Australian Field Ornithology 2020, 37, 100–104 http://dx.doi.org/10.20938/afo37100104

Copulation, interspecific aggression and other observed behaviours in a breeding pair of Australian Eurasian Fulica atra australis on a small urban wetland

Matthew Mo1* and David R. Waterhouse2

1P.O. Box A290, Sydney South NSW 1232, 24/1–5 Ada Street, Oatley NSW 2223, Australia *Corresponding author. Email: [email protected]

Abstract. A solitary breeding pair of Australian Eurasian Coots Fulica atra australis on a small wetland in Sydney, , was monitored during the 2015–2016 breeding season. Three breeding attempts were observed, during which two nest-platforms were built. Adults incubated eggs for 20–35 minutes at a time. Our monitoring recorded two observations of copulation and 58 observations of aggression towards a conspecific or other waterbird species. Aggression events most frequently involved lone or multiple Dusky Gallinula tenebrosa. Of five chicks recorded in one breeding attempt, only one survived >5 months.

Introduction survivorship. These observations also provide accounts of the timing of breeding attempts and nest change-over. Urban wetlands are suitable breeding sites for several avian species. The Eurasian Fulica atra is a common Methods waterbird that is particularly noted for its success in colonising modified wetlands (Mo 2018) including highly Observations were made at a constructed wetland urbanised areas (Minias et al. 2017). There are four situated within Moore Reserve, an urban park located in recognised, distributed over four continents Oatley and Hurstville Grove, Sydney, New South Wales. (Hashimoto & Sugawa 2013; Minias 2015; Gill & West The wetland spans ~2 ha and is fenced off to the general 2016); the nominate subspecies F. a. atra has the broadest public but visible from all edges by a surrounding walking range from Europe and northern Africa to eastern Asia and track. The vegetation is mainly dominated by Flax-leaved South-east Asia, whereas the Javan Coot F. a. lugubris Paperbark linariifolia, Prickly-leaved Paperbark is confined to East Java and north-western , M. styphelioides and Swamp She-oak Casuarina glauca. the New Guinea Coot F. a. novaeguineae to central New Mo & Waterhouse (2015) provided a more detailed Guinea, and the Australian F. a. australis to description of the study site, including a list of 23 waterbird Australia and New Zealand (Taylor & Kirwan 2020). Many species recorded at the wetland between 2001 and 2014. aspects of the behaviour of Eurasian Coots, including The waterbird assemblage had not changed significantly breeding habits, have been documented, but studies have during the observations in the present study. mainly focused on the nominate subspecies (e.g. Hiraoka 1996; Conigliaro et al. 2011; Lu 2011; Minias 2016). There Our study was prompted by the observation of nesting have been a few detailed but dated studies on breeding Australian Eurasian Coots in early August 2015. We habits in the Australian Eurasian Coot (e.g. Granville 1973; monitored this breeding pair over 39 observation hours Brown & Brown 1980). across 58 days between August 2015 and March 2016. Observation periods ranged from 10 to 135 minutes, during The Australian Eurasian Coot breeds in permanent or which written notes on behaviours such as copulation and ephemeral wetlands (Bedggood 1980; Pedler & Kovac aggression towards conspecifics and other species were 2013), as does the species as a whole (Hiraoka 1996; recorded. We also observed nest change-overs; where the Minias 2016; Walesiak et al. 2019), generally in spring members of the pair relieved each other more than twice and summer though the exact timing of breeding varies within an observation period, the individual incubation geographically (Maclean 1976; Read & Ebdon 1998). times were determined. We also recorded the number of Colonies of up to 30 nests have been recorded, as well as chicks present in each observation period to determine solitary nests on small wetlands (Gosper 1981; Marchant brood survival. & Higgins 1993). The large bulky nests may be situated on floating debris or dense emergent aquatic vegetation (Jackson & Lyall 1964; Macdonald 1968). Both males and Results females participate in incubation and rearing of chicks (Brown & Brown 1980). During the study period, there was a single pair of Australian We undertook an observational study of a breeding Eurasian Coots present at the wetland, as well as one pair of Australian Eurasian Coots during one breeding unpaired Coot. Over the 8 months, three breeding attempts season. Here, we report novel observations on copulation, were observed. The Coots were seen constructing a nest conspecific and interspecific aggression and brood from 9 to 29 August but did not appear to attend to it on Australian Eurasian Coot breeding behaviour 101

Table 1. Number of aggression events towards other waterbirds by Australian Eurasian Coots during different breeding stages, Moore Reserve, Oatley, New South Wales, 2015–2016. The number of that aggression was directed at is shown in brackets.

