Environment & Development Approvals

30/09/15

Penguins in the Void:

Proposal for Creation of Little Penguin Breeding Habitat

The Neck, Bruny Island.

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Acknowledgements

Sincere thanks are extended to all penguin researchers and managers who responded to requests for

information or provided details of others to contact. Particular thanks to Neil Blake, Fam Charko, Zoe

Hogg and Tiana Preston for extensive discussions regarding the St Kilda Breakwater, both electronically

and on site. Nicole Kowalczyk provided unpublished reports and diagrams of the St Kilda Breakwater.

Comments from Neil Blake, Nicholas Carlile and Tiana Preston improved an earlier draft.

Dave Houston volunteered an extensive network of contacts in New Zealand, and Philippa Agnew and

Kerry-Jayne Wilson both undertook field visits to provide contemporary images and information on

breakwaters and seawalls in New Zealand.

The Department of State Growth commissioned the report and provided financial support. Selena Dixon,

Tori Harvey, Jill Jones and Sven Meyer encouraged and supported BirdLife Tasmania’s proposals to explore

options for penguin-friendly road construction on Bruny Island.

Disclaimer

The information provided in this report is prepared by the author and intended for use by the Department

of State Growth. Whilst all endeavours have been made to ensure that the information provided is

accurate this does not guarantee that the material is free of error. As such the author will not be liable for

any error, omission or otherwise. However, should any error or omission be notified, the author will use

his best endeavours to correct the material and update this report.

Citation

This report should be cited as: Woehler, E. J. (2015) ‘Penguins in the Void: Proposal for the Creation of

Little Penguin Breeding Habitat on the Neck, Bruny Island’, Report to Department of State Growth,

prepared by BirdLife Tasmania, Hobart, Tasmania.

Images

Images courtesy of individual photographers. Images used with permission of the photographers.

Images used within this publication remain the property of the copyright holder.

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Table of Contents

Executive Summary 4

1. Introduction 6

1.1. Project Details 6

1.2. Purpose 7

1.3. Little Penguins 7

1.4. St Kilda Breakwater 7

2. Methods 9

3. Results and Discussion 9

3.1. Voids 9

3.2. Wave Regime 10

3.3. Little Penguins 10

3.4. Vegetation 10

3.5. Monitoring 10

4. Recommendations 11

4.1. Construction of a seawall for the Bruny Island Main Road at the Neck 11

4.2. Activities associated with seawall and road construction/upgrade 11

4.3. Post-construction, upgraded Bruny Island Main Road 11

4.4. Community and commercial involvement 12

References 13

Appendix 1. 14

Appendix 2. 15

Appendix 3. 26

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Executive Summary Little Penguins (Eudyptula minor) nest and moult in natural and artificial voids in seawalls and breakwaters

throughout coastal Australia and New Zealand. The size and characteristics of these voids are critical if

breeding is to be successful. If the voids or the entrances are too small they do not provide viable habitat

and if too large predators can access nesting penguins.

The proposed upgrade of Bruny Island Main Road at the Neck, will require some form of a seawall

construction to support the road upgrade. This provides an opportunity for construction to incorporate

breeding habitat for penguins through judicious placement of suitably-sized rocks and fill materials

commonly used for seawall constructions.

The St Kilda breakwater (Melbourne) contains penguin breeding habitat and was seen as a model for

seawall construction on the Neck, Bruny Island. Data from seawalls and breakwaters used by penguins

elsewhere around Australia and New Zealand provide additional information to inform the proposed

upgrade of Bruny Island Main Road at the Neck.

Little Penguin Eudyptula minor, at nest site, St Kilda Breakwater, June 2015. © Eric J Woehler

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1. Introduction

A number of Little Penguin breeding populations around Australia and New Zealand are known to use

artificial coastal structures for breeding and moulting following their construction. All of these structures

were built for civil purposes and were subsequently colonised by Little Penguins; there was no

consideration of Little Penguin requirements or potential utilisation during the design and construction.

It is believed that the proposed road upgrades on the Bruny Island Main Road at the Neck will be the first

time in Australia that considerations for creating Little Penguin breeding habitat are specifically included

into the design and construction of a road upgrade and associated seawall. By reviewing the design and

construction of structures used by Little Penguins elsewhere in Australia and New Zealand, the design and

construction of the proposed Bruny Island Main Road upgrade can benefit from experiences and learnings

elsewhere.

1.1. Project Details

The Department of State Growth (State Growth) has a long term goal to provide a continuous sealed road

between the ferry terminal at Roberts Point and Alonnah, the major population centre of Bruny Island.

Currently, sections of the Bruny Island Main Road, including the Neck, are unsealed lowering the standard

of the road and increasing safety risks. State Growth is proposing to seal Bruny Island Main Road through

the Neck in order to improve the capacity of the road, safety outcomes and reduce ongoing maintenance

costs.

The proposed section of road to be upgraded (see Figure 1) is approximately 2.5km long and will involve

bitumen sealing, minor realignment and elevation of the road surface. It is presumed that some form of

seawall will be required for the western flank of the road facing Isthmus Bay. An upgraded carpark is also

proposed in the immediate vicinity of the existing carpark area and viewing platform at Big Hummock on

the Neck.

