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Pittwater Waterbird Habitat
Survey and Mapping
K. Brandis, H. Watson and S. Ryall
Australian Wetlands and Rivers Centre
University of New South Wales
August 2012
2
Table of Contents
Project background .................................................................................................................... 4
Waterbirds ................................................................................................................................. 5
Shorebirds .................................................................................................................................. 6
Shorebird habitat requirements ................................................................................................ 6
Migratory waterbird conservation and management ............................................................... 8
Migratory waterbirds and the East Asian - Australasian Flyway ........................................... 8
International cooperation ...................................................................................................... 8
JAMBA and CAMBA ................................................................................................................ 9
ROKAMBA .............................................................................................................................. 9
Protecting species in Australia ............................................................................................. 10
Methods ................................................................................................................................... 11
Existing data and information gaps ..................................................................................... 11
Study site .............................................................................................................................. 12
Survey methodology ............................................................................................................ 12
Data collection ..................................................................................................................... 13
Boat Surveys ..................................................................................................................... 14
Ground Surveys ................................................................................................................ 14
Results ...................................................................................................................................... 19
Species abundance and diversity ......................................................................................... 19
Waterbird habitat ................................................................................................................ 32
Habitat use ........................................................................................................................... 32
Estuarine Habitats ................................................................................................................ 40
Disturbance .......................................................................................................................... 43
Discussion................................................................................................................................. 45
3
Climate change and sea level rise ........................................................................................ 45
Key findings .......................................................................................................................... 51
Recommendations ............................................................................................................... 51
References ............................................................................................................................... 52
Appendix 1: Table of Aquatic Birds for the Lower Hawkesbury River, Patonga Creek, Broken
Bay, Pittwater, and Brisbane Water, 1967-2011 ..................................................................... 53
Table of Figures
Figure 1 Waterbird survey sites in the Pittwater Estuary (see Table 1). ................................. 15
Figure 2 Waterbird counts per species per survey .................................................................. 23
Figure 3 Passerine counts per species per survey. .................................................................. 27
Figure 4 Raptor counts per species per survey. ....................................................................... 28
Figure 5 Total bird abundance (blue-boat survey; green–ground survey) and species diversity
(red) recorded for each survey. ............................................................................................... 28
Figure 6 Total waterbird abundance (blue-boat survey; green–ground survey) and waterbird
species diversity (red) recorded for each survey. .................................................................... 29
Figure 7: Cumulative species curve ......................................................................................... 29
Figure 8 Species diversity by survey site .................................................................................. 30
Figure 9 Number of species observed foraging in using each habitat type. ........................... 35
Figure 10 Number of species observed roosting in each habitat type. ................................... 35
Figure 11 Dominant type of habitat used at each survey site. Note this is not a habitat
classification of survey sites, as most sites have several habitat types present e.g. man-made
roosts and sandy beaches. ....................................................................................................... 39
Figure 12 Waterbird foraging and roosting habitat in the Pittwater Estuary. ........................ 42
Figure 13 Frequency of waterbird disturbance types recorded in Pittwater Estuary. ............ 43
Figure 14 Counts of different disturbance types at survey sites. ............................................ 44
Figure 15 Waterbird habitat areas likely to be impacted by sea level rise. ............................ 48
4
Project background
Waterbirds, both locally occurring and migratory, are an integral part of the ecosystem of
the Pittwater estuary. Pittwater is currently one of the few remaining known habitats of the
Bush Stone-curlew (an Endangered Species) in the Sydney Region. With a known pair in
Careel Bay. Despite the ecological significance of waterbirds, there is little baseline data on
their distribution. Being dependent on estuaries they are vulnerable to, and indicative of,
degradative processes. Climate change and sea level rise and changes to hydrodynamics
have the potential to modify the condition and extent of habitat available for waterbirds in
Pittwater.
Pittwater Council currently has, in draft form, the Pittwater Foreshore Floodplain Mapping
of Sea Level Rise Impacts report. The report provides a GIS layer identifying weekly, yearly
and extreme tides predicted for 2010, 2050 and 2100. The aim of the report is to review,
update and expand the current Estuarine Planning Level Mapping, to incorporate adopted
sea level benchmarks, within the framework of the NSW Floodplain Risk Management
Process. This will offer information about the likely current and future impacts of tidal
inundation due to sea level rise around the foreshore of the Estuary.
This project is aimed at building on the current and proposed waterbird studies by Hornsby
Council occurring within the management area of the Lower Hawkesbury Estuary
Management Plan. Hornsby also aims to identify where important migratory and estuarine
waterbird populations may be lost or re-established as a result of climate change. This
project will extend Hornsby’s work to a regional scale.
Pittwater extends from Mona Vale and Warriewood in the south, along the eastern ridge of
the Peninsular leading to Palm Beach and along the western ridge leading to West Head.
Pittwater estuary and surrounding lands contain a wide range of estuary habitats. These
include rocky shores, mangroves, seagrasses, saltmarsh, sandy shoals (as both fluvial deltas
and a flood tide marine shoal) and deep open water environments.
The Pittwater Native Fauna Management Plan (Ecotone Ecological Consultants June 2010)
states that some of the species which have historically visited and currently visit the area
are listed as Threatened Species. They are also listed on the China-Australia Migratory Bird
5
Agreement (CAMBA), Japan-Australia Migratory Bird Agreement (JAMBA) and the Republic
of Korea-Australia Migratory Bird Agreement (ROKAMBA). Under the terms of these
agreements Statutory Authorities in Australia are obliged to protect these birds from direct
threats and protect their habitats from degradation.
The plan also identified a number of historical and anecdotal records which indicated that
the area has held large numbers of migratory wading birds in the past. These include
Eastern Curlew (Numenius madagascariensis), Whimbrel (N. phaeopus), Bar-tailed Godwit
(Limosa lapponica), Common Greenshank (Tringa nebularia), Grey-tailed Tattler (T.
brevipes), Red Knot (Calidris Canutus) and Sharp-tailed Sandpiper (C. acuminate). The site
may possibly have been visited by Curlew Sandpiper (C. ferruginea), Terek Sandpiper (Xenus
cinereus), Red-necked Stint (C. ruficolis), Common Sandpiper (Actitis hypoleucos) and Pacific
Golden Plover (Pluvialis fulva).
Despite these data, there are significant knowledge gaps in estuarine bird distributions and
the future impacts of sea level rise. With data collected from both Hornsby and Pittwater we
will have a much greater picture of the impacts of climate change on estuarine wetlands and
migratory waterbirds on a regional scale.
Pittwater Council received a grant from the NSW Office of Environment and Heritage
Estuary Management Program to investigate the impacts of climate change on estuarine
wetland and migratory waterbirds in the Pittwater estuary. In undertaking such an
investigation baseline data survey is required.
Waterbirds
Waterbirds are a large and diverse group of birds including ducks, geese and swans (Order
Anseriformes); grebes (Order Podicipediformes); pelicans, darters and cormorants (Order
Pelecaniformes); herons, egrets, bitterns, ibis and spoonbills (Order Ciconiiformes); rails,
moorhens and coots (Order Gruiformes); and waders (Order Charadriiformes). Most are
exclusive to freshwater habitats such as rivers, lakes, dams and wetlands, however many
species can also be regularly found in saltwater, e.g. cormorants and many migratory
waders.