Species Pre-nesting Nest-building/ Chick-rearing No. aggression incubation events

Australian Eurasian Coot 2 (1 coot) 1 (1 coot, 6 moorhens) 3

Dusky 1 (5 moorhens) 5 (1 moorhen) 2 (1 moorhens) 22

3 (2 moorhens) 1 (2 moorhens)

3 (3 moorhens) 1 (6 moorhens)

3 (4 moorhens) 1 (9 moorhens)

2 (5 moorhens)

Purple Swamphen 4 (1 swamphen) 4 (1 swamphen) 8

Pacific Black Duck 5 (1 duck) 1 (1 duck) 8

1 (2 ducks) 1 (2 ducks)

Chestnut Teal 5 (1 duck) 4 (1 duck) 10

1 (2 ducks) Hardhead 1 (1 duck) 1 Australian Wood Duck 1 (1 duck) 1 Australasian Grebe 1 (1 grebe) 1 (1 grebe) 4

2 (2 grebes) Little Pied Cormorant 1 (1 cormorant) 1

Total 2 38 18 58

31 August. A second breeding attempt was monitored after tenebrosa was the main species involved in these the pair was observed brooding five chicks on a different altercations, followed by the Chestnut Teal Anas castanea, nest on 12 October. The last observation of this brood was Purple Swamphen Porphyrio porphyrio and Pacific Black made on 25 October. From 23 December, observations of Duck Anas superciliosa. Aggression events were all copulation signalled a third breeding attempt, which was triggered by waterbirds being within 5 m of the Coots, monitored until late March, after which the chicks could no except in one case during a period of nest construction longer be located. in which the Coots approached Dusky Moorhens on the water 30 m away to warn them off. Most aggression events were directed towards one Copulation or two birds at any time and generally only involved a brief pursuit; however, we did record 12 altercations with Copulation was observed on two occasions during the 3–9 Dusky Moorhens (Table 1) in which prolonged combat third breeding attempt. On 23 December, the male emitted occurred. In one event, the Coot pair was aggressive a call resembling pitt-pitt-pitt followed by the pair mating towards six Moorhens and one lone Coot. During these on semi-dry land on the edge of vegetative cover. The altercations, Coots typically approached with their wings following day, we observed the same approach behaviour and tails raised vertically (Figure 1). Coots and Moorhens by presumably the male on the water, though the other circled each other until either some of the birds retreated or Coot did not show interest and continued to forage. On the confrontation escalated to physical fighting. 31 December, the second observed copulation occurred During physical fights, Coots or Moorhens either on the water near the edge of the pond. In this event, the ran along the surface of the water at their opponent or male gripped his mate with his bill behind her neck and approached with neck outstretched and head pointing immersed her beneath the water. In both cases, copulation forward. During fighting, birds raked their claws at their lasted only a few seconds. opponent’s breast while flapping their wings and vocalising continually. In some cases, birds leaped on top of each other to push their opponent beneath the water. In Conspecific and interspecific aggression one fight, a Coot held a Moorhen beneath the water for >30 seconds. Fights lasted between 1 and 5 minutes. In We recorded 58 aggression events, predominantly some cases, when one Coot appeared to be overwhelmed during the time that the Coots were building their nests by the Moorhens, its mate left the nest to engage in combat. or incubating (Table 1). The Gallinula In one aggression event, a Coot attempted to chase off a 102 Australian Field Ornithology M. Mo & D.R. Waterhouse

Figure 1. One of the breeding Australian Eurasian Coots approaching an unpaired conspecific in an aggressive posture. Photo: Matthew Mo

Moorhen but was forced to retreat when four Moorhens initial observation and finally to one a further 6 days later. surrounded and pecked at the Coot. The sole surviving chick was consistently observed until 25 March, after which it did not appear to be present at the We also recorded one instance where a Coot pecked an Australian Wood Duck Chenonetta jubata in the back. This wetland. altercation occurred at the beginning of the third breeding attempt on the same day that copulation was observed (Table 1). Discussion

