@article {53368, title = {Ravens adjust their antipredatory responses to con- and hetero-specific alarms to the perceived threat}, journal = {Ethology}, volume = {124}, year = {2018}, month = {Jan-08-2018}, pages = {609 - 616}, abstract = {

Heterospecific alarm calls are typically found in situations where multiple species have a common predator. In birds, they are particularly common in mixed mixed-species flocks. In species with highly developed social and cognitive abilities like corvids, there is the potential for differential responses to heterospecific vs. conspecific calls according to the riskiness of the habitat. We tested the responses of free-ranging ravens (Corvus corax) to conspecific alarm calls and compared them to heterospecific alarm calls of jackdaws (Corvus monedula). We observed the proportion of ravens leaving the feeding site after the con- or hetero-specific playback was presented in a situation of low threat (wild boar\—Sus scrofa enclosure) and high threat of predation (wolf\—Canis lupus enclosure). We show that ravens responded to conspecific calls more intensively at the wolves than at the wild boar, but the response to conspecific calls was in both enclosures stronger than to the control (great tit\—Parus major song). The response to the heterospecific alarm was also stronger in the wolves\’ enclosure, but it did not differ from control in the wild boar enclosure. These findings suggest that ravens are aware of the meaning of the jackdaw alarm calls, but they respond to it only in a situation of high predatory threat (wolves are present). In the wild boar enclosure, the ravens probably consider jackdaws warning against some other predator, very probably harmless to ravens. This interpretation requires further testing, as both enclosures differ also in respect to other parameters like food quality and shelter availability.

}, keywords = {avoidance, corvid, honest signal, jackdaw, predator, threat}, doi = {10.1111/eth.2018.124.issue-810.1111/eth.12764}, url = {http://doi.wiley.com/10.1111/eth.2018.124.issue-8}, author = {N{\'a}carov{\'a}, Jana and Vesel{\'y}, Petr and Bugnyar, Thomas}, editor = {Tregenza, T.} } @article {52680, title = {The spider-like katydid Arachnoscelis (Orthoptera: Tettigoniidae: Listroscelidinae): anatomical study of the genus}, journal = {Zootaxa}, volume = {3666}, year = {2013}, month = {Apr-06-2013}, pages = {591}, abstract = {

This paper provides some observations on the anatomy of the neotropical katydid Arachnoscelis arachnoides Karny (In- secta: Orthoptera: Tettigoniidae). Arachnoscelis is a genus of predaceous katydids that comprise species that resemble spi- ders in their general body appearance. The type species, A. arachnoids, was described in 1891 from a single male collected in Colombia. Following the original description, these creatures were never found again, and were thought to have gone extinct or mistakenly assigned to the type locality. But between 1891 and 2012 four more species were described and in- correctly assigned to Arachnoscelis based on a similarity of body form. In this paper we present an anatomical comparai- son of Arachnoscelis and its relatives, and propose that Arachnoscelis should be treated as a monotypic genus. This implies that other species previously described in Arachnoscelis, should be placed in different genera.

}, keywords = {bushcricket, Colombia, predator, stridulation, ultrasound}, issn = {1175-5326}, doi = {10.11646/zootaxa.3666.410.11646/zootaxa.3666.4.11}, url = {http://biotaxa.org/Zootaxa/issue/view/zootaxa.3666.4}, author = {Montealegre-Z, Fernando and Cadena-Castaneda, Oscar J. and Benedict D. Chivers} }