the Cocos (Keeling) Islands - Department of the Environment · 1 Habitat suitability and island assessment for the potential translocation of Blue-tailed skinks (Cryptoblepharus egeriae)

1

Habitat suitability and island assessment

for the potential translocation of Blue-

tailed skinks (Cryptoblepharus egeriae) to

the Cocos (Keeling) Islands

Results from field work conducted on the Cocos

(Keeling) Islands in January 2014

Internal Report

Christmas Island National Park 2015

2

DOCUMENT INFORMATION

This report was prepared by the Christmas Island National Park, Natural Resource Management team.

PROJECT CONTRIBUTIONS

Report preparation:

Survey development and preparation: CINP NRM team, CIRAP

Field Work:

GIS preparation:

Data management:

Data analysis:

ACKNOWLEDGMENTS

Thanks to CIRAP members for providing advice and support for the project and to the Cocos staff who

made the field work possible by providing survey resources, local knowledge and staff time for the

survey. Thanks also to and who spent endless hours trawling through invertebrate

samples.

VERSIONS

The first draft version 1.0 of this report was produced on 23/03/2015

The final version of this report was produced on 4/06/2018

CITATION

This document can be cited as:

Director of National Parks (2014). Habitat suitability and island assessment for the potential

translocation of Blue-tailed skinks (Cryptoblepharus egeriae) to the Cocos (Keeling) Islands . Christmas

Island National Park Natural Resource Management Program: Report to the Department of the

Environment. Commonwealth of Australia 2014©.

The views expressed in this publication are not necessarily those of the Director of National Parks, the Minister of the Environment or the Commonwealth Government.

Information contained in this document and the associated database may be copied or reproduced for

study, research, informational or educational purposes, subject to inclusion of an acknowledgement of

the source.

COVER IMAGE

GIS preparation for the survey displaying priority survey islands of Pulu Siput and Pulu Labu.

3

CONTENTS

Figures ........................................................................................................................................................................ 4

Tables ......................................................................................................................................................................... 4

Background ................................................................................................................................................................ 5

Survey development .................................................................................................................................................. 5

initial assesments ................................................................................................................................................... 6

Pulu Ampang ...................................................................................................................................................... 6

Pulu-Wa-Idas ...................................................................................................................................................... 6

Pulu Blekok ......................................................................................................................................................... 6

Pulu Maraya ....................................................................................................................................................... 6

Pulu Blan Madar ................................................................................................................................................. 6

Pulu Siput ........................................................................................................................................................... 7

Methods ..................................................................................................................................................................... 7

Target species ........................................................................................................................................................ 7

Waypoint surveys ................................................................................................................................................... 8

Transect survey .................................................................................................................................................. 9

Habitat assesment.............................................................................................................................................. 9

Ink card survey ................................................................................................................................................... 9

Active/transit survey .............................................................................................................................................. 9

Static monitoring surveys ..................................................................................................................................... 10

Malise Traps ..................................................................................................................................................... 10

Intercept Traps ................................................................................................................................................. 10

Dry and Wet Pitfall Traps ................................................................................................................................. 10

Sweeps & beats ................................................................................................................................................ 10

Light traps ........................................................................................................................................................ 11

Camera monitoring .......................................................................................................................................... 11

Results ...................................................................................................................................................................... 11

Suitable Island assessment .................................................................................................................................. 11

Pulu Blan .......................................................................................................................................................... 13

Pulu Labu .......................................................................................................................................................... 14

4

Pulu Kembang .................................................................................................................................................. 15

Additional work done on Cocos ....................................................................................................................... 15

Reccommendations ................................................................................................................................................. 16

Survey Constraints/Survey element success ........................................................................................................ 17

Appendix .................................................................................................................................................................. 18

APPENDIX 1: Waypoint Datasheet .................................................................................................................. 18

APPENDIX 2: Ink Card Datasheet .................................................................................................................... 19

Appendix 3: Transit Datasheet ...................................................................................................................... 20

Appendix 4: Static monitoring datasheet ............................................................................................................ 21

Appendix 5: Waypoint results ....................................................................................................................... 22

