Dispersal Patterns, Mating Strategy and Genetic Diversity in the Short Nosed Fruit Bat <em>Cynopterus sphinx</em> (Chiroptera: Pteropodidae) in Southern India

The short-nosed fruit bat, Cynopterus sphinx is a common plant-visiting bat that is widely distributed throughout the Indo-Malayan region. In this chapter, we discuss the dispersal patterns, mating strategy and genetic diversity in the short-nosed fruit bat C. sphinx. We used a broad-range of techniques, including mark-recapture, radio-telemetry and molecular biology analyses. Our studies uncovered unique aspects of the dispersal, mating system and genetic diversity of these bats. Both the sexes of C. sphinx were found to disperse completely from the natal harems before subadult stage and young female C. sphinx become members of a harem much earlier than their male counterparts. The nonharem males are reproductively active, gain access to harem females and sire more offspring in July–August breeding season than March–April breeding season and presumably obtain some reproductive success. Our molecular study shows that considerable genetic diversity was observed in this species from different zonal populations, possibly due to complete dispersal of juveniles of both the sexes from their natal groups and gene flow between the zones. All these studies suggest not only a predictive framework for future studies, but also the use of these data in the management and meaningful conservation of this species

Cholinergic Circuits Integrate Neighboring Visual Signals in a Drosophila Motion Detection Pathway

SummaryDetecting motion is a feature of all advanced visual systems [1], nowhere more so than in flying animals, like insects [2, 3]. In flies, an influential autocorrelation model for motion detection, the elementary motion detector circuit (EMD; [4, 5]), compares visual signals from neighboring photoreceptors to derive information on motion direction and velocity. This information is fed by two types of interneuron, L1 and L2, in the first optic neuropile, or lamina, to downstream local motion detectors in columns of the second neuropile, the medulla. Despite receiving carefully matched photoreceptor inputs, L1 and L2 drive distinct, separable pathways responding preferentially to moving “on” and “off” edges, respectively [6, 7]. Our serial electron microscopy (EM) identifies two types of transmedulla (Tm) target neurons, Tm1 and Tm2, that receive apparently matched synaptic inputs from L2. Tm2 neurons also receive inputs from two retinotopically posterior neighboring columns via L4, a third type of lamina neuron. Light microscopy reveals that the connections in these L2/L4/Tm2 circuits are highly determinate. Single-cell transcript profiling suggests that nicotinic acetylcholine receptors mediate transmission within the L2/L4/Tm2 circuits, whereas L1 is apparently glutamatergic. We propose that Tm2 integrates sign-conserving inputs from neighboring columns to mediate the detection of front-to-back motion generated during forward motion

Bat foraging strategies and pollination of Madhuca latifolia (Sapotaceae) in southern India

The sympatrically occurring Indian short-nosed fruit bat Cynopterus sphinx and Indian flying fox Pteropus giganteus visit Madhuca latifolia (Sapotaceae), which offers fleshy corollas (approximate to 300 mg) to pollinating bats. The flowers are white, tiny and in dense fascicles The foraging activities of the two bat species were segregated in space and time. Cynopterus sphinx fed on resources at lower heights in the trees than P giganteus and its peak foraging activity occurred at 19 30 h, before that of P giganteus Foraging activities involved short searching flights followed by landing and removal of the corolla by mouth Cynopterus sphinx detached single corollas from fascicles and carried them to nearby feeding roosts, where it sucked the juice and spat out the Fibrous remains Pteropus giganteus landed on top of the trees and fed on the corollas in situ, its peak activity occurred at 20 30 11 This species glided and crawled between the branches and held the branches with claws and forearms when removing fleshy corollas with Its Mouth Both C sphinx and P giganteus consumed fleshy corollas with attached stamens and left the gynoecium intact Bagging experiments showed that fruit-set in bat-visited flowers was significantly higher (P < 0.001) than in self-pollinated flowers