BLOSSOM BAT MONITORING REPORT, KOALA BEACH ESTATE, WINTER 2013

Tweed Shire Council

PAGE LEFT INTENTIONALLY BLANK

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TABLE OF CONTENTS

INTRODUCTION ................................................................................................................................................................ 5

SPECIES PROFILE ................................................................................................................................................................... 5 BLOSSOM BAT MANAGEMENT AT KOALA BEACH ....................................................................................................................... 6

STUDY AREA DESCRIPTION ......................................................................................................................................... 7

METHODS ........................................................................................................................................................................... 8

BANKSIA AGE CLASS ASSESSMENT ............................................................................................................................................ 8 BLOSSOM BAT SAMPLING ....................................................................................................................................................... 9 BLOSSOM BAT POPULATION ESTIMATES ................................................................................................................................. 11 RADIO TRACKING ................................................................................................................................................................ 12

RESULTS ........................................................................................................................................................................... 13

TRAPPING RESULTS ............................................................................................................................................................. 13 BANKSIA RESOURCE ............................................................................................................................................................. 16 BLOSSOM BAT POPULATION ESTIMATE ................................................................................................................................... 17 RADIO TRACKING ................................................................................................................................................................ 18

DISCUSSION ..................................................................................................................................................................... 21

COMMON BLOSSOM BAT PLAN OF MANAGEMENT – REVIEW OF PERFORMANCE INDICATORS AND

PAST RECOMMENDATIONS ........................................................................................................................................ 22

BACKGROUND TO THE BBPOM ............................................................................................................................................ 22 REVIEW OF BBPOM PERFORMANCE INDICATORS .................................................................................................................... 23 REVIEW OF RECOMMENDATIONS PROPOSED FOLLOWING THE 2010 BLOSSOM BAT MONITORING ................................................. 24

REFERENCES ................................................................................................................................................................... 26

APPENDIX 1: BLOSSOM BAT MONITORING METHODOLOGY DESCRIBED WITHIN THE BLOSSOM

BAT PLAN OF MANAGEMENT .................................................................................................................................... 28

APPENDIX 2: COAST BANKSIA MONITORING PLOTS........................................................................................ 30

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General Notes

Acknowledgements:

The authors would like to thank the Koala Beach Wildlife and Habitat Management

Committee for supporting the monitoring and to Council’s NRM unit for assistance and

advice. Thanks especially to Marama Hopkins for her ongoing assistance with the project,

Tanya Fountain and Michael Banks for assistance with aspects of the field work, and Greg

Lollback for reviewing the draft report.

Report to be cited as:

Hannah, D. and Lewis, B.D. (2013). Blossom Bat Monitoring Report, Koala Beach Estate,

Winter 2013. Unpublished report to the Koala Beach Wildlife and Habitat Management

Committee on behalf of Tweed Shire Council.

Fauna monitoring licence information:

NPWS - No.S10524

NSW Agriculture Animal Care and Ethics – No:AW2001/040

5

INTRODUCTION

In winter 2007, monitoring using mist nets was undertaken to determine the relative

abundance of the Common Blossom Bat (Syconycteris australis) within a habitat reserve at

the Koala Beach Estate, Tweed Shire. This was the first formal monitoring undertaken for

the Blossom Bat at the Blossom Bat habitat reserve (BBR), in general accordance with the

approved Blossom Bat Plan of Management (BBPoM; Coburn and Markus, 2004). A second

round of monitoring using mist nets within the BBR was subsequently undertaken in July

2010 to compare changes in population estimates between monitoring events and provide

recommendations for future management of the Blossom Bat at Koala Beach.

This report presents results for the third Blossom Bat monitoring event at the BBR. The

monitoring utilised the mist netting methodology from the 2007 and 2010 surveys and also

incorporated a small radio tracking study to collect additional information on Blossom Bat

activity and roosting behaviour.

The aim of the Blossom Bat monitoring is to inform the Koala Beach Habitat and Wildlife

Committee on Blossom Bat habitat utilisation within the reserve and to guide future decision

making regarding habitat management for Blossom Bats within the Koala Beach Estate.

The species profile, and Blossom Bat management at Koala Beach is reproduced below from

the 2010 monitoring report (see Hannah and Lewis, 2010).

Species profile

The Common Blossom Bat is a small nectar/pollen specialist (Law, 1993) occurring

throughout tropical New Guinea south along the coast of Queensland into temperate NSW to

Hawks Nest on NSW mid north coast (Richards, 1983). In contrast to other Megachiropteran

bat species such as the flying-foxes, the blossom bat appears to be solitary, selecting roosts

within dense foliage of rainforest and swamp sclerophyll forests through much of its range

(Richards, 1983, Law, 1993). In northern NSW, roosts are often within close proximity to

exposed coastal heathlands (Law, 1993; Phillips et al., 1995) where bats are known to forage

primarily on the flowers of Coast Banksia (Banksia integrifolia) (Law, 1994 & 1996).

6

In NSW, the Common Blossom Bat is listed as Vulnerable under Schedule 1 of the NSW

Biodiversity Conservation Act 2016. Its listing is primarily due to the suspected reduction in

population and distribution, threatening processes such as clearing of critical winter food

resources, and the specialist nature of the blossom bat’s ecology (DECC, 2005).