Our observations of the wetland containing only a single Nesting and incubation breeding pair of Australian Eurasian Coots were similar to previously reported accounts on small wetlands (Brown The Coots built two nest-platforms during the study period, & Brown 1980; Gosper 1981). The seasonal timing of both situated on the edge of the pond bordered by reedbed. our observations fits within the breeding season of late Nest-platforms consisted of sedges (Cyperaceae), mostly July to mid January determined for New South Wales in dead strands, arranged to form a base ~50 cm above other studies (Maclean 1976; Bedggood 1980). Our study the water-line. They were ~50–100 cm in width with a demonstrates that this broad timeframe can afford further ramp structure for access. Nest materials were collected breeding opportunities within the year for pairs that have mainly from the reedbed but occasionally floating debris experienced failed breeding attempts. This resembles was used. After initial construction, the Coots continued observations of replacement clutches reported by Brown to gather strands intermittently, particularly as one & Brown (1980). approached the nest to relieve its mate incubating the eggs. Nest-maintenance activity appeared to increase directly after rainfall. Copulation Incubation was observed in the first and third breeding attempts. We recorded more than two nest change-overs There have been few published accounts of copulation within one observation period in the first breeding attempt in the Eurasian Coot (Glutz von Blotzheim et al. 1973; and within four observation periods in the third breeding Cramp & Simmons 1994) and only one in the Australian attempt. Incubation times ranged from 20 to 35 minutes subspecies (Granville 1973). We consider the pitt-pitt-pitt (n = 8). The mean incubation time was 27.5 minutes. calls that we heard from the male to be consistent with the greeting call described by Granville (1973). That account bears some similarity to our observations in that the male Fledgling survival also immersed his mate beneath the water while gripping her neck (Granville 1973). In the nominate subspecies, Observation of chicks in the third breeding attempt allowed multiple copulations daily have been recorded, up to the monitoring of fledgling survival. On 12 October, 12 per day (Cramp & Simmons 1994). Elsewhere, female five chicks were counted, although the brood-size Coots have been recorded avoiding their mate’s courtship from hatching was not known because of lack of earlier chases (Glutz von Blotzheim et al. 1973), as with our observations. Brood-size reduced to three 2 days after the observation. Australian Eurasian Coot breeding behaviour 103

Conspecific and interspecific aggression shown that waterbird aggression is driven primarily by males (Wood et al. 2017). Aggression events recorded in the present study involved We also observed Coots leaping on top of opponents nine of 23 waterbird species reported for the site in Mo & to try to submerge them, which does not appear to be Waterhouse (2015), the majority of which are unlikely to reported elsewhere. Pecking is commonly reported during pose threats to Coot nests or chicks. Similarly, Granville combat (Gullion 1952; Cramp & Simmons 1994; Taylor (1973) observed aggression towards non-threatening & van Perlo 2010); however, we also noted aggression species such as ducks and swans (Anatidae). Of the events that simply involved Coots pecking waterbirds as waterbirds present at our study site, only the Purple they swam past. This behaviour has been reported in the Swamphen and Dusky Moorhen were likely threats to the Australian Eurasian Coot (Bright 1935) but only when other Coots. Purple Swamphens have been known to usurp Coot such as cormorants encroach on their nest. nests (Brown & Brown 1980), and probably prey on Coot chicks based on known predation of other similar-sized waterbirds (Barker & Williams 2002; Balasubramaniam & Nesting and incubation Guay 2008). Similarly, the Dusky Moorhen has also been recorded attempting to prey on similar-sized waterbirds Our observations of Coots constructing two nests nearby (Mo & Waterhouse 2015). The motivational triggers for mirror reports of multiple nesting attempts by Jackson & Coots challenging other waterbirds remains unclear. Lyall (1964). Conversely, in other studies, Coots have re- The aggression behaviours recorded in the present used the same nest for replacement clutches (Brown & study strongly resembled postures and