6
While many species of waterbirds are not migratory, they can move large distances in
search of suitable habitat. These species are termed nomadic as their movements are not
necessarily seasonal and are determined by habitat availability not seasonal changes. These
species include ibis, pelicans, ducks, egrets, herons, cormorants, spoonbills and swans.
Shorebirds
Shorebirds, or waders, belong to the order Charadriiformes, excluding the Laridae (gulls and
terns). Typically birds of wetlands, shorebirds can occur in a wide range of habitats and are
diverse in their habitat preferences and life history. Many shorebirds are migratory
travelling up to 26,000 km each year between Australian and their breeding grounds in
Siberia, northern China and Alaska. A total of 63 shorebird species have been recorded in
NSW (Smith 1991). Thirty-four species are considered to occur in the Sydney region
(Appendix 1). Of these, 25 species are migratory; all breeding in northern hemisphere
except Double-banded Plover, which breeds in New Zealand. Thirteen migratory species
regularly recorded in Sydney area, the rest only occur occasionally or rarely. The remaining
nine shorebird species are resident within Australia, including species that breed locally,
breed on offshore islands, or that are nomadic and may travel great distances in response to
environmental conditions (Nebel, Porter et al. 2008). Data for shorebird abundance in the
lower Hawkesbury River are very limited.
Shorebird habitat requirements
Shorebird species use a variety of different wetland habitats for foraging, typically in or near
water, wading up to a depth of around 15cm for long-legged species. Shorebirds occur in
marine habitats including ocean beaches, rocky coastlines, intertidal mudflats. They also
occur in coastal wetland habitats and river estuaries, including saltmarsh and mangroves,
and in freshwater wetland habitats such as marshes, the margins of lagoons and along
creeks. Shorebirds will also utilise other potential habitats within urbanised areas including
parks with open grassland, golf courses, other types of open/undeveloped land, and may
use artificial structures as roosting habitat.
Some species of shorebirds are habitat generalists, while other species have specific
requirements for habitat type, and may be limited to either marine or freshwater habitats.
7
Most shorebird species prefer open habitats, and will avoid areas with tall vegetation,
although there are some species that use vegetated areas for cover or foraging (Latham’s
Snipe, Common Sandpiper), or for roosting (in mangroves - Whimbrel, Grey-tailed Tattler).
Species that forage in tidal habitats also require suitable alternative habitat as a high-tide
refuge. Shorebirds may roost in a range of different habitats and may travel some distance
from their feeding grounds to a suitable roost site. Roosts are usually in a location with an
open aspect as one of the most important factors is avoidance (or early detection) of
predators.
Shorebirds engage in a range of foraging strategies and will take a variety of prey items.
Some species use visual foraging to pick small invertebrates off the surface of the substrate,
others use their long pressure-sensitive bills for probing deep into mud to obtain buried
shellfish, worms or other invertebrates. Many species feed during the night, and for some
species - particularly plovers - this is their primary period for foraging. Foraging periods for
species of tidal habitats are constrained by the tide cycle rather than daylight.
Another important function of habitat for shorebirds is as a stop-over site while birds are on
migration. Similarly, coastal habitats can provide crucial alternative habitat, for birds of
resident and migratory species, when there are drought conditions inland.
Within the Hawkesbury River area, the principal shorebird habitats are the estuarine
mudflats exposed during low tide, mangroves, and other brackish or freshwater wetland
habitats occurring in the vicinity of the river.
Factors that affect habitat suitability for shorebirds include:
Prey availability – abundance/density of prey, distribution may be patchy
Disturbance – presence of actual or perceived predators, including humans
Patch size – small areas of habitat may be used by shorebirds only if there is
sufficient additional habitat nearby
Distance to other habitats - lack of suitable roosting locations might preclude use of
otherwise suitable foraging habitat.
8
Availability of high-quality foraging habitat – this is critical for the period preceding
migration, there is evidence that birds within the Sydney area may move elsewhere
for the final stages of pre-migration conditioning
Migratory waterbird conservation and management
The federal government Department of Sustainability, Environment, Water, Population and
Communities is the overarching authority to manage and conserve biodiversity in Australia.
The Department provides the following information on migratory shorebirds
(http://www.environment.gov.au/biodiversity/migratory/waterbirds/index.html)
Australia provides critical non-breeding habitat for millions of migratory waterbirds each
year. To ensure their conservation the Australian Government has fostered international
cooperation through a range of important agreements, including the Ramsar Convention
and the Convention on Migratory Species, bilateral agreements with Japan, China and the
Republic of Korea, and through the recently launched East Asian — Australasian Flyway
Partnership.
Migratory waterbirds and the East Asian - Australasian Flyway
Migratory waterbirds include species such as plovers, sandpipers, stints, curlews and snipes.
These birds make round trip migrations of up to 26,000 km each year between their
breeding grounds in the northern hemisphere and their non-breeding areas in the south.
These trips are made in several weeks, with brief stops at staging sites along the way to rest
and refuel for the next leg of their journey. The corridor through which these waterbirds
migrate is known as the East Asian - Australasian Flyway (the Flyway). It extends from
within the Arctic Circle, through East and South-east Asia, to Australia and New Zealand.
Stretching across 22 countries, it is one of 8 major waterbird flyways recognised around the
globe.
International cooperation
For over 30 years, Australia has played an important role in international cooperation to
conserve migratory birds in the Flyway, entering into bilateral migratory bird agreements
with Japan in 1974 (JAMBA), China in 1986 (CAMBA) and most recently the Republic of
Korea in July 2007 (ROKAMBA). Each of these agreements provide for the protection of
9
migratory birds from take or trade except under limited circumstances, the protection and
conservation of habitats, the exchange of information, and building cooperative
relationships.
JAMBA and CAMBA
The first two bilateral agreements relating to the conservation of migratory birds were
formed with the Government of Japan in 1974 and the People’s Republic of China in 1986.
The JAMBA and CAMBA agreements list terrestrial, water and shorebird species which
migrate between Australia and the respective countries. In both cases the majority of listed
species are shorebirds.
Both agreements require the parties to protect migratory birds by:
limiting the circumstances under which migratory birds are taken or traded
protecting and conserving important habitats
exchanging information
building cooperative relationships
The JAMBA agreement also includes provisions for cooperation on the conservation of
threatened birds. Australian government and non-government representatives meet every
two years with Japanese and Chinese counterparts to review progress in implementing the
agreements and to explore new initiatives to conserve migratory birds.
ROKAMBA
In April 2002, Australia and the Republic of Korea agreed to develop a bilateral migratory
bird agreement similar to the JAMBA and CAMBA. The ROKAMBA agreement was signed in
Canberra on 6 December 2006. The agreement entered into force on 13 July 2007. The
ROKAMBA formalises Australia's relationship with the Republic of Korea in respect to
migratory bird conservation and provides a basis for collaboration on the protection of
migratory shorebirds and their habitat.
