Impacts of introduced European hedgehogs on endemic skinks and weta in tussock grassland
C. Jones A D , G. Norbury B and T. Bell C
+ Author Affiliations
- Author Affiliations
A Landcare Research, PO Box 40, Lincoln 7640, New Zealand.
B Landcare Research, PO Box 282, Alexandra 9340, New Zealand.
C EcoGecko Consultants, 32 Egmont Street, New Plymouth 4310, New Zealand.
D Corresponding author. Email: jonesc@landcareresearch.co.nz
Wildlife Research 40(1) 36-44 https://doi.org/10.1071/WR12164
Submitted: 26 September 2012 Accepted: 22 December 2012 Published: 5 February 2013
Abstract
Context: Control of introduced pest species is based on the premise that there is a relationship between pest abundance and impact, but this relationship is rarely defined.
Aim: We investigated the impacts of introduced European hedgehogs (Erinaceus europaeus) on two species of small endemic skink (Oligosoma spp.) and flightless, nocturnal endemic orthopteran ground weta (Hemiandrus spp.), using an enclosure-based experimental manipulation of hedgehog density in tussock grasslands in the South Island of New Zealand.
Methods: We used capture–mark–recapture methods to estimate the densities of skinks before and after exposure to a range of hedgehog densities over a 3-month period and also compared changes in indices of abundance of skink demographic groups and ground weta.
Key results: Faecal analysis confirmed that hedgehogs consumed skinks and invertebrates in the enclosures. The proportional change between capture sessions in numbers of captured juvenile McCann’s skinks (O. maccanni) declined with increasing hedgehog density. Similarly, the proportional change in the numbers of ground weta encountered in pitfall traps showed a highly significant negative relationship with increasing hedgehog density. Total species abundances and numbers in other demographic skink groups did not change significantly in relation to hedgehog density. For overall skink abundance estimates, there was an apparent trend suggesting that changes in abundance were more negative with increasing hedgehog density, but this did not reach statistical significance for either skink species.
Conclusions: Our results confirmed that hedgehogs are important predators of small native fauna, but suggested that highly abundant prey populations may be buffered against significant impacts.
Implications: Less abundant prey and some demographic groups within populations, however, may be at significant risk from hedgehog predation.
Additional keywords: damage function, Erinaceus europaeus, experiment, Hemiandrus spp., Oligosoma maccanni, O. polychroma, predation.
References
Aguirre-Muñoz, A., Luna-Mendoza, L., Samaniego-Herrera, A., Félix-Lizárraga, M., Ortiz-Alcaraz, A., Rodríguez-Malagón, M., Méndez-Sánchez, F., González-Gómez, R., Torres-García, F., Latofski-Robles, M., Hernández-Montoya, J. C., Barredo-Barberena, J. M., Hermosillo-Bueno, M. A., Silva-Estudillo, N., and Soqui-Gómez, E. (2011). Island restoration in Mexico: ecological outcomes after systematic eradications of invasive mammals. In ‘Island Invasives: Eradication and Management’. (Eds C. R. Veitch, M. N. Clout and D. R. Towns.) pp. 250–258. (IUCN: Gland, Switzerland.) Available at http://www.issg.org/pdf/publications/Island_Invasives/pdfHQprint/3Aguirre-MunozI.pdf [verified 17 August 2012].Akaike, H. (1973). Information theory as an extension of the maximum likelihood principle. In ‘Second International Symposium on Information Theory’. (Eds B. N. Petrov and F. Csaki.) pp. 267–281. (Akademiai Kiado: Budapest, Hungary.)
Anderson, D. R. (2001). The need to get the basics right in wildlife field studies. Wildlife Society Bulletin 29, 1294–1297.
Atkinson, I. (1989). Introduced animals and extinctions. In ‘Conservation for the Twenty-first Century’. (Eds D. Western and M. C. Pearl.) pp. 54–75. (Oxford University Press: New York.)
Barwick, R. E. (1959). The life history of the common New Zealand skink Leiolopisma zelandica (Gray, 1843). Transactions of the Royal Society of New Zealand 86, 331–380.
Burnham, K. P., and Anderson, D. R. (2002). ‘Model Selection and Multimodel Inference: a Practical Information-theoretic Approach.’ 2nd edn. (Springer: New York.)