Figure 1: Location of the proposed road upgrade at the Neck, Bruny Island

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1.2. Purpose

The purpose of this report is to:

provide information on the use of artificial coastal constructions, such as seawalls and breakwaters

by Little Penguins (Eudyptula minor) for breeding and moulting, and

make design and construction recommendations for the proposed Bruny Island Main Road upgrade

works at the Neck, to accommodate Little Penguin breeding habitat.

Results and recommendations in this report will be used to inform future design of the road upgrade works.

1.3. Little Penguins

The Little Penguin is a coastal-nesting seabird found around Tasmania and the southern coastline of

Australia (Marchant and Higgins 1990, Brothers et al. 2001). Tasmania is believed to be the stronghold for

the species, but the available population data are old and relatively imprecise due to the time since surveys

were conducted and the relatively limited survey effort when originally collected (Brothers et al. 2001). The

Neck Colony on Bruny Island has been a focal site for tourists and residents on Bruny Island for decades,

with numbers of human visitors to the colony increasing significantly. The colony is inside the Bruny Island

Neck Game Reserve, managed by the Tasmania Parks and Wildlife Service.

The Bruny Island Main Road mostly extends along the western shoreline of the Neck immediately adjacent

to the mixed Little Penguin and Short-tailed Shearwater (Ardenna tenuirostris) colony. A low number of

nests are present between the Main Road and the western shore facing Isthmus Bay (Woehler 2015).

Several breeding pairs of Pied Oystercatchers are present on the western foreshore of the Bruny Island

Neck, and non-breeding shorebirds use the inter-tidal areas for feeding and roosting. It is considered likely

that the seawall will provide suitable roosting sites for shorebirds, and it is hoped that nesting by

oystercatchers may occur. Conversely, the presence of roosting gulls or cormorants may discourage or at

worst prevent, penguins nesting on the seawall.

1.4. St Kilda Breakwater

The St Kilda Breakwater (hereafter, SKB) is approximately 660m in length and extends from the St Kilda

Pier in Melbourne, Victoria (Figure 2). It was built to provide a safe harbour for yachts during the 1956

Melbourne Olympic Games. The first breeding pair of Little Penguins was observed on the SKB in 1974

(Kowalczyk et al. 2013), but Cullen (1989) proposes that penguins had likely been nesting for many years

before then. The penguin population is presently believed to exceed 1200 birds, and the number of

breeding sites has almost doubled in the past decade (Giling 2007).

The Little Penguin population has been subject to extensive research and there is a considerable data set

on the distribution and abundance of nesting penguins on the SKB (eg Cullen 1989, Giling 2007 and

Kowalczyk et al. 2013), with all reports and further data publicly available at

http://stkildapenguins.com.au/skp/).

The original SKB has been renovated on several occasions during the 1990s (Blake 1998) and two

additional extensions were added in 2013 (Kowalczyk et al. 2013). The renovations and extensions used

different construction techniques compared to the original construction, and have resulted in different

areas of the SKB being used and unused by Little Penguins, depending on substrate and construction

techniques.

The SKB was seen as an excellent model for the proposed upgrade to the Bruny Island Main Road due to

the requirement of some form of seawall along the west side of the Neck to protect the roadway. A visit

to the SKB provided the opportunity to assess the relative abundances of penguins along the breakwater in

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sections of different construction methods, and the vertical distribution of Little Penguins on the

breakwater flanks.

Figure 2. Aerial photograph of St Kilda Breakwater. The gate reduces the area open to the public, and was

built in November 2006, but was not operational until January 2007 (Giling 2007). The northern extension

is approximately 70m and southern extension is approximately 130m. Further details are provided in

Appendix 3. Base image from www.nationalmap.gov.au

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2. Methods

A review of identified examples of Little Penguins’ use of breakwaters and seawalls in Australia and New

Zealand was undertaken following an extensive consultation with Little Penguin researchers, coastal

managers and community penguin conservation groups throughout Western Australia, South Australia,

Victoria, New South Wales and New Zealand. A total of 27 persons were approached by email and

telephone requesting any information on Little Penguins’ use of breakwaters and seawalls and whether

engineering or technical drawings or specifications were available for the respective structures (Appendix

1).

A site visit to the St Kilda breakwater was undertaken on 2 and 3 June to obtain photographs of the

breakwater and to discuss penguin use of the structure with local penguin researchers and site managers.

Two visits to the breakwater were made and extensive discussions were undertaken on site and at the

Port Phillip EcoCentre with Neil Blake (Director) and Fam Charko (Community Engagement Manager), and

Tiana Preston and Zoe Hogg (St Kilda Penguin Study Group).

3. Results and Discussion

Little Penguins are both generalists and opportunists in their use of natural habitats and anthropogenic

structures for breeding. They will readily nest under vegetation, burrow into soft substrates, nest in natural

rock cavities and take advantage of shelter provided by coastal buildings, static items such as overturned

dinghies, and in igloos and nest boxes provided by community coastal care groups (Marchant and Higgins

1990).

