Altitudinal distribution of the entire invasive small mammal guild in the eastern dryland zone of New Zealand’s Southern Alps

Foster, Nicholas; Maloney, Richard F.; Seddon, Philip J.; Recio, Mariano R.; Khan, Saiful I.; Heezik, Yolanda van

doi:10.1007/s10530-021-02474-y

Cited by 9 publications

(20 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The probability of rabbit and hare presence also increased further from waterbodies. The establishment of rabbits and hares throughout the study area is consistent with observations that these species have been successful invaders of ecosystems worldwide, largely due to their rapid dispersal and reproduction, diverse diet and ability to adapt to harsh conditions (Barbar & Lambertucci, 2018;Courchamp et al, 2003;Foster et al, 2021).…”

Section: Are Landscape Elements Associated With Herbivore Presence?supporting

confidence: 86%

“…We conducted all surveys within a 4-week period, in February and March 2020, to minimize seasonal and weather variability between sites. At this time, snow cover was absent and mammal populations were likely to be occupying their maximal elevational ranges within the bounds of their current distribution (Foster et al, 2021).…”

Section: Data Collection Methodsmentioning

confidence: 99%

“…Williams et al (2014) identified exotic species as the most pressing threat to ecosystems in the Alps and recommended control of invasive species populations. Management of exotic herbivore populations can be guided by understanding herbivore habitat use and spatial variation in the effects of herbivory (Foster et al, 2014(Foster et al, , 2021. However, the associations between herbivore activity and landscape elements have not been investigated in the Alps.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Exotic herbivores dominate Australian high‐elevation grasslands

Hartley

Blanchard

Schroder

et al. 2021

Conservat Sci and Prac

View full text Add to dashboard Cite

Invasive species are major drivers of ecosystem degradation globally. How invasive herbivore impacts differ from native herbivore impacts remains understudied. We examined the relationships between herbivore sign and vegetation height, foliage density, cover of forbs, weeds, bare ground, and soil compaction across environmental and herbivore activity gradients in the mainland Australian Alps. We detected native and exotic herbivore sign at 32.8% and 94.0% of sites, respectively. Total herbivore activity was primarily attributed to exotic herbivores and was associated with elevation and grassland type.Greater horse (exotic) activity was associated with lower vegetation height, lower foliage density, higher forb cover, and higher soil compaction. Greater rabbit and hare (exotic) activity was associated with lower vegetation height, lower foliage density, and a higher cover of bare ground. Greater total herbivore activity was associated with greater weed cover. Neither deer (exotic) nor kangaroo and wallaby (native) activity was related to response variables. We demonstrate that exotic herbivores dominate mammalian herbivory in these grasslands, which evolved without analogous hooved species. Given the restricted distribution and high endemism of these ecosystems, and associations between exotic herbivores and characteristics of degraded grasslands, we recommend landscape-scale exotic herbivore management, focusing on maintaining ground cover and vegetation structure.

show abstract

Section: Are Landscape Elements Associated With Herbivore Presence?supporting

confidence: 86%

Section: Data Collection Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Exotic herbivores dominate Australian high‐elevation grasslands

Hartley

Blanchard

Schroder

et al. 2021

Conservat Sci and Prac

View full text Add to dashboard Cite

show abstract

“…Unlike other introduced mammal species in New Zealand hedgehogs are also known to hibernate in most regions limiting their activities primarily to spring and summer (Brockie, 1958). Although more commonly encountered at lower elevations they are infrequently encountered above 1500 m (Foster et al, 2021). Hedgehogs are known to predate a range of threatened taxa including, indigenous ground nesting birds, lizards and invertebrates, and it is thought that they represent major threats in certain habitats (Jones & Norbury, 2011;Jones et al, 2013).…”

Section: Hedgehogsmentioning

confidence: 99%

“…New Zealand's relatively mild climate allows many invertebrate species including carabids to breed all year round (Hutchison, 2007) which may lessen the impact of elevated hedgehog density as hedgehogs are only active for part of the year. It is also likely that in a damp elevated terrain of the Remutaka and Aorangi forest sites (150 -800m) hedgehog density is further limited relative to other habitat types such as open pasture (Foster et al, 2021;King & Forsyth, 2021). Olfactory-cued predators of invertebrates were, and in some areas still are, a significant part of the indigenous fauna in New Zealand in the form of kiwi (Castro et al, 2010).…”