Appendix 6: Static invertebrate results ......................................................................................................... 23

References ............................................................................................................................................................... 30

FIGURES

Figure 1: Islands surveyed during the January 2014 Cocos feasibility study..................................................... 12

Figure 2: Survey locations, effort and species detections on Pulu Blan ............................................................ 13

Figure 3: Survey locations, effort and species detections on Pulu Labu ........................................................... 14

Figure 4: Survey locations, effort and species detections on Pulu Kembang.................................................... 15

TABLES

Table 1: Desktop assessment - minimum island requirements ................................................................................. 5

Table 2: Details of the nine islands selected on Cocos for survey. ............................................................................ 6

Table 3: Species targeted and species threat matrix during active survey efforts during the 2014 Cocos

feasibility study .......................................................................................................................................................... 7

Table 4: Survey effort summary ........................................................................................................................... 11

Table 5: Summary of active survey detections..................................................................................................... 12

Table 6: Summary of passive survey detections .................................................................................................. 12

Table 7: Gecko samples taken from West and Home Islands during the 2014 Cocos feasibility survey ............. 16

5

BACKGROUND

The endemic Christmas Island blue-tailed skink (BTS) is one of four native Island reptiles, 3 of which are endemic,

two have recently disappeared from the wild. Fortunately, together with the Lister’s gecko (LG) a number of

individuals were rescued from the wild before they disappeared and were incorporated into a successful captive

breeding program on Christmas Island and Taronga Zoo. Translocation is one potential strategy for avoiding

extinction of the species and fortunately for BTS Christmas’ nearest Island neighbour, the Cocos (Keeling) Islands

may posses the characteristics that make it a suitable site for translocation including suitable habitat, lack of

predators or high chances of predator removal, lack of native competing species, and the ability to contain and

monitor a translocated population. Chances of successful translocation are further improved given BTS has been

shown to be highly adaptable to various habitats including disturbed and degraded environments (Cogger,

Sadlier et al. 1983) and (Cogger Pers Com, 2012). This report on the results of field work conducted in January

2014 aims to address objectives 1-4 from a scope of works document, ‘Christmas Island Reptile Feasibility Scope’

(Director of National Parks 2014) prepared for the director is part of a number of actions which must occur to

assess the feasibility of translocating BTS to the Cocos (Keeling) Islands.

SURVEY DEVELOPMENT

A desktop assessment of all islands within the southern atoll has been conducted to determine the most suitable

islands for possible reintroduction. This involved an assessment of island size, accessibility, and distance from

neighboring islands, tenure, height above sea level and vegetation complexity analysis.

Table 1: Desktop assessment - minimum island requirements

Size 1-12ha

Accessibility Must be easily accessible by boat or foot for monitoring and introduced predator management

Distance from nearest land Minimum 25m, and have no land bridge at low tide

Tenure Must not contain permanently or semi-permanently inhabited dwellings, be frequently visited (e.g. Direction Island), have cultural significance or other local islander use (e.g. farming)

Height above sea level Minimum 1.5msal, with elevated land area viewed favorably

Vegetation complexity Visual assessment of canopy height model and foliage coverage model

As a result a total of nine suitable islands, as is shown in

Table 2 were selected for further analysis during the field component of the feasibility study.

6

Table 2: Details of the nine islands selected on Cocos for survey.

The survey ran for a period of nine days during the early wet season from the 12th to the 20th of January 2014,

with a repeat survey planned during the dry season at a later date. The survey was structured so that field work

could be completed within the given timeframes and consists of three core components – waypoint surveys,

active/transit searches and invertebrate trapping. Access to most islands on Cocos is tide dependent adding a

level of complexity to the survey and as such survey hours were highly variable and involved some camping.

INITIAL ASSESMENTS

Following the arrival of the field team, and an initial assessment on each of the

nine islands was conducted. As a result this list was reduced to three islands being Pulu Blan, Pulu Labu and Pulu

Kembang. All three islands met the criteria of the desktop assessment and appeared to be moderately to highly

suitable as potential future release locations for C. egeriae. The following reasons are given for discounting each

of the other 6 islands deemed potentially suitable from the desktop assessment.