Choquenot, D., and Parkes, J. (2001). Setting thresholds for pest control: how does pest density affect resource viability? Biological Conservation 99, 29–46.
| Setting thresholds for pest control: how does pest density affect resource viability?Crossref | GoogleScholarGoogle Scholar |
Choquenot, D., Lukins, B., and Curran, G. (1997). Assessing lamb predation by feral pigs in Australia’s semi-arid rangelands. Journal of Applied Ecology 34, 1445–1454.
| Assessing lamb predation by feral pigs in Australia’s semi-arid rangelands.Crossref | GoogleScholarGoogle Scholar |
Clavero, M., and Garcia-Berthou, E. (2005). Invasive species are a leading cause of animal extinctions. Trends in Ecology & Evolution 20, 110.
| Invasive species are a leading cause of animal extinctions.Crossref | GoogleScholarGoogle Scholar |
Clout, M. N., and Veitch, C. R. (2002). Turning the tide of biological invasion: the potential for eradicating invasive species. In ‘Turning the Tide: the Eradication of Invasive Species’. (Eds C. R. Veitch and M. N. Clout.) pp. 1–3. (SSC Invasive Species Specialist Group, IUCN: Gland, Switzerland.)
Conn, P. B., Arthur, A. D., Bailey, L. L., and Singleton, G. R. (2006). Estimating the abundance of mouse populations of known size: promises and pitfalls of new methods. Ecological Applications 16, 829–837.
| Estimating the abundance of mouse populations of known size: promises and pitfalls of new methods.Crossref | GoogleScholarGoogle Scholar |
Cooch, E. G., and White, G. C. (Ed.) (Updated) 2007. ‘Program MARK: ‘a gentle introduction.’ 6th edn. Available at http://www.phidot.org/software/mark/docs/book/ [verified 11 March 2011].
Dillon, J. L. (1977). ‘The Analysis of Response in Crop and Livestock production.’ 2nd edn. (Pergamon Press: Oxford, UK.)
Engeman, R. M. (2005). Indexing principles and a widely applicable paradigm for indexing animal populations. Wildlife Research 32, 203–210.
| Indexing principles and a widely applicable paradigm for indexing animal populations.Crossref | GoogleScholarGoogle Scholar |
Freeman, A. B. (1997). Comparative ecology of two Oligosoma skinks in coastal Canterbury: a contrast with central Otago. New Zealand Journal of Ecology 21, 153–160.
Gibbs, G. W. (1998). Why are some weta (Orthoperta: Stenopelmatidae) vulnerable yet others area common? Journal of Insect Conservation 2, 161–166.
| Why are some weta (Orthoperta: Stenopelmatidae) vulnerable yet others area common?Crossref | GoogleScholarGoogle Scholar |
Hasegawa, M. (1990). The thrush Turdus celaenops as a pn avian predator of juvenile Eumeces okadae on Miyake-Jima, Izu Islands. Japanese Journal of Herpetology 3, 65–69.
Hitchmough, R. A., Hoare, J. M., Jamieson, H., Newman, D., Tocher, M. D., Anderson, P. J., Lettink, M., and Whitaker, A. H. (2010). Conservation status of New Zealand reptiles, 2009. New Zealand Journal of Zoology 37, 203–224.
| Conservation status of New Zealand reptiles, 2009.Crossref | GoogleScholarGoogle Scholar |
Hoare, J. M. (2006). Novel predators and naïve prey: how introduced mammals shape behaviours and populations of New Zealand lizards. Ph.D. Thesis, Victoria University of Wellington, Wellington, New Zealand.
Holmes, K. M., and Cree, A. (2006). Annual reproduction in females of a viviparous skink (Oligosoma maccanni) in a subalpine environment. Journal of Herpetology 40, 141–151.
| Annual reproduction in females of a viviparous skink (Oligosoma maccanni) in a subalpine environment.Crossref | GoogleScholarGoogle Scholar |
Hone, J. (1994) ‘Analysis of Vertebrate Pest Control.’ (Cambridge University Press: Cambridge, UK.)
Hone, J. (2007). ‘Wildlife Damage Control.’ (CSIRO: Melbourne.)
