Thursday, 5 December 2013

Survival Guide

From Camley Street Nature Park to the Arctic, it seems that invasive species have the potential to crop up just about everywhere! But what is it about these species that allows them to become so well established in the new locations across the globe? I've combined the traits of some of the top invaders to create the ultimate invasive species survival guide...
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Invasive Species Survival Guide

1. Climate Matching
Species that are introduced to a location where the environmental conditions are similar to that of their native range may be more likely to succeed (Bomford et al., 2005). This is as their physiological adaptations and behavioural responses are already suited to seasonal variations in temperature, precipitation.  

2. High competitive Ability

Species with a high competitive ability such as the Argentine ant (Holway, 1999) are more likely to acquire food, water and habitat resources that are necessary in order to survive.

3. High intrinsic rate of increase
The intrinsic rate of increase takes into consideration the number of surviving reproductive individuals, the proportion of these which are females, and the age at which females can reproduce. Thus the higher the intrinsic rate of increase, the more rapid population growth is. As a result, species that have a high intrinsic rate of increase are more likely to be successful invaders (Crawley et al., 1986).

4. High abundance in native range
Firn et al., (2011) studied the abundance of invasive plant species in their native and invasive range across eight countries, revealing that there was often a similar abundance in both locations. This suggests that if a species is very abundant in its native range it is likely to be abundant in its invasive range.

5. Availability of suitable habitat and vacant niche
Due to an increased availability of resources, a vacant niche means that an invasive species is more likely to become established in a new location. For example, ant species with different sized mandibles consume different sized food sources; allowing the species to be separated dependant on their food niche. Arndt (2006) showed that when the food niche was empty, species were successful invaders. However, when ants were introduced to a site where their niche was already occupied by an existing species, the invader did not establish.
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*Terms & Conditions:
To succeed as an invasive species not all traits are necessary (Daehler, 2003; Gallagher et al., 2010) however, a combination of multiple traits can be advantageous!  

6 comments:

  1. Hi Elena,

    What a great format for your post, I like it a lot. Are all these conditions equally important, or is there a ranking? And is there knowledge on which combinations of multiple traits are most advantageous?

    Cheers,

    Larissa

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    1. Hey Larissa,
      It largely depends on both the species and the environment which they are invading. From what I have read competitive ability seems to be particularly important. Other traits such as high abundance in native range can help, however species populations can sometimes differ between their native and invasive range. If you want to learn more I recommend the paper: "A meta-analysis of trait differences between invasive and non-invasive plant species" published by van Kleunen et al. (2010).
      Thanks
      Elena

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  2. Hi Elena,

    Loved the post - I'll be sure to keep this survival guide with me next time I leave the house!

    On a more serious note... I found your niche availability example, where ants with different mandibular sizes occupy different niches particularly interesting. The fact that resource availability alone is not sufficient to guarantee successful invasions highlights the great success of invasive species.

    Looking forward to your next posts!

    Katherine

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    1. Hi Katherine,
      Haha thanks for the comment! I agree, I found it particularly interesting reading about the traits which increase a species chance of successfully establishing in a new location! Importantly not all of these traits are necessary for every single case of successful invasion, so in some cases resource availability may be the deciding factor. However, I agree it is interesting to see just how well adapted some species are!
      Thanks
      Elena

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  3. What a clever post, Elena. It is amazing and sobering how important subtle differences can be to survival ...not only in the invading species arena.

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  4. Hi Michele, I agree - it certainly is a case of survival of the fittest amoung invasive species!

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