Title

Colonial Nesting Sites of (threatened) Eastern Great Egrets 

Alternate title

NESTING_EASTERN_GREAT_EGRET 

Purpose

This layer is one of a series created to record the known breeding site locations for threatened egret species (Little Egret, Intermediate Egret, Eastern Great Egret and Nankeen Night Heron). The data also shows areas where breeding may have occurred, and the years when known breeding events were recorded. The additional information on flood regimes was developed in the River Red Gum Investigation 2008 and provides the frequency of flood events and their duration for maintaining the nesting habitat. The areas have also been proiritised according to the conservation status of the species. 

Credit

Andrew Corrick, Martin O'Brien, staff from Cohuna, Echuca, Shepparton and Numurkah offices. 

Supplemental Information

History: Breeding sites have been recorded since 1929, through field inspections by boat by bird observers and in later years departmental staff. The early records were taken from literature, and later records were taken from internal records produced by department field staff. Wetland surveys in the 80's also provided breeding information. Current Design Issues: The data was created from 1:25,000 topographic maps and then transferred to 1:10,000 aerial photography using transparencies and this was then digitised into a spatial layer.The data was initially divided into breeding and no formal breeding records and then divided into species and the location field was populated where local names were available. Future Design Issues: Additional breeding events will be incorporated into the datasets when data is available.These datasets will be maintained in geodatabases. Correlating flood extents with breeding sites would be useful in the future. Related Documents: Flooding requirements for biodiversity values along the Victorian floodplain of the Murray Valley.. - James Fitzsimons, Paul Peake, Doug Frood, Mel Mitchell, Naomi Withers, Matt White and Rick Webster (2011) Victorian Naturalist Vol 128(2):48-85. 

Status

Under development  

Horizontal Accuracy

100m  

Code

4283 

Maintenance and update frequency

As needed  

Title

DIGITAL 10 

Topic category

• Biota

Use limitation

Data is restricted to land and water managers managing Gunbower and Barmah forests and biologists undertaking research in these areas. Subject to custodian approval 

Classification

Restricted  

Statement

Dataset Source: Field inspection of breeding sites, GPS recording of the boundary. Transfer onto 1:25,000 topographic maps, then transfer from transparency onto aerial photography and then digitising these boundaries. Dataset Originality: Primary 

Description

Collection Method: On ground inspection by foot using handheld GPS 

Description

Transfer to Topographic maps, then transfer to aerial photography based maps and the digitisation. 

Classification

Unclassified  

Attribute Quality

Comments

Attributes have been validated by field staff. 

Positional Accuracy

Comments

The locations of the breeding and non breeding sites were identified using a GPS and then transferring onto a 1:25,000 topographic map base. The extent of nesting within these areas varied, with some sites encompassing the full wetland and others only a portion of the wetland was included. Only the boundary of the part of the wetland where nesting was recorded was mapped. These areas the accuracy may have been better than 1:10,000. 

Conceptual Consistency

Comments

good 

Missing Data

Comments

Only sites along the River Murray have been recorded and larger associated wetlands adjacent to the river. Completeness Verification: Sites have been validated by field inspection and air survey. 

Excess Data