Huggett, A. (2005). The concept and utility of ‘ecological thresholds’ in biodiversity conservation. Biological Conservation 124, 301–310.
| The concept and utility of ‘ecological thresholds’ in biodiversity conservation.Crossref | GoogleScholarGoogle Scholar |
Huggins, R. M. (1989). On the statistical analysis of capture experiments. Biometrika 76, 133–140.
| On the statistical analysis of capture experiments.Crossref | GoogleScholarGoogle Scholar |
Huggins, R. M. (1991). Some practical aspects of a conditional likelihood approach to capture experiments. Biometrics 47, 725–732.
| Some practical aspects of a conditional likelihood approach to capture experiments.Crossref | GoogleScholarGoogle Scholar |
Jones, C. (2003). Safety in numbers for secondary prey populations: an experimental test using egg predation by introduced small mammals in New Zealand. Oikos 102, 57–66.
| Safety in numbers for secondary prey populations: an experimental test using egg predation by introduced small mammals in New Zealand.Crossref | GoogleScholarGoogle Scholar |
Jones, C., and Bell, T. (2010). Relative effects of toe-clipping and pen-marking on short-term recapture probability of McCann’s skinks (Oligosoma maccanni). The Herpetological Journal 20, 237–241.
Jones, C., and Norbury, G. (2006). Habitat use as a predictor of nest raiding by individual hedgehogs (Erinaceus europaeus) in New Zealand. Pacific Conservation Biology 12, 180–188.
Jones, C., and Norbury, G. (2011). Feeding selectivity of introduced hedgehogs Erinaceus europaeus in a dryland habitat, South Island, New Zealand. Acta Theriologica 56, 45–51.
| Feeding selectivity of introduced hedgehogs Erinaceus europaeus in a dryland habitat, South Island, New Zealand.Crossref | GoogleScholarGoogle Scholar |
Jones, C., and Sanders, M. (2005). European hedgehog. In ‘The Handbook of New Zealand Mammals’. 2nd edn. (Ed. C. M. King.) pp. 81–94. (Oxford University Press: Auckland, New Zealand.)
Jones, C., Moss, K., and Sanders, M. (2005). Diet of hedgehogs (Erinaceus europaeus) in the upper Waitaki Basin, New Zealand: implications for conservation. New Zealand Journal of Ecology 29, 29–35.
Lettink, M., Norbury, G., Cree, A., Seddon, P. J., Duncan, R. P., and Schwarz, C. J. (2010). Removal of introduced predators, but not artificial refuge supplementation, increases skink survival in coastal duneland. Biological Conservation 143, 72–77.
| Removal of introduced predators, but not artificial refuge supplementation, increases skink survival in coastal duneland.Crossref | GoogleScholarGoogle Scholar |
Lettink, M., O’Donnell, C. F. J., and Hoare, J. M. (2011). Accuracy and precision of skink counts from artificial retreats. New Zealand Journal of Ecology 35, 236–246.
Mack, R. N., Simberloff, D., Lonsdale, W. M., Evans, H., Clout, M., and Bazzaz, F. A. (2000). Biotic invasions: causes, epidemiology, global consequences and control. Ecological Applications 10, 689–710.
| Biotic invasions: causes, epidemiology, global consequences and control.Crossref | GoogleScholarGoogle Scholar |
Norbury, G. (2001). Conserving dryland lizards by reducing predator-mediated apparent competition and direct competition with introduced rabbits. Journal of Applied Ecology 38, 1350–1361.
| Conserving dryland lizards by reducing predator-mediated apparent competition and direct competition with introduced rabbits.Crossref | GoogleScholarGoogle Scholar |
Otis, D. L., Burnham, K. P., White, G. C., and Anderson, D. R. (1978). Statistical inference from capture data on closed animal populations. Wildlife Monographs 62, 1–135.
Patterson, G. B. (1984). The effect of burning-off tussock grassland on the population density of common skinks. New Zealand Journal of Zoology 11, 189–194.
| The effect of burning-off tussock grassland on the population density of common skinks.Crossref | GoogleScholarGoogle Scholar |
Patterson, G. B. (1992). The ecology of a New Zealand grassland lizard guild. Journal of the Royal Society of New Zealand 22, 91–106.
| The ecology of a New Zealand grassland lizard guild.Crossref | GoogleScholarGoogle Scholar |
Patterson, G. B., and Daugherty, C. H. (1990). Four new species and one new subspecies of skink, genus Leiolopisma (Reptilia: Lacertilia: Scincidae) from New Zealand. Journal of the Royal Society of New Zealand 20, 65–84.
| Four new species and one new subspecies of skink, genus Leiolopisma (Reptilia: Lacertilia: Scincidae) from New Zealand.Crossref | GoogleScholarGoogle Scholar |
Pech, R. P., Sinclair, A. E., and Newsome, A. E. (1995). Predation models for primary and secondary prey species. Wildlife Research 22, 55–64.
| Predation models for primary and secondary prey species.Crossref | GoogleScholarGoogle Scholar |
Reardon, J. T., Whitmore, N., Holmes, K. N., Judd, L. M., Hutcheon, A. D., Norbury, G., and Mackenzie, D. I. (2012). Predator control allows critically endangered lizards to recover on mainland New Zealand. New Zealand Journal of Ecology 36, 141–150.