PULU AMPANG

Pulu Ampang, the closest island identified as potentially suitable from the desktop assessment to Home Island

was quickly ruled out as it was being intensively used by Home Islanders as a chicken farm and rubbish dump.

PULU-WA-IDAS

On arrival it appeared that there was a significant land bridge exposed even during a normal high tide joining

Pulu-Wa-Idas to Pulu Ampang and Pulu Blekok, of which both were highly unsuitable.

PULU BLEKOK

Pulu Blekok was ruled out due to its high level of recreational use, large number of chickens and a significant land

bridge joining it to Pulu-Wa-Idas.

PULU MARAYA

Pulu Maraya was quickly ruled out due to its high visitation rate, small size, lack of suitable habitat and number

of chickens.

7

PULU BLAN MADAR

A brief ‘walk around’ was conducted on Pulu Blan Madar but this island was ruled out due to its high visitation

rate, lack of habitat complexity (predominance of Cocos nucifera) and obvious high density of predators (rats,

chickens and waterhens).

PULU SIPUT

Despite presenting with highly suitable habitat, Pulu Siput was disregarded for this survey due to its large size

(10.11ha) as well as the time and resources available for this survey. A brief transit survey was conducted on this

island and it quickly became obvious that anything short of a large scale release of animals (5000+) would

‘disappear’ on the island and be impossible to monitor. Furthermore, the removal of pest species such as rats,

cats, chickens and centipedes would prove far more costly and difficult than a smaller island. Pulu Siput also

contained a classic A. gracilipes supercolony and evidence of large scale fire activity. Should a second survey be

attempted on Cocos with more time & resources, this island could be looked at.

METHODS

TARGET SPECIES

During the active survey phase (Waypoint surveys and active/transit searches), species of significance – either

potential predators, competitors or species present that potentially indicate a healthy ecosystem (e.g. nesting

seabirds) were recorded. Evidence of deliberately lit fires was also recorded. Table 3 lists these species of

interest and for potential threats a matrix has been developed for potential impacts and possibility of

eradication.

Table 3: Species targeted and species threat matrix during active survey efforts during the 2014 Cocos feasibility study

Species Waypoint Transit Potential impact Possibility of eradication

High density YCA √ √

Low/Moderate - C. egeriae have been shown to eat YCA and exist in YCA supercolonies

Low - Re-colonisation by winged females likely and non-target invertebrate food items likely affected

Feral chicken √ √ High - Present in high densities on some Cocos islands High - Easy to remove

White-breasted waterhen √ √

Moderate - Relatively unknown but a known predator of invertebrates and other small animals Low - Highly mobile

Nankeen night heron √ √

Moderate - An opportunistic predator with a wide dietary range Nil - Native to Cocos

Nankeen kestrel √ √

Moderate - Specialises in small prey items including reptiles in open areas

Low - Highly mobile, although may not be present on Cocos

Buff-banded rail √ √

Moderate - Relatively unknown but a known predator of invertebrates and other small animals Nil - Native to Cocos

8

Black rat √ √

High - Present in very high densities on most Cocos islands

Moderate - Possibility reduces on larger islands and islands in close proximity to others

Feral cat √ √

High - A single cat on a small island is capable of significant impact

High - Easy to remove on a small island

House mouse √ √ High - Capable of consuming C. egeriae at all life stages

Moderate - Possibility reduces on larger islands and islands in close proximity to others