Reports of Little Penguins using breakwaters and seawalls were received from researchers and managers in

Tasmania, Western Australia, South Australia, Victoria, New South Wales and New Zealand (Appendices 2

and 3). Unfortunately, details of the boulder sizes or the construction techniques were provided only in a

low number of responses (Appendix 2).

Dave Houston and Philippa Agnew summarised their experiences in New Zealand that closely parallel the

construction of the SKB:

“… in my experience as long as the rock size is large enough (>0.5m), deep enough (not just a surface coat) and waves don't wash over it regularly, then spaces suitable for penguins to breed are provided. The highest density site I know of was the one alongside the railway in Oamaru - this one had boulders 2-3m (possibly more) in size providing plenty of gaps for penguins and limited access to researchers” (D

Houston, pers. comm.).

“… what seems to work best is rocks that are compacted together to form a flat surface where the water breaks and then above that, along the top the wall, the rocks are loosely sitting to allow the penguins to nest amongst them. A lower rock wall that is compacted seems to withstand wave damage better” (P

Agnew, pers. comm.).

3.1. Voids

Cullen (1989) provides the earliest description of the original SKB in terms of Little Penguins, in that “…

the structure of the breakwater consists largely of large boulders and pieces of masonry, offering at least in places a labyrinth of tunnels which would be suitable for the birds but which are not visible from the surface”.

Early discussions with members of the St Kilda Penguin Study Group (ie pre-site visit to the STB) identified

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that the presence and size of voids in the St Kilda breakwater were critical for Little Penguins’ use of the

breakwater for breeding and moulting. The original extent of the breakwater’s 1956 construction was

characterised by having a rubble and soil substrate/core with an outer rock armour layer. The location of

engineering plans, specifications or schematics of the St Kilda breakwater from the 1956 construction is

unknown.

While the presence of voids might appear intuitive as a prerequisite for penguins to nest within the

structure, less intuitive are the dimensions and other features of these voids. A roof is critical as this

provides shelter from rain and direct sunshine to the eggs and chicks, and reduces the visibility of the

nesting effort to predators. Voids also require relatively tight and small entrances to further reduce the

opportunity for predators to take eggs, chicks and adults from breeding sites. Larger voids without suitable

substrate and relatively easy access to penguins and predators are not used by penguins. Volunteers with

the St Kilda Penguin Study Group have attempted to modify the structure and dimensions of the voids to

encourage their use by penguins (N Blake and Z Hogg, pers. comm.).

Very few of the nest chambers on the SKB are visible from the path or from the boardwalk, but the vast

majority of nest chambers present on the STK are inferred from the prevalence of splash (faeces) on the

breakwater flanks, penguin tracks on the path on top of the breakwater or the presence of moult feathers

in cavities and along runways etc at the end of the breeding season (Appendix 3).

3.2. Wave Regime

The wave regime is also important: very few of the penguins on the SKB nest on the ‘seaward’ flanks (ie

facing south and southwest into Port Phillip Bay), N Blake and Z Hogg (pers. comm.). “One key

observation is that while penguins might roost casually on either side of the wall, the prospect of breeding

will be restricted to where there is least wave attack”, (N Blake, pers. comm.). It is believed that the wave

conditions inside Port Phillip Bay are more extreme than those in the d’Entrecasteaux Channel, so wave

climate or wave regime are likely to influence Little Penguin use of the proposed seawall on the Bruny

Island Main Road upgrade.

3.3. Little Penguins

There is a vertical component to the distribution of penguin nests and moult sites in the SKB and in the

seawalls and breakwaters in New Zealand. The penguins are typically confined the upper half to upper third

of the SKB flanks to avoid high tides, storm surges and wave splash. Dry, well-drained sites are critical for

the survival of the penguin eggs and chicks as rain and seawater will chill them rapidly and result in their

deaths from hypothermia.

3.4. Vegetation

The planting of native vegetation to reduce erosion (particularly of the finer grade fill) and to provide

shelter for penguins is encouraged. The use of Atriplex on the SKB has been only partially successful, but it

should be considered for the seawall as it provides shelter to penguins. Ground-covering species such as

Tetragonia and Rhagodia used throughout Tasmania by Little Penguins and also provide protection to

substrate, further reducing erosion. Further benefit is these species may encourage oystercatchers to nest

on the seawall.

3.5. Monitoring

The past and current uses of the SKB by Little Penguins and the understanding of the high value of the SKB

to the annual breeding effort of Little Penguins in Port Phillip Bay is due to the extensive monitoring

undertaken by the St Kilda Penguin Study Group. This is a remarkable effort spanning more than 30 years

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has generated a unique data set and supported a number of PhD studies.

Previous research and monitoring efforts at the Neck Colony by BirdLife Tasmania in conjunction with

Department of State Growth (Woehler 2015) and Kingborough Council (Vertigan and Woehler 2014) have

provided valuable baseline data on the distribution and abundance of Little Penguin at the colony; these

data are comparable with research undertaken elsewhere in Tasmania (eg Woehler et al. 2014, Woehler

and Vertigan 2015).

It is hoped that ongoing monitoring of the Neck Colony will provide a data set used for future assessments

of Little Penguin populations in southeast Tasmania. Annual surveys and some finer-scale monitoring of the

Little Penguins in the Neck Colony during and following the road construction and upgrade will be critical

for all evaluations of the potential impacts associated with the upgrade of the Bruny Island Main Road and

associated infrastructure.

