Thanks to group members Martin and Bernadette for letting us use this great camera footage they captured from a very busy Lyrebird mound just near the park in the Tarra Valley. The video catches a male Lyrebird at the peak of the breeding season, strutting his stuff in a full display.
Don’t miss your chance to be involved with Friends of Tarra-Bulga National Park Annual Lyrebird Survey. This year it will be held on Saturday, June the 3rd. The meeting point for all volunteers is the park visitors centre at 6.15 am. The Survey takes only 30 minutes from the time the sun rises and the birds start calling, Straight after the count a free breakfast for all volunteers will be provided at the Lyrebird Cafe. To secure your place please email email@example.com or call David on 0488035314 by Wednesday 31/5/2017
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.
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
The Annual Lyrebird Survey at Tarra-Bulga National Park has been carried out for the last 20 years as a means of detecting any changes of the population of the birds, within an area of the park covering from around the visitors centre area to the rainforest gully at the headwaters of Macks Ck. Although Lyrebirds are not considered endangered, they are at risk from natural disasters such as bushfires, habitat decline and attack from foxes, feral animals and domestic cats and dogs. The annual survey contributes to long term data on the density of the local population and helps park management plan their future management actions.
The Lyrebirds are counted not by attempting to spot them visually, but by listening out for their song. (Sometimes you may be lucky enough to see a bird but often they are out of sight perched in a tree canopy or in ferny understorey). The survey is undertaken during the Lyrebirds’ breeding season. At this time mature male Lyrebirds are all actively searching for females to mate with and it is during this time when they are reliably singing for much of the day. The survey is consistently undertaken at dawn (when the wind is often calmer and the Lyrebirds begin their morning calls, usually while perched up in a tree).
The count is carried out by distributing groups of volunteers across the survey area at
established monitoring points. Each of these points is marked with a numbered sign so that they can be found in the pre-dawn light. As the sun rises and the Lyrebirds start singing their varied repertoire, the volunteers use a compass to establish the direction the calls are coming from and estimate the distance (close, medium or far) that the call is coming from. The survey lasts for approximately 30 minutes, after which the volunteers generally go off and enjoy breakfast at the aptly named Lyrebird Cafe.
Once the survey is completed survey sheets are collected and the direction the calls were coming from are plotted as lines onto a map, where lines coming from several surrounding monitoring points meet, we can be confident that it is a location where a male Lyrebird was calling from.
This year our Annual Lyrebird Survey will be held on Saturday June the 18th. The more volunteers we have the better able we are to get an accurate indication of the number of birds in our survey area so attendance by anyone (no experience necessary) is much appreciated. The meeting point for all volunteers is at the park visitors centre at 6.15 am. The count takes only 30 minutes from the time the sun rises and the birds start calling, which means after you have enjoyed your free breakfast it will be about 8.30am and you will be free to enjoy the rest of your Saturday. To secure your place please email firstname.lastname@example.org or call David on 0488 035 314 by this Wednesday.
Friends of Tarra-Bulga have now been using remote cameras within the park to monitor wildlife for over three years. The table below shows results adjusted for the number of days cameras have been active in the field. We currently have eight cameras that are moved around to different sites on a regular basis. As of January 2015 the cameras had spent a combined total of over 5000 days in the field and were triggered by animal movements over 10,000 times.
The results show a number of interesting trends. For mammals most species have not varied much in the frequency of sightings over the 3 years with a few exceptions. There was a large jump in Koala sightings in 2014 most were at one site where a Koala developed a routine of passing by every couple of days. Feral Cat numbers have risen each year and Ring-tailed Possum sightings seem to have declined. (the figures for Ring-tails have been influenced heavily by one popular site).
There has been a massive jump in the numbers of birds that the cameras are detecting. The number Lyrebirds passing cameras have doubled each year. Bassian Thrush (Zoothera lunulata) sightings increased around 600% in 2014 and Brush Bronze-wing numbers skyrocketed from only 15 sightings in 2013 up to 404. Crimson Rosellas, Eastern Whipbirds, Pilotbirds and *Common Blackbirds all had a significant rise in detection. Two smaller species the White-browed Scrubwren and the Superb Fairy Wren were also ‘captured’ more often.
A reason for the jump in bird numbers may be due to camera placement. One site used in 2014 was very popular for ground dwelling bird, however this does not fully explain the rise, other camera sites were used in both years and showed a big increase ground dwelling birds from 2013. Fox control efforts in recent years may also be a factor helping the birds numbers increase. Our results have picked up a small rise in Fox numbers over the last few years. As our monitoring continues, time will tell if this greater abundance of bird sightings will be maintained.
A recent post reporting on the results of our camera trap monitoring program for 2013, identified a trend with Swamp Wallabies where numbers photographed by across the park by camera traps dropped very sharply after July. We have no real explanation for this, but as we gather further data, it will be interested to see large annual fluctuations in the Wallaby count continues.
We had an inquiry as to whether it was more common to record Swamp Wallabies in daylight or during the night-time, which is an interesting question and one which is easy to work out from our database. So after crunching some numbers here are some answers, not just for Swamp Wallabies, but for all our commonly recorded species.
Swamp Wallaby triggers are fairly regular at any time of day or night, they do seem to slow down as you might predict in the middle of the day, but then fire up to have their peak numbers in the early evening.
Although it is not particularly uncommon to see Wombats out during the day sometimes, perhaps surprisingly we have never had one trigger a camera between 8am to 4pm. They seem to have peak activity in the evening and another peak around 4am.
It’s no surprise that these Bandicoots are rarely seen, although we get fairly regular photos of them, they seem to have a definite peak of activity between 2am and 4am.
The graph shows here that there is never any time of day for animals to be complacent. Foxes can be active at any time of day, seems like they are marginally more common at night. Also have data on Feral Cats, they too can be around at all hours, but seem less likely than a Fox to be around in daylight.
Lyrebirds in Tarra-Bulga obviously need to make the most of the daylight hours. It seems there is a slightly greater chance they will be snapped by a camera in the morning, but overall any time of the day is good for them.