H. frenatus √ √

Moderate - A potential predator, competitor and vector for disease transmission

Low - difficult to remove entirely, but possible to reduce numbers

L. lugubris √ √ Low - Similar to L. listeri

Nil - Possibly native to Cocos

Mute gecko √ √



H. brookii √ √



R. braminus √ √ Nil Nil

Purple land crab √ NA NA

Any hermit crab √ NA NA

Giant centipede √ √ High - A proven predator of C.egeriae


Pandanus √ NA NA

Siam weed √ NA NA

Any nesting seabird √ √ NA NA

Fire √ √ High - Can possibly raise entire islands

High - through community consultation and awareness

WAYPOINT SURVEYS

A 90x90m (0.81ha) grid of centroid waypoints was superimposed over the selected islands and following the

initial island assessment 12 waypoint surveys were conducted. This grid enabled each island of interest to be

surveyed in at least two separate locations (Range 2-13), gave a total number of survey locations that can be

surveyed within the survey timeframe and allowed surveyors to detect spatial changes in environmental

conditions across the island. Each waypoint was tagged to ensure that the same location will be surveyed during

any subsequent survey period. General observations made by the observer at the waypoint included

information on weather, date & time and any species of interest detected at the waypoint during any of the

monitoring activities performed at the waypoint. The methods applied during this survey closely resemble those

9

used in The Christmas Island-wide Survey (Department of Environment and Heritage 2012). Appendix 1,

waypoint datasheet, contains the areas of information collected at each waypoint.

At each waypoint the following monitoring activities were preformed;

TRANSECT SURVEY

At each waypoint a 10x2m transect was extended in an easterly direction from the waypoint, or in a westerly

direction where an easterly bearing was impossible (running into the ocean, obstruction). Two different survey

techniques were employed along the transect including ant counts and destructive searches.

1. Ant Counts;

Following protocols prescribed in the CINP NRM book 3 separate ant counts were conducted at 5m intervals

along the transect. This observation will not give an accurate assessment of YCA supercolony presence but

enabled a comparison of YCA abundance between waypoints and islands.

2. Destructive survey;

One meter each side of the transect any moveable object (logs, leaf litter, tree bark, rocks etc) were

lifted/moved by the surveyor to check for the presence of any species of interest, specifically; reptiles,

centipedes and rats. Any small invertebrate as part of the invertebrate survey was collected during this time

either by hand or with the use of a pooter.

HABITAT ASSESMENT

Whilst at the waypoint surveyors made a subjective assessment on habitat quality, complexity and abundance of

the surrounding area. These observations were conducted by CINP staff experienced in the assessment of highly

suitable habitat for the endemic reptiles on Christmas Island and essentially drew comparisons of habitat

suitability at the site with those in favorable habitat on Christmas Island. Observations were given as either;

Nil – habitat type is absent,

Low – habitat type is poorly represented or poor quality,

Moderate – habitat type is represented and is moderately consistent with habitat on Christmas Island,

High – Habitat type is well represented and highly consistent with habitat on Christmas Island.

An overall assessment was performed assessing the location as either not suitable, suitable or highly suitable.

INK CARD SURVEY

As per methods prescribed in the CINP NRM book groups of 10 ink Cards were deployed at each survey waypoint

meaning a total of 120 ink cards were used during the survey. The ink cards were deployed during the active

diurnal surveys and retrieved 13-16 later by Cocos staff. Ink cards were not baited with an attractant as previous

experience on Cocos suggests that adding any attractant results in the ink card being destroyed by hermit crabs.

The datasheet for ink card deployment is shown in Appendix 2.

ACTIVE/TRANSIT SURVEY

Active searches were conducted in transit between waypoints, both nocturnally and diurnally. This involved

similar techniques employed during the Island-wide survey of Christmas Island with the methods stated in both

the CI NRM book and 2013 IWS methods (Department of Environment and Heritage 2012). Surveyors recorded

10

spatial information on any species of interest as is shown in Table 3. During this activity surveyors recorded all

detections of each species as point data with the exception of high density YCA and fire where polyline or ‘area’

information could be collected. Surveyors also had the ‘track’ function on their GPS turned on to record search

effort. Appendix 3 is the transit datasheet used in the survey.

STATIC MONITORING SURVEYS

Given the availability of equipment and the ability to complete the study in the given timeframe each island

regardless of size was surveyed at two locations for a period of 3 to 4 days. Each of the two locations on the

island of interest were chosen based on the feasibility of installing and retrieving the passive monitoring

equipment but every attempt was made to ensure that the two sites were not in close proximity with each other

and that they were in locations that represent the habitat types of the island.

