Researchers had been divided over whether the sound was vocal or not, but the latest study, published online in the Royal Society Proceedings B shows unequivocally that the tail feathers were the source of the sound. When the researchers cut back the tail feathers — which grow back in five weeks and do not affect the birds ability to fly — the males were unable to make the noise. Tests in wind ...

Camouflage is widespread throughout the natural world and conceals animals from predators in a vast range of habitats. Because successful camouflage usually involves matching aspects of the background environment, species and populations should evolve appearances tuned to their local habitat, termed phenotype-environment associations. However, although this has been studied in various species, ...

A new palaeocorystid crab, Joeranina houssineaui n. sp., is described from upper Cenomanian strata in southwest France, Being apparently derived from J. broderipii, the new species inhabited a sandier substrate environment than its predecessor. The incomplete holotype reveals portions of the internal pleurites, which are rarely seen in extinct crabs.

Carbonic anhydrase (CA) activity and relative expression of CA mRNA were measured in the gills of the euryhaline green crab Carcinus maenas in response to eyestalk ablation (ESA), injection of eyestalk extract and exposure to low salinity. For crabs acclimated to 32 p.p.t. salinity, ESA alone resulted in an increase in both CA activity and relative mRNA expression in the posterior, ion-transpor...

The intertidal burrowing crab Chasmagnathus granulatus is the dominant species in soft bare sediments and vegetated intertidal areas along the SW Atlantic estuaries (southern Brazil, 28° S, to northern Patagonia, 42° S). C. granulatus creates burrows that can reach densities of 60 burrows m–2, and its burrowing activities increase water and organic matter content of sediments. To evaluate the l...

Predator-prey interactions are important drivers in structuring ecological communities. However, despite widespread acknowledgement that individual behaviours and predator species regulate ecological processes, studies have yet to incorporate individual behavioural variations in a multipredator system. We quantified a prevalent predator avoidance behaviour to examine the simultaneous roles of p...

Shell disease syndrome is characterised by the external manifestation of black spot lesions in the exoskeletons of crustaceans. In the present study, gills, hepatopancreas and hearts from healthy (<0.05% black spot coverage) and diseased (5 to 15% coverage) edible crabs, Cancer pagurus, were examined histologically to determine whether this disease can cause internal damage to such crabs. There...

Potential sperm limitation has become a concern for blue crabs Callinectes sapidus in Chesapeake Bay. However, methods to quantify sperm in blue crabs are time intensive, which limits the sample size that can be obtained for sperm limitation studies. Our goal was to develop an efficient method for rapidly preparing spermathecae samples that more quickly quantifies sperm in blue crabs. Ultimatel...

Animals from invertebrates to humans benefit from information conspecifics make available, including information produced inadvertently. While inadvertent social information may frequently be exploited in nature, experiments have rarely been conducted in the wild to examine how such information helps animals in their natural ecology. Here I report a series of field experiments on free-living te...

The behavior of crabs tracking odor in turbulent chemical plumes was compared to the performance of computer simulations of search behavior operating in similar chemical signal environments. The movement of blue crabs (Callinectes sapidus) towards a source of food odor was studied in controlled flow conditions in a flume. The evolving chemical stimulus field of a similar chemical source in an e...