NSW National Parks and Wildlife Service
Environment Australia, June 2001
ISBN 0 7313 62829
Site assessment is critical to the successful recovery of the Bathurst Copper Butterfly. The site assessment will be undertaken by NPWS on an annual basis during the flying season of the butterfly between late August and late October. The site assessment has a number of components designed to monitor changes in the vegetation structure, distribution and density of butterflies within the habitat, condition of Blackthorn and presence of attendant ant. The data sheet attached will be amended to provide for the range of relevant observations. The site assessment also has a regulatory function in the detection or deterrence of illegal butterfly collection.
Site assessments should be undertaken with the property owner or manager. Joint assessment allows the landholder to be informed and involved in the recovery efforts.
The site assessment should be undertaken on calm sunny days during the flight season of the Bathurst Copper Butterfly between late August and late October. While the emergence of butterflies varies considerably between sites there is generally a peak of activity during September.
A fixed reference point consisting of a steel post and metal tag has been located within or adjacent to each Bathurst Copper Butterfly site. Photos of the core or typical habitat will be taken from these reference points every two years. The photos will be used to monitor changes in the structure of the vegetation that may be linked to changes in the number of adults.
The key to habitat monitoring is the understanding that the Bathurst Copper Butterfly requires sunny exposed sites. Photo monitoring will detect shrub competition with the host Blackthorn that may indicate that a low intensity prescribed burn is required. Alternatively a severe fire event may result in recruitment of Acacia sp. or Eucalyptus sp. occurring as dense stands that within a small Bathurst Copper Butterfly site may exclude the butterfly by shading out a site.. In this situation hand thinning of the vegetation may be required.
Where the habitat is identified as a fire risk to adjacent property the fuels will be assessed as part of the site assessment using the Overall Fuel Hazard Guide (McCarthy et al 1998).
Site assessment requires an estimate of the distribution and relative abundance of Bathurst Copper Butterflies at each site each year. This information is critical to understanding the natural population dynamics and response to events such as fire. It is also critical for detecting the loss or decline of adult numbers so that threats or causes can be determined and remedial actions taken. Within the metapopulation structure potential habitat may be colonised or abandoned. Monitoring should attempt to detect and map these changes.
The actual area of habitat for each Bathurst Copper Butterfly site is described on an air photo provided under the Site Description in Appendix 1. The distribution and occurrence of butterflies is described by walking the site and marking the air photo where butterflies are observed and making notes on the number, condition and behaviour, particularly if the butterfly are mating or feeding. Where the butterfly are feeding notes should be made on the species involved.
This method relies on a subjective description where the adult number estimate is categorised between common and none observed. It represents the minimum action required to monitor the number of Bathurst Copper Butterfly at each site. A much better method for estimating the population is described by van Praagh (1996) and has been applied to the Eltham Copper Butterfly Paralucia pyrodiscus lucida in Victoria.
The NPWS will seek funding for a quantitative survey of the Bathurst Copper Butterfly at each site using the protocols established for the Eltham Copper. If funding is not successful then basic monitoring by NPWS will be carried out.
Blackthorn plants should be randomly checked for presence of the attendant ant and any observations marked on the air photo and recorded on the data sheet.
Comment should be made on the growth form of the Blackthorn particularly whether juvenile plants are present, resprouting is occurring or whether plants are represented primarily by mature plants with mature foliage. The extent of grazing of the Blackthorn foliage should also be noted although it may not necessarily reflect Bathurst Copper Butterfly activity.
As part of the annual site assessment a record will be made of issues or threats to the butterfly or its habitat. The assessment will recommend the appropriate remedial action consistent with the recovery plan.
As part of the annual site assessment process, surveillance of Bathurst Copper Butterfly sites will be undertaken. The NPWS will liaise with site owners, neighbours and the entomological community regarding the illegal collection of butterfly specimens and encourage the reporting of suspicious activity. The presence of NPWS officers should deter illegal collection and enhance the possibility of collectors being detected.
Bathurst Copper Butterfly Site Assessment
Date: Time: (period)
Weather: (Sunny/overcast/wind/temperature etc)
Butterfly: (Number observed/breeding/larvae/location/behaviour
Vegetation: (Species flowering/utilised)
Insects: (Other insects on Bursaria, presence of P. aurifera etc)