Biological Invasions (2020) 22, 329-338

Rebecca L. O'Rourke, Jennifer R. Anson, Amelia M. Saul and Peter B. Banks (2020)
Limits to alien black rats (Rattus rattus) acting as equivalent pollinators to extinct native small mammals: the influence of stem width on mammal activity at native Banksia ericifolia inflorescences
Biological Invasions 22 (2), 329-338
Abstract: Alien species are a major cause of species extinctions globally and the effects of introductions can become substantial, especially once aliens become entrenched and impossible to eradicate. Some entrenched aliens may assume niches of extinct native species that are functionally similar, but the capacity of an alien to perform specialised ecological processes is unknown. Here we examine the potential for the alien black rat (Rattus rattus) to effectively pollinate native Banksia ericifolia in heath at North Head, Sydney where endemic mammalian pollinators such as brown antechinus (Antechinus stuartii) and eastern pygmy-possums (Cercartetus nanus) had been locally extinct prior to recent reintroductions. Using artificial inflorescences, we compared the use of inflorescences, visit frequency and duration of alien black rats to reintroduced natives according to the stem diameter of the inflorescence. Black rats were the most frequent visitor and they spent similar or more time at artificial inflorescences as natives, but they also spent more time visiting inflorescences with thicker stem diameters. In contrast, the native mammals visited artificial inflorescences regardless of the stem thickness. We suggest that, as black rats are heavier than the native mammals, this could limit their capacity as substitute pollinators of B. ericifolia. This finding shows the importance of understanding the extent of the benefits of aliens before relying on them as functional replacements for extinct natives.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Rattus rattus		Australia (South+SE)