Multilateral cooperation on migratory bird conservation JAMBA, CAMBA and ROKAMBA
provide an important mechanism for pursuing conservation outcomes for migratory birds,
including migratory shorebirds. However, the bilateral nature of these agreements limits
their scope and ability to influence conservation across the flyway. Australia has therefore
10
also encouraged multilateral cooperation for migratory bird conservation through the
Partnership for the East Asian-Australasian Flyway.
Protecting species in Australia
All migratory bird species listed in the annexes to these bilateral agreements are protected
in Australia as matters of national environmental significance under the Commonwealth
Environment Protection and Biodiversity Conservation Act 1999.
11
Methods
Pittwater Council’s estuary waterbird habitat survey and mapping project aims to identify
important waterbird habitat and gather baseline data on waterbird populations within the
Pittwater estuary.
Existing data and information gaps
A review of existing information in Council reports indicates that there is little data on the
occurrence of waterbirds in the Pittwater estuary, with the exception of survey records for
Careel Bay.
Careel Bay has been recognised as the most significant area of estuarine wetlands in the
Pittwater LGA (Smith and Smith 1997). The most recent data is from bird surveys carried out
for Pittwater Council in 2006-7 (Coughlan 2008). Earlier surveys were completed in 2001
and 1997 (Smith and Smith 1997; Smith and Smith 2001), and Smith and Smith (1997)
compiled additional observations for Careel Bay dating back to 1971. These data provide a
relatively long-term record for the waterbird populations occurring at Careel Bay.
The Pittwater LGA native fauna management plan (Pittwater Council and Ecotone Ecological
Consultants 2010) incorporates additional data for bird species within the Pittwater LGA –
including species occurring in wetlands beyond the extent of the Pittwater estuary –but to
date there have been no systematic surveys of the estuarine region.
Waterbirds occur in other areas within the Pittwater estuary where suitable habitat exists. A
variety of substrate and vegetation types can be found across the estuary, including sandy
beaches, intertidal mudflats, mangroves, creeks, rocky shorelines, open water and seagrass
beds. These may provide habitat for a diverse range of waterbirds, although many patches
of habitat are small. The Pittwater estuary is also highly modified by humans - much of the
eastern shoreline is altered by urban development, undeveloped areas are frequently used
by people for recreation and there is a high level of boating activity on the water. However,
some waterbird species successfully exploit modified environments, and may be attracted
to developed areas for foraging opportunities, or to use man-made structures as alternative
habitat.
12
This waterbird survey project determined the current distribution and abundance of
waterbirds across the Pittwater estuary. It also examined habitat use by waterbird species
to determine the specific areas used and their significance for meeting species’ habitat
requirements. This information will then be used to assess the potential impact of sea level
rise and associated habitat loss for waterbird species populations in the Pittwater estuary.
Study site
The Hawkesbury River is one of the major rivers of the coastal region of NSW. The Pittwater
Estuary on which this study focuses is located to the north of Sydney and includes the body
of water enclosed between West Head and Barrenjoey Head, the shoreline and adjacent
estuarine wetlands (Figure 1).
Survey methodology
We use the term ‘waterbirds’ to mean bird species that live on marine or fresh water or in
wetland habitats. This includes families of ducks, cormorants, grebes, rails, herons, ibis,
shorebirds, gulls, terns, pelicans, penguins and seabirds. We will also record the occurrence
of other bird species that are particularly associated with or restricted to estuarine habitats,
including raptors (e.g. White-bellied Sea Eagle, Osprey, Whistling Kite), kingfishers and
passerines (e.g. Mangrove Gerygone).
We identified areas with suitable habitat for waterbird species from maps and recent aerial
photos of the Pittwater estuary.
A site-based approach was used to collect survey data for the estuary. These data can be
used to examine local waterbird distribution and habitat use in detail, as well summarise
waterbird populations for the estuary as a whole. Survey sites are shown on a map of the
region in Figure 2 and listed in Table 1.
The nature of the Pittwater landscape means that two complementary methods are
required to survey for waterbirds: observations made by boat and from the land (Table 1).
Boat surveys allow open water habitats and continuous stretches of coastline to be
surveyed more readily, and are invaluable for reaching sites with no road access, or that are
otherwise difficult to access from the land. Land-based surveys are preferable for sites
13
where shallow water makes it difficult to approach by boat, and where species may occur in
vegetated habitats away from open water.
The western side of Pittwater was surveyed by boat only, as there was limited road access,
while the eastern side was primarily surveyed from the land, however inaccessible sites
were surveyed by boat, and we aimed to include as many other eastern sites as possible
during boat surveys to maximise the number of visits for those sites.
Surveys were conducted during the months of January to June 2012. While this time period
was relatively short it aimed to coincide with visiting periods of migratory shorebirds to
eastern Australia. The length of the survey period should allow us to observe if there is
seasonal variation in waterbird species abundance during summer, autumn and early
winter. Migratory shorebirds will typically be present until late March, although immature
birds of some species (e.g. Eastern Curlew) may stay through the winter. Most other
waterbird species are Australian residents, although may have seasonal movements for
breeding and in response to local conditions.
Data collection
Surveys for waterbirds will be carried out by 1-2 experienced observers, using binoculars
and a telescope where necessary.
At each site we will identify all waterbird species, record the number present and the
habitat type where the birds are observed. We will observe the behaviour of the birds, and
record the predominant behaviour at the time of survey, as a means of determining habitat
use at that site. We expect to assign three categories for behaviour/habitat use: foraging
(feeding or actively searching for food), roosting (resting or preening), or active (engaged in
some other activity, such as walking or swimming). We will also record any other significant
activity if observed, such as breeding, or events where we observe disturbance to
waterbirds.
In addition, at each site we will record the time of the survey, the stage of the tide and
whether people or dogs are present, or any other observable factor that may affect whether
birds are present or absent at the site.
14
We will also record the conditions on each survey day, including the time of high tide and
the maximum temperature, windspeed and rainfall during the survey period.
Boat Surveys
Boat surveys were conducted monthly using a boat with an outboard motor (Table 1).
Shorelines and open waters were surveyed. Surveys were conducted by two experienced
observers. Shorelines of major tributaries were surveyed from a slow moving boat travelling
at approximately 5 knots. Bays and inlets were surveyed from a stationary boat. Species
were observed using binoculars.
Boat surveys were conducted on a range of tides, including low and high tide to include both
potential low tide feeding sites and high tide roosting sites.
Ground Surveys
Ground surveys were conducted by two observers on foot. Ground surveys were conducted
on average once a month (Table 1). Species were observed using binoculars and telescope
when required.
15
Figure 1 Waterbird survey sites in the Pittwater Estuary (see Table 1).
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32
1
57
56
55
54
5352
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49
48
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44
43
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37
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1110
¯0 1 20.5 Km
Scotland Is.
Careel Bay
McCarrs Ck
Pittwater
Barrenjoey
The Basin
Legend
Pittwater Estuary
! surveysites
Intertidal flats
Mangroves
16
Table 1 Sites surveyed for waterbirds, dates (2012) and survey type (blue – survey by boat; green – ground based survey).