Blossom Bat Management at Koala Beach

The presence of the Blossom Bat within the Koala Beach Estate (formerly Searanch) was

confirmed during initial surveys for the Fauna Impact Statement by Phillips et al., (1995). At

that time, it was suggested that the Koala Beach Estate, whilst not supporting a resident

population of the Blossom Bat, did constitute a regionally significant food resource for the

Blossom Bat, particularly during winter months (Phillips et al., 1995). Subsequently, an area

of Blossom Bat habitat consisting of about 1.2 hectares of Coast Banksia dominated forest

was reserved as part of the final subdivision approval (referred to hereafter as the Blossom

Bat Reserve).

The BBPoM was prepared and approved in 2000 and included recommendations for the

management of the reserved Blossom Bat habitat area and for monitoring the use of this

habitat by Blossom Bats (Coburn and Markus, 2000). The rationale for the monitoring was to

establish whether the Blossom Bats are continuing to use the Coast Banksia food resources

regardless of the proximity of housing developments and associated disturbance. The

BBPoM was subsequently revised in 2004 as at the time of preparing the BBPoM, the final

layout details of Stage 5, which adjoins the Blossom Bat Reserve habitat, was not known. It

was recommended in the revised BBPoM that since the monitoring of impacts from the

proximity of housing developments and associated disturbance to the Reserve were yet to be

established, that the annual monitoring proceed from the date of completion of Stage 5 for at

least the prescribed 3 years (Coburn and Markus, 2004). The subdivision certificate for

Stage 5 (A, B and C) of Koala Beach Estate was released December 2004.

In response to the monitoring requirements within the BBPoM, a three-day monitoring

program was initiated within the BBR during July 2007 by Tweed Shire Council. Monitoring

methodology was based on that outlined within the BBPoM. Up until this time, however, no

monitoring of Blossom Bats based on the methods outlined within the BBPoM had been

undertaken. Since the time of initial surveys for the Koala Beach Fauna Impact Statement,

7

only a two-day monitoring episode, one day in June and one day in August 2001, had been

undertaken at the site (Phillips, 2004).

STUDY AREA DESCRIPTION

The Blossom Bat Reserve comprises about 1.2 hectares of Coast Banksia dominated forest

on southern facing slopes of a low ridge within the Koala Beach Estate. The site is bounded

by Stages 4 and 5 in the south and west respectively and forested lands to the north and east

(refer Figure 1). A Tweed Shire Council owned water reservoir is located directly to the east.

The geology and soils are described in Morand (1996) and consists of metamorphics of the

Neranleigh-Fernvale Group, with erodible, strongly acid, hardsetting and dispersive soils of

low fertility (Morand 1996).

Coast Banksia dominates the sub canopy with the occasional emergent Northern Grey

Ironbark (Eucalyptus siderophloia) and Brushbox (Lophostemon confertus). A large

prominent fig was located within the Reserve at the time of surveying. Regenerating

Brushbox, Acacia species, and the occasional Tuckeroo (Cupaniopsis anarcardioides) is

present in the mid to upper stratum. The ground layer is dominated by the introduced grass

(Setaria sphacelata) especially along cleared edges. Native grasses including Kangaroo

Grass (Themeda australis) and Bladey Grass (Imperata cylindrica) were co-dominant

particularly in the south-west and south-east sections of the site.

Adjacent vegetation to the north and east is generally described as sclerophyll open to closed

forest dominated by Coastal Blackbutt (Eucalyptus pilularis), Grey Ironbark, Pink Bloodwood

(Corymbia intermedia), Small-fruited Grey Gum (E. propinqua) and Brushbox, with a

subcanopy of Forest Oak (Allocasuarina torulosa). A patch of about 1.66 hectares of low

Forest Oak dominated forest occurs directly to the north of the BBR and has been similarly

reserved as habitat for the Glossy Black Cockatoo (Calyptorhynchus lathami) which are

known to regularly feed at the site.

8

Figure 1: Blossom Bat Habitat Reserve (yellow polygon), Koala Beach Estate, Tweed

Shire (2015 Aerial photo)

METHODS

Monitoring was generally in accordance with the BBPoM (refer Appendix 1) except where

noted below.

Banksia age class assessment

Blossom Bat monitoring in 2007 investigated Coast Banksia flowering abundance and age

class of Coast Banksia trees (see Hannah and Lewis, 2007). Information was used to better

understand relationships between Blossom Bat densities and food resources at the time of

sampling. The abundance of productive inflorescences was estimated at 9,555

inflorescences per hectare in 2007 which clearly suggested at the time that the BBR was a

‘high-food’ site (after Law, 1996). That is, other ‘high food’ Coast Banksia sites investigated

in northern NSW averaged between approx. 6,500 to 10,000 productive inflorescences per

hectare during peak winter flowering periods (Law, 1996).

9

Monitoring in 2010 and 2013 assessed Coast Banksia age class only to provide updated

information on the successional stage of the food resource. Monitoring of Coast Banksia was

undertaken during the same time period as Blossom Bat sampling. The age class of Coast

Banksia trees was assessed within fifteen permanent plots measuring 5 m x 5 m. Plot

location details are provided in Appendix 2.

Coast Banksia trees located within plots were separated into three age classes based on

height and included juvenile trees < 1.5 m, immature trees 1.5 – 3.0 m, and mature trees >

3.0 m. Coast Banksia are known to first flower after about 2 – 3 years depending on site

conditions (R. James pers. comm., 11/8/07). This has been confirmed from past

observations at the subject site where no trees in the juvenile age class had developed

flowers. Stem diameters for trees beyond about 3 m tall were distinctly larger than those

within the immature height class and were therefore considered mature (pers. obs.).

