2016 Lyrebird Survey Results

In the pre-dawn darkness on Saturday the 18th of June, twenty-five volunteers and one Park Ranger were greeted with perfectly calm conditions for Tarra-Bulga National Park’s Annual  Lyrebird Survey. Overnight showers had passed by leaving moist dripping foliage in their wake.

The survey is designed to monitor the density of Lyrebirds living in 60ha comprising of wet sclerophyll and cool temperate rainforest immediately to the east of the Tarra-Bulga National Park Visitors Centre. There are sixteen monitoring points strategically placed throughout the site and volunteers move to each site before adult male Lyrebirds start their morning calls at dawn. Volunteers then use a compass to record the direction and proximity of the Lyrebird calls. This year we had enough volunteers to cover all but one of the monitoring points.

2016 Lyrebird Survey
2016 Lyrebird Survey crew ready for action.

Following the survey, lines representing the direction of the calls are plotted onto a map, and triangulation is used to establish the spots where birds were calling from. This year the results indicate we had at least nine (male) Lyrebirds calling in our 60ha zone. This corresponds to a density of one adult male Lyrebird per 6.7 ha. You can also assume that there will be female lyrebirds and immature males or non-calling males within our target area. To account for this to get our overall population of Lyrebirds we multiply the number of calling males by a factor of 2.5. It is believed that male Lyrebirds do not begin to breed until they are around 6 or 7 years old.

Summary of Tarra-Bulga National Park Lyrebird Surveys

Summary of Tarra-Bulga National Park Lyrebird Surveys

2016 Survey Map
Map showing bearings taken from monitoring points and the estimated location of calling male Lyrebirds from the 2016 survey.

 

 

Lyrebird Survey Map

To all of those people who did the Lyrebird Survey this map can give an indication of what was going on this year.Geographic Information System (GIS) software was used to plot the location of all of the monitoring sites. Then the lines coming out from each site were drawn using the information that all the volunteers recorded during the survey. Once all the lines have been drawn we can then find points where several lines from different monitoring points intersect. At these points we can be confident that there was a Male Lyrebird calling during the survey period.

Tarra Bulga Lyrebird Survey 2012 Map
Tarra Bulga Lyrebird Survey 2012 Map