Investigating geographic variation in the displays of the Albert’s lyrebird Birds sing with dialects Bird species around the world show an enormous diversity in communication signals, particularly in song. This is most obvious when comparing different species, but within species song may also vary substantially between locations. Birdsong is a largely learnt behaviour, and may be particularly subject to change over relatively short periods of time. Young birds are unlikely to be perfect mimics, and small changes during the song-learning process can accumulate over time to produce different dialects, much in the same way as humans have location-specific dialects or accents (Mason et al. 2017). Changes during the learning process can be random, or may be driven by factors such as female preference, or sound transmission properties of different habitats changing how the adult song is perceived by learning birds (Podos and Warren 2007). Differences in vocalisations between populations may be exacerbated if high levels of habitat fragmentation and isolation prevent movement between populations, creating an even stronger mating barrier between populations that may already be at risk as females stop to recognise the songs of other populations (Sebastián- González and Hart 2017). Individual dialects may therefore be suited to particular habitats or social preferences, can tell us about the level of isolation of populations, and may influence interactions between populations, and so should be considered in species conservation. The Albert’s lyrebird (Menura alberti) is one such species that has a highly fragmented range and is suspected to show a large diversity in acoustic signals. Albert’s lyrebirds are found in the high altitude rainforests of northeast NSW and southeast Queensland where the males perform elaborate displays including mimicry, dance, and their own songs, to attract a mate (Higgins et al. 2001). This species has suffered a history of habitat loss and degradation, and estimates of population size are uncertain, classifying Albert’s lyrebirds as near threatened on the IUCN red list (BirdLife International 2016). Geographic variation in the male’s songs has been described before but never quantified, nor have the mechanisms of variation been explored (Robinson and Curtis 1996). BirdLife Northern NSW kindly contributed funding to my PhD exploring cultural variation in the Albert’s lyrebird. Throughout my research I will quantify and map the observed variation in their displays, and explain this variation in terms of habitat, geographic separation, and social factors. Working with the Albert’s lyrebird Male Albert’s lyrebirds display during the winter months, performing their elaborate song and dance displays on a platform made of vines and branches. They are highly territorial, often using only one or a small number of display platforms. Their display is made of several components: a lyrebird- specific “whistle” song that is often heard first when approaching the bird (Figure 1), a mimetic sequence consisting of the mimicry of a handful of local species and non-vocal sounds such as wing beats and beak clicks (Figure 2), a low-frequency, rhythmic lyrebird-specific song known to lyrebird enthusiasts as “gronking”, and a variety of dance-like movements such as tail raising and shimmering, bobbing, and branch shaking. While locals are familiar with the sounds of the Albert’s lyrebird, their visual displays are hard to observe, and explanations of their extraordinary behaviours remain uncertain. Figure 1: An example of whistle song from a male recorded at the Border Ranges National Park (NSW) near Forest Tops campground. This example can be heard at www.animalecologylab.org/fiona-backhouse.html. A B C D E F C G H Figure 2: Excerpt of sequential song from Tamborine NP, QLD. (A) Crimson Rosella Platycercus elegans, (B) Satin Bowerbird Ptilonorhynchus violaceus, (C) Wing beats, (D) Satin Bowerbird, (E) Green Catbird Ailuroedus crassirostris, (F) Satin Bowerbird, (G) Australian King-Parrot Alisterus scapularis, (H) Satin Bowerbird. This was part of a longer sequence that was repeated multiple times. This sequence can be heard at www.animalecologylab.org/fiona-backhouse.html. To understand the patterns of variation in Albert’s lyrebird displays I spent May to July of 2018 finding and recording birds with the help of a volunteer. I focussed my efforts on five main areas throughout their range (Figure 3); Border Ranges and Mt Jerusalem National Parks (NSW), and Lamington, Tamborine, and Main Range National Parks (QLD). At each of these locations I found five to six adult males and collected high-quality audio recordings using a handheld microphone. Albert’s lyrebirds are notoriously shy, so most recordings were made out of sight of the bird in order to avoid disturbance and to record natural behaviour. Figure 3: A map of the five main study sites. (A) Border Ranges National Park, (B) Mt Jerusalem National Park, (C) Lamington National Park Binna Burra