Senescing or dead Coast Banksia trees were also recorded within plots to determine the

influence of drought or other natural or stochastic events effecting the community.

Blossom Bat sampling

Blossom Bats were sampled over three consecutive nights from the 25 to 27 July 2013.

Timing was consistent with the 2007 and 2010 monitoring events in regards to seasonality

and coinciding with estimated peak flowering of Coast Banksia at the site. Weather data for

the monitoring period was summarised from the Bureau of Meteorology Station located at

Coolangatta Airport (refer Table 1 below). In brief, temperatures were mild and there was no

rainfall recorded on site during mist netting.

Table 1: Weather data during survey period

Date Min. o/night temp. (0C)

Max. daily temp. (0C)

Rainfall (mm)

25/07/2013 14.5 19.7 0 26/07/2013 12.4 21.8 0.4 27/07/2013 10.5 22.1 0

(Source: Coolangatta Station, Bureau of Meteorology)

Bats were captured using 1-inch gauge monofilament mist-nets measuring 9 m, 12 m and 18

m lengths. All nets consisted of 4 shelves, and were set between 2 - 5 m above the ground.

Nets were attended at all times by at least two experienced observers and furled during day

light hours. For each night of mist netting, five nets consisting of 2 x 12 m nets, 1 x 18 m net,

10

and 2 x 9 m nets were set. The number of nets open at any one time varied depending on the

activity of bats and non-target nocturnal fauna such as flying foxes.

Net sizes and their placement configurations were generally the same for all three monitoring

events. In general, mist-nets were open between 1830 and 2400 hrs. Mist netting effort is

summarised in Table 2.

Mist-nets were distributed primarily along the top of the ridge and the southern facing mid-

slopes as Banksias in this area appeared to contain more inflorescences. Once established

prior to trapping on the first evening, mist-nets were left in-situ over the three nights. Net

avoidance did not seem to be an issue during past monitoring events and was similarly not

considered to be relevant to the current monitoring event.

Captured blossom bats were removed immediately from nets, aged (i.e. adult or juvenile),

and their sex noted. On the first two nights of trapping, captured Blossom Bats were marked

with a texta-paint on their dorsal fur with the location of marking differing between nights 1

(head) and night 2 (rump). This enabled a population estimate to be derived if one or more

individuals were recaptured during the course of the field survey. Bats were always released

at point of capture and as soon possible after being captured (bats would not be held

overnight and released the following evening). When multiple bats were caught at the same

time, they were held in separate cloth bags until being released. Care was taken when

handling flying foxes, Blossom Bats, and microbats due to the risk of Australian Bat

Lyssavirus. The proposed procedure for using mist nets considered the ARRP Wildlife

Survey Guidelines and the DEC Threatened and Biodiversity Survey and Assessment -

Guidelines for Developments and Activities.

Blossom Bat abundance was calculated based on a catch per unit effort approach. That is,

the number of bats captured per 100 mist-net metre hours (nmh). This approach is

consistent with the other studies in similar habitats in northern NSW (e.g. Law 1993, 1994,

1996) and would then lend itself to direct comparisons with those studies.

Table 2: Summary of Blossom Bat mist netting effort, Koala Beach 2013

Date / Location name

Net reference

Net length

(m)

Time open

Time closed

Hours open

nmh / net

nmh / night

Night 1 25/7/13

top 12 N1 12 19.00 24.00 5 60

11

Date / Location name

Net reference

Net length

(m)

Time open

Time closed

Hours open

nmh / net

nmh / night

top 9 N2 9 19.00 24.00 5 45

mid 12 N3 12 19.15 23.45 4.5 54

mid 9 N4 9 19.00 23.45 4.75 42.75

bottom 18 N5 18 19.30 23.30 4 72 273.75

Night 2 26/7/13

top 12 N1 12 18.45 23.30 4.75 57

top 9 N2 9 18.30 23.30 5 45

mid 12 N3 12 18.45 23.15 4.5 54

mid 9 N4 9 18.30 23.15 4.75 42.75

bottom 18 N5 18 18.45 23.15 4.5 81 279.75

Night 3 27/7/13

top 12 N1 12 18.30 23.45 5.25 63

top 9 N2 9 18.45 23.45 5 45

mid 12 N3 12 19.00 23.30 4.5 54

mid 9 N4 9 18.45 23.30 4.75 42.75

bottom 18 N5 18 19.30 23.00 3.5 63 267.75

Total nmh

821.25

1 nmh = length of respective mist-net multiplied by the length of time each net was deployed

Blossom Bat population estimates

Because there were three nights of sampling and individuals were not identifiable, the

Schnabel method (Schnabel, 1938) was used to estimate abundance. This method is an

extension of the popular Petersen method that is limited to two trapping occasions. Like the

Petersen method, the Schnabel method assumes that the population size is closed,

probability of capture does not change throughout the sampling periods, capture probability is

equal for all individuals and marks are not lost (Krebs, 1989). Considering the short trapping

period and the methodology used, it is likely all assumptions were met. Schnabel’s population

estimate is:

�̂� =Σ(𝐶𝑡𝑀𝑡)

Σ𝑅𝑡

where:

Ct = total number of individuals caught in sample t;

Mt = number of marked individuals in the population just before sample t was taken;

Rt = number of individuals marked for the first time and released in sample t.