Survey No. and date 1 2 3 4 5 6 7 8 9 10 11
27 Jan. 9 Feb. 18 Feb. 28 Feb. 6 Mar. 27 Mar. 3 April 27 April 2 May 31 May 1 June
1 Avalon Sailing Club
2 Barrenjoey Head - ocean
beach
3 Barrenjoey Head -
Pittwater beach
4 Barrenjoey Head - rocks
5 Bayview boat ramp
6 Bayview channel
7 Bayview Golf Course
8 Bayview Park
9 Bayview Spit
10 Bayview Yacht Racing
Association
11 Bonnie Doon Wharf
12 Browns Bay
13 Cabbage Tree Creek
14 Careel Bay
15 Careel Bay - end of
George St
16 Careel Bay north
17 Careel Bay wetlands
18 Church Point
19 Clareville Beach Reserve
20 Coasters Retreat
21 Currawong Beach
22 Elvina Bay
23 Florence Park
17
24 Great Mackerel Beach
25 Little Lovett Bay
26 Longnose Bay
27 Longnose Point
28 Lovett Bay
29 Lucinda Park
30 Maybanke Cove
31 McCarrs Creek 1
32 McCarrs Creek 2
33 McCarrs Creek Reserve
34 Morning Bay
35 Newport
36 Newport Yacht Clubs
37 Scotland Island - south
38 Palm Beach golfcourse
39 Paradise Beach
40 Portugese Bay
41 Refuge Cove
42 Resolute Beach
43 Robotmown grass
44 Salt Pan Cove
45 Sandy Beach
46 NSW Maritime
47 Scotland Island - north
48 Snapperman beach reserve
49 Soldiers Point
50 Taylors Point Reserve
51 The Basin
52 Towlers Bay
18
53 Trehame Cove
54 West Head
55 West Head beach
56 Winnererremy Foreshore
Reserve
57 Woody Point
19
Results
Species abundance and diversity
A total of 30 bird species were recorded during boat and ground surveys from January to
June 2012 (Table 2). This total included 25 waterbird species, two passerine species and two
species of raptor (Table 2). Two species are identified as migratory as listed under the EPBC
Act 1999, the White-bellied sea eagle (Haliaeetus leucogaster), and Eastern curlew
(Numenius madagascariensis). These species are also listed under the Japan-Australia
Migratory Bird Agreement (JAMBA), the China-Australia Bird Agreement (CAMBA) and/or
the Republic of Korea-Australia Migratory Bird Agreement (ROKAMBA) (Table 2).
Not all species were recorded on all surveys (Figure 2). Species encountered most frequently
throughout the survey period included: Silver gull, Masked lapwing, Little pied cormorant
and the White-faced heron. These species were observed on each survey. Records of
passerine species listed here were not the result of targeted surveys but were incidental
observations made during the course of waterbird surveys.
The most abundant species recorded was the Silver gull with a group of 50 individuals
recorded at Snapperman Beach Reserve on survey 7 (Figure 2).
20
Table 2 Bird species recorded during Pittwater surveys January – June 2012. Species are identified into general groupings (waterbird, passerine and raptor), whether they are a migratory species under the EPBC Act 1999, and if they are listed on the Japan -Australia Migratory Bird Agreement (JAMBA), the China-Australia Bird Agreement (CAMBA) and the Republic of Korea-Australia Migratory Bird Agreement (ROKAMBA).
Common name Scientific name Waterbird Passerine Raptor Migratory species JAMBA CAMBA ROKAMBA
Australasian darter Anhinga navaehollandiae (melanogaster) x
Australasian gannet Morus serrator x
Australian pelican Pelecanus conspicillatus x
Australian white ibis Threskiornis molucca x
Australian wood duck Chenonetta jubata x
Azure kingfisher Ceyx (Alcedo) azureus
x
Black-winged stilt Himantopus himantopus x
Chestnut teal Anas castanea x
Crested tern Thalasseus (Sterna) bergii x
Domestic geese Anser anser domesticus x
Dusky moorhen Gallinula tenebrosa x
Eastern Curlew Numenius madagascariensis x
x x x x
Great cormorant Phalacrocorax carbo x
21
Great egret Ardea ibis x x
Grey teal Anas castanea x
Little black cormorant Phalacrocorax sulcirostris x
Little pied cormorant Microcarbo (Phalacrocorax) melanoleucos x
Masked lapwing Vanellus miles x
Northern mallard Anas platyrhynchos x
Pacific black duck Anas superciliosa x
Pied cormorant Phalacrocorax varius x
Purple swamphen Porphyrio porphyrio x
Royal spoonbill Platelea regia x
Sacred kingsfisher Todiramphus sanctus
x
Silver gull Chroicocephalus (Larus) navaehollandiae x
Striated (Mangrove) heron Butorides (Ardeola) striata x
Whistling kite Haliastur sphenurus
x
White faced heron Egretta (Ardea) novaehollandiae x
22
White-bellied sea eagle Haliaeetus leucogaster
x
x
23
Figure 2 Waterbird counts per species per survey
0
1
2
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Australasian darter
0
1
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Australasian gannet
0
1
2
3
4
5
6
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Australian pelican
0
1
2
3
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Australian white ibis
0
1
2
3
4
5
6
7
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Australian wood duck
0
1
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Black-winged stilt
24
0
1
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Chestnut teal
0
1
2
3
4
5
6
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Crested tern
0
1
2
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Domestic geese
0
1
2
3
4
5
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Dusky moorhen
0
1
2
3
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Eastern curlew
0
1
2
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Great cormorant
25
0
1
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Great egret
0
1
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Grey teal
0
1
2
3
4
5
6
7
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Hybrid duck
0
1
2
3
4
5
6
7
8
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Little black cormorant
0
5
10
15
20
25
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Little pied cormorant
0
5
10
15
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Masked lapwing
26
0
1
2
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Northern mallard
0
2
4
6
8
10
12
14
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10s11
Co
un
t
Survey number
Pied cormorant
0
1
2
3
4
5
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Pacific black duck
0
1
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Purple swamphen
0
10
20
30
40
50
60
70
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Silver gull
0
1
2
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Royal spoonbill
27
Figure 3 Passerine counts per species per survey.
0
2
4
6
8
10
12
14
16
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
White-faced heron
0
0.5
1
1.5
2
2.5
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Striated heron
0
1
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Azure kingfisher
0
1
2
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
Sacred kingfisher
28
Figure 4 Raptor counts per species per survey.
Figure 5 Total bird abundance (blue-boat survey; green–ground survey) and species diversity (red) recorded for each survey.
0
1
2
3
4
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey number
White-bellied sea eagle
0
1
2
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t Survey number
Whistling kite
0
20
40
60
80
100
120
140
160
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey
29
Figure 6 Total waterbird abundance (blue-boat survey; green–ground survey) and waterbird species diversity (red) recorded for each survey.
