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Introduction
In February 2003 the Australasian Bat Society resolved to recommend minimum standards for bat detector surveys and reporting for fauna impact statements, fauna assessments, research papers and survey reports.
These standards require that each report include three features: a sample frequency vs time graph for each species identified during the survey; a description of the characteristics used to distinguish between species and a description of the reference library used (Reardon 2003).
This guide will assist consultants and bat researchers to improve their identifications by supporting their own reference libraries with a large library of bat calls collected from throughout the State. It may help consultants with areas and species they are less familiar with.
The guide will also assist people who use consultants to undertake ultrasonic identification. It will help them understand and monitor results provided to them as graphs without having to acquire an extensive detailed knowledge of how Anabat works.
The guide is not intended to be a replacement for reference libraries; it should support your own local library of calls. We highly recommend that any person undertaking ultrasonic bat identifications record as many reference calls from the area that they intend to work as possible.
Over 1200 reference calls recorded from individuals of known species throughout NSW were used to develop this guide. The guide and calls are available to download from http://www.nationalparks.nsw.gov.au/batcalls. Copies of the reference library may be obtained from Michael Pennay if access to the Internet is not possible or technical problems are experienced.
Background
This guide describes how bats can be identified from the ‘echolocation’ calls used for navigation. Echolocation calls are high frequency sounds made by the bat to assist with navigation, these are usually beyond the range of human hearing (i.e.ultrasonic).
In Australia, as with most other places in the world, only the small insect-eating bat species (known as michrochiropterans or microbats) echolocate. The fruit and blossom bats (known as megachiropterans or megabats) use their eyesight and sense of smell to navigate and to find their food of fruit and blossoms. The echolocation calls of bats are often species specific within a region. By using one of a number of ultrasonic bat detectors (such as the Anabat system used in this guide, Titley Electronics Pty Ltd, Ballina, NSW) recordings of these calls can be made and used to identify bats.
This guide follows on from work done in 2000 to produce the Key to the bat calls of south-east Queensland and north-east New South Wales (Reinhold et al. 2001), which used reference calls collected from throughout that region. Bat calls from other parts of NSW have been much less intensely studied than the North Eastern corner.
At present our data are not comprehensive enough to compile a definitive key of bat calls for the entire State. However, we have produced a guide to those calls we do know, which can be used to assist bat researchers with identifying calls from throughout the State.
Bat detectors have become one of the standard methods for surveying bats since the early 1990’s. They have the benefit of being able to record free flying wild bats without having to capture them. Unfortunately there have been problems of subjectivity and reliability in the identification of the calls recorded (NPWS 1998, Reinhold et al. 2001). The reliability problems appear to have stemmed from two main causes, the underestimation of variation within bat calls, and overlapping call characteristics between some species in certain regions (Reinhold et al. 2001, Reardon 2003).
It has only recently become apparent that the range of call types and call characteristics produced by some Australian bat species can vary considerably even within specific geographic areas. Call characteristics have also been found to vary significantly within a species over its geographic range (Reinhold et al. 2001, Law et al. 2002). Realisation of the extent of variation and potential overlap has increased our awareness of the importance of collecting reference calls from the areas where
Introduction
In February 2003 the Australasian Bat Society resolved to recommend minimum standards for bat detector surveys and reporting for fauna impact statements, fauna assessments, research papers and survey reports.
These standards require that each report include three features: a sample frequency vs time graph for each species identified during the survey; a description of the characteristics used to distinguish between species and a description of the reference library used (Reardon 2003).
This guide will assist consultants and bat researchers to improve their identifications by supporting their own reference libraries with a large library of bat calls collected from throughout the State. It may help consultants with areas and species they are less familiar with.
The guide will also assist people who use consultants to undertake ultrasonic identification. It will help them understand and monitor results provided to them as graphs without having to acquire an extensive detailed knowledge of how Anabat works.
The guide is not intended to be a replacement for reference libraries; it should support your own local library of calls. We highly recommend that any person undertaking ultrasonic bat identifications record as many reference calls from the area that they intend to work as possible.
Over 1200 reference calls recorded from individuals of known species throughout NSW were used to develop this guide. The guide and calls are available to download from http://www.nationalparks.nsw.gov.au/batcalls. Copies of the reference library may be obtained from Michael Pennay if access to the Internet is not possible or technical problems are experienced.
Background
This guide describes how bats can be identified from the ‘echolocation’ calls used for navigation. Echolocation calls are high frequency sounds made by the bat to assist with navigation, these are usually beyond the range of human hearing (i.e.ultrasonic).
In Australia, as with most other places in the world, only the small insect-eating bat species (known as michrochiropterans or microbats) echolocate. The fruit and blossom bats (known as megachiropterans or megabats) use their eyesight and sense of smell to navigate and to find their food of fruit and blossoms. The echolocation calls of bats are often species specific within a region. By using one of a number of ultrasonic bat detectors (such as the Anabat system used in this guide, Titley Electronics Pty Ltd, Ballina, NSW) recordings of these calls can be made and used to identify bats.
This guide follows on from work done in 2000 to produce the Key to the bat calls of south-east Queensland and north-east New South Wales (Reinhold et al. 2001), which used reference calls collected from throughout that region. Bat calls from other parts of NSW have been much less intensely studied than the North Eastern corner.
At present our data are not comprehensive enough to compile a definitive key of bat calls for the entire State. However, we have produced a guide to those calls we do know, which can be used to assist bat researchers with identifying calls from throughout the State.
Bat detectors have become one of the standard methods for surveying bats since the early 1990’s. They have the benefit of being able to record free flying wild bats without having to capture them. Unfortunately there have been problems of subjectivity and reliability in the identification of the calls recorded (NPWS 1998, Reinhold et al. 2001). The reliability problems appear to have stemmed from two main causes, the underestimation of variation within bat calls, and overlapping call characteristics between some species in certain regions (Reinhold et al. 2001, Reardon 2003).
It has only recently become apparent that the range of call types and call characteristics produced by some Australian bat species can vary considerably even within specific geographic areas. Call characteristics have also been found to vary significantly within a species over its geographic range (Reinhold et al. 2001, Law et al. 2002). Realisation of the extent of variation and potential overlap has increased our awareness of the importance of collecting reference calls from the areas where
calls will be analysed. With this has come the development of regional based reference call libraries.
The Australasian Bat Society recently proposed certain standards in bat detector based surveys be adopted as a universally applied protocol throughout Australasia (Reardon 2003). The Australasian Bat Society standards recommend a call analyst to be in possession of, have access to, or be able to produce a reference library of calls for each species from the region where the bat calls are being analysed.
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