Biodiversity Assessment - Cape York Peninsula
Cape York Peninsula
Introduction
The Cape York Peninsula bioregion consists of a complex geology dominated by the Torres Strait Volcanics in the north. The metamorphic rocks and acid intrusive rocks of various ages of the Coen-Yambo Inlier run north- south along the eastern margin of the region and encompass the high-altitude/high-rainfall areas of Iron Range and McIlwraith Range. The deeply dissected sandstone plateaus and ranges of the Battle Camp Sandstones lie in the south of the region adjacent to the undulating Laura Lowlands composed of residual weathered sands and flat plains of colluvial and alluvial clays, silts and sands. The west of the region is dominated in the south by the extensive Tertiary sand sheets dissected by the intricate drainage systems of the Holroyd Plain, the Tertiary laterite of the undulating Weipa Plateau and the low rises of Mesozoic sandstones. The northern extension of the Weipa Plateau and extensive coastal plains adjoin the Gulf of Carpentaria. Extensive aeolian dunefields lie in the east associated with Cape Bedford/Cape Flattery in the south and the Olive and Jardine Rivers.
The most extensive vegetation types are predominantly Eucalyptus tetrodonta woodlands, usually in association with bloodwoods Corymbia nesophila, C. hylandii or C. clarksoniana, and Melaleuca viridiflora low open-woodlands. Other extensive vegetation types include Corymbia clarksoniana, Eucalyptus chlorophylla and E. cullenii woodlands, grasslands and grassy open-woodlands, heathlands, and sedgelands, and notophyll vine forests, with semi-deciduous mesophyll vine forests on the eastern ranges and deciduous vine thickets on drier western slopes. Extensive mangrove forests are found in Kennedy Inlet in the north east of the region and estuaries on both the west and east coasts. The bioregion has a tropical humid/maritime climate, with rainfall varying from 1000 mm to 1600 mm.
There are 9 subregions within the Cape York Peninsular Bioregion.
Summary of overall condition and trend
The overall condition of Cape York Peninsula is good with some declines in ecosystems, wetlands, riparian vegetation and species. Only limited clearing of vegetation has occurred in the bioregion. One of the main potential agents of change in the bioregion is the impact of altered fire regimes on vegetation.
Continental landscape stress classes are predominantly 4, with one 3 and one 5 as assessed by the Landscape Health report (1 is most stressed, 6 is least stressed).
Summary of conservation priorities
Major deficiencies in the protected area system include parts of the east coast and inland. The establishment of Indigenous Protected Areas and joint conservation management arrangements should be encouraged on Aboriginal and Torres Strait Islander lands.
Natural values
Special values of the Cape York Peninsula bioregion include habitat for a large number of rare and threatened flora species. All subregions have high ecosystem diversity and endemism, and provide refugia for wetland fauna. One of the significant values of the bioregion is its relative intactness. Cape York contains highly diverse ecosystems ranging from rainforests, woodlands, shrublands heaths, sedgelands, grasslands and mangroves, in a relatively intact condition. Over 100 Gondwanian plant species have been recorded in the bioregion, and the area is an important key to understanding the evolutionary development of Australian flora and fauna.
This region also contains the most significant and undisturbed habitat for the Estuarine Crocodile (Crocodylus porosus) in Queensland. The islands provide significant nesting habitat for Flatback turtles (Natator depressus), Hawksbill turtles (Eretmochelys imbricata) and Green turtles (Chelonia mydas).
Click here to link to a table of natural values within each subregion
Wetlands
There are 19 wetlands of national significance in this bioregion, including freshwater lakes, sand plains, dune fields, beach ridges, swamps, lakes and intertidal flats. The major occurrence of the wetlands is on the plains and shores along the coastal areas. Many of these wetlands have high value as wilderness areas, support rare or uncommon plant communities, provide important fish habitat, crocodile habitat and drought refuge.
The wetlands are in good or near pristine condition. In only a few areas the trend in condition is declining. The main threatening process is due to the impacts of feral animals. Grazing pressure and the invasion of exotic weeds are also significant threats.
A further 22 wetlands have been identified as significant at a regional level. The condition, trend and threatening processes of these wetlands are not known.
Nationally important wetlands
Map: IBRA map showing DIWA locations, towns, subregions, major roads and reserves and most common threatening processes.
Click here to link to a table of Australia's Important Wetlands (Directory of Important Wetlands of Australia): their type, condition, trend and threatening processes within each subregion.
Regionally important wetlands
Click here to link to a table of provisional identification of wetlands of regional significance: their type and special values within each subregion. The reliability of the overall subregional assessment is indicated.
Click here to link to a table of provisional identification of wetlands of regional significance: their condition, trend and threatening processes within each subregion.
