Bats in the Bush!


Little Forest Bat (Vespadelus vulturnus)

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NCT's Yellowbox is helping to protect these incredible bats. In the BioBlitz we undertook on Wirran (the Yellowbox property) we had bat expert, Ray Mjadwesch, come along and assess the health of the local bat populations. A variety of different species were detected by both trapping as well as deploying sonar recordings.

Watch the video here:

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Full Bat Report from the Yellowbox BioBlitz on Wirran:

Micro-Bat Survey

Howes Valley: “Wirran” for the Nature Conservation Trust (October 2015)

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This Micro-bat Survey Report has been prepared by Raymond Mjadwesch (BAppSci) of Mjadwesch Environmental Service Support; survey was conducted under OEH SL100530 and under DPI ACEC approval.

The information contained herein is complete and correct to the best of my knowledge. This document has been prepared in good faith and on the basis that neither MESS nor its personnel are liable (whether by reason of negligence, lack of care or otherwise) to any person or entity for any damage or loss whatsoever which may occur in respect of any representation, statement or advice herein.

Acknowledgements: The Nature Conservation Trust funded and hosted the “Wirran” Bioblitz survey; in the field James Forbes, Tiffany Mason (birds), Kate Smillie (2 of Kate’s harp photos are included herein) and Victoria Graham provided appreciated assistance, and a sumptuous menu. Michael Murray (mammals) and Damian Michael (reptiles and amphibians) observations during the survey were also a real treat.

Introduction

“Wirran” is a 344.48ha Nature Conservation Trust property adjoining the north of Yengo National Park, in the Sydney Basin Bioregion of New South Wales. The property and priorities for management are described in the NCT’s Plan of Management – Wirran (2011); this report forms the micro-bat component of surveys of the fauna of the property.

Methodology

Trapping

2 harp traps were deployed on the nights of 12th – 14th October 2015 at “Wirran”; a different habitat type was sampled every night, according to the following stratifications.

Habitat Type 1: Rock Outcrop

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Sandstone outcropping is a frequent occurrence in the local landscape, providing roosting (cliff crevice / cave) and open foraging habitat; this unit was sampled with a harp trap for 1 night.

Habitat Type 2: Boggy Creekline

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Open boggy creek-lines occupy the valley floors, being deep peaty and watered habitats with an open canopy. This unit was sampled for 1 night with a harp trap.

Habitat Type 3: Ironbark Grassy Forest

A small unit of Ironbark grassy forest occurs on a more fertile saddle of the ridgeline in the north-east of “Wirran”; this unit was sampled for 1 night with a harp trap.

Habitat Type 4: Residual Sandstone Forest

A shrubby sandstone forest with grass trees and banksias dominates much of the landscape at and around “Wirran”; this unit was sampled for 2 nights.

Habitat Type 5: White Box Woodland

The mid- to lower slopes of Mount Wareng are often dominated by an open White Box woodland, which extends in sections down to the track through “Wirran” in the east of the allotment. This unit was sampled for 1 night.

Locations sampled are illustrated in the figure below.

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Sonar Detection

An Anabat II sonar recording device was deployed for 3 nights, sampling openings in the canopy in the northern, central and eastern sections of the holding. Locations sampled are illustrated in the figure above.

Results

Harp traps provided 2 Little Forest Bats (Vespadelus vulturnus), with one each at the rock outcrop (Harp 1 Night 1) and in the boggy creek-line (Harp 2 Night 1), and 2 Long-eared Bats (Nyctophilus gouldii) from the Ironbark Forest (Harp 1 Night 2).

Periods over which sonar recordings took place, with counts of the number of calls of each species for each location where recording took place are summarised in the table below.