12

The associated standard error is calculated as:

𝑆𝐸 = √Σ𝑅𝑡

(Σ𝐶𝑡𝑀𝑡)2

Radio Tracking

Radio tracking of two females and two males to investigate day roosting habitats of Blossom

Bats was undertaken during monitoring at the BBR. The roosting location for bats was

recorded using GPS and included a description of the roost site including vegetation

characteristics and topographic location.

The radio tracking methodology was generally as follows:

Transmitters were single stage glue-on type VHF transmitter weighing 0.95 grams.

Battery life was approximately 32 days @ 30 pulses per minute.

Transmitters were estimated to weigh approx. 5.9% of the mean body weight of

Blossom Bats (ranging between 5.3% for females and 6.3% for males). Estimates

were based on previous trapping data from the BBR.

Pregnant or lactating females were excluded from the study.

Prior to attachment, each transmitter was tested for functionality.

Captured Blossom Bats selected for radio tracking were removed immediately from

nets, aged (i.e. adult or juvenile), and their sex noted.

Their dorsal fur was clipped and the transmitter glued (using 'Supaglue' or Vetbond)

to the fur mid-dorsally between the shoulder-blades, with the aerial protruding

posteriorly.

The bat was then held within the catch bag and allowed to become accustomed to the

transmitter prior to releasing at the point of capture.

Bats were then radio tracked immediately to understand their activity post release.

Bats were then radio tracked each day and night to gain information on roosting and

activity at the BBR.

Radio tracking commenced on the 26 July 2013 (the second day of trapping) and

continued until the 22 August 2013.

13

Searches for roosting bats involved traverses on foot into adjacent bushland areas

within the Koala Beach Estate, as well as driving searches targeting suitable roosting

habitat (identified from published literature) in surrounding areas including Pottsville,

Hastings Point, Round Mountain, Cudgera Creek, and Reserve Creek. On one

occasion, scanning for bats was undertaken for a 1.5-hour period from a helicopter

(Robinson 22) flying low over the search areas noted above.

Blossom Bats were not intended to be re-captured to remove transmitters given that from

past experience with radio tracking insectivorous bats and as reported in the literature,

transmitters are generally gleaned or groomed off in 1-2 weeks after attachment. For

example, Campbell (2009) noted that for Myotis macropus, transmitters tended to be

groomed off after an average of 6.2 ± 0.6 days (n = 10). Spencer and Fleming (1989) noted

that Nyctimene robinsoni (a small Fruit Bat slightly larger than the Blossom Bat) is very adept

at using its thumb claws to tear off a radio tag attached to its body, with transmitters

dislodged after 3 days given sufficient purchase. Spencer and Fleming (1989) changed the

glue type used and ensured sufficient adhesion, although still noted that transmitters had

fallen off after 5-8 days. Law (1993) noted in his study of Blossom Bats in northern NSW that

Blossom Bats recaptured after transmitters had been scratched off, showed no signs of skin

damage and had not lost weight (n = 5 bats).

RESULTS

Trapping results

Mist netting returned a total of 18 captures of 13 individuals from 821.25 nmh (Table 3).

Total captures were similar to 2007, where 19 captures from 14 individuals were recorded;

albeit from less mist net hours, which totalled 586.5 nmh in 2007. Captures were highest in

2010 where trapping returned a total of 33 captures from 24 individuals over a total of 717

nmh. The ratio of males to female bats captured was 9 males to 5 females in 2007, 12 males

to 12 females in 2010, and 4 males to 8 females during the 2013 monitoring; that 2013 result

showing a sex bias of females to males (refer Table 4). This bias was similarly evidenced

when looking at total captures with 12 females to 6 males (includes re-captures).

Captures of Blossom Bats increased steadily over the three trapping nights monitoring in the

current study (refer Table 3 and Figure 2). However, when comparing capture rates per 100

14

nmh across all monitoring events, the 2013 monitoring event was amongst the lowest capture

rates recorded at the BBR (refer Figure 3).

During the current monitoring, all bats captured on night 1 (n = 3) were recaptured on night 2.

These three bats were then recaptured on night three. Note that these three bats were

carrying transmitters although one of the females had gleaned the transmitter off on night 1

but could still be identified during subsequent trapping nights from the trimmed dorsal pelage

and paint markings.

Captures per mist-net metre hours among hourly periods from dusk until midnight were

compared for the 2007 and 2010 monitoring events. Captures were highest between about

1830 and 1930 hours for both years, then trailing off to no captures after 2130 hrs in 2007

and 2230 hrs in 2010 (refer Hannah and Lewis, 2010). This trend was similar for the 2013

monitoring with highest numbers of bats captured between 1900 and 2200 hrs. Only 1 bat

was captured between 2200 and 2300 hrs and no bats captured after 2300 hrs.

Table 3: Summary of blossom bat captures during sampling

Sampling event nmh

Number of bats captured Night 2*

Night 3 ^ Night 3 ^^

Night 3 ^^^

Night 1 273.75 3 n/a n/a n/a n/a

Night 2 279.75 6 3 n/a n/a n/a

Night 3 267.75 9 n/a 0 0 3

Total 821.25 18

* Recaptures from Night 1; ^ re-captures of bats caught Night 1 only; ^^ re-captures of bats caught N2 only; ^^^ re-captures of bats caught N1 and N2.

