Three new species of narrowly endemic snapping shrimp, genusAlpheus(Decapoda: Caridea: Alpheidae) from the Persian Gulf

Three new species of snapping shrimps of the genusAlpheusare described from the Persian Gulf. These belong to theAlpheus edwardsiispecies-group, which is mainly characterized by unarmed orbital hoods and the presence of dorsal and ventral notches on the palm of the major chela.Alphus ankerisp. nov. shows a close affinity toA. pacificusDana, 1852 andA. heronicusBanner & Banner, 1982 bearing no balaeniceps crests in both sexes on the dactylus of the minor chela, and the merus of the major chela of both sexes are unarmed. This species differs from the closely related species by the absence of an overhanging proximal shoulder in the major chela. The other rock crevice inhabiting species,A. mohammadpourisp. nov. is diagnosed by exhibiting sexual dimorphism in its balaeniceps crests and the armed merus of the major chela. These two characters are similar to those recorded for three sandy/rubble dwelling species:A. inopinatusHolthuis & Gottlieb, 1958,A. lobidensDe Haan, 1849 andA. australiensisBanner & Banner, 1982. This new species is distinguishable from these latter species by the shape of the minor chela and colour pattern. A coral inhabiting speciesA. abumusasp. nov. appears to be closely related toA. maindroniCoutière, 1898, showing an armed merus of the major chela and the absence of spine-like seta on the ischia of the third legs. This last new species is easily discriminated fromA. maindroniby longer antennular segments, a markedly concave frontal margin between the rostrum and orbital hood, and a different colour pattern.

Ants learn to rely on more informative attributes during decision-making

Evolutionary theory predicts that animals act to maximize their fitness when choosing among a set of options, such as what to eat or where to live. Making the best choice is challenging when options vary in multiple attributes, and animals have evolved a variety of heuristics to simplify the task. Many of these involve ranking or weighting attributes according to their importance. Because the importance of attributes can vary across time and place, animals might benefit by adjusting weights accordingly. Here, we show that colonies of the ant Temnothorax rugatulus use their experience during nest site selection to increase weights on more informative nest attributes. These ants choose their rock crevice nests on the basis of multiple features. After exposure to an environment where only one attribute differentiated options, colonies increased their reliance on this attribute relative to a second attribute. Although many species show experience-based changes in selectivity based on a single feature, this is the first evidence in animals for adaptive changes in the weighting of multiple attributes. These results show that animal collectives, like individuals, change decision-making strategies according to experience. We discuss how these colony-level changes might emerge from individual behaviour.

Winter bat activity in the Canadian prairies

Periodic arousal from hibernation among mammalian hibernators is poorly understood. In bats, arousal is often associated with flight. We acoustically monitored two rocky areas along the Red Deer River in southeastern Alberta for bat activity in autumn, winter, and spring months. We found bats to be active in all months and at unexpectedly cold temperatures (coldest activity –8 °C). Bats were active even when ambient temperatures remained below 0 °C during the day and night. We documented Myotis ciliolabrum (Merriam, 1886), Myotis evotis (H. Allen, 1864), and Eptesicus fuscus (Beauvois, 1796) flying outside hibernacula in winter. Active E. fuscus that we captured in mid-winter of 2004–2005 weighed less than bats captured in the fall, but masses ranged from 14.0 to 21.0 g, indicating that some individuals still had fat reserves. Captured individuals were of various ages, with a male bias. Using radiotelemetry, we located the first natural rock-crevice hibernacula for male and female E. fuscus in the Canadian prairies. Winter roosts were narrow, deep rock crevices or erosion holes located in steep valley walls. We found evidence to suggest that dehydration may be a driving force for winter flights.

Woody and arboreal habitats of the Green Salamander (Aneides aeneus) in the Blue Ridge Mountains

The green salamander (Aneides aeneus) is primarily considered a rock crevice dwelling species. However, many early observations from Kentucky, Tennessee, Virginia, and West Virginia report A. aeneus taken from woody and arboreal habitats. There have been only four published records of A. aeneus using such habitats within the Blue Ridge Disjunct population of southwest North Carolina, northeast Georgia, and northwest South Carolina, and no records since 1952. Here I report two personal observations of A. aeneus using arboreal habitats in North Carolina. Additionally, I report nine observations, made by others, of A. aeneus using woody, arboreal, or otherwise non-rock-crevice habitats in North and South Carolina, including the first non-rock-crevice A. aeneus nesting record for the Blue Ridge. I also speculate that woody and arboreal habitats play a much larger role in the life-history of A. aeneus than generally thought, and that the rarity of A. aeneus is linked to the loss of American Chestnut and old-growth forests.