Section: General Observationsmentioning

confidence: 99%

The impact of mammalian insectivores Rattus rattus (Rat), Mus musculus (Mouse) & Erinaceus europeus (Hedgehog) on the size and abundance of mainland Coleoptera and Orthoptera

Hewitt¹

View full text Add to dashboard Cite

<p>The impact of introduced mammalian predators on indigenous vertebrates is relatively well documented, however the general responses of indigenous invertebrate communities is less well known. Many indigenous invertebrates, particularly the large flightless species such as those in the genus Deinacrida (Orthoptera) and Anagotus (Curculionidae) have been extirpated from much of their range due largely to the impacts of introduced predators. Despite these well-known examples very little is known about the general impact of introduced predators on invertebrate communities. Beginning in 2012 pitfall traps and artificial wētā motels were established across seven study sites in the Aorangi and Remutaka ranges east of Wellington alternately baited with squid and monitored two to three times annually. Mammal tracking took place in the form of tracking tunnels giving three mammal indexes for rats (Rattus rattus), mice (Mus musculus) and hedgehogs (Erinaceus europeus). Cavity dwelling wētā in wētā motels were measured and counted in situ whilst pitfall trapped Coleoptera and Orthoptera were transported to the lab for measuring and identification. Linear mixed effects model, type 3 ANOVAS and generalised linear mixed models were used to examine whether mammal index had any impact on the size and the catch or occupancy of invertebrates. Increased rat and mouse tracking was associated with reduced coleoptera catch whilst increased hedgehog tracking was correlated with increases in Coleoptera catch. Pitfall trapped wētā (Hemiandrus spp) showed strong negative responses to increased rat tracking, neutral responses to mice and positive responses to hedgehogs. Tree wētā (Hemideina crassidens) occupancy rates declined in response to increased mouse abundance whilst the mean size of tree wētā residing in wētā motels showed an increase in response to rats and mice. These results show the complexity of understanding mammal invertebrate interactions which cannot be expected to be the same in all environments or across all taxa. Environmental factors typically impact far more strongly on invertebrate populations than they do on vertebrates and can obscure the impacts of top down predation in such studies. The results reported in this study only became apparent after 5+ years of sampling, demonstrating the importance of long-term temporal analysis of invertebrate communities in response to mammals before trends start to emerge. More research is required into the basic ecology and population dynamics of invertebrate communities before more general trends can be discerned.</p>

show abstract

Pushing the limits: ship rat (Rattus rattus) population dynamics across an elevational gradient in response to mast seeding and supplementary feeding

et al. 2022

View full text Add to dashboard Cite

Understanding marginal habitat use by invasive species is important for predicting how distributions may change under future climates. We investigated the influence of food availability and temperature on ship rat (Rattus rattus) distribution and density across a forested elevational gradient in New Zealand by measuring ship rat demographics following a beech (Nothofagaceae) mass seeding event (‘mast’) at three elevation bands (20–80, 400–500, 800–900 m asl). We tested whether declining food availability limits rat populations at the highest elevation band post-mast by experimentally increasing food abundance above baseline food availability. When our study started 4 months post-seedfall, rats at mid- and low- elevations were at high densities (11.4–16.5 ha−1). Rats at higher elevations were barely detectable, but densities peaked (9.4 ha−1) 10 months post-seedfall, with the initial increase possibly driven by immigration from lower elevations. All populations declined sharply over the next year. Supplementary feeding at high elevation increased survival, recruitment, and density of rats through winter, 16 months post-seedfall, relative to unfed grids, suggesting food limitation. However, both fed and non-fed populations declined to zero by the following spring, perhaps due to stoat (Mustela erminea) predation. Our results suggest that low food availability plays a significant role in restricting rats from cool, high elevation environments. The variation in the timing and magnitude of ship rat responses to the pulsed resource across the gradient also highlights the importance of initial population size and spatial processes as factors modulating ship rat responses to pulsed resources across a landscape.

show abstract

Altitudinal distribution of the entire invasive small mammal guild in the eastern dryland zone of New Zealand’s Southern Alps

Cited by 9 publications

References 39 publications

Exotic herbivores dominate Australian high‐elevation grasslands

Exotic herbivores dominate Australian high‐elevation grasslands

The impact of mammalian insectivores Rattus rattus (Rat), Mus musculus (Mouse) & Erinaceus europeus (Hedgehog) on the size and abundance of mainland Coleoptera and Orthoptera

Pushing the limits: ship rat (Rattus rattus) population dynamics across an elevational gradient in response to mast seeding and supplementary feeding

Contact Info

Product

Resources

About