behaviours Brown 1980) and even over subsequent years (Marchant reported in a range of rails elsewhere (Taylor & van Perlo & Higgins 1993). Our observations showed shorter 2010). Our observations of Coots circling opponents incubation times by each Coot than other studies. Change- correspond with ‘patrolling’ behaviour described by Gullion overs reported in Marchant & Higgins (1993) were ‘hourly’, (1952) in studies of the American Coot F. americana. As thus about half the frequency of our observations. with our observations, patrolling typically takes place until the opponent retreats or the confrontation escalates to physical combat (Gullion 1952; Ryder 1959; Burger 1973). Fledgling survival We also observed Coots approaching opponents in the wing-arching posture, which matches the ‘hunched-display’ The five Coot chicks recorded in the third breeding attempt described by Cramp & Simmons (1994). The hunched- fit within the clutch-sizes of three to seven reported display has been reported in the Australian subspecies elsewhere (Macdonald 1968; Brown & Brown 1980). We by Granville (1973). Gullion (1952) reported a similar attribute the disappearance of the lone surviving fledgling to approach behaviour termed ‘swanning’, although Gullion’s dispersal from the wetland based on other authors reporting (1952) descriptions of posture did not specifically include Coot fledglings reaching independence at 5 weeks of age the raised tail that we observed in the present study. (Granville 1973; Marchant & Higgins 1993). Therefore, we consider fledgling survival in this breeding attempt to be Our observations of Coots challenging other waterbirds 20% (one of five chicks hatched), significantly lower than with an outstretched neck and head pointing forward fledgling survival rates of 61–84% in other studies of the strongly resembles ‘shield-showing’ (Cramp & Simmons Australian subspecies (Jackson & Lyall 1964; Macdonald 1994) and ‘charging’ (Gullion 1952) described in overseas 1968) and the nominate subspecies (Alley & Boyd 1947; studies. Coots running at opponents over the surface Askaner 1959; Sage 1969). of the water has also been documented in rails, termed ‘splattering’ by Gullion (1952). In the American Coot, it has been showed to be a relatively effective means of Conclusion eliciting retreat in opponents. Hence, splattering typically enables Coots to mount confrontations while lowering The breeding biology of the Eurasian Coot as a species the probability of escalating to physical combat, unlike is well understood (Brown & Brown 1980; Lu 2011; Minias charging approaches alone (Marchant & Higgins 1993). 2016) but our observations contribute to the limited Splattering has been previously observed in the Eurasian published accounts of copulation (Granville 1973) and Coot (Cramp & Simmons 1994), including the Australian fledgling survival in the Australian subspecies (Jackson subspecies (Macdonald 1968). & Lyall 1964; Macdonald 1968). The present study also Actual physical combat has been observed in a range of further demonstrates that the lengthy breeding season of rails (e.g. Gibbons 1989; Marchant & Higgins 1993). Gullion the Australian Eurasian Coot (Maclean 1976; Bedggood (1952) described combat bouts in the American Coot very 1980) allows breeding pairs to undertake as many as three similar to those that we observed, including Coots sitting breeding attempts within a single breeding season (Brown on their tail and striking their opponent with their claws & Brown 1980). Recorded aggression events involved a and bill to push the opponent off balance and force it onto range of waterbird species, many of which do not appear its back. We observed one particularly escalated fight in to represent any immediate threat. Aggression was most which a Coot held a Dusky Moorhen beneath the water. notable between Coots and Dusky Moorhens, particularly Such fights in rails have been observed to result in death during the nest-building and incubation stage. (Henshaw 1918) and, in the American Coot, when more than two individuals are involved, some may mistakenly Acknowledgements attack their own mate (Gullion 1953). The involvement of We thank Angela Berry and Lachlan Garland for helping to locate both members of a breeding pair in combat bouts is not literature sources. Useful comments from Richard Loyn and two unusual (Cramp & Simmons 1994), although studies have anonymous reviewers helped improve the manuscript. 104 Australian Field Ornithology M. Mo & D.R. Waterhouse