In addition to Little Penguins, future efforts should include surveys for nesting and roosting by gulls,

cormorants and oystercatchers, and monitoring of breeding populations if present.

4. Recommendations

4.1. Construction of a seawall for the Bruny Island Main Road at the Neck

Adopt where possible the construction techniques of the areas on the St Kilda Breakwater used by

Little Penguins for the Bruny Island Main Road upgrade, to facilitate the potential maximum use of

the seawall by Little Penguins for breeding and moulting.

Fencing or some form of barrier on top of the seawall will prevent penguins gaining access to the

Bruny Island Main Road from the seawall. It is recommended that the fencing/barrier is 30 – 40cm

in height to prevent penguins from climbing/jumping over the fence/barrier. A solid fence or barrier

also serves as a visual barrier to flying birds, reducing the potential for bird strikes. A solid fence or

barrier also reduces the light spill from vehicles onto the seawall and adjacent foreshore.

Fencing or some form of barrier to prevent penguins gaining access to the Main Road from the

colony/eastern side of the road.

4.2. Activities associated with seawall and road construction/upgrade

Fence off stockpiles of construction materials to prevent their use as nesting sites. Consider

minimising the volumes of construction materials on site overnights and weekends if stockpiles

cannot be fenced off.

Where possible, the timing of major construction, earth works and habitat modification should be

undertaken during the nominal Little Penguin and Short-tailed Shearwater non-breeding period,

between 1 May - 30 August.

Where possible, there should be minimal construction operations undertaken at night, as this is the

time when the Little Penguins and Short-tailed Shearwaters are most active in, around and above

the colony (in the case of the shearwaters).

If there is to be any form of additional nocturnal lighting associated with the construction area for

safety (or other) reasons, the illumination should be kept to a minimum, use red light wherever

possible and avoid illuminating the main Neck Colony area. This is critical for both Little Penguins

and Short-tailed Shearwaters, as illumination can disorient shearwaters flying above the colony, and

the penguins returning to their burrows.

Monitoring of Neck Colony consistent with previous surveys and any newly constructed potential

habitat for penguins during construction. This recognizes that birds may attempt to colonise and

breed on seawall and roadway during construction activities – and if this does occur, the

Department/PWS will need a response strategy developed before/during construction.

4.3. Post-construction, upgraded Bruny Island Main Road

Consideration for roadway illumination in the vicinity of the Neck Colony to be red or sodium

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(yellow-orange) lighting to minimise the potential for disorienting shearwaters flying above the

colony, and penguins returning to their burrows.

Construction of the seawall to include a barrier that prevents the headlights of cars, busses and

trucks using the elevated and upgraded Bruny Island Main Road adjacent to the Neck Colony from

illuminating the water, foreshore and top of the seawall.

Investigate the use of native vegetation (local provenance where possible) to reduce the potential

for erosion of substrate material in the seawall, and to reduce light spill from vehicle lights on the

roadway onto the habitat area. Native species such as Rhagodia and Tetragonia are excellent

ground cover species, and Atriplex provides shelter to penguins from surface predators.

Monitoring of Neck Colony consistent with previous surveys and any newly constructed potential

habitat for penguins following construction to determine if, when and where penguins (and

potentially other species) attempt to colonise and breed on the seawall.

Monitoring of the use of the seawall by gulls and cormorants for breeding or roosting as their

presence may reduce the use of the seawall by penguins.

Investigate the use of polyethylene nest boxes to monitor the colonisation of the seawall following

construction. These have been used effectively in Manly and are preferred over wooden boxes or

concrete igloos for monitoring the breeding population. Wooden nest boxes could also be used to

encourage the colonisation of the seawall by Little Penguins following construction.

4.4. Community and commercial involvement

Consider the formation of a community-based care group on Bruny Island (one model could be

under Wildcare) that could potentially be involved in future surveys and monitoring of penguins in

the Neck colony and on the seawall if penguin colonise it, noting that such efforts require PWS

permits and approvals.

The care group could also undertake planting activities on the seawall to promote native vegetation

and the removal of weeds.

Given the high level of use of the Neck colony by commercial operators on Bruny Island and

elsewhere for ecotourism, some consideration for commercial support of community efforts is

warranted.

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References Blake N 1998. Report on Stage 4 St Kilda Breakwater reconstruction Impact on Little Penguin colony.

Unpublished report, 9pp. Available from http://stkildapenguins.com.au/skp/?page_id=12

Brothers N, Pemberton D, Pryor H, Halley V 2001. Tasmania’s offshore islands: seabirds and other natural features. Hobart, Tasmanian Museum and Art Gallery, 643 pp.

Cullen JM 1989. St Kilda penguins. Unpublished report to St Kilda Council, 10pp. Available from

http://stkildapenguins.com.au/skp/?page_id=12

Fitzgerald Constructions Australia and NSC Australia 2015. St Kilda Harbour Development Breakwater

Extensions. Unpublished presentation, 28 May 2015.