Figure 7: Cumulative species curve
0
20
40
60
80
100
120
140
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey
0
5
10
15
20
25
30
35
s1 s2 s3 s4 s5 s6 s7 s8 s9 s10 s11
Co
un
t
Survey
30
Figure 8 Species diversity by survey site
0
2
4
6
8
10
12
14
16
Ava
lon
Sai
ling
Clu
b
Bar
ren
joey
He
ad -
oce
an b
each
Bar
ren
joey
He
ad -
Pit
twat
er…
Bar
ren
joey
He
ad -
ro
cks
Bay
view
bo
at r
amp
Bay
view
ch
ann
el
Bay
view
Go
lf C
ou
rse
Bay
view
Par
k
Bay
view
Sp
it
Bay
view
Yac
ht
Rac
ing…
Bo
nn
ie D
oo
n W
har
f
Bro
wn
s B
ay
Cab
bag
e T
ree
Cre
ek
Car
eel
Bay
Car
eel
Bay
- e
nd
of
Ge
org
e St
Car
eel
Bay
no
rth
Car
eel
Bay
wet
lan
ds
Ch
urc
h P
oin
t
Cla
revi
lle B
each
Re
serv
e
Co
aste
rs R
etre
at
Cu
rraw
on
g B
each
Elvi
na
Bay
Gre
at M
acke
rel B
eac
h
Litt
le L
ove
tt B
ay
Lon
gno
se B
ay
Lon
gno
se P
oin
t
Luci
nd
a P
ark
May
ban
ke C
ove
McC
arrs
Cre
ek
1
McC
arrs
Cre
ek
Res
erve
Mo
rnin
g B
ay
New
po
rt
New
po
rt Y
ach
t C
lub
s
NSW
Mar
itim
e
Pal
m B
each
go
lfco
urs
e
Par
adis
e B
eac
h
Po
rtu
gese
Bay
Re
fuge
Co
ve
Re
solu
te B
each
Ro
bo
tmo
wn
gra
ss
Salt
Pan
Co
ve
San
dy
Bea
ch
Sco
tlan
d Is
lan
d -
no
rth
Sco
tlan
d Is
lan
d -
so
uth
Snap
per
man
bea
ch r
ese
rve
Sold
iers
Po
int
Tayl
ors
Po
int
Res
erve
The
Bas
in
Tow
lers
Bay
Treh
ame
Co
ve
We
st H
ead
Win
ner
err
emy
Fore
sho
re…
Wo
od
y P
oin
t
No
. of
spec
ies
Site
passerines raptors waterbirds
31
Mallards
White-faced heron
Little black cormorants
32
Waterbird habitat
Waterbirds were observed using nine main habitat types (Table 3, Figure 9, Figure 10):
Tidal sand flats
Man-made roosts e.g. boats, jetties
Rocky shorelines including trees and logs over water
Mangroves
Sandy beaches
Grassy parklands
Ponds
Shallow water
Open water e.g. channel
Use of these habitat types included behaviour such as foraging and roosting. No nesting was
observed during the surveys.
Habitat use
Table 3 Habitat use by waterbirds observed during surveys.
Habitat use Habitat type Species observed using habitat
Foraging
mangroves White-faced heron
Australian white ibis
open water Little pied cormorant
Pied cormorant
Silver gull
Pacific black duck
White-faced heron
Dusky moorhen
Australasian darter
shallow water Silver gull
Little pied cormorant
Royal spoonbill
White-faced heron
tidal sand flats Masked lapwing
Silver gull
Australian white ibis
White-faced heron
Striated heron
Eastern curlew
33
Chestnut teal
Australian wood duck
grass areas Purple swamphen
Dusky moorhen
Masked lapwing
Australian wood duck
Australian white ibis
White-faced heron
Silver gull
ponds Grey teal
Dusky moorhen
rocky shoreline White-faced heron
sandy beaches Masked lapwing
White-faced heron
Silver gull
tidal creek Dusky moorhen
Teal sp.
Roosting
logs/trees Little pied cormorant
Pied cormorant
White-bellied sea eagle
Striated heron
White-faced heron
boat Little black cormorant
Little pied cormorant
Pied cormorant
Silver gull
White-faced heron
Crested tern
grass Australian wood duck
Pacific black duck
Masked lapwing
posts in water White-faced heron
Little pied cormorant
Silver gull
jetty Pacific black duck
Little black cormorant
Little Pied cormorant
Pied cormorant
Silver gull
Masked lapwing
White-faced heron
34
Australian pelican
Australasian darter
Crested tern
mangroves Little pied cormorant
Little black cormorant
White-faced heron
Royal spoonbill
Australian white ibis
rocky shoreline Little pied cormorant
Little black cormorant
Pied cormorant
Great cormorant
Australasian darter
Australian pelican
Black-winged stilt
White-faced heron
Whistling kite
White-bellied sea eagle
Masked lapwing
Silver gull
sandy beaches Crested tern
Silver gull
Masked lapwing
Australian wood duck
Australian pelican
White-faced heron
Pacific black duck
35
Figure 9 Number of species observed foraging in using each habitat type.
Figure 10 Number of species observed roosting in each habitat type.
0
2
4
6
8
10
mangroves openwater
shallowwater
tidal sandflats
grassareas
ponds rockyshoreline
sandybeaches
tidal creek
No
. Sp
ecie
s
habitat types
0
2
4
6
8
10
12
14
16
18
20
rocky shoreline man-made roosts grass areas sandy beaches mangroves
No
. of
spe
cie
s
habitat type
36
Tidal sand flats
Man-made roosts
37
Rocky shorelines
Mangroves
38
Sandy beaches
Parklands, grassy areas
39
Figure 11 Dominant type of habitat used at each survey site. Note this is not a habitat classification of survey sites, as most sites have several habitat types present e.g. man-made roosts and sandy beaches.
!
_̂_̂
%
!
"
#
#
_̂
!!
X
!
X"
X
!
_̂
_̂
#
_̂
X
#
_̂
"
%
%
!
!
!
!%
#
!
!
!
!
#
!
$
!
%
#
!
!
!
!
_̂
%
!
X
$ $
$
%
"
"
9
8
7
6
5
4
32
1
57
56
55
54
5352
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
1514
13
12
1110
Scotland Is.
Careel Bay
McCarrs Ck
Pittwater
Barrenjoey
The Basin
¯
Legend
# grassy parklands
! man-made
! mangroves
$ open water
% rocky shoreline
_̂ sandy beach
" shallow water
X tidal flats
Pittwater Estuary
0 1 20.5 Km
40
Estuarine Habitats
With reference to the report 'Estuarine habitat mapping and geomorphic characterisation of
the lower Hawkesbury river and Pittwater estuaries’ Astles, K., West, G., Creese, R.G. 2010,
these surveys focused on the Pittwater Estuary sections of the Lower Hawkesbury Estuary
within Pittwater Local Government Area. Estuarine habitat mapping of the Lower
Hawkesbury Estuary identified eight unique estuarine habitats (Astles et al. 2010). These
included:
I. Seagrass
II. Mangroves
III. Saltmarsh
IV. Mudflats
V. Sandflats
VI. Rocky reef
VII. Foreshore habitat i.e. jetties, parks
VIII. Water column
Of these, we observed four of these habitat categories being used by waterbirds and
shorebirds; mudflats, foreshore habitats (man-made roosts, rocky shorelines, parklands)
mangroves, and sandflats. Mangroves can provide roosting sites and sheltered foraging
areas, while sandflats can provide areas for foraging (Figure 12). Foreshore habitats provide
areas for foraging and roosting.