It was determined that insect sampling should follow that of previous studies conducted in the IOT, i.e. the

Biodiversity Monitoring Program on Christmas Island (James 2007) and an invertebrate survey undertaken by

Monash University in 2005 on the Cocos islands (Neville, Yen et al. 2005). Both these studies employed the use of

pitfall, malaise, intercept and light traps, as well as sweep and beat netting. In addition to these methods, the

sampling also utilised sticky traps and camera deployment, mainly to indicate the presence of rats and other

vertebrate species

MALISE TRAPS

One Malaise trap was deployed at each site on trees that were accessible to the surveyors. They were not

deployed in the canopy of the vegetation but mostly suspended just above ground level for the duration of the

catching period. The traps used were those deployed during the BMP between 2004/06 and many repairs had to

be made to the nets. It is not clear if these repairs impaired the efficacy of the traps, in relation to the amount of

insects caught, so if further assessment of insects is required, the purchase of new malaise traps could be

considered.

INTERCEPT TRAPS

One Intercept trap (water trap) was deployed in an area that appeared a natural pathway for insects flying

through vegetation. Again, these traps were utilised during the Biodiversity and Monitoring program Christmas

Island (2004-2006) and due to the age of the plastic intercept screen it is thought that the opaque nature of the

screen may have prevented more insects being trapped due to the screen being detected by flying insects.

DRY AND WET PITFALL TRAPS

Two lengths of drift line fencing of approximately 15m were deployed at each survey location and in total 5 dry

and 5 wet pitfall traps were installed along this fencing. The wet pitfalls proved to be very attractive to the local

land crab and as such, wet pitfall samples were badly affected, with most being pulled up by the land crab and

samples not collected. The dry pitfalls did not suffer the same fate as the wet pitfalls but there was some

removal by land crabs and many were filled with sand. Samples proved to be small as can be seen from the data

collected.

SWEEPS & BEATS

Sweep netting was employed by both surveyors at each site by simply sweeping the survey area for 5 min,

beating whatever vegetation was present with the net and disturbing coconut husk piles and dead coconut

fronds and sweeping the net over the heap.

11

LIGHT TRAPS

One light trap was deployed at each site for the duration of the survey period. Light traps proved to be difficult to

get samples, mainly due to equipment malfunction. Only a very small number of light trap samples were

collected, as indicated in the results. As the BTS are diurnal feeders, it is most likely that insects caught this way

would be, at best, opportunistic prey items or larval stages could be possibly available as prey to the BTS.

CAMERA MONITORING

A total of three ScoutGuardtm cameras were deployed at one of the static monitoring sites on each island. They

were placed low to the ground (50-100cm) with the aim of detecting potential mammalian or avian predators.

The following Table (Table 4) depicts the total survey effort for the survey.

Table 4: Survey effort summary

RESULTS

SUITABLE ISLAND ASSESSMENT

Three islands were surveyed during the January survey being Pulu Blan, Pulu Labu and Pulu Kembang. All three

islands met the criteria of the desktop assessment and appeared to be moderately to highly suitable as potential

future release locations for C. egeriae. Each of the three islands surveyed offered significantly different habitat

and each had their pro’s and con’s.

12

Figure 1: Islands surveyed during the January 2014 Cocos feasibility study

Table 5: Summary of active survey detections

Table 6: Summary of passive survey detections

13

PULU BLAN

This island was the smallest of the three surveyed (2.08ha) and may be at risk of flooding with only 0.1ha above

1.5masl, however this island is a long way (1.35km) from the atoll shelf. There was a single Pondok on the island,

however it appeared disused. Two main habitats existed on the island dominated by Cocos nucifera and Pemphis

acidula scrub. Invertebrates appeared particularly abundant in the Pemphis scrub and the island supports very

high densities of H. frenatus, the highest that the surveyors had seen on either Cocos or Christmas Islands and

occasional G. mutilata. Other potential risks include evidence of fire from Cocos locals burning off rubbish,

presence of rats and a small colony of reef egrets breeding in the Pemphis scrub.