Giling D 2007. Distribution of an urban little penguin (Eudyptula minor) colony on the St Kilda breakwater. Unpublished report, 29pp. Available from http://stkildapenguins.com.au/skp/?page_id=12

Klomp NI, Meathrel CE, Wienecke BC, Wooller RD 1991. Surface nesting by Little Penguins on Penguin

Island, Western Australia. Emu 91, 190-193.

Kowalczyk N, Blake N, Finger A 2013. St Kilda Breakwater Development: Penguin protection project 2013. Final Report. Unpublished report by Port Phillip EcoCentre, 45pp.

Marchant S, Higgins PJ (1990) Handbook of Australian, New Zealand and Antarctic birds. Volume 1.

Melbourne, Oxford University Press, 1400 pp.

Norman FI, Dann P, du Guesclin P, Drynan D (ms) Recoveries of Little Penguins Eudyptula minor flipper-

banded at colonies in western Victoria. Draft ms to be submitted to Corella.

Vertigan P, Woehler EJ 2014. Survey for Little Penguins Eudyptula minor along the d’Entrecasteaux Coast, Verona Sands to Kettering, November 2012 – January 2013. Tasmanian Bird Report 36, 14-21.

Woehler EJ 2015. Little Penguins at the Bruny Island Neck, 2014/15. Report to Department of State

Growth, May 2015. BirdLife Tasmania Technical Report 2015-03, 16pp.

Woehler EJ, Vertigan P 2015. Huon Island surveys, 2014/15. BirdLife Tasmania Technical Report 2015-04,

9pp.

Woehler EJ, Vertigan P, Ruoppolo V 2014. Little Penguins Eudyptula minor at Bicheno: Preliminary surveys and community contributions 2013/14. Report to GSB Council, NRM S and PWS, June 2014. BirdLife

Tasmania Technical Report 2014-05, 10 pp.

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Appendix 1. Little Penguin researchers and managers who were approached during this study, requesting information on

Little Penguins’ use of breakwaters and seawalls.

Philippa Agnew, New Zealand

Barry Baker, Tasmania

Margaret and Tim Bennett, Tasmania

Peter Bennett, New Zealand

Neil Blake, Victoria

Jess Bourchier, South Australia

Belinda Cannell, Western Australia

Nicholas Carlile, Sydney

Fam Charko, Victoria

Andre Chiaradia, Victoria

Rohan Clarke, Victoria

Tonia Cochran, Tasmania

Diane Columbelli-Negrel, South Australia

Peter Dann, Victoria

Lloyd Davis, New Zealand

Nic Dunlop, Western Australia

Peter Gaze, New Zealand

Zoe Hogg, Victoria

David Houston, New Zealand

Kristie King, New South Wales

Lauren Kivisalu, South Australia

Nicole Kowalczyk, Victoria

Perviz Marker, Tasmania

Amanda Mitchelson, Victoria

Greg Napp, New Zealand

David Nicholls, Geelong

Tiana Preston, Victoria

Matt Rayner, New Zealand

Kerry-Jayne Wilson, New Zealand

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Appendix 2. Photographs and texts from Little Penguin researchers and managers in Western Australia, South Australia,

Victoria (excluding St Kilda), New South Wales, Tasmania and New Zealand approached for this study. The

selected photographs show various seawalls that include a mix of large and smaller rocks. The role of the

smaller rocks in providing suitable nesting platforms within the voids is perhaps the most critical aspect of

the constructions.

Western Australia

Little Penguins were reported using limestone rockwalls on Garden Island, Western Australia (B Cannell,

pers. comm.). No further details were provided. Klomp et al. (1991) report that 13% of penguin nests on

Penguin Island (WA) are, “… under wood, concrete or other human structures”.

South Australia

Little Penguins were believed to have nested in the rock walls on Granite Island (Victor Harbour), but their

current status is unknown (P Dann, pers. comm.), as the colony on the island has decreased in recent years.

However, other advice received from Flinders University was that, “… I have not heard of any little penguins using breakwaters in any of the SA populations that we are monitoring. In SA, penguins on rocky islands such as Granite Island (near Victor Harbour) and Kangaroo Island use a mix of artificial and natural rock based burrows”, (D Colombelli-Négrel, pers. comm.).

Victoria (excluding St Kilda)

(a) Little Penguins were reported nesting, “in the wind break wall between the lighthouse and the light keeper’s house on Gabo Island in December 1983” (P Dann, pers. comm.).

(b) P Dann also reported a, “few nesting in the harbour/breakwater walls in Portland Harbour and usually a few moulting there”.

(c) K King reported on her experience at Warrnambool, “… in my time working with the Middle Island colony at Warrnambool, I never heard of or encountered penguins utilising any coastal infrastructure. However, I would be surprised if they didn’t because Warrnambool’s breakwater and viaduct areas would provide ideal nesting habitat” (K King, pers. comm.).

New South Wales

(a) No Little Penguins were known to, “use artificial structures except nesting boxes and the odd swimming pool infrastructure around Sydney Harbour” (N Carlile, pers. comm.).

