Clean and Green Urban Water Bodies Benefit Nocturnal Flying Insects and Their Predators, Insectivorous Bats

Nocturnal arthropods form the prey base for many predators and are an integral part of complex food webs. However, there is limited understanding of the mechanisms influencing invertebrates at urban water bodies and the potential flow-on effects to their predators. This study aims to: (i) understand the importance of standing water bodies for nocturnal flying insect orders, including the landscape- and local-scale factors driving these patterns; and (ii) quantify the relationship between insects and insectivorous bats. We investigated nocturnal flying insects and insectivorous bats simultaneously at water bodies (n = 58) and non-water body sites (n = 35) using light traps and acoustic recorders in Melbourne, Australia. At the landscape scale, we found that the presence of water and high levels of surrounding greenness were important predictors for some insect orders. At the water body scale, low levels of sediment pollutants, increased riparian tree cover and water body size supported higher insect order richness and a greater abundance of Coleopterans and Trichopterans, respectively. Most bat species had a positive response to a high abundance of Lepidopterans, confirming the importance of this order in the diet of insectivorous bats. Fostering communities of nocturnal insects in urban environments can provide opportunities for enhancing the prey base of urban nocturnal insectivores.DFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische Universität Berli

Bats in a Farming Landscape Benefit from Linear Remnants and Unimproved Pastures

Schemes designed to make farming landscapes less hostile to wildlife have been questioned because target taxa do not always respond in the expected manner. Microbats are often overlooked in this process, yet persist in agricultural landscapes and exert top-down control of crop pests. We investigated the relationship between microbats and measures commonly incorporated into agri-environment schemes, to derive management recommendations for their ongoing conservation. We used acoustic detectors to quantify bat species richness, activity, and feeding in 32 linear remnants and adjacent fields across an agricultural region of New South Wales, Australia. Nocturnal arthropods were simultaneously trapped using black-light traps. We recorded 91,969 bat calls, 17,277 of which could be attributed to one of the 13 taxa recorded, and 491 calls contained feeding buzzes. The linear remnants supported higher bat activity than the fields, but species richness and feeding activity did not significantly differ. We trapped a mean 87.6 g (±17.6 g SE) of arthropods per night, but found no differences in biomass between land uses. Wider linear remnants with intact native vegetation supported more bat species, as did those adjacent to unsealed, as opposed to sealed roads. Fields of unimproved native pastures, with more retained scattered trees and associated hollows and logs, supported the greatest bat species richness and activity. We conclude that the juxtaposition of linear remnants of intact vegetation and scattered trees in fields, coupled with less-intensive land uses such as unimproved pastures will benefit bat communities in agricultural landscapes, and should be incorporated into agri-environment schemes. In contrast, sealed roads may act as a deterrent. The "wildlife friendly farming" vs "land sparing" debate has so far primarily focussed on birds, but here we have found evidence that the integration of both approaches could particularly benefit bats.Financial support was provided by a “Science Grant” from The Paddy Pallin Foundation in partnership with the Royal Zoological Society of NSW (http://www.paddypallinfoundation.org.au/index.php/current/sciencegrants), a WildCountry Science Council student top-up (http://www.wilderness.org.au/campaigns/wildcountry/wild-country-science-council-members), the Australian Government’s Department of Industry, Innovation, Science, Research and Tertiary Education Australian Postgraduate Award to PL (http://www.innovation.gov.au/research/researchblockgrants/pages/australianpostgraduateawards.aspx), and a CSIRO student top-up scholarship to PL (http://www.csiro.au/Portals/Careers/Work-experience-and-scholarships/Postgraduate-scholarships/Flagship-Postgrad-Scholarships.aspx). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Global synthesis of conservation studies reveals the importance of small habitat patches for biodiversity

Island biogeography theory posits that species richness increases with island size and decreases with isolation. This logic underpins much conservation policy and regulation, with preference given to conserving large, highly connected areas, and relative ambivalence shown toward protecting small, isolated habitat patches. We undertook a global synthesis of the relationship between the conservation value of habitat patches and their size and isolation, based on 31 systematic conservation planning studies across four continents. We found that small, isolated patches are inordinately important for biodiversity conservation. Our results provide a powerful argument for redressing the neglect of small, isolated habitat patches, for urgently prioritizing their restoration, and for avoiding simplistic application of island biogeography theory in conservation decisions.Peer reviewe

Predicting bee community responses to land-use changes: Effects of geographic and taxonomic biases

Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises

The conservation value of Australia's stock route network : a multi-taxonomic approach to management and planning

