- 5.1 PBC 201: Gametes and embryos in the female reproductive tract
- 5.2 PBC 203: Blocking embryonic development in Brushtail Possums
- 5.3 PBC 204: Immune responses in pouch young and adult possums
- 5.4 PBC 205: Synchronised oestrus
- 5.5 PBC 206: Immunoglobulin transfer
- 5.6 PBC 208: Riboflavin carrier protein
- 5.7 PBC 209: Control of reproduction by targeting the possums pituitary gland through the use of GnRH-toxin conjugates
- 5.8 PBC 210: Biological control of fertility for possum and Tb management
- 5.9 PBC 211: Immunology of bovine tuberculosis
- 5.10 PBV 2250: Manipulation of possum viruses
- 5.11 PBV 251: Parastrongyloides trichosuri
5. Possum Biocontrol
5.1 PBC 201: Gametes and embryos in the female reproductive tract
| Programme Title: | Gametes and embryos in the female reproductive tract |
| Programme Leader: | Professor John Rodger |
| Institution: | Marsupial CRC Limited |
Additional work is being completed on the final report for this project and a summary is therefore unavailable for inclusion in this report. The results of this project will be included in the next Research Results report.
5.2 PBC 203: Blocking embryonic development in Brushtail Possums
| Programme Title: | Blocking embryonic development in Brushtail Possums |
| Programme Leader: | Professor Lynne Selwood |
| Institution: | University of Melbourne |
Additional work is being completed on the final report for this project and a summary is therefore unavailable for inclusion in this report. The results of this project will be included in the next Research Results report.
5.3 PBC 204: Immune responses in pouch young and adult possums
| Programme Title: | Immune responses in pouch young and adult possums |
| Programme Leader: | Des Cooper |
| Institution: | Macquarie University |
Additional work is being completed on the final report for this project and a summary is therefore unavailable for inclusion in this report. The results of this project will be included in the next Research Results report.
5.4 PBC 205: Synchronised oestrus
| Programme Title: | Synchronised oestrus |
| Programme Leader: | Bernie McLeod |
| Institution: | AgResearch |
Additional work is being completed on the final report for this project and a summary is therefore unavailable for inclusion in this report. The results of this project will be included in the next Research Results report.
5.5 PBC 206: Immunoglobulin transfer
| Programme Title: | Immunoglobulin transfer |
| Programme Leader: | Jerome Demmer |
| Institution: | AgResearch |
Additional work is being completed on the final report for this project and a summary is therefore unavailable for inclusion in this report. The results of this project will be included in the next Research Results report.
5.6 PBC 208: Riboflavin carrier protein
| Programme Title: | Riboflavin carrier protein |
| Programme Leader: | Ken McNatty |
| Institution: | AgResearch |
Additional work is being completed on the final report for this project and a summary is therefore unavailable for inclusion in this report. The results of this project will be included in the next Research Results report.
5.7 PBC 209: Control of reproduction by targeting the possums pituitary gland through the use of GnRH-toxin conjugates
| Programme Title: | Control of reproduction by targeting the possums pituitary gland through the use of GnRH-toxin conjugates |
| Programme Leader: | Dr Doug Eckery |
| Institution: | AgResearch |
Additional work is being completed on the final report for this project and a summary is therefore unavailable for inclusion in this report. The results of this project will be included in the next Research Results report.
5.8 PBC 210: Biological control of fertility for possum and Tb management
| Programme Title: | Biological control of fertility for possum and Tb management |
| Programme Leader: | Dr P.E. Cowan |
| Institution: | Landcare Research, Lincoln |
Summary
Demographic responses to fertility control
Population abundance has shown the greatest decline on sterility treatment sites, compared with control sites. Recruitment of locally born young was successfully suppressed by sterility treatments, with 80 percent sterility resulting in a 66 percent reduction in yearling recruitment on average compared with control sites. Results suggest that fertility control can suppress productivity and recruitment in brushtail possum populations. Hence, in the absence of significant immigration, populations will decline unless regulated by density-dependent feedback processes.
Behavioural responses to fertility control
Castrated male possums had a lower rate of movement and a smaller range size than intact males, but the differences were not significant. Preliminary results suggest that methods of fertility control that alter behaviour and breeding by interfering with reproductive hormones can reduce the incidence of disease where transmission is principally by direct contact. This result, if proven, has considerable implications for the management of disease in wildlife, especially Bovine Tb in possums.
Background
This research assess the effects of fertility control in wild possum populations and is an essential step in validating biological control of possums by manipulating fertility. The results of these field experiments will be applicable to a wide range of methods proposed for biological control of possum fertility.
Approach & Outcomes
A replicated field experiment is measuring the response of wild possum populations to various levels of sterilisation. At two sites, 80 percent of females were sterilised by tubal ligation; 50 percent of females were sterilised on another two sites; and two sites served as controls (0 percent sterilised). Parameters such as abundance, survival and recruitment are being estimated using mark-recapture statistics to determine the effect of sterility treatments. The effect of disrupting normal endocrine function on possum behaviour was also studied. Thirteen possums (6 males and 7 females) that had their gonads surgically removed and 22 sexually intact possums (11 males; 11 females) were fitted with radiocollars and their movements monitored during the breeding season. Differences in movement patterns and home ranges between sterilised and intact possums were compared. To determine the effect of disrupting endocrine function on the transmission rates of commonly occurring disease in possums, Leptospira balcanica, twenty two possums (10 males; 12 females) testing negative for L. balcanica, were surgically sterilised by removing their gonads in January 2000. These possums and at least 40 non-treated possums are subject to bimonthly trapping to determine their L. balcanica status.
5.9 PBC 211: Immunology of bovine tuberculosis
| Programme Title: | Immunology of bovine tuberculosis |
| Programme Leader: | Dr Bryce Buddle |
| Institution: | AgResearch |
Additional work is being completed on the final report for this project and a summary is therefore unavailable for inclusion in this report. The results of this project will be included in the next Research Results report.
5.10 PBV 2250: Manipulation of possum viruses
| Programme Title: | Manipulation of possum viruses |
| Programme Leader: | Tao Zheng |
| Institution: | AgResearch |
Additional work is being completed on the final report for this project and a summary is therefore unavailable for inclusion in this report. The results of this project will be included in the next Research Results report.
5.11 PBV 251: Parastrongyloides trichosuri
| Programme Title: | Parastrongyloides trichosuri |
| Programme Leader: | Chuck Shoemaker |
| Institution: | AgResearch |
Additional work is being completed on the final report for this project and a summary is therefore unavailable for inclusion in this report. The results of this project will be included in the next Research Results report.
Contact for Enquiries
Farm Monitoring Programme Manager
Monitoring and Evaluation
MAF Policy
PO Box 2526
Wellington
NEW ZEALAND
Phone: +64 4 894 0623
Fax: +64 4 894 0741
Contact this person