Figure 2: Survey locations, effort and species detections on Pulu Blan

14

PULU LABU

Pulu Labu had significantly varied and complex vegetation including a number of large Calophyllum inophyllum

trees and other remnant vegetation including Termanalia catappa, Scaevola taccada, Pemphis acidula and

Cordia subcordata in the dominant Cocos nucifera vegetation. Pulu Labu was the largest island surveyed (4.05ha)

with a large area well above sea level (0.79ha above 1.5m ASL). There was a seemingly disused Pondok on this

island and little evidence of visitation including no evidence of fire. Interestingly, densities of gecko species

appeared relatively low with H. frenatus, G. mutilata and L. lugubris all found in relatively equal abundance,

again invertebrate densities appeared high. Despite appearing as the most suitable island on Cocos, Pulu Labu is

only 25m from South Island and a significant land bridge develops on even a modest low tide. Rats were also

present, although only on ink cards. Pulu Labu is also very difficult to access, with a short window available for

boat access only possible on high tides.

Figure 3: Survey locations, effort and species detections on Pulu Labu

15

PULU KEMBANG

Like Pulu Labu, Pulu Kembang had significantly varied vegetation, though not quite to the same extent. There

were significant areas of unidentified vine thicket, Guettarda speciosa, Pemphis acidula and Scaevola taccada,

Cordia subcordata and Argusia argentia. At 3.38ha and with 0.67ha above 1.5m ASL, risks of tidal flooding seem

relatively low aside from a significant swampy area on the inner-Western side. The island is also relatively

isolated with Pulu Wak Banka at 126m being the nearest island. There were two Pondok’s that may have some

intermittent activity, and there were significant areas of fire damage and some resident chickens. Rats were

abundant and a water hen was also present. Densities of G. mutilata were high while L. lugubris and H. frenatus

were also present, no doubt making use of the seemingly abundant invertebrate community. Despite the

presence of some perceived threats it is the opinion of the surveyors ( ) that

this is the most suitable island of the three surveyed due to the absence of a land bridge, complex habitats,

moderate size and easy access. Further work and a complete invertebrate assessment may help confirm this.

Figure 4: Survey locations, effort and species detections on Pulu Kembang

ADDITIONAL WORK DONE ON COCOS

Due to the identification and subsequent biosecurity alert for H. parvimaculatus all survey islands including West

and Home islands were checked for the presence of this species. No H. parvimaculatus were identified by either

Following the biosecurity alert being released on the 17th of February 2014 however, a

number of likely H. parvimaculatus specimens have been presented to Cocos National Parks staff with samples

taken for formal identification. Whilst surveying for geckos on Home Island, high densities of an unknown

Hemidactylus species were noticed on the large Calophyllum inophyllum trees near the jetty. Two samples were

taken and photos were sent to WA museum) and WA DPaW) for identification

between the 12th and 17th of February 2014. By the 17th of February they had confirmed that the species was

Hemidactylus platyurus. A biosectrity alert has been released for this species.

16

Additionally, gecko samples were taken from Home and West Islands for disease analysis. These samples were

sent to at Taronga with the final assays and report due in the near future. Samples were not taken

from the survey islands as formalin was only acquired after night work had been completed on the three islands

of interest.

Table 7, below details the samples taken.

Table 7: Gecko samples taken from West and Home Islands during the 2014 Cocos feasibility survey

RECCOMMENDATIONS

It is the strong opinion of the two surveyors that the habitat complexity and available resources (food, shelter &

water) found on the three islands surveyed are likely to be capable of supporting significant populations of C.

egeriae. A number of prohibitive factors remain such as the presence of Pondoks (Cocos island community

support), presence of predators and costs of their removal, risks of C. egeriae escaping to neighboring islands,

presence of competing reptile species (gecko’s) and risks of flooding from storm surge events.

Due to the limited time and resources, failure of some survey elements (pitfall traps) and lack of repeat surveying

we recommend that a second survey be conducted on the atoll. The original survey was conducted in January,

during the ‘wet season’, if a repeat survey were to be conducted we suggest performing the survey during the

‘dry season’ (August – November) in an attempt to detect any seasonal changes in the environment.

