Hi all,
Please see below / attached an update on EBB translocation from David Bain.
Regards,
Charles Hunter
Paddington, Sydney
David Bain <> wrote:
Subject: Eastern Bristlebird translocation -BA
Date: Mon, 12 Feb 2007 19:05:15 +1100
From: "David Bain" <>
To: <>
CC: <>,
"Jack Baker" <>,
<>
Charles Hunter,
I am responding to an email you sent to Rob Whelan regarding an update on the
translocation of eastern bristlebirds at Jervis Bay which he forwarded onto me.
I have attached a brief overview of the project with some basic survey
results. Hope this is of use to you and Birds Australia.
Regards,
David
David Bain
Ecologist
Eco Logical Australia Pty Ltd
Phone: (02) 49815424
Fax: (02) 49815615
3/57 Donald St, PO Box 603
Nelson Bay, NSW 2315
www.ecoaus.com.au
Saving the endangered Eastern Bristlebird: A trial reintroduction
David Bain
12th February 2007
INTRODUCTION
The Eastern Bristlebird Dasyornis brachypterus is a prime candidate for
endangered species translocation. There is probably fewer than 2000
bristlebirds remaining in isolated populations throughout its range, with some
populations on the brink of extinction. The current distribution of the
bristlebird is fragmented and owing to the species poor dispersal abilities,
the colonisation of new areas of habitat is unlikely. This trial reintroduction
of the bristlebird has been undertaken to help re-establish the species in part
of its former range and to reduce the impact of fire to the species, which is
seen as one of the major threats facing the bristlebird.
The aims for the reintroduction were to relocate bristlebirds across Jervis
Bay from Bherwerre Peninsula to Beecroft Peninsula. Incorporated within this
framework were two investigations, the first looking at the post release
behaviour of translocated bristlebirds and their long-term survival and
reproduction, the second looking at the effects of the reintroduction on the
source population.
RESULTS
Released individuals
Overall the translocation of bristlebirds across Jervis Bay was a success.
Over the three years of this project, 50 bristlebirds have been released on
Beecroft Peninsula from 2003 -2005. Radio-tracking of released individuals has
showed that they settled into the habitat quickly. Within days after the first
release in 2003 bristlebirds were heard calling in the release environment and
bristlebirds were still recorded calling in October 2006, 18 months after the
final translocation in 2005. Released bristlebirds were radio-tracked after
release and have been shown to have settled in the habitat within that period.
Surveys of translocated individuals were carried out each year in spring time,
six months after the end of the radio-tracking period.
Three transects were annually surveyed and combined with some call playback
work to estimate the number of bristlebirds on Beecroft Peninsula (Table 1). In
2005 two bristlebirds were observed without bands, indicating that breeding had
taken place. In the most recent surveys no birds were observed close enough to
examine whether or not they were banded. During the surveys many bristlebirds
were heard calling, including some dueting with other bristlebirds.
Table 1: Total number of EBBs observed during surveys on Beecroft Peninsula
Year
(# released)
Total observed on Beecroft
2003 (15)
11
2004 (20)
21
2005 (15)
30
2006
21
The drop in the total number of bristlebirds observed may reflect the fact
that the call playback surveys this year were restricted by time constraints
and weather, resulting in the surveys being carried out in windy weather in the
late morning. This was also the first year of surveys without a release of
bristlebirds.
Conversely, the drop in the number observed may be an indication that the
population is under stress. Problems associated with surveying this cryptic
species in the dense vegetation that it prefers, makes the detection of changes
in the reintroduced population difficult. This was the first year of monitoring
without an associated release of bristlebirds earlier in the year.
Consequently, the results from surveys planned for October 2007 will be
critical in understanding the ongoing condition of the reintroduced Beecroft
population.
Source population
In total 51 bristlebirds were caught from Bherwerre Peninsula, 46 from Jervis
Bay National Park and 5 from Booderee National Park. Only 50 were translocated
as one bristlebird died during banding in the first year. The impact of this
removal seems to have been minimal on the source population at this stage.
There have been small fluctuations in bristlebird numbers in the immediate
source area, although these fluctuations have been less than the numbers of
bristlebird removed and have not been significantly different from the control
location.
CONCLUSION
Although the full results have not been presented here, these results
indicate the level of preliminary success seen in this trial reintroduction.
Bristlebirds were caught, processed, transported and released successfully.
Bristlebirds have been continually calling in the release environment and are
known to be interacting together. Monitoring in the release site into the
future will help to determine how successful the project really has been. In
the source population, monitoring has shown that the removals have not caused
any significant impacts to the local Bherwerre Peninsula population.
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