Riparian Zones
Cape York Peninsula bioregion includes the catchments of the Jardine, the Normanby, the Lockhart, Wenlock, the Olive Pascoe, the Embly and the Dulcie Rivers. Seven of the nine subregions have recorded good condition for the riparian zones. Riparian zones in two subregions, the Coastal Plain, and the Holroyd Plain recorded fair condition, with the Coastal Plain declining in condition due to gazing pressure.
Map: Riparian threatening processes.
Click here to link to a table of riparian zones: their average condition, trend and threatening processes for each subregion. The reliability of this overall assessment is indicated.
Ecosystems at risk
Within Cape York, there are six endangered and 81 vulnerable regional ecosystems. This equates to approximately 3 and 38 percent respectively of the total number of ecosystems occurring in the bioregion. The most common threatened vegetation types are the tropical and subtropical rainforests and dry rainforests, tussock grasslands, and melaleuca forests and woodlands. Eucalypt woodlands with shrubby understories are also threatened. Many ecosystems are naturally restricted and are therefore classified as threatened. Weed invasion often associated with changed fire regimes and grazing pressure are the main external threats to these ecosystems.
The majority of ecosystems under threat tend to occur on alluvial plains, or are those of restricted distribution occurring on the ranges, plateaus, scarps and hills. Only one ecosystem is identified as rapidly declining and this is due to broad scale clearing and fragmentation. Fourteen ecosystems were identified as declining in condition.
Map: IBRA map showing frequency of threatening processes for ecosystems.
Click here to link to a table of provisional list of threatened ecosystems in Australia: their broad vegetation type (National Vegetation Information System - Major Vegetation Subgroup), recommended status, current legislative protection as a threatened ecosystem, trend and bioregional distribution. These ecosystems are arranged in the bioregion of their principal occurrence. The reliability of the recommended status is indicated.
Click here to link to a table of provisional list of threatened ecosystems in each subregion: their threatening processes.
Click here to link to a table of provisional list of threatened ecosystems in each subregion: their recommended recovery actions
Species at risk
There are 103 species listed as threatened in the bioregion, 22 are considered endangered and 81 vulnerable under the Nature Conservation Act 1992. The general trend of populations of the threatened species is declining. Recovery of the majority of the threatened species requires significant intervention. The key threatening processes are related to human disturbances and broad scale vegetation clearing. Significant pressure is also exerted from an increase in fragmentation and loss of remnants and predation by feral animals. Species such as the hawksbill turtle, spotted-tailed quoll and the large green-banded blue butterfly are rapidly declining in the bioregion.
Table: Threatened species for each taxon within the bioregion
| State Listing | Commonwealth Listing | ||||
|---|---|---|---|---|---|
| Endangered | Vulnerable | Endangered | Vulnerable | Extinct | |
| Amphibians | 0 | 0 | 0 | 0 | 0 |
| Birds | 3 | 13 | 5 | 5 | 0 |
| Insects | 2 | 5 | 0 | 0 | 0 |
| Fish | 0 | 0 | 0 | 0 | 0 |
| Mammals | 3 | 4 | 0 | 0 | 0 |
| Plants | 13 | 54 | 7 | 45 | 0 |
| Reptiles | 1 | 5 | 1 | 3 | 0 |
| Total | 22 | 81 | 13 | 53 | 0 |
Map: IBRA map showing frequency of threatening processes for species.
Click here to link to a table of species at risk in each subregion: their status, trend and subregional distribution. The reliability of the assessment of trend is indicated and whether recovery plans have been prepared.
Click here to link to a table of species at risk in each subregion: their threatening processes.
Click here to link to a table of species at risk in each subregion: their status recommended recovery actions.
Eucalypts and Acacias
Cape York Bioregion has five endemic acacias across four subregions, and one endemic eucalypt as shown in the table below. Their condition and trend of these species are unknown.