Stock routes have been a feature of the Australian landscape since the mid-1800s. Originally established to provide corridors of forage and shelter for livestock droved 'on the hoof', the vegetation within them remained standing while vast tracts in the surrounding landscape were cleared to make way for agriculture. However, livestock are now more commonly transported in trucks, so managing authorities no longer receive adequate income from droving permits to offset costs. At the commencement of this PhD it was being suggested that some stock routes would be lost to freehold tenure, in spite of the fact that many scientists believed them to be of great value for conservation. This project was structured into three distinct sections, aimed at providing evidence for the values of stock routes, and advice on how to best manage and plan for them into the future. The first section took the form of a literature review and spatial analysis, where I demonstrated that stock routes plays a considerable role in biodiversity conservation, recreation, tourism, preserving Indigenous cultural heritage, and as a stock refuge. I also found that they occupy fertile, low-lying areas of the landscape, and contain associated vegetation communities which have been preferentially cleared for agriculture and are under-represented in protected areas. In the second empirical section of the project I conducted surveys of three taxonomic groups which provide ecosystem services: woodland birds, wild bees, and insectivorous microbats. Data were collected from 32 stock routes which varied in width and vegetation condition, and in the fields adjacent to these stock routes. Statistical modelling was then used to quantify the response of each group to local and landscape variables characterising the survey sites. Although specific responses were different for each taxonomic group, there were some consistencies in my findings. Scattered trees in fields had a positive effect on all taxa, and the value of both native pastures and formal conservation areas close to the stock routes was also a recurring pattern. In the final section of my thesis I concentrated on the debate surrounding connectivity; whether it should be included as a goal in conservation planning, and whether this will result in trade-offs with habitat area and quality, or economic costs. It would seem logical to plan for connectivity if some stock routes are to be sold whilst others are retained for conservation purposes. Using them as a case study, I ran a Marxan minimum-set analysis which demonstrated that only certain connectivity approaches had effects on the costs and siting of reserves in conservation planning, and these effects were substantial only when conservation targets were set high. At the time of writing, the future of the stock route network remains as uncertain as it was in 2009. However, through this work I have been able to provide a much more solid foundation for potential conservation decisions than was previously available. I have also demonstrated that the stock route network is an indispensible environmental heritage asset, which should be retained and managed for conservation in perpetuity.-- provided by Candidate

Value of large-scale linear networks for bird conservation: A case study from travelling stock routes, Australia

a b s t r a c t We investigated the potential role of the travelling stock route network, Australia, in the conservation of declining birds. We surveyed 32 linear remnants and 24 adjacent agricultural fields of crop, native pasture or exotic pasture, for woodland birds. Compared to surrounding agricultural fields, linear remnants provided better habitat for woodland birds. Within the remnants, vegetation structural complexity was a better predictor of woodland bird richness than remnant width. In the fields the highest number of species was found in native pastures, and there was also a positive association with the number of scattered trees retained. Interestingly, there was a negative association with the width of the stock route running next to the field, with narrower linear remnants providing a greater source of avian visitors to farmland. Our findings suggest that investments in woodland bird habitat may be best spent protecting smaller, better quality remnants, or enhancing structural complexity of the vegetation already present. Existing networks of linear remnants present a low cost opportunity for regional scale conservation across extensively cleared agricultural landscapes

Managing tensions around urban flying-fox roosts

Flying-foxes are large bats that feed on nectar, pollen and fruit at night, and roost by day in colonies in the thousands. They are amongst the most mobile mammals on Earth and can track changes in floral resources across much of Australia’s north and east, where they are pivotal for pollination and seed dispersal in forests. Populations have experienced declines since European colonisation due to habitat destruction and persecution, and the Grey-headed and the Spectacled flying-fox are listed as threatened nationally

Supporting wild pollinators in a temperate agricultural landscape: Maintaining mosaics of natural features and production

Pollination has received attention recently due to reported sharp declines of . Apis mellifera in several locations, and it has been proposed that diverse native bee communities may be key for continued pollination of economically important crops. However, there is some inconsistency in the literature as to how these communities should best be managed. To address this issue, we collected bees from an intensively managed agricultural region in eastern Australia using blue vane traps. Both linear remnants of vegetation, which form part of a larger corridor network, and adjacent fields of native and exotic pastures, wheat, canola, and lucerne were sampled. A total of 3249 individual bees, representing four families and 36 species were collected. Highly modified environments of nectar-bearing crop supported the most species-rich bee assemblages, and the highest abundance of individual bee species. Distance from the remnants did not limit the body size of species occupying fields (up to 400. m). However, richness of bee assemblages also responded positively to the presence of conservation land in nearby areas, or the number of remnant native trees surrounding traps. Linear remnants of native vegetation contributed to assemblage heterogeneity by adding unique species to the regional pool. Our findings indicate that agricultural industries that currently rely on pollination by . A. mellifera should ensure that intensive land use is complemented by untilled areas in the form of conservation land, or farm dams and scattered trees in fields, to support wild pollinators that may act as insurance against further future losses of managed hives

Value of large-scale linear networks for bird conservation: A case study from travelling stock routes, Australia

We investigated the potential role of the travelling stock route network, Australia, in the conservation of declining birds. We surveyed 32 linear remnants and 24 adjacent agricultural fields of crop, native pasture or exotic pasture, for woodland birds

Scholarly shortcomings and a lack of evidence beleaguer bee sampling critique: A response to Prendergast and Hogendoorn (2021)

Prendergast and Hogendoorn (2021) comment on the ‘methodological shortcomings’ of Australian bee studies, but forgo the opportunity to provide a balanced assessment of the relative merits of different survey methods to inform future studies (for a constructive example of this see Packer & Darla‐West 2021). Instead, they single out standardised survey tools for bees (pan traps and vane traps) as the focus of their criticism and strongly advocate sweep netting and direct observation by skilled entomologists as the ‘pre‐eminen[t]’ methods for bee surveys. They consistently criticise the published work of a small number of Australian authors (particularly ourselves) and claim that any results from pan trap and vane trap samples lead to ‘incorrect conclusions’ about bee biodiversity