a response to lynx being malnourished. The value of these observations is that they highlight the adaptability of some lynx to opportunistically use novel prey species during the decline phase of cyclic Snowshoe Hare.
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Adriaense, Jessie E. C., Jordan S. Martin, Martina Schiestl, Claus Lamm, and Thomas Bugnyar. "Negative emotional contagion and cognitive bias in common ravens (Corvus corax)." Proceedings of the National Academy of Sciences 116, no. 23 (May 20, 2019): 11547–52. http://dx.doi.org/10.1073/pnas.1817066116.
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Emotional contagion is described as an emotional state matching between subjects, and has been suggested to facilitate communication and coordination in complex social groups. Empirical studies typically focus on the measurement of behavioral contagion and emotional arousal, yet, while highly important, such an approach often disregards an additional evaluation of the underlying emotional valence. Here, we studied emotional contagion in ravens by applying a judgment bias paradigm to assess emotional valence. We experimentally manipulated positive and negative affective states in demonstrator ravens, to which they responded with increased attention and interest in the positive condition, as well as increased redirected behavior and a left-eye lateralization in the negative condition. During this emotion manipulation, another raven observed the demonstrator’s behavior, and we used a bias paradigm to assess the emotional valence of the observer to determine whether emotional contagion had occurred. Observers showed a pessimism bias toward the presented ambiguous stimuli after perceiving demonstrators in a negative state, indicating emotional state matching based on the demonstrators’ behavioral cues and confirming our prediction of negative emotional contagion. We did not find any judgment bias in the positive condition. This result critically expands upon observational studies of contagious play in ravens, providing experimental evidence that emotional contagion is present not only in mammalian but also in avian species. Importantly, this finding also acts as a stepping stone toward understanding the evolution of empathy, as this essential social skill may have emerged across these taxa in response to similar socioecological challenges.
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Bodey, Thomas W., Robbie A. McDonald, and Stuart Bearhop. "Mesopredators constrain a top predator: competitive release of ravens after culling crows." Biology Letters 5, no. 5 (July 2009): 617–20. http://dx.doi.org/10.1098/rsbl.2009.0373.
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Although predator control programmes rarely consider complex competitive interactions among predators, it is becoming clear that removal of larger ‘superior’ competitors often releases the ‘inferior’ ones and can precipitate trophic cascades. In contrast, our study indicates that culling hooded crows Corvus cornix appears to release a larger competitor, the common raven Corvus corax . Ravens ranged more widely, and the predation of artificial nests was significantly faster (although total predation was similar), after the removal of crows. Our study provides evidence of a novel reversal of competitive release where a larger species was freed from constraints imposed on its distribution and behaviour by a smaller species, and emphasizes the importance of considering community and ecosystem effects of predator manipulations when undertaken for conservation or game management.
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Gryz, Jakub, and Dagny Krauze-Gryz. "Indirect Influence of African Swine Fever Outbreak on the Raven (Corvus corax) Population." Animals 9, no. 2 (January 30, 2019): 41. http://dx.doi.org/10.3390/ani9020041.
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Carrion plays a crucial role in the raven’s diet. In the past, domestic pig carrion was widely available in Poland. This changed with an African swine fever (ASF) outbreak and the introduction of strict procedures aimed at stopping the virus from spreading. We compared data from Central Poland (field and forest mosaic, study area of 105 km2) for two periods, i.e., before (2011–2014) and after the ASF outbreak (2015–2018). In breeding seasons, nests of ravens were found, juveniles were counted, and the time when juveniles left their nests was recorded. Diet composition data were based on pellet analysis and direct observations of feeding birds. The number of breeding pairs dropped from 12.3 to 7.5 in the second period. Breeding parameters were similar. However, birds in the second period had fewer fledglings per successful pair. Domestic pig carrion was found to be an important food item, and with its limited supply, ravens changed their diet, i.e., they fed on the carrion of dogs and cats or preyed on small vertebrates more often. Overall, our study points to a crucial role of the availability of the carrion of big farm animals (i.e., domestic pig) in maintaining the high density of breeding raven populations.
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RAVERA, Sonia. "Two new species of Arthopyrenia from Italy." Lichenologist 38, no. 1 (December 19, 2005): 21–26. http://dx.doi.org/10.1017/s0024282905004809.
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Arthopyrenia tuscanensis Coppins & S. Ravera and A. coppinsii S. Ravera are described as new to science. They share the characteristic tadpole-shaped ascospores with a conical lower cell, but are otherwise comparable to A. salicis A. Massal.
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Webb, William C., William I. Boarman, and John T. Rotenberry. "Common Raven Juvenile Survival in a Human-Augmented Landscape." Condor 106, no. 3 (August 1, 2004): 517–28. http://dx.doi.org/10.1093/condor/106.3.517.
