Skip to main content
Log in

Long-term impacts of an introduced ungulate in native grasslands: Himalayan tahr (Hemitragus jemlahicus) in New Zealand’s Southern Alps

  • Original Paper
  • Published:
Biological Invasions Aims and scope Submit manuscript

Abstract

Ungulates have been widely introduced to new locations, often increasing to high densities that impact on native plant communities. Himalayan tahr (Hemitragus jemlahicus) were introduced to New Zealand in 1904 and now occupy about 9600 km2 of the Southern Alps. Managers aim to control tahr to reduce impacts to native montane grasslands. We used a network of 111 permanent plots in eight catchments to estimate the long-term impacts of tahr on total vegetation cover and snow tussock (Chionochloa spp.) height. The proportion of sub-plots containing faecal pellets was used as a measure of tahr activity. Total vegetation cover increased during the study period but declined non-linearly with increasing tahr activity, with the most rapid decline occurring as tahr activity increased from low levels (i.e. a highly-vulnerable relationship). Tussock height declined weakly as a function of time during the study period, but declined strongly with increasing tahr activity (a proportionate relationship). A proportional effect of tahr activity on adult tussock height and a non-linear logarithmic effect of tahr activity on vegetation cover indicate that species other than tussocks were highly sensitive to tahr activity, even at very low levels. We conclude that tahr had significantly impacted total vegetation cover and tussock height during 1990–2013. Although vegetation cover appears to still be recovering from the high tahr densities that occurred prior to the 1970s, managers need to control tahr to lower levels, to further reduce their impacts on montane grasslands.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

Similar content being viewed by others

References

  • Atkinson IAE, Greenwood RM (1989) Relationships between moas and plants. N Z J Ecol 12:67–96

    Google Scholar 

  • Augustine DJ, McNaughton SJ (1998) Ungulate effects on the functional species composition of plant communities: herbivore selectivity and plant tolerance. J Wildl Manag 62:1165–1183

    Article  Google Scholar 

  • Bates D et al (2014) lme4: linear mixed-effects models using Eigen and S4. R package version 1.0-6 edn. http://CRAN.R-project.org/package=lme4

  • Bee JN et al (2010) Spatio-temporal feeding selection of red deer in a mountanious landscape. Austral Ecol 35:752–764

    Article  Google Scholar 

  • Beguin J, Pothier D, Côté SD (2011) Deer browsing and soil disturbance induce cascading effects on plant communities: a multilevel path analysis. Ecol Appl 21:439–451

    Article  PubMed  Google Scholar 

  • Burnham KP, Anderson DR (2002) Model selection and multimodel inference: a practical information-theoretic approach. Springer, New York

    Google Scholar 

  • Caughley G (1970a) Eruption of ungulate populations, with emphasis on Himalayan thar in New Zealand. Ecology 51:53–72

    Article  Google Scholar 

  • Caughley G (1970b) Liberation, dispersal and distribution of Himalayan thar (Hemitragus jemlahicus) in New Zealand. N Z J Sci 10:23–33

    Google Scholar 

  • Coomes DA et al (2003) Factors preventing the recovery of New Zealand forests following control of invasive deer. Conserv Biol 17:450–459

    Article  Google Scholar 

  • Côté SD et al (2004) Ecological impacts of deer overabundance. Annu Rev Ecol Evol Syst 35:113–147

    Article  Google Scholar 

  • Crawley MJ (2013) The R book. Wiley, West Sussex

    Google Scholar 

  • Cruz J, Thomson C, Parkes JP (2014) Impact of himalayan tahr (Hemitragus jemlahicus) on snow tussocks in the Southern Alps, New Zealand. Landcare Research, Lincoln, p 28

    Google Scholar 

  • Department of Conservation (1993) Himalayan thar control plan. Department of Conservation, Christchurch, p 68

    Google Scholar 

  • Donne TE (1924) The game animals of New Zealand: an account of their introduction, acclimatization, and development. J Murray, London

    Google Scholar 

  • Duncan K, Holdaway R (1989) Footprint pressures and locomotion of moas and ungulates and their effects on the New Zealand indigenous biota through trampling. N Z J Ecol 12:97–101

    Google Scholar 

  • Evju M et al (2009) Grazing responses in herbs in relation to herbivore selectivity and plant traits in an alpine ecosystem. Oecologia 161:77–85

    Article  PubMed  Google Scholar 

  • Flueck WT (2010) The slippery slope of exporting invasive species: the case of Himalayan tahr arriving in South America. Biol Invasions 12:1467–1475

    Article  Google Scholar 

  • Flux JE (1967) Hare numbers and diet in an alpine basin in New Zealand. Proc N Z Ecol Soc 14:27–33