15

Figure 2: Captures of Blossom Bats averaged over 100 nmh over three consecutive

nights (N1, N2 and N3) in 2013

Figure 3: Comparison of average Blossom Bat captures per net metre hours among

all monitoring events within the Koala Beach Estate

2.18

3.9

3.2

4.6

2.2

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

August 1994(Phillips et. al.

1995)

June&August2001 (Phillips

2004)

July 2007(Hannah &

Lewis 2007)

July 2010(Hannah andLewis 2010)

July 2013(presentstudy)

No

. b

losso

m b

ats

/100 n

mh

16

Table 4: Summary of blossom bat captures among sexes

Sampling event sex

Number of bat

captured

Night 2 (Re-captures from N1)

Night 3 (Re-captures from N2)

Night 3 (Re-captures from N1 & N2)

nmh

Night 1 273.75

male 1 n/a n/a n/a

female 2 n/a n/a n/a

Total new individuals 3

Night 2 279.75

male 1 1 n/a n/a

female 2 2 n/a n/a

Total new individuals 3

Total recaptures 3

Total captures 6

Night 3 267.75

Male 2 n/a 0 1

female 4 n/a 0 2

Total new individuals 6

Total recaptures 3

Total captures 9

Grand total individuals male 4

female 8

Total recaptures male 2

female 4

Total captures male 6

female 12

18

Banksia resource

Plot data yielded 49 Coast Banksia trees from the 15 plots (375 m2) compared to 60 and 57

trees recorded in 2010 and 2007 respectively. Approximately 63% of Coast Banksia trees

during the 2013 count were classed as mature (up from 53% in 2010) and 16% as immature

(slightly down from 22% in 2010). Percentage of juvenile Coast Banksia in 2013 plots had

increased from 3% in 2010 to 20% in 2013 suggesting some ongoing recruitment of the

banksia foraging resource. Average numbers of trees in all age classes is presented in

Figure 4 below.

17

Figure 4: Comparison of 2007, 2010 and 2013 Coast Banksia age classes determined

from plot counts

Blossom Bat population estimate

The mark-recapture study estimated that 12 (± 0.03 SE) Blossom Bats occurred in the BBR

(~1.2 ha) at the time of the survey. This equates to 10 bats per hectare. A comparison of

population estimates between the three monitoring events since 2007 is presented in Table

5. The number of bats caught and the ratio between the number of bats caught and the

number of recaptured bats differed between years. While there was a large difference in

abundance estimate between 2010 and 2013, the three trapping sessions were not enough

to indicate a strong decline.

Table 5: Blossom Bat population estimates (SE) corrected to bats per hectarea

returned from 2007, 2010 and 2013 monitoring at Koala Beach Estate.

2007 population estimate (bats/ha)

2010 population estimate (bats/ha)

2013 population estimate (bats/ha)

24 (0.05)

29 (0.01)

12 (0.03)

a = divide estimate by 1.2 ha; note that 2007 and 2010 estimates have been re-calculated based on the Schnabel method (Schnabel, 1938).

18

Radio tracking

A total of five bats with an average weight of 15.875 ± 1.3 g (SD) were captured and

equipped with transmitters and tracked intermittently, day and night, for 27 days. Transmitters

were all 6% or less of total body mass of bats. Transmitters from two bats were found; one

from a female (TX262) underneath a Coast Banksia at the BBR the following day after being

attached, and one from a second female (TX241) 16 days after attachment. The transmitter

found at the BBR was reattached to a female Blossom Bat captured on the second night of

trapping.

Two of the radio tracked bats were tracked to roosts; one female to six different roosts

(TX222) and a second female to one roost (TX241) (refer Figure 5). The transmitter relating

to TX241 was located on the ground in a gully about 730 m north of the BB Reserve. The

transmitter was presumed to have been gleaned off while the bat was at the roost.

A female Blossom Bat (TX222) was tracked to six separate roosts, all within Brushbox

(Lophostemon confertus) open forest with a regenerating rainforest understorey. All roosts

were in a localised area about 300-400 m from the BBR. On five of the six occasions when a

roost site was located, TX222 was visually observed at the roost and was always solitary.

Over a five day period from the 26-30 July 2013, TX222 was recorded at five separate roosts.

Roost 1 (R1) was about 1.1 m above the ground in suspended dead Brushbox leaves within

a Domatia tree (Endiandra discolor). R2 was under a Cabbage Palm frond (Livistona spp.)

about 2.2 m above the ground. R3 was inside exfoliated Brushbox bark suspended about 1.5

m above the ground in a Broad-leaved Lilly Pilly (Acmena hemilampra). R4 was within the

same gully as R3 and in dead Brushbox leaves, suspended 1.8 m above the ground in a

Plum Myrtle (Pilidiostigma glabrum). R5 was approx. 20 m from R2, within Brushbox bark

about 2.0 m above the ground suspended in a Plum Myrtle. A sixth roost site (R6) for TX222

was recorded on the 4 August 2013. The roost was located within dead Brushbox leaves

suspended in a Domatia tree about 1.7 m above the ground.