(b) K King reported on her experiences at Manly, “Manly’s penguins are well known for nesting and moulting under the Manly Wharf in small numbers (max. 5 pairs per season). I believe the birds actually nest around the interface between the sand and the wharf decking. The penguins are guarded nightly by the local ‘Penguin Wardens’ during the breeding season but are highly vulnerable to disturbance, human interference, and dog/boat attack. Mortality and injury rates are fairly high for penguins nesting at the wharf”

(K King pers. comm.).

Tasmania

(a) Little Penguins were reported, “up on the NW coast there are places where [Little Penguins] nest in rock armour (large boulders) which have been used for infrastructure”, “… one is around Burnie Beach … the seawall around the surf club … the rock armour below the children’s play area and that has been used again by penguins” (P Marker, pers. comm.).

(b) Little Penguins nest within the Grassy harbour seawall, King Island. “The breakwater is 5 to 6m high above sea level. The big rocks are 2 to 3 metres high and stand as they tumbled out of the trucks. The penguins … just find a crevice and make it their home. The penguins roost amongst these huge rocks” (M

Bennett pers. comm.).

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Grassy Harbour breakwater (landward face). M Bennett is standing at the high-water mark.

Image © Tim Bennett.

Top surface of Grassy Harbour breakwater. Image © Tim Bennett.

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Little Penguin splash amongst the boulders, Grassy Harbour breakwater. M Bennett shown for scale. Image

© Tim Bennett.

New Zealand

Reports of Little Penguins using breakwaters and seawalls at six localities were received.

(a) Little Penguins were reported using the breakwaters at the mouth of the Buller River (Westport

Harbour) on the west coast of South Island. Nests were reported to be present in the, “numerous crevices between the large rock making the breakwater” and that, “… the rocks are large, 1m and up to 3m or so piled loosely so there are many penguin sized spaces between, from memory on a 60-70 degree slope, steep but penguins can climb them. The penguins cross a sandy beach to reach the seawall”. A visit to the

site located tracks crossing the sandy beach and disappearing into the rock jumble; the wall is described to

be about 4-5m high (K-J Wilson, pers. comm.).

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Seawall boulders used by nesting Little Penguins at the mouth of the Buller River (Westport Harbour).

Images © Kerry-Jayne Wilson.

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(b) In the Nelson region (central north coast), rock protection on the breakwaters of Port Tarakohe and

Port Nelson provide penguin habitat, but some nest boxes may have been used (D Houston pers. comm.).

P Gaze also reported that, “… here in Nelson where a vertical concrete revetment was erected as a seawall on the landward side of large boulder riprap. All of which has been built over with decking etc. In this case I got the engineers to drill holes in the concrete slabs, level with the riprap. A nest box was installed behind the wall on top of free draining pea gravel and then the whole thing was back filled. Concrete has been poured to create a path for the penguins thru the rip rap” P Gaze (pers. comm.).

Profile view of decking over boulder riprap. The rocks are mostly 0.5 - 1m in diameter. At the top of the

rock riprap there is about 0.8m of the vertical revetment exposed between the rocks and the decking.

Image © Pete Gaze.

View of the concrete pathway on top of boulders and the vertical concrete slab at top with the entrance

for penguins above high tide level (at far right of deck). Image © Pete Gaze.

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Concrete used to bind loose rocks and to create path through the rip rap for the penguins. Image © Pete

Gaze.

(c) Little Penguins were reported using the breakwater at Tarakohe Harbour on the northwest coast,

South Island, a situation that were described as, “the best example I can think of is the work Mike Ogle did at the Tarakohe Harbour in Golden Bay. Google Images will give you an idea: https://www.google.co.nz/search?newwindow=1&hl=en&site=imghp&tbm=isch&source=hp&biw=1324&bih

=731&q=tarakohe+harbour&oq=tarakohe+harbour&gs_l=img.1.0.0i24.1341.7004.0.8750.18.17.0.0.0.0.411.1

950.2-2j3j1.6.0.ekpsrh...0...1.1.64.img..13.5.1554.FDUAna3hzPs” (P Gaze, pers. comm.).

G Napp, a ranger involved with the Tarakohe Harbour project reported on the project that has many

parallels with the proposed construction of the Bruny Island Main Road:

“I am a ranger in Golden Bay that was involved with the project to encourage penguins to nest on the western breakwater at Tarakohe Harbour. We wished to reduce the number of penguins getting run over on the coast road. Penguins do still cross the road and do get run over but at least some of the population doesn’t have to cope with that threat. We worked with the Tasman District Council (who own and manage the harbour) to do the work. The harbour manager was supportive of the project but didn’t want any disruption to the port operation. The eastern breakwater is used by commercial boats and also houses the marina, so we didn’t do any work there (though penguins do nest in crevices on the eastern side). We had a couple of truckloads of soil donated. We piled soil along each side of the breakwater still allowing for vehicle access. We buried wooden penguin boxes within the soil mounds and directed the entrances to the seaside. We planted the soil rows with flax, toetoe, and taupata. We have had some weed invasion but have largely left the weeds as they still provide cover.

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Tarakohe seawall used by little penguins for nesting. Image © Greg Napp.

Little Penguin nest boxes being installed on the Tarakohe seawall. Image © Greg Napp.