References Macdonald, R. (1968). The Australian Coot established on Virginia Alley, R. & Boyd, H. (1947). The hatching and fledgling success of Lake, Wanganui. Notornis 15, 234–237. some Coot. British Birds 11, 199–203. Maclean, G.L. (1976). Rainfall and avian breeding seasons Askaner, T. (1959). Observations on the breeding biology in the in north-western New South Wales in spring and summer Coot (Fulica atra). Var Fagelvarld 18, 285–310. 1974-1975. Emu 76, 139–142. Balasubramaniam, S. & Guay, P. (2008). Purple Swamphens Marchant, S. & Higgins, P.J. (Eds) (1993). Handbook of Australian, (Porphyrio porphyrio) attempting to prey upon Black Swan New Zealand & Antarctic Birds, Volume 2: Raptors to Lapwings. (Cygnus atratus) eggs and preying upon a cygnet on an urban Oxford University Press, Melbourne. lake in Melbourne, Australia. Wilson Journal of Ornithology Minias, P. (2015). Sex determination of adult Eurasian Coots 120, 633–635. (Fulica atra) by morphometric measurements. Waterbirds 38, Barker, D. & Williams, M. (2002). Breeding of Brown Teal (Anas 191–194. chlorotis) at Okiwi, Great Barrier Island. Notornis 49, 199–208. Minias, P. (2016). Reproduction and survival in the city: Which Bedggood, G.W. (1980). Birdlife between Lake Tyers and Marlo, fitness components drive urban colonisation in a reed-nesting . Australian Bird Watcher 8, 147–162. waterbird? Current Zoology 62, 79–87. Bright, J. (1935). Notes on a few birds of the Rochester District. Minias, P., Włodarczyk, R., Minias, A. & Dziadek, J. (2017). Emu 34, 293–302. How birds colonise cities: Genetic evidence from a common Brown, R.J. & Brown, M.N. (1980). Eurasian Coots breeding on waterbird, the Eurasian Coot. Journal of Avian Biology 48, irrigation dams near Manjimup, . Corella 4, 1095–1103. 33–36. Mo, M. (2018). A survey for waterbirds on the Elizabeth Macarthur Burger, J. (1973). Competition between American Coots and Agricultural Institute demonstration site, Menangle, New South Franklin’s Gulls for nest sites and egg predation by the coots. Wales. Corella 42, 91–98. Wilson Bulletin 85, 449–451. Mo, M. & Waterhouse, D.R. (2015). Responses of brooding Conigliaro, M., Battisti, C., Amori, G. & Luiselli, L. (2011). Diving Australasian Grebes Tachybaptus novaehollandiae to other times and pecking rates of the Eurasian Coot (Fulica atra) waterbirds. Australian Field Ornithology 32, 176–182. in different habitat types: A pilot study. Rendiconti Lincei 22, Pedler, R.D. & Kovac, K. (2013). Waterbirds on the Arcoona 47–53. Lakes in arid , 2007–2010. Australian Field Cramp, S. & Simmons, K.E.L. (Eds) (1994). Handbook of the Ornithology 30, 79–96. Birds of Europe, the Middle East and North Africa. Oxford Read, J.L. & Ebdon, F.R. (1998). Waterbirds of the Arcoona University Press, Oxford, UK. Lakes, an important arid-zone wetland complex in South Gibbons, D.W. (1989). Seasonal reproductive success of the Australia. Australian Bird Watcher 17, 234–244. Moorhen Gallinula chloropus: The importance of male weight. Ryder, R.A. (1959). Interspecific intolerance of the American Coot Ibis 131, 57–68. in Utah. Auk 76, 414–442. Gill, B.J. & West, R.C. (2016). Counts of waterbirds at Western Sage, B.L. (1969). Breeding biology of the Coot. British Birds 62, Springs Lake, Auckland, New Zealand. Notornis 63, 142–151. 134–143. Glutz von Blotzheim, U.N., Bauer, K.M. & Bezzel, E. (1973). Taylor, B. & Kirwan, G.M. (2020). Eurasian Coot Fulica atra. Handbuch der Vögel Mitteleuropas. Band 5. Akademische In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & Verlagsgesellschaft, Frankfurt am Main, Germany. de Juana, E. (Eds). Birds of the World. Cornell Lab of Gosper, D.G. (1981). Survey of birds on floodplain-estuarine Ornithology, Ithaca, New York. wetlands on the Hunter and Richmond rivers in northern N.S.W. Taylor, B. & van Perlo, B. (2010). Rails: A Guide to Rails, Crakes, Corella 5, 1–18. Gallinules and Coots of the World. Pica Press, London. Granville, I. (1973). The behavior of the Australian Coot, Fulica atra Walesiak, M., Górecki, G. & Brzeziński, M. (2019). Recovery of australis (Gould, 1845), during the 1972-73 breeding season Eurasian Coot Fulica atra and Great Crested Grebe Podiceps at Virginia Lake, Wanganui. BSc (Hons) thesis. University of cristatus breeding populations in an area invaded by the Canterbury, Christchurch, New Zealand. American Mink Neovison vison. Acta Ornithologica 54, 73–83. Gullion, G.W. (1952). The displays and calls of the American Wood, K.A., Ponting, J., D’Costa, N., Newth, J.L., Rose, P.E., Coot. Wilson Bulletin 64, 83–97. Glazov, P. & Rees, E.C. (2017). Understanding intrinsic Gullion, G.W. (1953). Territorial behavior of the American Coot. and extrinsic drivers of aggressive behaviour in waterbird Condor 55, 169–186. assemblages: A meta-analysis. Behaviour 126, Hashimoto, H. & Sugawa, H. (2013). Population trends of 209–216. wintering Eurasian Coot Fulica atra in east Asia. Ornithological Science 12, 91–105. Henshaw, F.W. (1918). Some pugnacious coots. Condor 20, 92. Hiraoka, T. (1996). Utilisation of artificial floating objects as Received 25 March 2020, accepted 15 May 2020, nest platforms by Little Grebes and Eurasian Coots in Lake published online 28 July 2020 Teganuma, central Japan. Journal of Yamashina Institute of Ornithology 28, 108–112. Jackson, R. & Lyall, H. (1964). An account of the establishment of the Australian Coot in the Rotorua district with some notes on its nesting habits. Notornis 11, 82–86. Lu, X. (2011). Reproductive ecology of three Tibetan waterbird species, with special reference to life-history alterations along elevational gradients. Zoological Studies 50, 192–202.