Bats with radio transmitters were monitored periodically at the BBR between 4 and 6 hours

after dusk to understand their fidelity to the banksia foraging resource. One bat (TX222)

visited the BBR every night for 13 consecutive nights then was not recorded again. On seven

occasions, the bat was recorded at the BBR within the first hour after dusk. On two

19

occasions, TX222 was recorded leaving the nearby gully roost area and flying directly to the

BBR.

A male Blossom Bat (TX281) was recorded at the BBR on eight separate occasions between

the 26 July and the 22 August 2013. On three occasions TX281 was recorded within the

BBR in the first hour after dusk. Despite this, no roost sites were located for TX281 in the

Koala Beach Estate or nearby surrounding areas.

20

Figure 5: Blossom Bat roost locations with bat identification.

21

DISCUSSION

For each monitoring event, the age classes of Coast Banksia trees were counted. For this

period, there were slightly more juvenile trees counted compared to the two previous

monitoring events, an increase in the number of immature trees counted, minimal change in

the numbers of mature trees and a decline in the number of dead trees counted since 2010.

These differences however don’t appear to be significantly different.

This lack of recruitment of juvenile Coast Banksia trees has been identified previously at the

BBR. A review of threats on Blossom Bats and their habitats (summarised in Hannah and

Lewis, 2007, 2010) suggested that many areas of Banksia integrifolia healthland are in

senescence due to: germination and recruitment suppression by weed infestations (AKF,

2004); high seedling mortality rates due to grazing by herbivores and intense competition for

soil moisture during summer (Price and Morgan, 2003); and the absence of fire creating

unsuitable soil conditions (Bennett and Attiwill, 1996). Disturbance trials within the BBR

(including the use of fire to suppress grassy weeds and stimulate soil conditions) undertaken

during 2008 and 2012 did not result in significant regeneration (pers. comm. Rhonda James,

Bushland Restoration Services, May 2013). The trials highlighted the importance of ongoing

weed control as the primary control measure to facilitate regeneration of Coast Banksia at the

site in addition to exclusion of the Swamp Wallaby from plots within the reserve as a

secondary measure.

Existing information on Blossom Bat roosting habitat from the Koala Beach area is limited to

bats radio tracked to three separate roosts by Phillips et al. (1995) and consisted of a

Syzygium oleosum in swamp oak forest about 300 m south-east of the Blossom Bat Reserve,

a banana plantation and adjacent wet sclerophyll/rainforest vegetation about 2.5 km to the

north west of the site, and wet sclerophyll/rainforest vegetation about 5.5 km south south-

west from the site. This current study contributes further information on roosting locations

within the local area – all of which occur within public land managed for conservation

purposes. Roosts detected in this study were all located in lower canopy rainforest species

in Brushbox sclerophyll forest. These roost types are considered typical for Blossom Bats in

northern NSW (see Law, 1993).

Based on distances to roosts recorded by Phillips et al. (1995), it was highlighted in the

BBPoM that the substantial commuting distances recorded for these bats indicate that the

BBR is likely to represent a locally and regionally significant food resource for the species

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(Markus and Coburn, 2000). Phillips et al. (1995) also suggested that the Koala Beach site,

while providing temporary roosting sites at specific times through the year, does not support

a resident population of Blossom Bats. Winter monitoring, including radio tracking of bats in

the present study, suggests that the BBR is continuing to provide an important food resource

for Blossom Bats; the repeated returns to site by radio tracked bats supporting this.

Of further note is that vegetation within the broader area is likely to have changed since the

time of the initial surveys in 1994 through removal of cattle grazing, an absence of fire,

ongoing weed management and supplementary planting. This is likely to have influenced

understory vegetation structure and composition resulting in a transition towards a rainforest

understory. As a result, it is feasible that parts of Koala Beach Estate could support a

resident population of the Blossom Bat. Monitoring at other times of the year may assist in

addressing this management question.

COMMON BLOSSOM BAT PLAN OF MANAGEMENT – REVIEW OF PERFORMANCE

INDICATORS AND PAST RECOMMENDATIONS

Background to the BBPoM

The main objective of the management of the Blossom Bat at Koala Beach Estate is to

facilitate the continued use of the site by the species for the purposes of both roosting and

foraging. To facilitate this, the BBPoM proposed three key objectives:

1. To maintain and enhance the available resources for this species within and outside the

identified significant habitat (i.e. the Blossom Bat Reserve) to ensure that the regional

importance of the site as a food resource is not lost as a result of development.

2. To monitor the Blossom Bat population on the Koala Beach site at intervals throughout the

development period to assess whether the primary objective, i.e. that the site continues to be

used by this species, has been achieved.

3. To collect baseline information about the Blossom Bat population using the Koala Beach

site, i.e. approximate numbers, sex ratios, demographics, distribution of roost sites etc. for

future comparative purposes.

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Management measures proposed within the BBPoM included:

weed management to limit degradation and habitat quality

community involvement and education

fire management (to reduce fire hazard impacting on Banksia recruitment) and

site enhancement strategies such as supplementary planting and restricted access.

In addition, the BBPoM proposed that management objectives also be undertaken externally

to the Reserve through enhancement plantings around the estate, monitoring of large

isolated Coast Banksia trees for Blossom Bat activity, and actively managing other potential

roosting areas on the site.

Review of BBPoM Performance Indicators

Performance indicators were established as part of the BBPoM to gauge the success of the

plan through establishing whether the Blossom Bats are continuing to use the site and the

likely size of the population utilising the site from year to year. The performance measures

from the BBPoM are addressed in Table 6 below based on outcomes of the 2013 monitoring

event.

