The effects of fire on insectivorous bats and their resources in Cape York Peninsula, Australia

2021 ◽  
Author(s):  
◽  
Julie Broken-Brow
Keyword(s):  
2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Dongge Guo ◽  
Jianan Ding ◽  
Heng Liu ◽  
Lin Zhou ◽  
Jiang Feng ◽  
...  

Abstract Background Why a variety of social animals emit foraging-associated calls during group foraging remains an open question. These vocalizations may be used to recruit conspecifics to food patches (i.e. food advertisement hypothesis) or defend food resources against competitors (food defence hypothesis), presumably depending on food availability. Insectivorous bats rely heavily on vocalizations for navigation, foraging, and social interactions. In this study, we used free-ranging big-footed myotis (Myotis macrodactylus Temminck, 1840) to test whether social calls produced in a foraging context serve to advertise food patches or to ward off food competitors. Using a combination of acoustic recordings, playback experiments with adult females and dietary monitoring (light trapping and DNA metabarcoding techniques), we investigated the relationship between insect availability and social vocalizations in foraging bats. Results The big-footed myotis uttered low-frequency social calls composed of 7 syllable types during foraging interactions. Although the dietary composition of bats varied across different sampling periods, Diptera, Lepidoptera, and Trichoptera were the most common prey consumed. The number of social vocalizations was primarily predicted by insect abundance, insect species composition, and echolocation vocalizations from conspecifics. The number of conspecific echolocation pulses tended to decrease following the emission of most social calls. Feeding bats consistently decreased foraging attempts and food consumption during playbacks of social calls with distinctive structures compared to control trials. The duration of flight decreased 1.29–1.96 fold in the presence of social calls versus controls. Conclusions These results support the food defence hypothesis, suggesting that foraging bats employ social calls to engage in intraspecific food competition. This study provides correlative evidence for the role of insect abundance and diversity in influencing the emission of social calls in insectivorous bats. Our findings add to the current knowledge of the function of social calls in echolocating bats.


Zootaxa ◽  
2013 ◽  
Vol 3620 (1) ◽  
pp. 1-42
Author(s):  
A. EWART ◽  
L. W. POPPLE

Three new species are described in the genus Drymopsalta Ewart, previously known only from D. crepitum Ewart and D. daemeli Distant. The three new species occur in Southern Queensland and Northern Territory. D. wallumi sp. nov. occurs along coastal S.E. Queensland, whereas D. hobsoni sp. nov. is restricted to the Bringalily State Forest, near Inglewood, southern inland Queensland. D. acrotela sp. nov. is found in the Litchfield National Park and other locations near Jabaluka, Cahills Crossing, E. Alligator River and Nourlangie, all across the northern Northern Territory. D. crepitum occurs on the Cape York Peninsular extending into the southern Gulf, while D. daemeli occurs in two localised regions in central coastal N.S.W. Each of the species inhabits heath vegetation, often spilling-over into adjacent tree foliage. The species of Drymopsalta are small and inconspicuous cicadas (<15 mm body length) with relatively high frequency songs (~15 to 22 kHz). The temporal structures of the normal calling songs follow a similar pattern in each species, consisting of the emission of short chirps (comprising 2–16 ticks). Between the chirps are emitted one (D. wallumi, D. hobsoni, D. acrotela), two (D. daemeli) or 1–9 (D. crepitum) intervening single ticks. The species can be distinguished by the timing and the number of these single ticks relative to the adjacent chirps with the notable exception of D. hobsoni and D. acrotela. The calling songs of these two allopatric species are indistinguishable, an unusual feature in Australian cicadas. Two additional song variants are described, a more unstructured chirping song without intervening single ticks observed in each of the species except D. crepitum, and periodic extended buzzing echemes emitted within the calling songs (excepting the D. wallumi song).


2009 ◽  
Vol 34 (2) ◽  
pp. 196-209 ◽  
Author(s):  
GABRIEL CROWLEY ◽  
STEPHEN GARNETT ◽  
SUSAN SHEPHARD
Keyword(s):  

Biotropica ◽  
1977 ◽  
Vol 9 (2) ◽  
pp. 73 ◽  
Author(s):  
M. B. Fenton ◽  
N. G. H. Boyle ◽  
T. M. Harrison ◽  
D. J. Oxley

2016 ◽  
Vol 202 ◽  
pp. 10-19 ◽  
Author(s):  
Bradley K. Clarke-Wood ◽  
Kim M. Jenkins ◽  
Brad S. Law ◽  
Rachel V. Blakey

1976 ◽  
Vol 54 (4) ◽  
pp. 526-530 ◽  
Author(s):  
M. B. Fenton ◽  
G. K. Morris

By using a 'black light' and playback of sounds made by foraging insectivorous bats, we examined opportunistic feeding behavior of bats near Camp Verde, Arizona, between 1 and 10 June 1975. Bats were significantly most active during 15-min periods when the light was on and insects were aggregated over it. Bats feeding over the light selectively pursued and captured larger insects, apparently ignoring the smaller ones. Bats did not respond to sounds simulating feeding buzzes of bats, but showed a slight response to the foraging sounds of other bats. Opportunistic feeding by insectivorous bats allows effective exploitation of patchily distributed food resources and can lead to selective feeding when 'hatches' of insects are involved. Opportunistic feeding is not incompatible with selective feeding, and may eventually be established as a strategy common to most insectivorous bats.


2004 ◽  
Vol 7 (4) ◽  
pp. 417-425 ◽  
Author(s):  
Robert Heinsohn ◽  
Robert C. Lacy ◽  
David B. Lindenmayer ◽  
Helene Marsh ◽  
Donna Kwan ◽  
...  

2004 ◽  
Vol 20 (4) ◽  
pp. 397-407 ◽  
Author(s):  
Christoph F. J. Meyer ◽  
Christian J. Schwarz ◽  
Jakob Fahr

We studied activity patterns and habitat use by insectivorous bats in Comoé National Park, Ivory Coast. Bat foraging activity was quantified along five transects representing three different habitat types using acoustic monitoring and captures with mist nets and harp traps. Aerial insect abundance was assessed using a light trap; in addition shrub and tree arthropods were sampled. Bat activity was significantly and positively related to insect availability and ambient temperature, whereas increased visibility of the moon had a negative influence on flight activity. Together, these factors best explained both total bat activity and activity of bats hunting in open space and edge habitats. The interaction between temperature and light intensity was the best predictor of activity by species foraging in obstacle-rich forest habitats, however, the regression model had a low predictive value. Overall, a large proportion (c. 50%) of the variation in bat activity appeared to be a consequence of transect- and/or habitat-specific influences. We found a significant non-linear relationship between the activity of QCF (quasi-constant frequency) and FM–QCF (frequency modulated – quasi-constant frequency) bats and the phase of the moon, with lowest levels of activity occurring near full moon. We interpret this lunar-phobic behaviour as a reflection of a higher predation risk during moonlit periods. For FM (steep frequency modulated) and CF (constant frequency) bats, no significant correlation was found, although there was a trend suggesting that these bats at least were not negatively affected by bright moonlight. Foraging activity of bats was positively correlated with the abundance of atympanate moths; however, no such correlation was found for tympanate moths.


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