@article {50497, title = {Social calls honestly signal female competitive ability in Asian particoloured bats}, journal = {Animal Behaviour}, volume = {127}, year = {2017}, month = {Jan-05-2017}, pages = {101 - 108}, abstract = {

Why a variety of social animals vocalize during agonistic foraging interactions remains obscure. One possibility is that these signals advertise the signaller\&$\#$39;s competitive ability, playing a role in the defence of food resources, yet there is limited evidence in support of this idea. Here, we used adult female Asian particoloured bats, Vespertilio sinensis, to test whether individual variation in competitive ability when foraging can be explained by social calls. Using synchronized infrared video and audio recording, we monitored bat social vocalizations, dominance rank and weight gain in triads under controlled food conditions. Additionally, subsequent playbacks, consisting of experimental stimuli, echolocation pulses and silence, were presented to feeding bats in a laboratory. Analyses showed that females uttered low-frequency social calls composed of one to five syllable types during feeding competition. The rates of social vocalizations increased with reduced food availability. Interestingly, dominance score and weight gain correlated weakly with body size, but positively with call rate and associated parameters. Playback of social calls inhibited the visits of bats to the focal food dish compared to playback of silence and echolocation pulses. The amount of food consumed was greatly reduced in the presence of experimental stimuli versus controls. Collectively, these results highlight that acoustic signals serve as an honest indicator of bat competitive ability.

}, keywords = {aggressive interaction, bats, competitive ability echolocation, foraging, social call}, issn = {00033472}, doi = {10.1016/j.anbehav.2017.03.012}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0003347217300842}, author = {Luo, Bo and Lu, Guanjun and Chen, Kelly and Guo, Dongge and Huang, Xiaobin and Liu, Ying and Feng, Jiang} } @article {47814, title = {Three-dimensional sonar beam-width expansion by Japanese house bats ( Pipistrellus abramus ) during natural foraging}, journal = {The Journal of the Acoustical Society of America}, volume = {141}, year = {2017}, month = {Jan-05-2017}, pages = {EL439 - EL444}, abstract = {

Three-dimensional directivity patterns of sonar sounds emitted by Japanese house bats (Pipistrellus abramus) during natural foraging were measured by a 44-channel microphone array. Just before prey capture, the terminal frequency (TF) of emitted sounds decreased, and the beam width (mean\ \±\ standard deviation) expanded from 40\ \±\ 10\° to 63\ \±\ 9\° (horizontal) and from 32\ \±\ 10\° to 52\ \±\ 7\° (vertical). P. abramus decrease the TF to simultaneously expand the beam width in both the horizontal and vertical planes, while retaining the target within the three-dimensional acoustic field of view at the final stage of capture.

}, issn = {0001-4966}, doi = {10.1121/1.4981934}, url = {http://asa.scitation.org/doi/10.1121/1.4981934}, author = {Motoi, Kazuya and Sumiya, Miwa and Fujioka, Emyo and Hiryu, Shizuko} }