    Google Scholar 

  • Forsyth DM (1997) Ecology and management of Himalayan thar and sympatric chamois in the southern alps, New Zealand. PhD dissertation, Lincoln University, Lincoln

  • Forsyth DM (1999) Long-term harvesting and male migration in a New Zealand population of Himalayan tahr Hemitragus jemlahicus. J Appl Ecol 36:351–362

    Article  Google Scholar 

  • Forsyth DM, Caley PA (2006) Testing the irruptive paradigm of large-herbivore dynamics. Ecology 87:297–303

    Article  PubMed  Google Scholar 

  • Forsyth DM, Hickling GJ (1998) Increasing Himalayan tahr and decreasing chamois densities in the eastern Southern Alps, New Zealand: evidence for interspecific competition. Oecologia 113:377–382

    Article  Google Scholar 

  • Forsyth DM, Tustin KG (2005) Himalayan tahr. In: King CM (ed) The handbook of New Zealand mammals. Oxford University Press, Melbourne, pp 361–373

    Google Scholar 

  • Forsyth DM, Parkes JP, Hickling GJ (2000) A case for multi-species management of sympatric herbivore pest impacts in the central Southern Alps, New Zealand. N Z J Ecol 24:97–103

    Google Scholar 

  • Forsyth DM et al (2010) Impacts of introduced deer and extinct moa on New Zealand ecosystems. N Z J Ecol 34:48–65

    Google Scholar 

  • García MB, Picó FX, Ehrlén J (2008) Life span correlates with population dynamics in perennial herbaceous plants. Am J Bot 95:258–262

    Article  PubMed  Google Scholar 

  • Groffman PM et al (2006) Ecological thresholds: the key to successful environmental management or an important concept with no practical application? Ecosystems 9:1–13

    Article  Google Scholar 

  • Hickling GJ, Forsyth DM (2000) Assessment of the extent of alpine areas being utilised as possum habitat in Westland. Lincoln University, Lincoln

    Google Scholar 

  • Hone J (2007) Wildlife damage control. CSIRO Publishing, Collingwood

    Google Scholar 

  • Horsley SB, Stout SL, deCalesta DS (2003) White-tailed deer impact on the vegetation dynamics of a northern hardwood forest. Ecol Appl 13:98–118

    Article  Google Scholar 

  • Husheer SW, Allen RB, Robertson AW (2006) Suppression of regeneration in New Zealand mountain beech forests is dependent on species of introduced deer. Biol Invasions 8:823–834

    Article  Google Scholar 

  • Kelly D et al (2000) Predation satiation and extreme mast seeding in 11 species of Chionochloa (Poaceae). Oikos 90:477–488

    Article  Google Scholar 

  • Körner C (1999) Alpine plant life: functional plant ecology of high mountain ecosystems. Springer, Heidelberg

    Book  Google Scholar 

  • Lee WG et al (2000) Long-term effects of defoliation: incomplete recovery of a New Zealand alpine tussock grass, Chinochloa pallens, after 20 years. J Appl Ecol 37:348–355

    Article  Google Scholar 

  • Lever C (1994) Naturalized animals: the ecology of successfully introduced species. Cambridge University Press, Cambridge

    Google Scholar 

  • Long JL (2003) Introduced mammals of the world: their history, distribution and influence. CSIRO Publishing, Collingwood

    Google Scholar 

  • Mark AF et al (1989) An ecological survey of the central part of the Eyre ecological district, northern Southland, New Zealand. J R Soc N Z 19:349–384

    Article  Google Scholar 

  • Mayer R et al (2009) Effects of grazing exclusion on species composition in high-altitude grasslands of the Central Alps. Basic Appl Ecol 10:447–455

    Article  Google Scholar 

  • McCarthy MA, Possingham HP (2007) Active adaptive management for conservation. Conserv Biol 21:956–963

    Article  PubMed  Google Scholar 

  • Molau U (2010) Long-term impacts of observed and induced climate change on tussock tundra near its southern limit in northern Sweden. Plant Ecol Divers 3:29–34

    Article  Google Scholar 

  • Mysterud A (2006) The concept of overgrazing and its role in management of large herbivores. Wildl Biol 12:129–141

    Article  Google Scholar 

  • Norbury GL et al (2015) Density-impact functions for terrestrial vertebrate pests and indigenous biota: guidelines for conservation managers. Biol Conserv 191:409–420

    Article  Google Scholar 

  • Nugent G, Parkes JP, Tustin KG (1987) Changes in the density and distribution of red deer and wapiti in northern Fiordland. N Z J Ecol 10:11–21

    Google Scholar 

  • Nugent G, Fraser W, Sweetapple PJ (2001) Top down or bottom up? Comparing the impacts of introduced arboreal possums and ‘terrestrial’ ruminants on native forests in New Zealand. Biol Conserv 99:65–79

