Waterbird use of farm dams in south-eastern Australia: abundance and influence of biophysical and landscape characteristics

Abstract

Background: While agriculture has taken much environmental water in Australia's Murray-Darling Basin, agricultural expansion has resulted in a vast number of farm dams, almost three-quarters of a million in the Murray-Darling Basin alone.Methods: Over a summer we studied (1) waterbird abundance and species richness and (2) the influence of biophysical and landscape characteristics across 49 farm dams at a large mixed-enterprise farm in northern Victoria on the southern reach of the Murray-Darling Basin.Results: On average, dams were found to host 27.1 ± 71.1 individuals/ha and 1.8 ± 2.9 species per pond. Such densities are comparable to those on natural wetlands. Dam surface area and perimeter and amount of vegetation were positively and strongly correlated with the Rallidae density (birds/ha), but no other parameters were strongly correlated with any other functional group. The landscape in which the dams were embedded had a highly significant effect (p < 0.001) on the number of birds found on a dam. Conclusions:Our research needs to be complemented with further studies in other parts of the Basin and on other taxa, but given at our site they supported similar densities of individuals and species to natural wetlands, and given the fact that there are 710,539 farm dams in the Murray-Darling Basin, which hosts much of Australia's waterbird fauna, it is reasonable to suggest that farm dams are overlooked, and possibly very important, avian biodiversity hotspots. It also highlights the importance of a landscape setting, in which dams are situated, on the number of birds using the dams.

Improved management of farm dams increases vegetation cover, water quality, and macroinvertebrate biodiversity

“…The Murray-Darling Basin, in southeastern Australia, is the nation's most important food-producing area and supports more than 650,000 farm dams with more than 2.1 GL of water stored, primarily for domestic livestock (Srikanthan et al, 2015). While farms dams can be important for biodiversity conservation (Brainwood and Burgin, 2009) (Hamilton et al, 2017;Hazell et al, 2001Hazell et al, , 2004, degraded dams can have significant negative impacts on the environment such as acting as a major source of greenhouse gases (Ollivier et al, 2019). Enhancement of farm dams to improve vegetation cover around and within them could reduce greenhouse gas emissions and improve water quality, in turn enhancing the value of such areas for livestock production (Willms et al, 2002) and biodiversity (Hamilton et al, 2017).…”

“…While farms dams can be important for biodiversity conservation (Brainwood and Burgin, 2009) (Hamilton et al, 2017;Hazell et al, 2001Hazell et al, , 2004, degraded dams can have significant negative impacts on the environment such as acting as a major source of greenhouse gases (Ollivier et al, 2019). Enhancement of farm dams to improve vegetation cover around and within them could reduce greenhouse gas emissions and improve water quality, in turn enhancing the value of such areas for livestock production (Willms et al, 2002) and biodiversity (Hamilton et al, 2017). However, there is limited information on biodiversity responses to management interventions to improve the condition of farm dams (Lewis-Phillips et al, 2019).…”

Increased livestock weight gain from improved water quality in farm dams: A cost-benefit analysis

“…Finally, we excluded potential positive externalities, including increased biodiversity [ 4 , 24 ], or changes in greenhouse emissions [ 6 ] and mental health effects for farmers. These were not included due to lack of information.…”

“…The production approach we adopted aimed to quantify the benefit of additional weight gain due to consumption of good versus poor-quality water, compared to the costs of installing the requisite dam infrastructure. We did not model any specific positive or negative externalities, although increased biodiversity in renovated dams [ 23 , 24 ], reduced greenhouse gas emissions [ 6 ] and mental health outcomes for farmers (Professor P. Batterham, Director, Centre for Mental Health Research, The Australian National University, personal communication, November 23 2020) are candidates for future analysis. Notably, we also did not account for periodic and acute livestock health issues associated with poor quality drinking water such as poisoning associated with blue green algae blooms or disease outbreaks such as Leptospirosis.…”

The value of artificial farm ponds to Australian eastern long-necked turtles

“…Many of the world's natural wetlands have been drained, filled in, or converted to other types of water bodies during the past three centuries (Davidson, 2014;Hu et al, 2017), with consequent loss of biodiversity and ecosystem services (Kingsford et al, 2016). Conversely, numerous artificial wetlands have been created for various reasons, and can play an important role in conservation of biota such as macrophytes (Hrivna ´k et al, 2014;Bubikova & Hrivna ´k, 2018), invertebrates (Espan ˜ol et al, 2015;Samways et al, 2020), fish (Casas et al, 2011;Davis & Moore, 2016), amphibians (Dalbeck & Weinberg, 2009;Brand & Snodgrass, 2010), birds (Hamilton et al 2017;Giosa et al, 2018) and bats (Stahlschmidt et al, 2012;Sirami et al, 2013). However, anthropogenic wetlands are not necessarily a substitute for natural wetlands, because they may favour different species (Hazell et al, 2004;Bellio et al, 2009;Reyne et al, 2021).…”