A test of whether rabbit abundance increases following predator control in a rural landscape

Mandy Barron; Natalie de Burgh; Grant Norbury

doi:10.1071/WR24043

RESEARCH ARTICLE (Open Access)

Next Contents Vol 51(8)

A test of whether rabbit abundance increases following predator control in a rural landscape

Mandy Barron ^A , Natalie de Burgh ^B and Grant Norbury

^C ^*

+ Author Affiliations

- Author Affiliations

^A Manaaki Whenua Landcare Research, Lincoln 7608, New Zealand.

^B Hawke’s Bay Regional Council, Napier 4110, New Zealand.

^C Manaaki Whenua Landcare Research, Alexandra 9392, New Zealand.

^* Correspondence to: norburyg@landcareresearch.co.nz

Handling Editor: Penny Fisher

Wildlife Research 51, WR24043 https://doi.org/10.1071/WR24043

Submitted: 19 March 2024 Accepted: 8 July 2024 Published: 25 July 2024

© 2024 The Author(s) (or their employer(s)). Published by CSIRO Publishing. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)

Abstract

Context

In New Zealand and Australia, rural landowners believe that local control of invasive predators aimed at protecting the indigenous biota exacerbates European rabbit (Oryctolagus cuniculus) problems on their land.

Aims

We tested this using rabbit index data collected in replicated areas with and without predator control in rural landscapes of the Hawke’s Bay region of New Zealand.

Methods

Spotlight data were available from two ecological restoration areas. For the Cape to City area, data were collected from 2016 to 2021, with three sites subjected to ongoing predator control (traps deployed in 2016 and 2017) and two sites untreated. For the Poutiri Ao ō Tāne area, data were collected from 2012 to 2021, with two sites subjected to ongoing predator control (beginning in 2012) and three sites untreated. Generalised linear mixed-effects models were used to assess whether predator control was a statistically significant predictor of rabbit counts. Cameras were also deployed annually, beginning in 2015, in the treatment and non-treatment areas in Cape to City. Mixed-effects models were fitted to the camera detection data using a ‘Before After Control Impact’ framework to assess whether camera detection rates of rabbits changed with predator control.

Key results

Contrary to landowner expectations, fewer rabbits were counted under spotlight at the predator control sites at Cape to City, although no effect was detected in the camera detection data. More rabbits were counted on the predator control sites at Poutiri Ao ō Tāne, but this effect was not statistically significant and only became apparent in the last 2 years of the 9-year monitoring period.

Conclusions

The effects of predator control on rabbit abundance indices in the Hawke’s Bay region were contradictory and inconclusive. This suggests that the influence of predators on rabbit populations is minor compared with other sources of population limitation or regulation, such as disease and poor food quality.

Implications

The absence of a definitive predator effect should reassure landowners concerned about potential rabbit population outbreaks following predator control.

Keywords: human−wildlife conflict, population limitation, population regulation, predator control, predators, predator−prey dynamics, rabbits, rabbit irruptions.

References

Bates D, Mächler M, Bolker B, Walker S (2015) Fitting linear mixed-effects models using lme4. Journal of Statistical Software 67, 1-48.
| Crossref | Google Scholar |

de Burgh N, Glen AS, Mayo K, Mitchell M (2021) Using para-aminopropiophenone (PAPP) as a tool to control feral cats in Hawke’s Bay, New Zealand. New Zealand Journal of Ecology 45, 3424.
| Google Scholar |

Doherty TS, Davis RA, van Etten EJB, Algar D, Collier N, Dickman CR, Edwards G, Masters P, Palmer R, Robinson S (2015) A continental-scale analysis of feral cat diet in Australia. Journal of Biogeography 42, 964-975.
| Crossref | Google Scholar |

Gibb JA, Williams JM (1994). The rabbit in New Zealand. In ‘The european rabbit: the history and biology of a successful colonizer’. (Eds HV Thompson, CM King) pp. 158–204. (Oxford University Press: Oxford, UK)

Gillies CA, van Heezik Y (2021) Family Felidae. In ‘The Handbook of New Zealand Mammals’. 3rd edn. (Eds CM King, DM Forsyth), pp. 343–370. (CSIRO Publishing: Melbourne, Vic, Australia)

Glen A, Peace J (2021) Predator and biodiversity response monitoring in Cape to City: annual report 2021. Unpublished contract report LC3982 for Hawke’s Bay Regional Council.