Tidal sandflats were the habitat used for foraging by the greatest number of different
species (n=8; Figure 9). The availability of diverse foraging habitats is limited in the Pittwater
Estuary. There are relatively few areas of mangroves, saltmarsh, or sandflats, and there are
no areas of mudflats (Table 4; Figure 12).
Rocky shorelines (n=12), and other foreshore habitats such as jetties (n=10) provided
roosting habitat for the greatest number of species (Figure 10). This is a habitat type that is
relatively common in the Pittwater Estuary (Table 4,
Table 5, Figure 12).
41
Table 4 The availability of estuarine habitats used by waterbirds in the Pittwater Estuary, and as a proportion of total availability in the Lower Hawkesbury Estuary (LHE).
Estuarine Habitats Area/No. in Pittwater
Estuary
% of total available in LHE
Mangroves 17.48 ha 1.75
Saltmarsh 2.68 ha 0.92
Mudflats 0 0
Sandflats 88.154 ha 26.22
Jetties
Wharves
9
677
56.0
49.0
Recreational parks 15.725 km 53.42
Source: Astles et al. 2010.
The Hawkesbury-Nepean River system, of which Pittwater Estuary is a part of, has the
fewest estuarine areas of all coastal river systems (Creese et al. 2009). This is because the
Hawkesbury-Nepean River is effectively a drowned river valley (Creese et al. 2009) resulting
in very few tidal shallow water areas. As a result there are limited areas of suitable habitat
for waterbirds and shorebirds.
Key migratory waterbird sites in NSW include the Parramatta River, Botany Bay, Port
Hacking, and Hunter Estuary.
Table 5 Available roosting and foraging habitat in Pittwater Estuary (see Figure 12).
Habitat use Total area (ha) No. of patches Mean patch size (ha)
Roosting 17.48 184 0.09
Foraging 132.82 58 2.29
Man-made roosting habitat 686 structures
42
Figure 12 Waterbird foraging and roosting habitat in the Pittwater Estuary.
¯0 1 20.5 Km
Scotland Is.
Careel Bay
McCarrs Ck
Pittwater
Barrenjoey
The Basin
Legend
Man-made roosting habitat
Pittwater Estuary
Foraging habitat
Roosting/foraging habitat
43
Disturbance
Disturbance was classified into six broad categories (Figure 13):
1) Human activity, for example swimming, golf, walking, camping, and picnicking.
2) Dogs on leash
3) Dogs off leash
4) Vehicles
5) Other wildlife
6) Construction noise
Sixty one per cent of survey sites (n=34) recorded disturbance to waterbirds (Figure 14).
Human activities were the greatest cause of disturbance to waterbirds (n=44) while dogs off
leash were the second greatest (n=40) cause of disturbance and potentially more of a threat
to waterbirds and dogs were often observed chasing birds (Figure 13). The disturbance to
waterbirds as a result of human activities, including dog walking in Pittwater is not
surprising given the large number of foreshore parks. However the recorded instances of
disturbance caused by dogs off leash were much higher than disturbance caused by dogs on
leash (Figure 13).
Figure 13 Frequency of waterbird disturbance types recorded in Pittwater Estuary.
0
5
10
15
20
25
30
35
40
45
50
human activity vehicle dogs off leash constructionnoise
dogs on leash other wildlife
Co
un
t o
f d
istu
rban
ce r
eco
rded
Disturbance category
44
Figure 14 Counts of different disturbance types at survey sites.
0
1
2
3
4
5
6
7
8
9
Ava
lon
Sai
ling
Clu
b
Bar
ren
joey
He
ad -
oce
an b
each
Bar
ren
joey
He
ad -
Pit
twat
er
be
ach
Bay
view
bo
at r
amp
Bay
view
ch
ann
el
Bay
view
Go
lf C
ou
rse
Bay
view
Par
k
Bay
view
Sp
it
Bay
view
Yac
ht
Rac
ing
Ass
oci
atio
n
Bro
wn
s B
ay
Car
eel
Bay
Car
eel
Bay
- e
nd
of
Ge
org
e St
Car
eel
Bay
no
rth
Ch
urc
h P
oin
t
Cla
revi
lle B
each
Re
serv
e
Co
aste
rs R
etre
at
Flo
ren
ce P
ark
Gre
at M
acke
rel B
eac
h
Litt
le L
ove
tt B
ay
Luci
nd
a P
ark
May
ban
ke C
ove
McC
arrs
Cre
ek
Res
erve
Mo
rnin
g B
ay
Pal
m B
each
go
lfco
urs
e
Re
fuge
Co
ve
Re
solu
te B
each
Ro
bo
tmo
wn
gra
ss
San
dy
Bea
ch
Sco
tlan
d Is
lan
d -
no
rth
Sco
tlan
d Is
lan
d -
so
uth
Snap
per
man
bea
ch r
ese
rve
Tayl
ors
Po
int
Res
erve
Tow
lers
Bay
Win
ner
err
emy
Fore
sho
re R
ese
rve
Co
un
t o
f d
istu
rban
ce t
ype
Survey site
other wildlife dogs on leash construction noise dogs off leash vehicle human activity
45
Discussion
The sites in Pittwater Estuary with the greatest species diversity of waterbirds were Careel
Bay (n=13), Bayview Golf Course (n=12) and Barrenjoey Head/Beach (n=10). Species found
at Careel Bay were predominantly wading species such as herons, ibis, spoonbills and
lapwings. Bayview Gold Course was dominated by herbivorous species such as ducks,
moorhens and swamphens. Barrenjoey Head/Beach was dominated by pisciverous species
such as cormorants and pelicans. Bayview Gold Course recorded the highest single species
abundance on two occasions of Australian Wood Duck (n=79 on the 27/4/2012 and n=74 on
the 31/05/2012).
These surveys recorded relatively low numbers of waterbird abundance. However these are
consistent with surveys conducted on other parts of the Lower Hawkesbury Estuary (Brandis
and Watson, 2011; Recher 2012). The cumulative species curve (Figure 7) which illustrates
the detection of new species during each subsequent survey only began to flatten at survey
10 out of a total of 11 surveys. This may suggest that further surveys could have detected
additional species, however the diversity of species recorded during these limited surveys is
consistent with previous studies. These surveys recorded 30 out of a total 59 species
historically recorded for the Pittwater Estuary. It should be noted that some of the species
listed here have been observed only once, e.g. the Australasian bittern, and that some
survey records span >40 years e.g. Atlas and H. Recher data.
Climate change and sea level rise
Climate change is projected to cause significant alterations to aquatic processes, including
food web structures, population dynamics, biodiversity, and primary and secondary
production. It will also affect the range, distribution and habitat quality/quantity of aquatic
flora and fauna (Wrona et al. 2006).
Direct effects of sea level rise will result in increased water depths, changes in tidal variation
(both mean tide level and tidal range), altered water movement patterns, and increased
seawater intrusion into estuaries and rivers (Short and Neckles 1999). These changes will
result in a redistribution of habitats in affected areas including a potential loss of intertidal
habitats for waterbirds and shorebirds (Galbraith et al. 2002). The ability of habitats to be
46
redistributed in the Pittwater Estuary is influenced by a significant number of variables.