Table 6: Blossom Bat Plan of Management Performance Measures (Coburn and

Markus, 2000)

Performance indicators Response

Successful maintenance and regeneration of Coast Banksia stands within and beyond the area of significant habitat;

Ongoing management within the Reserve is maintaining a local and regional food resource for Blossom Bats within the BBR. The monitoring to date has not assessed Coast Banksia stands beyond the Reserve.

Maintenance of the area of significant habitat in its current undeveloped state; and

The BBR is fenced and gated. There was very little evidence of illegal access and associated activities such as illegal dumping of rubbish. Following the 2007 monitoring, regular slashing of a fire break through the reserve was initiated and is ongoing.

Comparison of the number of captures of Blossom Bats per metre/hour between years.

Blossom Bat captures per unit effort within the BBR have remained stable since surveys commenced in 1994.

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Review of recommendations proposed following the 2010 Blossom Bat Monitoring

The following recommendations were proposed following the 2010 Blossom Bat monitoring

and aimed to facilitate the continued use of the site by the Blossom Bat for the purposes of

both roosting and foraging. These recommendations are reviewed in Table 7 below.

Table 7: Review of 2010 Blossom Bat monitoring recommendations

2010 Recommendation Response following 2013 monitoring

Blossom Bat monitoring recommendations

Recommendation 1: Given that development is ongoing within the Koala Beach Estate, monitoring of the Blossom Bat population is recommended at the current frequency of every 3 years.

Another round of monitoring is supported given that development of the Estate is nearing completion. This monitoring could be expanded to other key food resource planting areas.

Recommendation 2: Monitoring of the Blossom Bat resource including age-class assessment should be undertaken in accordance with Blossom Bat population monitoring to ensure assisted regeneration activities are facilitating Coast Banksia recruitment within the habitat reserve.

Ongoing in association with Blossom Bat population monitoring

Recommendation 3: The identification and subsequent development of a proposal to monitor a selection of isolated Coast Banksia trees as per the BBPoM should be investigated and discussed with the Koala Beach Wildlife and Habitat Management Committee (KBWHMC) for consideration and feasibility. This aspect of the BBPoM has not been addressed to date.

Not addressed to date. It is recommended that mapping of Coast Banksia trees within (and nearby) to the estate is considered and these areas incorporated into the broader site management / restoration actions.

Recommendation 4: As proposed within the recommendations of the 2007 Blossom Bat monitoring report, consideration should be given to implementing a radio tracking study in conjunction with a Blossom Bat monitoring event to better understand whether a resident population of Blossom Bats occurs within the estate.

Completed – 7 new roosting locations recorded and all occurring within lands managed for conservation purposes associated with the Koala Beach Estate.

Habitat management recommendations Note - Past disturbance trials (including plot burns) have been undertaken within the Reserve although did not result in any significant increase in Coast Banksia seedling recruitment. Consequently, the key habitat management measure recommended for the Reserve is ‘ongoing assisted regeneration through control of woody weeds and exotic grasses’.

Recommendation 5: Ongoing assisted regeneration through control of woody weeds

Ongoing

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and exotic grasses within and adjacent the Blossom Bat habitat reserve is supported to ensure that the regional importance of the site as a food resource for Blossom Bats is maintained.

Recommendation 6: Slashing of the two existing tracks within the Reserve should be ongoing to ensure fire protection for the site. Currently, Tweed Shire Council undertakes this slashing funded through the Koala Beach environmental levy program.

Ongoing

Recommendation 7: Exclusion of herbivores (swamp wallaby/hare/rabbits) using tree guards (or similar) around Coast Banksia seedlings is proposed to help facilitate juvenile tree recruitment.

Status of this recommendation needs to be confirmed. This action to be discussed with bushland restoration contractors to determine necessity and/or feasibility.

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REFERENCES AKF (2004). Koala Beach, Koala Plan of Management, Report prepared for the Ray Group Pty. Ltd., February 2004. Bennett, L. T. and P. M. Attiwill (1996). "The Nutritional Status of Healthy and Declining Stands of Banksia Integrifolia on the Yanakie Isthmus, Victoria". Australian Journal of Botany, 45: 15–30. Campbell, S. (2009). So long as it’s near water: variable roosting behaviour of the large-footed myotis (Myotis macropus). Australian Journal of Zoology, 57: 89–98. Coburn, D. K. and Markus, N. (2004). Plan of Management for the Queensland Blossom Bat Syconycteris australis on the Koala Beach Residential Estate; prepared in accordance with conditions relating to the NSW National Parks and Wildlife Service License No. TS0092 on behalf of the Australian Koala Foundation, DECC (2005). Common Blossom Bat, NSW Department of Environment: http://www.environment.nsw.gov.au/threatenedspeciesapp/profile.aspx?id=10785. Hannah, D. and Lewis, B.D. (2007). Blossom Bat Monitoring Report, Koala Beach Estate, Winter 2007. Report to the Koala Beach Wildlife and Habitat Management Committee on behalf of Tweed Shire Council. Hannah, D. and Lewis, B.D. (2010). Blossom Bat Monitoring Report, Koala Beach Estate, Winter 2010. Unpublished report to the Koala Beach Wildlife and Habitat Management Committee on behalf of Tweed Shire Council. Krebs, C.J. (1989). Ecological Methodology. HarperCollinsPublishers: New York Law, B.S. (1993). Roosting and foraging ecology of the Queensland Blossom Bat (Syconycteris australis) in north-eastern New South Wales: Flexibility in response to seasonal variation. Wildlife Research, 20: 419-431. Law, B.S. (1994). Banksia nectar and pollen: dietary items affecting the abundance of the Queensland Blossom Bat Syconycteris australis in southern Australia. Australian Journal of Ecology, 19:425-434. Law B.S (1996). Residency and site fidelity of marked populations of the common blossom bat Syconycteris australis in relation to the availability of Banksia inflorescences in New South Wales, Australia. Oikos, 77: 447-458. Morand D.T., 1996, Soil Landscapes of the Murwillumbah-Tweed Heads 1:100,000 Sheet map and report, NSW Department of Land and Water Conservation. Phillips, S. 2004. Koala Beach Stage 1 Initial Koala Monitoring Program Results for Koala Beach Community Koala Management Committee; in AKF 2004, Eight Part Tests for Significance, Sports Fields and Access Road, Koala Beach Estate, Pottsville. Phillips, A. Parnaby, H, and Fitzgerald, M. (1995). Fauna survey of lands associated with the proposed Searanch residential development, Tweed Shire, New South Wales. Consultants report to RDC Pty. Ltd.