    Article  Google Scholar 

  • Ohashi H et al (2014) The impact of sika deer on vegetation in Japan: setting management priorities on a national scale. Environ Manag 54:631–640

    Article  Google Scholar 

  • Pardo I et al (2015) Long-term responses of plant communities to herbivore exclusion at high elevation grasslands. Biodivers Conserv 24:3033–3047

    Article  Google Scholar 

  • Parkes JP (2006) Does commercial harvesting of introduced wild mammals contribute to their management as conservation pests? In: Allen RB, Lee G (eds) Biological invasions in New Zealand. Springer, Heidelberg, pp 407–420

    Chapter  Google Scholar 

  • Parkes JP, Forsyth DM (2008) Interspecific and seasonal dietary differences of Himalayan thar, chamois and brushtail possums in the central Southern Alps, New Zealand. N Z J Ecol 32:46–56

    Google Scholar 

  • Parkes JP et al (2006) Adaptive management experiments in vertebrate pest control in New Zealand and Australia. Wildl Soc B 34:229–236

    Article  Google Scholar 

  • Pekelharing CJ, Parkes JP, Barker RJ (1998) Possum (Trichosurus vulpecula) densities and impacts on fuchsia (Fuchsia excorticata) in south westland, New Zealand. N Z J Ecol 22:197–203

    Google Scholar 

  • R Core Team (2013) R: a language for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. https://www.R-project.org/

  • Rose AB, Platt KH (1987) Recovery of northern Fiordland alpine grasslands after reduction in the deer population. N Z J Ecol 10:23–33

    Google Scholar 

  • Rose AB, Platt KH (1990) Age-states, population structure, and seedling regeneration of Chionochloa pallens in Canterbury alpine grasslands, New Zealand. J Veg Sci 1:89–96

    Article  Google Scholar 

  • Rose AB, Platt KH (1992) Snow tussock (Chionochloa) population responses to removal of sheep and European hares, Canterbury, New Zealand. N Z J Bot 30:373–382

    Article  Google Scholar 

  • Simberloff D (1995) Why do introduced species appear to devastate islands more than mainland areas? Pac Sci 49:87–97

    Google Scholar 

  • Stritar ML et al (2010) Introduced ungulate herbivore alters soil processes after fire. Biol Invasions 12:313–324

    Article  Google Scholar 

  • Tanentzap AJ et al (2009) Landscape-level vegetation recovery from herbivory: progress after four decades of invasive red deer control. J Appl Ecol 46:1064–1072

    Article  Google Scholar 

  • Tustin KG, Challies CN (1978) The effects of hunting on the numbers and group sizes of Himalayan thar (Hemitragus jemlahicus) in Carneys creek, Rangitata catchment. N Z J Ecol 1:153–157

    Google Scholar 

  • Tustin KG, Parkes JP (1988) Daily movement and activity of female and juvenile Himalayan thar (Hemitragus jemlahicus) in the eastern southern alps, New Zealand. N Z J Ecol 11:51–59

    Google Scholar 

  • Wardle P (1991) Vegetation of New Zealand. Cambridge University Press, Cambridge

    Google Scholar 

  • Wardle DA et al (2001) Introduced browsing mammals in New Zealand natural forests: aboveground and belowground consequences. Ecol Monogr 71:587–614

    Article  Google Scholar 

  • Wright DM et al (2012) Impacts of culling and exclusion of browsers on vegetation recovery across New Zealand forests. Biol Conserv 153:64–71

    Article  Google Scholar 

  • Yokomizo H et al (2009) Managing the impact of invasive species: the value of knowing the density-impact curve. Ecol Appl 19:376–386

    Article  PubMed  Google Scholar 

  • Zuur AF et al (2009) Mixed effects models and extensions in ecology with R. Springer, New York

    Book  Google Scholar 

Download references

Acknowledgments

This study was funded by the New Zealand Department of Conservation. We thank all the field staff and contractors who helped with field work, particularly Morgan Coleman (Landcare Research) and Neil Bolton (DOC). The late Phil Knightbridge was instrumental in keeping the study going long term. Kerry Weston (Department of Conservation) helped sort out the long-term datasets. A. Gormley, S. Richardson, T. Easdale and G. Norbury (all Landcare Research) and two anonymous reviewers provided helpful comments on previous versions of the manuscript.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Jennyffer Cruz.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary material 1 (DOCX 608 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Cruz, J., Thomson, C., Parkes, J.P. et al. Long-term impacts of an introduced ungulate in native grasslands: Himalayan tahr (Hemitragus jemlahicus) in New Zealand’s Southern Alps. Biol Invasions 19, 339–349 (2017). https://doi.org/10.1007/s10530-016-1283-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10530-016-1283-2

Keywords

Navigation