These include but are not limited to: the position of the habitat patch in the Estuary, the
surrounding topography, the extent of surrounding land development, changes in the
movements of sediment, changes in tidal reach, the response of aquatic and terrestrial
vegetation and changes in the food web structure.
Galbraith et al. (2002) report that the most severe losses of habitat are likely to occur at
sites where the coastline is unable to move inland because of steep topography or seawalls
and that the effects of sea level rise may be exacerbated by additional anthropogenic
factors. This is particularly applicable to the Pittwater Estuary where the western side is
bounded by steep sided ridges while the eastern side is bounded by residential
development. There are limited options for the natural relocation of suitable waterbird
habitats.
The Cardno report (2010) examined the impact of sea level changes on foreshore flood
planning levels for Pittwater LGA. They calculated foreshore flood planning levels for five
general foreshore types; grassed and sandy gently sloping foreshores, natural rocky
foreshores, vertical sea walls and mangroves. The report found that that the predominant
foreshore type for the developed parts of Pittwater foreshore is sea walls of varying heights
(typically 1-1.5 m high). Natural rocky shoreline and natural slope (grassed and/or sandy)
were the other typical foreshore types observed. Mangroves were also observed in Careel
Bay.
This report found that the habitats used most frequently for foraging by waterbirds and
shorebirds were tidal flats and grassy areas (Figure 9). These are areas with typically low
elevations and may be most impacted by sea level rise (Table 6,Figure 15). Depending upon
their position within the estuary these habitats may either move inland if possible, or
disappear from that location. The habitats used most frequently for roosting were rocky
shorelines and man-made structures such as jetties and wharves (Figure 10). These habitat
types may not be as impacted by sea level rise as those areas used for foraging.
47
Table 6 Area of waterbird habitat most at risk from sea-level rise.
Waterbird habitat type Total area (ha)
Foraging 132.82
Roosting 17.48
Total area of habitat threatened 150.30
Projected effects on migratory shorebirds include altered migration routes and timing; a
possible increase in the incidence of mortality and decreased growth and productivity from
disease and/or parasites; and, probable changes in habitat suitability and timing of
availability (Wrona 2006). These surveys recorded only one species of migratory shorebird,
the Eastern Curlew, and only observed three individuals in the Careel Bay area. The impact
on Eastern Curlew using the Pittwater Estuary is difficult to determine as abundance was
very low. It may be that these individuals were not residents but were still moving to more
significant shorebird sites such as Botany Bay. Further surveys may record additional
migratory species, however the results of these surveys were consistent with those from the
Lower Hawkesbury Estuary (Brandis et al. 2011).
48
Figure 15 Waterbird habitat areas likely to be impacted by sea level rise.
¯0 1 20.5 Km
Scotland Is.
Careel Bay
McCarrs Ck
Pittwater
Barrenjoey
The Basin
Legend
Waterbird habitat threatened by sea level rise
Pittwater Estuary
49
Table 7 Comparison of species records between UNSW 2012 surveys and others.
All waterbird species recorded UNSW 2012
ATLAS 1970-2012
H. Recher 1967-2011
Smith & Smith 1997
Smith & Smith 2001
Australasian bitterna
x Australasian darter X
x
Australasian gannet X
x Australian pelican X x x x x
Australian white ibis X
x x x
Australian wood duck X Azure kingfisher X
x x Bar-tailed godwit
x x
Black swan
x
x
Black-winged stilt X Brown goshawk
x
Buff banded rail
x Bush-stone curlew
x
x
Cattle egretb
x x
Chestnut teal X
x Collared sparrowhawk
x
Common sandpiper
x
Crested tern X x x x x
Domestic goose X
x
Dusky moorhen X x Eastern Curlew X x x x x
Fluttering Shearwater
x Great cormorant X
x
x
Great egret X
x x Grey teal X
x
Grey-tailed tattler
x
Little black cormorant X
x x x Little egret
x x
Little fairy penguin
x x Little pied cormorant x x x x x
Mangrove gerygone
x
x Mangrove warbler
x
Masked lapwing x x x x Nankeen kestrel
x
Northern mallard x
x x
Pacific black duck x x x x x Parasitic Jaeger
x
Peregrine falcon
x Pied cormorant x x x
x
Pied oyster catcher
x
50
Pomarine Jaegerc
x
Purple swamphen x Red-capped dotteral
x
Royal spoonbill x x
x Sacred kingfisher x
x x
Silver gull x
x x x Southern stone plover
x
Straw-necked Ibis
x
Striated (Mangrove) heron x x x x x
Wedge-tailed Eagle
x Whimbrel
x x x x
Whistling kite x x x x x
White-bellied sea eagle x x x x White-faced heron x x x x x
White-fronted ternd
x
White-headed stilt x a Single record from 1970; no observations since.
b cannot recall any sightings in at least 5 years or since 2006, and no records in the books; present on Danger Is in 2011 – H. Recher (Appendix 1).
c Pomarine jaegar and Arctic jaegar are difficult species to differentiate; it may be that there has only been one species of Jaegar observed. Both UNSW and H. Recher observations were of single birds.
d No recent records of white-fronted terns. Numbers of Crested Tern are now 50% of 20-30 years ago. – H. Recher (Appendix 1).
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Key findings
In summary, the key finding of this report are:
1) There were low numbers of migratory shorebirds observed in the Pittwater Estuary
during January-June 2012 but that these findings were not unusual or unexpected
when compared with other datasets.
2) Due to the geomorphology of the Hawkesbury River, including the Pittwater Estuary
there are very few large tidal shallow water estuary areas to provide suitable
migratory shorebird habitat. Within the Pittwater Estuary the largest shallow water
tidal areas include Careel Bay and the Maybanke Cove/Winnererremy Foreshore
Reserve areas, however when compared to other areas such as Botany Bay these
areas are relatively small. The limited availability of suitable roosting and foraging
habitat in the Pittwater Estuary is consistent with the low numbers of migratory
shorebirds observed during these surveys.
Recommendations
The recommendations from this report include the following points:
1) We would recommend a longer term survey be carried out, for at least a 12 month
period. A longer term survey will identify seasonal changes in species diversity and
abundance and may identify additional habitat areas. This could potentially be done
using council staff and/or local interest groups.
2) We would recommend a review of dog off leash areas with regards to proximity to
waterbird habitats.
3) With regards to Council’s planning for rising sea levels it may be appropriate for
Council to identify areas where waterbird habitat may shift to as sea levels rise and
existing habitat becomes unsuitable.
52
References
Astles, K., West, G., Creese, R.G. (2010) Estuarine habitat mapping and geomorphic
characterisation of the lower Hawkesbury river and Pittwater estuaries. Industry &
Investment NSW, Port Stephens Fisheries Institute.
Brandis, K and Watson, H. (2011) Estuarine Wetland and Migratory Bird Survey and Priority
Habitat Mapping. Final report to Hornsby Shire Council. Australian Wetlands and Rivers
Centre, University of New South Wales.
Coughlan, R. (2008). Pittwater LGA bird survey 2006-2007. Report to Pittwater Council.