Endemic Eucalypts and Acacias
| CYP1 | Acacia sp. (Iron Range D.G.Fell DF2327) |
| CYP2 | Acacia solenota |
| CYP4 | Acacia sp. (Harmer Creek J.R.Clarkson+ 9133) |
| CYP7 | Acacia ommatosperma |
| CYP7 | Acacia sp. (Mekunga Creek J.R.Clarkson 4373) |
| CYP6 | Eucalyptus acroleuca |
Birds
While not the most diverse bioregion, Cape York Peninsula has by far the greatest degree of range limitation. Seventeen species occur nowhere else in Australia. Fourteen of these are primarily rainforest species of the northern Peninsula and are shared with New Guinea. Of the others, the Pale-bellied White-eye occurs only on small islands off the Peninsula coast, the Spotted Whistling-Duck has only recently been noticed on wetlands of the north-west Peninsula, and is turning out to be more common than first thought, and the Critically Endangered Herald Petrel has been recorded breeding on Raine Island, although not recently. For a further 29 species, a major part of the population occurs in the bioregion. Four of these (Red-tailed Tropicbird, Great Frigatebird, Common Noddy and Black Noddy) breed on Great Barrier Reef islands, and are widespread in the western Pacific. Nineteen species are rainforest taxa shared primarily with the Wet Tropics. The remaining limited range taxa (the Sarus Crane, the White-streaked Honeyeater, Brown-backed Honeyeater, Black-backed Butcherbird, and the Endangered Buff-breasted Button-quail and Golden-shouldered Parrot) are tropical woodland species shared with bioregions to the south, with the crane and the butcherbird also occurring outside Australia. The three other threatened taxa for which the Peninsula is important, Endangered local subspecies of Crimson and Star Finch and the Red Goshawk, are also tropical woodland species. There are no major populations of introduced species. An apparent increase in rainforest and mangrove birds probably reflects a greater energy among birdwatchers trying to see the distinctive Peninsula species, which were more accessible in the second than the first Atlas period. Elsewhere in the bioregion there has been a policy among local birdwatchers to visit sites randomly. Using this approach, the surveys have not indicated any overall change in reporting rate for woodland or grassland guilds.
Status: Highly diverse tropical avifauna, with an exceptionally large limited range fauna with links to New Guinea.
Rare and threatened: Southern Cassowary and 33 limited range species in rainforest; Red Goshawk, Buff-breasted Button-quail, Golden-shouldered Parrot, Star Finch, Crimson Finch and 4 limited range species in woodland or grassland; 6 species on offshore islands.
Increasers: Cattle Egret.
Indicators: Emu, Australian Bustard, Latham's Snipe, Squatter Pigeon, Varied Lorikeet, Golden-shouldered Parrot, Brown Treecreeper, Jacky Winter, Restless Flycatcher, Varied Sittella, Black-faced Woodswallow, Star Finch.
Trend: Detected trends probably sampling artefacts.
Scenario: Probable continued decline in grassland and open woodland birds.
Actions: Ensure representative areas have reduced or closely-managed grazing by exotic herbivores. Re-establish fine-scale burning mosaic. See also Action Plan for Australian Birds 2000 Coordinated Conservation Plan: Laura Basin.
Click hereto download a summary report including the physical characteristics of the bioregion, a species list, and summary statistics [Excel file]. The file may open on your screen. To save it to your system 'Save as' under the File menu.
Mammals
Number of species and status
There are 79 mammal species within this bioregion. (The maximum number of species recorded in a bioregion is 86 and the minimum is 25).
Click here to link to a table of number of species in each status class for this bioregion.
Click here to link to a list of mammal species and their status for this bioregion.
Critical weight range
The critical weight range (35 - 5500 g) of mammals is the size range of Australian mammals that have been most affected by environmental changes following European settlement. In this bioregion, the proportion of mammal fauna within the critical weight range is .57. (The maximum proportion of fauna within the critical weight range recorded in a bioregion is 0.632 and the minimum is 0.222).
Faunal Attrition Index
Faunal attrition is a measure of contraction or loss of species richness with a region. A high index value means many species have declined or are extinct in the bioregion. The index can be used to compare the status of mammal fauna to regional attributes such as changes since European settlement and average annual rainfall. The Faunal Attrition Index for mammals in this bioregion is .05. (The maximum faunal attrition index value recorded in a bioregion is 0.66 and the minimum is 0).
Click here to link to a table of Faunal Attrition Index for groups of mammals shows the contributions of each group to overall patterns of faunal decline.
Faunal Contraction Index
A range contraction index is a measure of the extent to which the range inhabited by a particular species has contracted. A high index value means that many of the species comprising the region's original mammal fauna have contracted from a high proportion of the regions they originally occurred in. The faunal contraction index for the mammal fauna in this bioregion is .08. (The maximum faunal contraction index value recorded in a bioregion is 0.51 and the minimum is 0.07).
Faunal Endemism Index
Endemic species are those restricted to certain regions. Regions containing endemic species are considered to have high biodiversity conservation values because opportunities to conserve those species do not exist elsewhere. A high index value means that the species comprising the original mammal fauna typically occurred in few bioregions. The faunal endemism index value for the mammal fauna in this bioregion is .79. (The maximum faunal endemism index value recorded in a bioregion is 0.79 and the minimum is 0.52).