Reeve, N. (1994). ‘Hedgehogs.’ (T. and A.D. Poyser: London.)
Ruscoe, W. A., Sweetapple, P. J., Perry, M., and Duncan, R. P. (). Effects of spatially extensive control of invasive rats on abundance of native invertebrates in mainland New Zealand forests. Conservation Biology , .
Sanders, M. D., and Maloney, R. F. (2002). Causes of mortality at nests of ground-nesting birds in the upper Waitaki Basin, South Island, New Zealand: a 5-year video study. Biological Conservation 106, 225–236.
| Causes of mortality at nests of ground-nesting birds in the upper Waitaki Basin, South Island, New Zealand: a 5-year video study.Crossref | GoogleScholarGoogle Scholar |
Sax, D. F., and Gaines, S. D. (2008). Species invasions and extinction: the future of native biodiversity on islands. Proceedings of the National Academy of Sciences, USA 105, 11 490–11 497.
| Species invasions and extinction: the future of native biodiversity on islands.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhtVSjtr%2FP&md5=55a2be34d32a0dad3f89ac06cbb93d17CAS |
Sinclair, A. R. E., and Pech, R. P. (1996). Density dependence, stochasticity, compensation and predator regulation. Oikos 75, 164–173.
| Density dependence, stochasticity, compensation and predator regulation.Crossref | GoogleScholarGoogle Scholar |
Spitzen-van der Sluijs, A. M., Spitzen, J., Houston, D., and Stumpel, A. H. P. (2009). Skink predation by hedgehogs at Macraes Flat, Otago, New Zealand. New Zealand Journal of Ecology 33, 205–207.
Stephens, T., Brown, D., and Thornley, N. (2002). ‘Measuring Conservation Achievement: Concepts and Their Application over the Twizel Area.’ Science for Conservation 2002. (Department of Conservation: Wellington, New Zealand.)
Towns, D. R. (1975). Ecology of the black shore skink, Leiolopisma suteri (Lacertilia: Scincidae), in boulder beach habitats. New Zealand Journal of Zoology 2, 389–407.
| Ecology of the black shore skink, Leiolopisma suteri (Lacertilia: Scincidae), in boulder beach habitats.Crossref | GoogleScholarGoogle Scholar |
Vitousek, P. M., D’Antonio, C. M., Loope, L. L., Rejmanek, M., and Westbrooks, R. (1997). Introduced species: a significant component of human-caused global change. New Zealand Journal of Ecology 21, 1–16.
Watts, C. H., Armstrong, D. P., Innes, J., and Thornburrow, D. (2011). Dramatic increases in weta (Orthoptera) following mammal eradication on Maungatautari – evidence from pitfalls and tracking tunnels. New Zealand Journal of Ecology 35, 261–272.
Whitaker, A. H., Tocher, M. D., and Blair, T. (2002). ‘Conservation of Lizards in Otago Conservancy 2002–2007.’ (Department of Conservation: Wellington, New Zealand.)
White, G. C. (2005). Correcting wildlife counts using detection probabilities. Wildlife Research 32, 211–216.
| Correcting wildlife counts using detection probabilities.Crossref | GoogleScholarGoogle Scholar |
White, G. C., and Burnham, K. P. (1999). Program MARK: survival estimation from populations of marked animals. Bird Study 46, S120–S139.
| Program MARK: survival estimation from populations of marked animals.Crossref | GoogleScholarGoogle Scholar |
White, G. C., Anderson, D. R., Burnham, K. P., and Otis, D. L. (1982). ‘Capture–Recapture and Removal Methods for Sampling Closed Populations.’ LA-8787-NERP. (Los Alamos National Laboratory: Los Alamos, NM.)
Williams, B. K., Nichols, J. D., and Conroy, M. J. (2002). ‘Analysis and Management of Animal Populations.’ (Academic Press: San Diego, CA.)
Wilson, D. J., Wiedemer, R. L., and Clark, R. D. (2007). Sampling skinks and geckos in artificial cover objects in a dry mixed grassland–shrubland with mammalian predator control. New Zealand Journal of Ecology 31, 169–185.
Wroot, A. J. (1984). Feeding ecology of the European hedgehog, Erinaceus europaeus. Ph.D. Thesis, University of London, UK.