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Price, J.N. and J.W. Morgan (2003). Mechanisms controlling establishment of the non-bradysporous Banksia integrifolia (Coast Banksia) in an unburnt coastal woodland. Austral Ecology, 28: 82-92. Richards, G.C. (1983). The Queensland Blossom Bat, In The Complete Book of Australian Mammals. Ed R. Strahan. Angus and Robertson: Sydney. Schnabel, Z.E. (1938). The estimation of the total fish population of a lake. The American Mathematical Monthly, 45: 348-352. Spencer, H.J. and Fleming, T.H. (1989). Roosting and Foraging Behaviour of the Queensland Tube-nosed Bat, Nyctimene robinsoni (Pteropodidae): Preliminary Radio-tracking Observations. Aust. Wildlife Research, 16: 413-20. Watson, P. (2006). Fire Frequency Guidelines and the Vegetation of the Northern Rivers Region, Draft 2. Report prepared for the Hotspots Fire Project.

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APPENDIX 1: BLOSSOM BAT MONITORING METHODOLOGY DESCRIBED WITHIN

THE BLOSSOM BAT PLAN OF MANAGEMENT

Monitoring is to be undertaken in accordance with the current adopted Blossom Bat Plan of

Management and is described as follows:

1 (a) Monitor use of the reserved Blossom Bat habitat area and additional Coast Banksia

(Banksia integrifolia) habitat over one survey period between July and September. The

timing of monitoring should coincide as far as possible with peak flowering of Coast Banksia

on the site.

1(b) Monitoring includes mist-netting for Blossom Bats in the Blossom Bat habitat area and

should comprise a minimum of 1000 net metre/hours over 3 consecutive nights. (note from

authors – refer 2007 monitoring report for review on minimum mist net hours which

was refined to a minimum of 500 mist net hours to record 10 Blossom Bats)

1(c) Record the sex, weight, reproductive status, any signs of illness or injury, and forearm

length for each captured individual.

1(d) Temporarily mark captured individuals by application of nail polish or similar non-harmful

marking to the claws on the feet of individual bats to identify return visits.

1(e) It is recommended in the Plan of Management that existing large Coast Banksias within

the residential development at the Koala Beach Estate which may also serve as food

resources for the Blossom Bat be the subject of monitoring. Identification of suitable trees

and co-operation of landholders should be investigated in the first round of monitoring.

2. Assess the condition of the Blossom Bat habitat area and provide information including

but not restricted to: general tree health and any tree death; recruitment of Coast Banksia

(Banksia integrifolia); and disturbance (e.g. tree removal, branch lopping, dumping of garden

wastes, fire, and weed development). Report on condition of plantings, if any.

3. Provide a report of monitoring results and recommend revision to the Blossom Bat Plan of

Management if deemed necessary.

3(a) The report should be provided on disk as a Word document, and as a printed hard copy.

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3(b) Copies of the report are to be provided to:

Koala Beach Wildlife and Habitat Management Committee;

Department of Environment and Conservation (Threatened Species Unit in Coffs

Harbour).

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APPENDIX 2: Coast Banksia monitoring plots

Figure 2.1: Vegetation monitoring plot locations (Scale = 1:1200; 2007 aerial

photograph. Plot size was 5 x 5 m)

Table 2.1: Coast Banksia monitoring plot location data

Transect No. Plot distance along transect1

Zone2 Easting Northing

1 7 56 554988 6861644

1 36 56 554994 6861676

2 4 56 554964 6861635

2 18 56 554967 6861644

3 36 56 554943 6861644

3 63 56 554948 6861672

4 4 56 554912 6861615

4 24 56 554921 6861615

5 30 56 554897 6861612

5 50 56 554899 6861630

6 7 56 554885 6861556

6 48 56 554889 6861606

7 30 56 554863 6861578

7 72 56 554870 6861622

7 107 56 554879 6861654

Total Transect = 7 Total Plots = 15 1 transects commenced at zero delineated by the eastern end of a wooden boundary fence; 2 Datum = WGS84

N