We also built 4 concrete ramps up the sides of the breakwater to make it a bit easier for penguins to find their way up. I don’t know how well used these are. We have extended the boxes along the side of the public car park on the breakwater (western side of the car park). The western side is used by recreational boaties to launch their trailer boats. There doesn’t appear to be any conflict between penguin nesting and boat launching.

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We have placed approximately 90 boxes. We have used a couple of different designs for boxes. Our first boxes were very basic. Our second generation have a much longer entrance tunnel and a side opening into the tunnel to make it harder for larger animals to push in (e.g. dogs). I was out there a couple of weeks ago and counted at least 22 pairs using boxes. There were also some pairs that were using ‘natural gaps’ between breakwater rocks” (G Napp pers. comm.).

(d) Oamaru

Oamaru (central east coast, South Island) had a retaining wall constructed from very large boulders

adjacent to the railway that had hundreds of birds living in it. The current state is unknown as it was subject

to major storm damage some years back). Lower numbers of birds lived in rock protection along wharfs

and around the edge of the harbour at Oamaru (D Houston pers. comm.).

In response to a request for photographs, P Agnew visited the seawall and advised, “I went out and took a few photos today… I didn't see any sign of penguins but I have in the past (and we're outside of the breeding season so their presence may not be obvious). What seems to work best is rocks that are compacted together to form a flat surface where the water breaks and then above that, along the top the wall, the rocks are loosely sitting to allow the penguins to nest amongst them. A lower rock wall that is compacted seems to withstand wave damage better”, P Agnew (pers. comm.).

Oamaru seawall used by Little Penguins to nest. Image © Philippa Agnew.

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Holmes Wharf at Oamaru, where the penguins nest within the rocks. Image © Philippa Agnew.

(e) Auckland

On Waiheke Island near Auckland (North Island), rock protection around the wharf facilities provides a

few nesting places for penguins (D Houston pers. comm.).

(f) Timaru

P Agnew visited Timaru and met with locals who are monitoring the little penguins there. She reported

that, “apparently the penguins were going into the container yard and causing issues for the Port, so the Port created a rock wall on the seaward side of the road next to the yard to give the penguins somewhere to nest. This has worked a treat and the penguins do occupy the rock wall” (P Agnew pers. comm.).

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Timaru seawall used by Little Penguins for breeding. Image © Philippa Agnew.

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Timaru seawall used by Little Penguins for breeding. Image © Philippa Agnew.

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Appendix 3.

St Kilda Breakwater - The greatest level of details for the construction of a seawall or breakwater used by

Little Penguins is available for the St Kilda Breakwater in Port Phillip Bay, Melbourne.

The following description is derived from the site visit on 2 and 3 June 2015, on-site discussions with N

Blake (Port Phillip EcoCentre), Dr T Preston and Z Hogg (both St Kilda Penguin Study). Additional details

are from Blake (1998) and from correspondence with Z Hogg and N Blake (pers. comm.).

Figure Appendix 3 – 1. Schematic of the St Kilda Breakwater, Port Phillip Bay. The central path on top of

the breakwater is shown in yellow, with the breakwater flanks in white on either side. The northern and

southern extensions (constructed 2013) are shown. The approximate extents of the four stages of

reconstruction are also shown, and have been used to reference photographs and construction in the

Appendix 3 text.

The St Kilda Breakwater reconstruction was undertaken in May- June over four years (1995 - 98) to avoid

the breeding and moult seasons. The four stages involved approximately equal lengths of the wall (each

around 160m). The rocks used in the 2013 construction ranged in mass between 0.2t to 8t (Fitzgerald

Constructions Australia and NSC Australia, 2015).

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Stage 1 was at the area abutting the end of the pier, which at the time had only a couple of penguins

present. This area was well populated within a few years of the construction being completed, and is

presently believed to accommodate up to 15% of the overall population on the breakwater. A likely cause

is the extra layer of rock provided better cover for the penguins from people.

Stages 3 and 4 were the outer 320m of the breakwater, with stage 4 being roughly from 'the bend' (where

the wall turns sharply more westerly). In general, pre-existing nest sites in these areas continued to be

occupied. The penguin population grew dramatically in the five years from 1998, but it is not possible to

correlate the growth of the population with the soil placed during the reconstruction. Increased penguin

activity was also recorded in areas where no soil had been added.

This soil was placed on top of the wall, along the path. The soil has been successfully covered with

vegetation (especially Rounded Noon-flower Disphyma crassifolium subsp. clavellatum) that has eliminated

erosion on the shoulder. Recent efforts have plugged eroding edges to the path in stage 2 which has

minimal vegetation established (see Figures Appendix 3 – 2 to 4).

Saltbush Atriplex cinerea was planted on the breakwater by Earthcare St Kilda following the 1995 – 98

reconstruction, but a relatively large amount of the Saltbush has died since 2004 when it was last mapped,

probably due to the drought conditions experienced (Z Hogg, pers. comm.).

Figure Appendix 3 – 2. Photograph looking northwestward along Stage 3 towards the bend showing

extensive revegetation of the top of the Breakwater path and flanks (see text). Image © N Blake, used with

permission.