New Endemism Index
Extant (still surviving) species that have undergone major range contractions can be considered 'new endemics'. Bioregions that contain new endemic species are often important refugia for threatened species. The new endemism index for the mammal fauna in this bioregion is unknown. (The maximum new endemism index value recorded in a bioregion is 0.93 and the minimum is 0.5).
Table: Translocated Species
There is no data available for this table within the bioregion.
Exotic Mammals
The number of introduced exotic mammal species that occur within this bioregion is 9. (The maximum number of introduced exotic mammal species in a bioregion is 16 and the minimum is 5).
Click here to link to a list of introduced exotic mammal species for this bioregion.
Extinct mammal species
The number of extinct mammal species that previously occurred within this bioregion is 0. (The maximum number of extinct mammal species in a bioregion is 29 and the minimum is 0).
Table: Extinct Species
There is no data available for this table within the bioregion.
Management responses
Reserve consolidation
The Cape York Peninsular has 11.68% of its total area under reserve tenure, with 11 National Parks and 3 Resource Reserves. These reserves include 80% of the regional ecosystems present in the bioregion, and incorporate 56 of the 87 threatened ecosystems. Protected areas consist of a range of ecosystem types varying from those occurring on marine deposits to hills and ranges.
The major reservation priorities consist of vine forests, heath and Melaleuca communities. The priority communities include 3.8.1 - Complex mesophyll vine forest occurring on basalt lowlands, 3.2.19 - Leucopogon yorkensis ? Asteromyrtus brassii open heath on old beach ridges, 3.8.3 - Eucalyptus and bloodwood woodlands on basalt flows, 3.3.11 - Melaleuca leucadendra ? Eucalyptus tereticornis open forest on alluvium, 3.5.3 - Semi-deciduous notophyll vine forest restricted to lateritic Carnegie Tablelands and 3.3.62 - Grassland/sedgeland with Pandanus spp. confined to Torres Strait Islands and lowland grasslands.
The Cape York Peninsula is a lower priority bioregion for further reservation due the current reasonable level of representation and fewer threatening processes when compared to other bioregions.
Click here to link to a table of comprehensiveness, adequacy and representativeness (CAR) of the National Reserve System in terms of ecosystems and area sampled and a ranking of reserve management. The bioregional priority for consolidating the National Reserve System is based on this CAR analysis and threat.
Click here to link to a table of bioregional and subregional priorities and ecosystem priorities to consolidate the National Reserve System and associated ecosystem constraints.
Off-park conservation for species and ecosystem recovery
Priority groups in Cape York Peninsula include native grasslands, rainforest patches, wet eucalypt forest, riparian systems, shallow wetlands, grassland fauna, and freshwater fauna. Recovery plans exist for the Golden Shouldered Parrot, and Cassowary.
Grassland and wet eucalypt forest threatened by woody weed invasion as a result of grazing by stock and changed fire management, while increased fire frequency and intensity affects rainforest patches. Conservation management actions include conservation agreements with leaseholders and traditional owners and regional fire management plans. Freshwater systems and western woodlands require inventory. Constraints to protection of these habitats include changed fire regime and feral pig damage. Wetland and riparian areas require the rehabilitation of areas infested with sicklepod. This is essential if the spread of the weed is to be controlled.
Integrated NRM
Natural resource management projects that are being implemented in the bioregion relate to capacity building with stakeholders and environmental management systems, and integration of landcare, catchment and property planning as part of the CYPLUS process. Priorities for Natural Resources Management include
- Integrated fire and grazing management
- Feral pest and weed control
- Cooperative indigenous conservation management programs
Map: IBRA map showing frequency of recovery actions (species).
Map: IBRA map showing frequency of recovery actions (ecosystems).
Map: IBRA map showing existing projects part of NRM.
Click here to link to a table of contribution of integrated Natural Resource Management to the protection of biodiversity in each subregion: existing measures and effectiveness.
Table: The contribution of integrated Natural Resource Management to the protection of biodiversity in each subregion: feasible opportunities and comments.
There is no data available for this table within the bioregion.
Further Information & Gaps
Data gaps and research priorities
The main data gaps are ecological and life history data, floristic data and fauna survey information.
References
Environment Australia 2000. Revision of the Interim Biogeographic Regionalisation of Australia (IBRA) and the Development of Version 5.1. - Summary Report. Department of Environment and Heritage, Canberra.
A complete list of references is available by clicking here.
Further information
View the Landscape Health in Australia report.
View the Terrestrial Biodiversity Assessment 2002 report.
Download the Terrestrial Biodiversity Assessment 2002 Database - Biodiversity Audit Data Entry System (BADES), and specifications
Click here to link to a table of some major data gaps in each subregion in terms of protecting biodiversity.
PDF files
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