Following assessment of the final report, should the advice from CIRAP be that we proceed with future Christmas

Island reptile translocations on Cocos, we believe that the success of any translocations would be benefited by

the following;

1. Threatening process removal

Elimination or control of perceived threats such as rats, cats, waterhens, centipedes and/or competing

reptile species should be considered if feasible. Costs and effort will have to be considered. Other threats

such as deliberately lit fires and chickens will have to be eliminated through community consultation.

2. Habitat restoration

Species Location Date Sample Type Stored In

L. Lugubris West Island 13.01.2014 Whole cadaver 70% ethanol

H. Platyurus Home Island 16.01.2014 Whole cadaver 10% Buff Formalin

H. Platyurus Home Island 16.01.2014 Dissected cadaver 10% Buff Formalin

H. Frenatus West Island 17.01.2014 Whole cadaver 10% Buff Formalin

H. Frenatus West Island 17.01.2014 Whole cadaver 10% Buff Formalin

H. Frenatus West Island 17.01.2014 Dissected cadaver 10% Buff Formalin



G. Mutilata West Island, old jetty 19.01.2014 Dissected cadaver 10% Buff Formalin

G. Mutilata West Island, old jetty 19.01.2014 Dissected cadaver 10% Buff Formalin
















Reptile Feasability Study - January 2014

Southern Atoll - Cocos Keeling Island

17

The islands surveyed already have significant areas of habitat suitable for C. egeriae but this could be

enhanced through some weeding, limited Cocos nucifera removal and re-vegetation with locally native (and

Christmas Island native) species such as Pisonia grandis, Guettarda speciosa, Pemphis acidula, Termanalia

catappa, Cordia subcordata, Calophyllum inophyllum and Argusia argentia.

3. Careful consultation with the Cocos islands community will have to be implemented as each of the islands

are used for various purposes by the local community including Pondoks (holiday shack owners), camping,

fishing, chicken farming, forest burning and cultural reasons. It will be important to engage the relevant

stakeholders at every stage of the process.

SURVEY CONSTRAINTS/SURVEY ELEMENT SUCCESS

Unfortunately some of the survey elements failed, specifically many of the pitfall traps as they appeared to be

irresistible to the land and hermit crabs. At some sites most samples were lost in this way and any future pitfall

work will have to be conducted in a manner where the land crabs are excluded from the traps. Time constraints

and difficulties working around tidal movements meant that sampling periods for some survey elements such as

the malaise, intercept and camera traps were limited.

18

APPENDIX

APPENDIX 1: WAYPOINT DATASHEET

19

APPENDIX 2: INK CARD DATASHEET

20

APPENDIX 3: TRANSIT DATASHEET

21

APPENDIX 4: STATIC MONITORING DATASHEET

22

APPENDIX 5: WAYPOINT RESULTS

23

APPENDIX 6: STATIC INVERTEBRATE RESULTS

24

25

26

28

29

30

REFERENCES

Cogger, H., R. Sadlier and E. Cameron (1983). The terrestrial reptiles of Australia's island territories. Canberra, Australia, Australian National Parks and Wildlife Service.

Department of Environment and Heritage, E. A. (2012). Christmas Island National Park, Core Natural Resource Programs. Commonwealth of Australia 2012, Christmas Island National Park - Natural Resource Management Program: Report to the Department of Sustainability, Environment, Water, Population and Communities

Director of National Parks (2014). Christmas Island Reptile Feasibility Scope. Canberra, Department of the Environment.

James, D. J. (2007). Christmas Island biodiversity monitoring programme: summary report, December 2003 to April 2006. P. A. North. Canberra.

Neville, P., A. Yen, D. O’Dowd, M. Archer and K. MacGregor (2005). Cocos (Keeling) Islands terrestrial invertebrate survey 2005. Perth, Western Australia, Monash University: 1-68.

Documents

the Cocos (Keeling) Islands - Department of the Environment · 1 Habitat suitability and island assessment for the potential translocation of Blue-tailed skinks (Cryptoblepharus egeriae)