02746nas a2200277 4500008004100000245007300041210006900114490000800183520187700191653002702068653003002095653002402125653002102149653003202170653002102202100003202223700002502255700001802280700002002298700002202318700002602340700001902366700001902385700002302404856004102427 2022 eng d00aThe effect of inundation on frog communities and chorusing behaviour0 aeffect of inundation on frog communities and chorusing behaviour0 v1453 a

Globally, river regulation has degraded wetlands, including parts of the Murray-Darling Basin (MDB), an ecologically significant basin in Australia. Frogs in a floodplain environment largely depend on habitats created by river flows, but little is known about how frogs in the northern MDB are impacted by river regulation. We tested how wetland inundation affected frogs in a catchment of the northern MDB. We surveyed frogs between 2015 and 2019 to determine long-term changes in the community composition associated with wetland inundation from river flows. Additionally, we recorded nightly soundscapes for four days before and after the arrival of river flows between 2019 and 2020. The abundance and richness of frog species increased during larger inundation events leading to altered community composition (beta diversity). Warmer temperatures increased frog species richness, and frog community dominance decreased with decreasing vegetation cover (i.e., the relative abundance became more even across species). The abundance of five frog species (Limnodynastes tasmaniensis, Limnodynastes fletcheri, Crinia parinsignifera, Litoria peronii, and Litoria latopalmata) was higher in response to increased inundation extent. The total species richness of chorusing frogs increased after the arrival of river flows; six species chorused over the four nights preceding flow, whereas eight species chorused following the flow arrival, but the responses varied among species and sites. Frog species richness increased at three sites after flows, but not at others. After inundation, the choruses of Limnodynastes tasmaniensis increased whereas Limnodynastes fletcheri decreased. Our findings indicate that wetland inundation is beneficial for frog communities and suggest that chorusing behaviour varied in response to river flows inundating floodplain wetlands.

10aEnvironmental watering10aFalse-colour Spectrograms10aFloodplain wetlands10aLong term survey10apassive acoustic monitoring10aRiver regulation1 aSarke, Mohammad, Abdur Razz1 aMcKnight, Donald, T.1 aRyder, Darren1 aWalcott, Amelia1 aOcock, Joanne, F.1 aSpencer, Jennifer, A.1 aPreston, David1 aBrodie, Sheryn1 aBower, Deborah, S. uhttps://bio.acousti.ca/it/node/5848502008nas a2200181 4500008004100000245008500041210006900126490000600195520141700201653002601618653002401644653003201668653002201700653001701722100002301739700002301762856004101785 2022 eng d00aMid-frequency song and low-frequency calls of sei whales in the Falkland Islands0 aMidfrequency song and lowfrequency calls of sei whales in the Fa0 v93 a

Although sei whales (Balaenoptera borealis) are distributed throughout the globe, their behaviour and vocal repertoire are poorly described. We used passive acoustic monitoring to describe the vocal behaviour of sei whales in the Falkland Islands, between December 2018 and April 2019. We isolated more than 2000 low-frequency calls for manual classification, of which 510 calls with high signal-to-noise ratio were quantitatively measured. Five categories of stereotyped call types in the 15–230 Hz range were described, some with multiple subcategories. These included some similar to previously described calls (e.g. downsweeps), but others that were novel in acoustic structure and frequency band. In the mid-frequency range, we documented a highly stereotyped, hierarchically structured and rhythmically repetitive song display. Songs were arranged in phrases with a structure composed of repetitive sub- phrases, and a diverse variety of sounds in the 1–5 kHz range. Singing commenced in late February, despite the presence of whales and calls since early December, and continued through April. These acoustic properties and behavioural characteristics indicate that this is likely a male breeding display similar to songs and singing of other balaenopterids. This is the first detailed description of a song display for sei whales, highlighting the importance of the Falkland Islands.

10aBalaenoptera borealis10alow-frequency calls10apassive acoustic monitoring10asinging behaviour10asong display1 aCerchio, Salvatore1 aWeir, Caroline, R. uhttps://bio.acousti.ca/it/node/5848402298nas a2200253 4500008004100000245011100041210006900152520150700221653001701728653001501745653001701760653001201777653001901789653001601808653003201824653001601856653001801872100002001890700001901910700002301929700002601952700002201978856004402000 2022 eng d00aTemporal occurrence of three blue whale populations in New Zealand waters from passive acoustic monitoring0 aTemporal occurrence of three blue whale populations in New Zeala3 a

Describing spatial and temporal occurrence patterns of wild animal populations is important for understanding their evolutionary trajectories, population connectivity, and ecological niche specialization, with relevance for effective management. Throughout the world, blue whales produce stereotyped songs that enable identification of separate acoustic populations. We harnessed continuous acoustic recordings from five hydrophones deployed in the South Taranaki Bight (STB) region of Aotearoa New Zealand from January 2016 to February 2018. We examined hourly presence of songs from three different blue whale populations to investigate their contrasting ecological use of New Zealand waters. The New Zealand song was detected year-round with a seasonal cycle in intensity (peak February–July), demonstrating the importance of the region to the New Zealand population as both a foraging ground and potential breeding area. The Antarctic song was present in two distinct peaks each year (June–July; September–October) and predominantly at the offshore recording locations, suggesting northbound and southbound migration between feeding and wintering grounds. The Australian song was only detected during a 10-day period in January 2017, implying a rare vagrant occurrence. We therefore infer that the STB region is the primary niche of the New Zealand population, a migratory corridor for the Antarctic population, and outside the typical range of the Australian population.

10abioacoustics10ablue whale10adistribution10aecology10amarine mammals10aNew Zealand10apassive acoustic monitoring10apopulations10avocalizations1 aBarlow, Dawn, R1 aKlinck, Holger1 aPonirakis, Dimitri1 aColberg, Mattea, Holt1 aTorres, Leigh, G. uhttps://doi.org/10.1093/jmammal/gyac106