section, (D) Tamborine Mountain, (E) Main Range National Park Goomburra section. I also searched for their display platforms, which are often hard to distinguish from the rest of the rainforest floor! Most platforms were found by gaining a visual of the bird during his display, others were found by pinpointing his location by sound. I set up remote-sensing wildlife cameras funded by BirdLife Northern NSW and automated sound recorders called SM4s at the located platforms in order to record the displays without disturbing the performers by my presence. This approach proved very effect and males happily performed in front of the cameras and sound recorders (see figure 4). Figure 4: A still taken from a video of one of the males at the Border Ranges National Park (NSW) near Forest Tops campground. The full video can be viewed at www.animalecologylab.org/fiona-backhouse.html. Exploring Albert’s lyrebird dialects I am currently exploring the differences in lyrebird-specific “whistle” song between populations. This has involved measuring acoustic properties of the whistle using spectrograms in the program Raven Pro 1.5 (Cornell Lab of Ornithology, Ithaca). Spectrograms are a visual representation of sound with time on the x-axis and frequency (or pitch) on the y-axis, and amplitude represented by the colour intensity (e.g. Figure 5). They can be read much like a piece of music, and can be used to measure attributes such as the frequency range or duration of a note within the song. It was noticeable in the field and from the recordings that all populations have clearly different songs. Some components of the song were very similar between most populations, such as the introductory notes and the final ascending whistle, but the middle section of the song varied substantially (Figure 5). I am interested in quantifying the extent of these differences, and comparing them to the geographic distance between populations. From preliminary analyses on acoustic measures it was clear that the four eastern populations (Border Ranges, Mt Jerusalem, Lamington and Tamborine) were close together, though still with their differences, whereas the songs from Main Range National Park were considerably different. This result may reflect the relatively large geographic distance between this population and the other sampling sites (Figure 3). Figure 5: Albert's lyrebird territorial song from (A) Mt Jerusalem NP (NSW), and (B) Lamington National Park (QLD). A PCA using acoustic variables showed these two populations in separate clusters, and a GLMM run on the first principal component confirmed these two populations as significantly different. I have also found that most populations have more than one distinct type of whistle song. Multiple discreet song types within an individual’s repertoire have been reported before (Robinson and Curtis 1996) but the degree to which they share these with other males have not been described. My data suggest that some song types may be closely shared by all males within a population, but that other song types may only be shared between close neighbours, with a different assemblage of songs being used by males only 5km away. This indicates that it may be socially advantageous to sing the same song as your neighbour, or that males are only interacting with other males in a very restricted area. Contribution of BirdLife Northern NSW The videos recorded using the cameras funded by BirdLife Northern NSW provide evidence that Albert’s lyrebirds coordinate their visual displays with particular vocalisations. In particular, movements during the gronking song appear to be made in strict time with the vocalisations. This will be explored further when I have obtained more footage of male displays. Excitingly, two cameras captured footage of females visiting the displaying male (one in the Border Ranges NP, one in Main Range NP). Sexual interactions between males and females have rarely been documented in this species and so I expect that the footage collected over the three years of my study will provide valuable information with which to further understand the behaviour of Albert’s lyrebirds. Future directions I am currently working on the first empirical paper of my PhD. I have two more field seasons to complete which will expand on my highly successful first season, with a particular focus on collecting more videos and longer-term acoustic monitoring of focal males. My first year working with the Albert’s lyrebird opened up a whole world of questions about their behaviour, but provided me with a wealth of data to answer these questions with! References BirdLife International. 2016. Menura alberti. The IUCN Red List of Threatened Species 2016. Higgins, P. J., J. M. Peter, and W. K. Steele. 2001. The Handbook of Australia, New Zeland and Antarctic Birds. Oxford University Press, Melbourne, Victoria. Mason, N. A., K. J. Burns, J. A. Tobias, S. Claramunt, N. Seddon, and E. P. Derryberry. 2017. Song evolution, speciation, and vocal learning in passerine birds.