Approximately 60m3 of soil medium (a compost blend of recycled sandy soil and chipped green waste) was

placed along the inner shoulder of the breakwater in Stage 4. This material is similar to the soil used in

Stage 3. Placement along the inner shoulder allowed the soil to filter down into the spaces between rocks

creating suitable 'platforms' for nesting on.

In the 1998 reconstruction, a layer of smaller basalt rock (c.70 -120mm) was placed on the path (shown in

yellow in Appendix 3-1). This served as a barrier to prevent too much soil falling from the path into the

voids between rocks on the flanks. These rocks can be overlain with even smaller rocks to increase the

screening effect. The seaweed/sand mix might also be important. The seaweed content in the mix serves to

bind it rather let it drain like sands through the hourglass, and the seaweed also has trace elements that

promote healthy plant growth.

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The penguin population is now more evenly spread along the length of the breakwater than before the

reconstruction. This is particularly due to the marked increase in penguin sites between the Kiosk and the

fence in 1996 – 1998 (Stage 1). Recently established penguin sites within Stage 3 occur predominantly along

the shoulder of the breakwater. It is reasonable to conclude that this has been encouraged by the

distribution of soil along sections of the inner shoulder during the Stage 3 reconstruction.

Addition of a consistent cover or comparatively larger 'armour rock' in the 1995-98 reconstruction may

have contributed to the breakwater becoming more evenly colonised as they give the penguins greater

protection, both from weather and possible predators or disturbances, than much of the previous

breakwater did. This is indicated by the relative difficulty experienced by the St Kilda Penguin Study Group

when attempts are made to capture birds as part of the research and monitoring programs.

In the Southern Extension, the smallest of the armour rocks are 1m in size and greater, with many more

than 2m. Rocks of this size are placed at least 2 rocks deep and no smaller rocks or soil can be seen in the

voids. It is worth noting that the new extensions were not designed to accommodate penguins. In fact it

was seen as desirable not to encourage penguin presence in the Southern Extension near the end of the

pier as this area is accessible to other public uses such as fishing and dog-walking.

Figure Appendix 3 – 3. Photograph looking along Stage 4 towards the end of the Breakwater showing

revegetation of the top of the Breakwater path. Image © N Blake, used with permission.

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Figure Appendix 3 – 4. Photograph showing manual effort to plug drainage channels forming in the shoulder

of the path using small stones. These channels result in erosion of the breakwater path substrate. These

efforts are undertaken in Stage 1 and 2 areas where vegetation has not established. Little Penguin tracks are

visible in the sand. Image © N Blake, used with permission.

Figure Appendix 3 – 5. Photograph looking east showing the Southern Extension to the St Kilda

Breakwater, June 2015. There are only penguins at the very top next to the path on the southern

extension. There are none further on the southern extension (Z Hogg, pers. comm.). In the new (2013)

extensions, the larger rocks and associated wider voids between them do not provide a suitable substrate

for penguin nest sites. Image © Eric J Woehler.

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Figure Appendix 3 – 6. Photograph looking north showing the Northern Extension (groyne) to the St Kilda

Breakwater, June 2015. The larger sized rocks with no infill material prevents the use of the extension by

penguins due to the wide voids between the rocks (N Blake and Z Hogg, pers. comm.). Image © Eric J

Woehler.

Figure Appendix 3 – 7. Photograph looking east of the northern flank of Stage 1 of the St Kilda Breakwater

adjacent to the Kiosk and St Kilda Pier, June 2015. There is extensive use of the flank by penguins as a

result of the inter-connected voids amongst the loosely packed, relatively smaller rocks. Image © Eric J

Woehler.

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Figure Appendix 3 – 8. Photograph showing the northern flank of Stage 1 of the St Kilda Breakwater, June

2015. Z Hogg shown for scale. The extensive penguin splash indicates recent penguin activity. In the Stage 1

area, the 'armour' rock width varies between 0.5 and 1.2m. There are much smaller (150 - 300mm) rocks

underlay the armour rock layer. Soil and fine gravels are also present in this underlay (N Blake, pers.

comm.). Image © Eric J Woehler.

Figure Appendix 3 – 9. Photograph showing the northern flank of Stage 2 of the St Kilda Breakwater, June

2015. The extensive penguin splash indicates recent penguin activity. Image © Eric J Woehler.

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Figure Appendix 3 – 10. Photograph showing the northern flank of Stages 1 and 2 of the St Kilda

Breakwater, June 2015. The walkway extends for approximately 70m at the High Water Mark. The

surviving saltbush plants are used by Little Penguins, providing shelter from the weather and predators. The

gate and fence preventing human access to the main part of the breakwater is shown. Image © Eric J

Woehler.

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Figure Appendix 3 – 11. Schematics for the Northern Extension (groyne), St Kilda breakwater (Fitzgerald

Constructions Australia and NSC Australia 2015).

Figure Appendix 3 – 12. Schematics for the Southern Extension, St Kilda breakwater (Fitzgerald Constructions Australia and NSC Australia 2015). The schematic

for the southern extension should not be taken to represent a suitable structure for penguin nesting. However, if this design included an additional layer of smaller

rock and soil to fill voids in the underlying layer of larger rock it would effectively have all of the characteristics of the Stage 1 - 4 construction.