Glen AS, Perry M, Yockney I, Cave S, Gormley AM, Leckie C, Dickson R, Rakete-Stones W, Rakete-Stones P, Norbury GL, Ruscoe WA (2019) Predator control on farmland for biodiversity conservation: a case study from Hawke’s Bay, New Zealand. New Zealand Journal of Ecology 43, 3358.
| Google Scholar |

Holden C, Mutze G (2002) Impact of rabbit haemorrhagic disease on introduced predators in the Flinders Ranges, South Australia. Wildlife Research 29, 615-626.
| Crossref | Google Scholar |

King CM, Veale AJ, Murphy EC, Garvey P, Byrom AE (2021) Family Mustelidae. In ‘The handbook of New Zealand mammals’. 3rd edn. (Eds CM King, DM Forsyth) pp. 285–342. (CSIRO Publishing, Melbourne)

Lennox RJ, Gallagher AJ, Ritchie EG, Cooke SJ (2018) Evaluating the efficacy of predator removal in a conflict-prone world. Biological Conservation 224, 277-289.
| Crossref | Google Scholar |

McKelvie-Sebileau P (2020) Landholder perceptions of predator control in the Cape to City region: results from the Rural Survey (2020). Unpublished report by Eastern Institute of Technology, Auckland.

Newsome AE, Parer I, Catling PC (1989) Prolonged prey suppression by carnivores – predator-removal experiments. Oecologia 78, 458-467.
| Crossref | Google Scholar | PubMed |

Norbury G, Jones C (2015) Pests controlling pests: does predator control lead to greater European rabbit abundance in Australasia? Mammal Review 45, 79-87.
| Crossref | Google Scholar |

Norbury GL, Reardon JT (2023) Total response models as a conceptual management framework for conserving vulnerable secondary prey. Conservation Science and Practice 5, e12983.
| Crossref | Google Scholar |

NPCA (2020) Pest rabbits: monitoring and control good practice guidelines. National Pest Control Agencies, Wellington, New Zealand.

Pech RP, Sinclair ARE, Newsome AE, Catling PC (1992) Limits to predator regulation of rabbits in Australia: evidence from predator-removal experiments. Oecologia 89, 102-112.
| Crossref | Google Scholar | PubMed |

R Development Core Team (2019) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. Available at https://www.r-project.org/

Read J, Bowen Z (2001) Population dynamics, diet and aspects of the biology of feral cats and foxes in arid South Australia. Wildlife Research 28, 195-203.
| Crossref | Google Scholar |

Reddiex B (2004) Effects of predation and rabbit haemorrhagic disease on rabbit population dynamics in New Zealand. PhD Thesis, Lincoln University, Lincoln, New Zealand.

Reddiex B, Hickling GJ, Norbury GL, Frampton CM (2002) Effects of predation and rabbit haemorrhagic disease on population dynamics of rabbit (Oryctolagus cuniculus) in North Canterbury, New Zeland. Wildlife Research 29, 627-633.
| Crossref | Google Scholar |

Russell JC, Innes JG, Brown PH, Byrom AE (2015) Predator-Free New Zealand: Conservation Country. BioScience 65, 520-525.
| Crossref | Google Scholar | PubMed |

Williams K, Parer I, Coman B, Burley J, Braysher M (1995) Managing Vertebrate Pests: Rabbits. Australian Government Publishing Service.