The infamous cane toad (Rhinella marina, formerly Bufo marinus) was introduced into Queensland in the 19305 in a failed
attempt to control insect pests that were damaging sugar cane crops. In this practical, we will discuss the impact that cane
toads have had on native vertebrates, and how the invasion process might be assisting the evolution of improved dispersal
ability in this highly invasive pest.

Impact on native vertebrates

In light ofthe attached readings, consider the following questions on the impact of cane toads on Australian vertebrates:

1. What kinds of selective pressures are cane toads exerting on native wildlife?

2. What do these selective pressures mean for populations of native vertebrates (both in the short and longer term)?
Invasion and dispersal ability (Practical Report)

In this section of the practical, we will be taking various morphometric measurements of cane toads (snout-vent length; hind
limb length) collected from two locations, populations “A” and “B”. Recent evidence suggests that cane toads at the front line of
the invasion (i.e. those that are spreading into new areas) have longer hind limbs than those from populations near where the
toads were first released in the 193os. This indicates that selection may be favouring greater dispersal ability. Your task is to
use the data from today’s practical to infer which specimens of the two groups (A or B) were collected from a new population
and which were collected from a longer, more established one. Apart from inferring the likely source ofthe two cane toad
populations, you will also be expected to use the data to make some generalisations about the adaptability ofthis highly
invasive pest.