Environmental Engineering Reference
In-Depth Information
while 15 nests were not visited as they were outside the area of interest. Two
additional brolga nests were located during ground-truthing which were not identi-
fied during the aerial surveys.
Aerial surveys in 2009 and 2010 (Biosis Research
2011
) covered an area of
approximately 800 km
2
in 60 person-hours, with a further 40 person-hours
undertaken to ground-truth observed nests, for a total of 100 person-hours. In
2012/2013 we covered the same spatial extent on the ground over approximately
200 person-hours.
Number and Timing of Aerial Surveys
Based on the nests monitored in 2009/2010 (Biosis Research
2011
), during the two
aerial surveys undertaken by Biosis Research in 2009, 50 % and 75 % of nests
would have been available for detection, while 87.5 % of nests would have been
availablefordetectionduringoursurveyinthesameyear(Fig.
4
). The percentage
of the total number of nests for the season which was available for detection on a
single aerial survey varied between years. In 2009/2010 average availability per
week was 45 %, with a maximum availability of 87.5 % (seven of eight nests active)
duringthesecondandthirdweeksofDecember.In2012/2013averageavailability
was 27 %, with a maximum of 44 % (four of nine nests active) during the fourth
Week
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2
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1
3
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5
1111
6
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7
1111 111111
8
11
1
11111
1
2
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11
3
1
4
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5
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7
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Fig. 4
Active brolga
Grus rubicunda
nest period for the 2009-2010 (Biosis Research
2011
) and
2012(EcologyandHeritagePartnersunpublisheddata)breedingseasons.Datesofaerialsurveys
for the 2009/2010 season are shown as
solid lines
(
white
Biosis Research,
black
Ecology and
HeritagePartners)