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AbstractAnthropogenic resource subsidies have contributed to the dramatic increase in the abundance of Common Ravens (Corvus corax) in the western Mojave Desert, California, during the past 30 years. To better understand the effects of these subsidies on raven demography, we examined whether survival to juvenile departure from the natal territory could be predicted by a set of environmental and morphological variables, such as nest proximity to anthropogenic resources and juvenile condition. We captured 240 juvenile ravens over 2 years and marked them prior to fledging. Nest proximity to anthropogenic resources and earlier fledging dates significantly predicted raven juvenile survival to departure from the natal territory. The best-fitting mark-recapture models predicted postdeparture survival as a function of time since fledging, nest proximity to anthropogenic resources, and year hatched. The positive effect of nest proximity to anthropogenic resources influenced postdeparture survival for at least 9 months after fledging, as revealed by the mark-recapture analysis. Annual survival was 47% for first-year, 81% for second-year, and 83% for third-year birds. Our results support the hypothesis that anthropogenic resources contribute to increasing raven numbers via increased juvenile survival to departure as well as increased postdeparture survival. We expect raven numbers to grow in concert with the growing human presence in the Mojave Desert unless raven access to anthropogenic resources is diminished.La Sobrevivencia Juvenil de Corvus corax en un Paisaje Mejorado por HumanosResumen. Los subsidios de recursos antropogénicos han contribuido al aumento dramático de la abundancia del cuervo Corvus corax en el occidente del desierto de Mojave durante los últimos 30 años. Para entender los efectos de estos subsidios en la demografía del cuervo, examinamos si la sobrevivencia hasta la salida de los juveniles del territorio natal podría ser predicha por un conjunto de variables morfológicas y ambientales, tales como su cercanía a los recursos antropogénicos y la condición de los juveniles. En dos años capturamos 240 cuervos juveniles y los marcamos antes que desarollaran plumas de vuelo. La cercanía del nido al punto de subsidio más cercano y las fechas tempranas de emplumamiento predijeron significativamente la sobrevivencia de los juveniles hasta su salida del teritorio natal. Los modelos de marcaje y recaptura más adecuados predijeron la sobrevivencia posterior a la salida del territorio como una función del tiempo desde el momento de emplumamiento, la cercanía al punto más cercano de subsidio y el año de nacimiento. Según el análisis de marcaje y recaptura, el efecto positivo de la cercanía a subsidios antropogénicos influye en la sobrevivencia después de la salida del territorio hasta por lo menos 9 meses después del emplumamiento. La sobrevivencia anual fue de 47% en el primer año, de 81% en el segundo año y de 83% para aves en su tercer año. Nuestros resultados apoyan la hipótesis de que los recursos antropogénicos contribuyen al crecimiento de los números de cuervos aumentando la sobrevivencia juvenil antes y después de su salida de los territorios natales. Esperamos que los números de cuervos aumenten en relación con la presencia humana en el desierto de Mojave a menos que su acceso a los recursos antropogénicos sea disminuido.
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Kitwiwattanachai, Chanatip, and Neil D. Pearson. "Inferring Correlations of Asset Values and Distances-to-Default from CDS Spreads: A Structural Model Approach." Review of Asset Pricing Studies 5, no. 1 (February 24, 2015): 112–54. http://dx.doi.org/10.1093/rapstu/rav001.
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Badmaev, A. A. "Traditional Buryat Beliefs About Birds." Archaeology, Ethnology & Anthropology of Eurasia 48, no. 2 (June 26, 2020): 106–13. http://dx.doi.org/10.17746/1563-0110.2020.48.2.106-113.
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This study, based on ethnographic, linguistic, and folk materials, describes and interprets Buryat ideas of birds. The analysis of lexical data reveals the principal groups of birds according to the Buryat folk classification. The bat’s status is indistinct, since bats are not subordinate to the kings of the animal world. Diagnostic criteria underlying the classification of birds are outlined. The main criterion was whether a bird was beneficial or harmful. Ornithomorphic images in Buryat mythology, folklore, and ritual are described. Cult birds and bird totems are listed, and relics of local bird cults (those relating to swan, goose, duck, pigeon, and eagle) are revealed. Birds with positive connotations are the swan, crane, swallow, pigeon, eagle, and eagle-owl. Those with negative connotation are the kite, raven, crow, quail, cuckoo, and hoopoe). The attitude toward ducks, hawks, magpies, and jackdaws is ambivalent. Certain birds (ducks and ravens) were related to cosmogonic ideas; others (swan, goose, eagle, etc.) were endowed with a werewolf capability. The raven, the cuckoo, and the hoopoe symbolized natural cycles, whereas the magpie and the quail were associated with the soul. The role of bird images in the mytho-ritual practices is discussed. The Buryat mythological ideas reflected not only specific ethnic views of certain birds, but also universal ones.