Table 1. Bat Calls Summary

Common Name Scientific Name Night 1 Night 2 Night 3
2100-0300 2245-0700 2057-0625
White-striped Freetail Bat Austronomus australis 58 3 5
Gould’s Wattled Bat Chalinolobus gouldii 29 1 2
Chocolate Wattled Bat Chalinolobus morio 4
Little Bentwing Bat Miniopterus australis 5 10 2
Common Bentwing Bat Miniopterus schreibersii 2 1
East Coast Freetail Bat Mormopterus norfolkensis 3 13
Freetail Bat Mormopterus Species 4 49 4
Gould’s Long-eared Bat Nyctophilus gouldii 2T
Eastern Horseshoe Bat Rhinolophus megaphyllus 3
Greater Broad-nosed Bat Scoteanax ruepelii 5
Eastern Broad-nosed Bat Scotorepens orion 10 1
Eastern Forest Bat Vespadelus pumilis 19 3
Little Forest Bat Vespadelus vulturnus 10+2T 31 48

Impending rain / locally stormy weather reduced recording time on night 1; lower rates of activity on nights 2 and 3 may have been on account of unsettled and cooler weather in the latter parts of the survey period.

The Australasian Bat Societies standards for bat survey (Reardon 2003) recommend that reports identifying bat species from detected sonar (Anabat) data include samples of frequency vs time graphs, and descriptions of characteristics used to distinguish between species. These follow for all of the bat species identified in this report with the exception of the Long-eared Bat (N. gouldii), with some examples of variations in calls for some species. The reference call library used in these identifications was Bat Calls of New South Wales – Region based guide to the echolocation calls of microchiropteran bats (Pennay M, Law B, Reinhold L 2004).

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Austronomus australis: 10-15kHz, flat to sloping. Identification is certain
Chalinolobus gouldii: alternating between 28 and 32 kHz. Overlaps with Mormopterus ssp at 29-31kHz; call fragments and flat calls from either species, and Momopterus ssp in attack phase, can be confused with each other, but the alternating call illustrated here is definitely that of Chalinolobus gouldii.
Chalinolobus gouldii: alternating between 28 and 32 kHz. Overlaps with Mormopterus ssp at 29-31kHz; call fragments and flat calls from either species, and Momopterus ssp in attack phase, can be confused with each other, but the alternating call illustrated here is definitely that of Chalinolobus gouldii.
Chalinolobus morio: characteristic frequency 52-54 kHz, alternating in shape and frequency
Chalinolobus morio: characteristic frequency 52-54 kHz, alternating in shape and frequency
Minioterus australis: characteristic frequency 54 – 60kHz, tail down-sweeping.
Minioterus australis: characteristic frequency 54 – 60kHz, tail down-sweeping.
Miniopterus schreibersii: characteristic frequency 46 kHz
Miniopterus schreibersii: characteristic frequency 46 kHz
Mormopterus norfolkensis: characteric frequency 31 kHz, flat, some calls alternating by 2 kHz
Mormopterus norfolkensis: characteric frequency 31 kHz, flat, some calls alternating by 2 kHz
Rhinolophus megaphyllus: 68 kHz, call cannot be mistaken for any other species.
Rhinolophus megaphyllus: 68 kHz, call cannot be mistaken for any other species.
Scotorepens orion: characteristic frequency 34-37 kHz, steeply sloping. Easily confused with Falsistrellus tasmaniensis, identified as S. orion on the basis of short down-sweeping tail in some calls (example below).

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Scoteanax ruepelii: characteristic frequency between 32 & 36 kHz.
Scoteanax ruepelii: characteristic frequency between 32 & 36 kHz.
Vespadelus pumilis: characteristic frequency 54-58 kHz, tail hooked.
Vespadelus pumilis: characteristic frequency 54-58 kHz, tail hooked.
Vespadelus vulturnus: characteristic frequency 51-54 kHz, varying within call (tight circling behaviour)
Vespadelus vulturnus: characteristic frequency 51-54 kHz, varying within call (tight circling behaviour)

Some Supplementary Observations

Additional opportunistic observations of an assortment of plants and animals are annotated in the Figure below.

Supplementary photographs from the survey are included on the CD accompanying this report.
Supplementary photographs from the survey are included on the CD accompanying the printed report.

 

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Bibliography

Churchill S 2008 Australian Bats (2nd Ed) Allen & Unwin, Crows Nest

Nature Conservation Trust 2011 Plan of Management for Wirran

Pennay M, Law B, Reinhold L 2004 Bat Calls of New South Wales – Region based guide to the echolocation calls of microchiropteran bats

Reardon T 2003 Standards in bat detector based surveys The Australasian Bat Society Newsletter 20 : 41- 43