Creese, R.G., Glasby, T.M., West, G., Gallen, C. (2009) Mapping the habitats of NSW
estuaries. Report to the Hunter Central Rivers Catchment Managment Authority September
2009. Industry & Investment NSW, Port Stephens Fisheries Institute.
Galbraith, H., Jones, R., Park, R., Clough, J., Herrod-Julius, S., Harrington, B., Page, G. (2002).
Global climate change and sea level rise: potential losses of intertidal habitat for shorebirds.
Waterbirds 25, 173-183.
Nebel, S., J. Porter, et al. (2008) Long-term trends of shorebird populations in eastern
Australia and impacts of freshwater extraction. Biological Conservation 141: 971-980
Pittwater Council and Ecotone Ecological Consultants (2010). Native fauna management
plan for the Pittwater local government area.
Recher, H. (pers. comm. 2012) Table of Aquatic Birds for the Lower Hawkesbury River,
Patonga Creek, Broken Bay, Pittwater, and Brisbane Water, 1967-2011.
Short, F. T., Neckles, H.A. (1999). The effects of global climate change on seagrasses. Aquatic
Botany 63, 169-196.
Smith, P. and J. Smith (1997). Bird habitat study of Careel Bay. Report to Pittwater Council.
Smith, P. and J. Smith (2001). Waterbird survey of Careel Bay. Report to Pittwater Council.
Wrona, F. J., Prowse, T.D., Reist, J.D., Hobbie, J.E., Levesque, L.M.J., Vincent, W.F. (2006).
Climate change effects on aquatic biota, ecosystem structure and function. AMBIO: A
journal of the Human Environment 35, 359-369.
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Appendix 1: Table of Aquatic Birds for the Lower Hawkesbury River, Patonga
Creek, Broken Bay, Pittwater, and Brisbane Water, 1967-2011
Harry F. Recher
Senior Fellow, The Australian Museum, College St., Sydney, NSW
LHR (Lower Hawkesbury River from Road Bridge to Juno Pt. and Iron Pots), PC (Patonga
Creek), BB (Broken Bay from Juno to Lion Island and Barrenjoey and immediate ocean), PITT
(Pittwater inside West Head and Barrenjoey), BW (Brisbane Water)
LOCATION No’s Year
SPECIES LHR PC BB PITT BW
Little Penguin X X X 0’S 67-11
Fluttering Shearwater X 000’S
Wedge-tailed Shearwater X 0’S 67-11
Sooty Shearwater X 0’S 67-11
Short-tailed Shearwater X X 000’S
Big Black Cormorant X X X X X 0’S 67-11
Little Black Cormorant X X X X X 0’S 67-11
Big Pied Cormorant X X X X X <10 67-11
Little Pied Cormorant X X X X X 0’S 67-11
Anhinga (Darter) X X X X X 1-10 67-11
Australian Gannet X X X 1-10 67-11
Australian Pelican X X X X X 0’S 67-11
Buff-banded (Banded) Landrail X 1 Mid-
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Mar'2012 DIs
White-fronted Tern** X X X 1-10
Crested Tern X X X X X 10-30 67-11
Silver Gull X X X X X 00’S 67-11
Parasitic Jaeger X X X X 1-2 67-11
Pomarine Jaeger X X X X 1-2 67-11
Spur-winged Plover (Masked
lapwing)
X X X 1-10 67-11
Red-capped Dotteral X 1-10
Eastern Curlew X X 1-10 67-11
Whimbrel X X 1-10 67-11
Bar-tailed Godwit X X 1-10 67-11
Grey-tailed Tattler X X 1 DIs
Common Sandpiper X X 1 DIs
Sharp-tailed Sandpiper X* 1 2008 DIs
White-headed Stilt X X 10-20 irreg.
Avocet X 2 Oct'11
Pied Oystercatcher X X 2,3 DIs
Oct’ 11; 3-5
birds
2 Pied Oystercatcher Dangar Island
on 17-18 June 2012
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Southern Stone Plover X X 2-4 Careel Bay &
Riley's Is.
White Ibis X X X X X 0’S irreg. 67-11
Straw-necked Ibis X X X X X 0’S irreg. 67-11
Black-billed Spoonbill X X 1-2 2 on DIs,
6.6.12
White-faced Heron X X X X X 0’S 67-11
Little Egret X X X X <10 irreg. 67-11
Great Egret X X X X <10 irreg. 67-11; 1
on D Is
13.5.12
Nankeen Night Heron X 10
Mangrove Heron X X X X X 20-25 67-12
Cattle Egret*** X 5-25 irreg. ?. but
seen 2011 &
2012 at DIs
Black Swan X X X <10 irreg
Wood Duck X 20-30 67-11
Australian Black Duck X X X X X 10-20 67-11
Chestnut Teal X X X X X 20-20 67-11
Grey Teal X X X X X 10-20 67-11
Mallard & hybrids, incl. Muscovy X <10 67-11
White-breasted Sea Eagle X X X X X 20-30 67-11
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Whistling Kite X X X X X 20-30 67-11
Azure Kingfisher X X X <10 67-11
NOTES:
1. 67-11 indicates regular occurrence with birds being recorded annually, if not every month
2. irreg. are birds that I see every few years or even more often, but definitely not every year. Numbers can be highly variable.
3. other birds are infrequent or, at least, seldom seen. Numbers are usually in 1s and 2s at most.
4. * one bird 2008 on Dangar Island
5. numbers are a gauge only and refer to numbers when the birds are present
6. ** I have no recent records of white-fronted terns. Numbers of Crested Tern are now 50% of 20-30 years ago.
7. Most species seem as common today as in 1970s. There are more pelicans, but cormorant numbers are even. Little Blacks in Lower Hawkesbury fluctuate in abundance from <10 to 50+. Often roost on DIs
8. Duck numbers, except for Wood Duck, are lower now than in 1970s abd 80s, even the early 90s.
9. *** cannot recall any sightings in at least 5 years or since 2006, and no records in the books; present on DIs in 2011
NOTES
1. The flats and shallows around Dangar Island have never been good for migratory waders. Curlew, whimbrel, and Bar-tailed Godwit are regular (annual) transients, but generally the water on the flats is too deep for small waders. Spur-winged Plover and White-faced Heron use the flats, Dangar Beach, and Dangar foreshores throughout year. Numbers have been consistent since 1967, with 2-6 plovers (6 in 2011/12; good season for reproduction) and 2-6 herons. Herons are pair territorial, but out of nesting season there can be groups of up to 8 birds along lower river and BB. The other migratory waders may occur more frequently than I indicate, but they rarely stay more than a few days and so are probably missed more often than not. Main loafing area on lower river is the rocky spit at east end of Dangar (Mullet) Beach. Dogs are a problem on the spit and along the beach.
2. Mangrove Warbler. We did not record warblers during our surveys of mangroves in The Gut (Brooklyn) in the '70s (I can extract exact dates) nor at Careel Bay in the '70s. I recall seeing warblers up river near Spencer in the '70s and thinking they were first records. I do not see or hear warblers in Patonga Creek, but have not done a thorough search in recent
57
years. Same for Pumpkin Creek which I visit ~ once/year, but missed 2011. I have never checked the mangroves in Porto Bay and have not paid much attention to those in Brooklyn since the '70s when we were fighting to stop the Council and Lands Dept. from clearing them.