McMahon, CR and Brook, BW and Bowman, DMJS and Williamson, GJ and Bradshaw, CJA, Fertility partially drives the relative success of two introduced bovines (Bubalus bubalis and Bos javanicus) in the Australian tropics, Wildlife Research, 38, (5) pp. 386-395. ISSN 1035-3712 (2011) [Refereed Article]
Copyright 2011 CSIRO
Official URL: http://dx.doi.org/10.1071/WR10174
Context. Some large herbivores introduced to Australia have achieved population densities so high as to cause
considerable ecological damage. Intriguingly, others have been relatively less successful and have correspondingly
perturbed their new environments less. An excellent example is two similar-sized bovine species that established feral
populations in the Northern Territory of Australia in the mid-19th century. Asian swamp buffalo (Bubalus bubalis) rapidly
colonised the tropical savannas, causing ecological degradation, especially on freshwater swamps. In contrast, banteng
(Bos javanicus) are restricted to their point of introduction and have caused relatively negligible ecological damage.
Understanding the reasons of this differential success is of theoretical and applied interest and contributes to managing large
herbivore populations for ex situ conservation and feral-animal control.
Aims. To compare the population structure of buffalo and banteng on the basis of shot samples, so as to construct life tables
for four contemporary (low-density) buffalo populations, and collated data from previous work from three historical
(high-density) buffalo populations and one banteng population (the only extant ex situ population in existence). Further, to
provide a validation of age estimation with and without informed priors in a Bayesian model comparing horn length and ages
estimated from tooth cementum annuli. Finally, to interpret our results in the context of relative invasion potential of the two
Key Results. For both species, survival of juveniles was the most important demographic component influencing
deterministic population growth. However, buffalo have the demographic capacity to recover swiftly after control because of
high survival and fertility rates across a range of population densities. Fertility of buffalo was historically greater than that of
banteng, and buffalo fertility increased as their populations were reduced.
Conclusions. These findings highlight how subtle differences in demographic rates and feeding ecology can influence the
success (high population growth and range expansion) of large herbivores, knowledge which is increasingly important for
managing invasive species effectively.
Implications. We show that that individual life-history traits and demographic performance, especially fertility, play an
important role in determining the spread of invasive bovids in a novel environment.
|Item Type:||Refereed Article|
|Keywords:||age, banteng, fertility, herbivores, invasive species, life table, survival, swamp buffalo, wildlife management.|
|Research Division:||Biological Sciences|
|Research Field:||Population Ecology|
|Objective Group:||Control of Pests, Diseases and Exotic Species|
|Objective Field:||Control of Plant Pests, Diseases and Exotic Species in Forest and Woodlands Environments|
|Creator:||Bowman, DMJS (Professor David Bowman)|
|Creator:||Williamson, GJ (Mr Grant Williamson)|
|Web of Science® Times Cited:||1|
|Deposited By:||Plant Science|
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