To Sum Up

Throughout this blog I have demonstrated the impact invasive/introduced species can have on an area.  I’ve discussed the Can toad and how this amphibian has/is rapidly sweeping across Australia assisting in the decline of population numbers but unlike many have claimed, the Cane toad is not responsible for the extinction of any specific specie.  In addition, the presence of the Cane toad is also driving the evolution of some Australian snakes as they deal with the presence of the Cane toad.

I’ve discussed my personal, frequent experience with an invasive weed commonly known as Broom.  This weed spreads almost just as fast as the time it takes for you to remove its presence in the first place.  This weed is a great example for having a competitive advantage over the native vegetation in the area.  Not only is this plant known for outcompeting but it is also known to have effects on the native fauna.  This plant can be poisonous if ingested by cattle for example.  Broom also blocks pathways and corridors for smaller species.  Large amounts of money and time are invested each year in managing this plant.

The feral pig in Australia is known for destroying habitat among other things.  The Camel although providing a source of economic income and not only a cost has its own impact in their environments often consuming native vegetation and destroying habitats and fence lines. 

I am still interested in researching this topic of invasive species to learn more about the consequences especially possible positive consequences introduced species may have on the environment.  I feel there is so much more to be learned in this area of study.

Camels in Australia

Not being from Australia I was somewhat surprised when I had learned just a couple weeks ago that there were Camels in Australia.  Granted I had never really given much thought to this particular idea but at the same time Australia, even in the outback, is not exactly where I expect to find Camels.  I was even more intrigued when a conversation was brought up about the Camels in Australia and how there is a rumour of ongoing studies showing that this introduced species may also be serving a potential benefit benefit which intrigued me even more. Therefore, I thought it only made sense to research this topic some more.

The camels were introduced into Australia in the 1800’s.  They were brought in to assist in the discovery and exploration of Australian land as they were more efficient and cost effective compared to what a horse, mule, or ox was capable of (Big Black Dog Communications Pty Ltd 2009).

The negative impacts of introducing the camel, like many introduced species were unknown at the time of introduction.  With the current estimated population size of about one million camels in Australia the impacts include environmental, social and economic issues (Government of South Australia 2013).  According to the Government of South Australia, that population size is expected to double within the next 10 years (2013). 

Through just browsing the internet I found multiple sites advertising camel rides and safaris provided throughout Australia for the most part.  Being that there is a market for this tourism attraction one potential benefit is from an economic perspective.  There are currently at least one hundred camel farms throughout Australia providing multiple purposes (Paroz 2008).  Services provided by the farms are camels for export, meat, tourism and weed control (Paroz 2008).  Therefore, I was able to find some information tying camels to an environmental benefit of grazing upon areas which contain woody, prickly weeds that are not generally consumed by other animals.  While camels will eat a variety of vegetation such as these woody weeds, camels are found to be ineffective when it comes to consuming these weeds when they are mixed with thick vegetation (Paroz 2008).

Camels, while an introduced species, appear to provide some slight benefits such as weed control but at the same time they also contain the negative impacts as seen by many introduced species.  However, being that such economic gain has come from the camels, it is highly unlikely to see them disappear any time soon.  There are a few methods of control in place for the camels under the State Feral Camel Management Project per the Government of South Australia (2013), which is a joint effort exercising various methods of control.  Some methods include funding for enclosures, and harvesting (Government of South Australia 2013).

References:

Creators Big Black Dog Communications Pty Ltd, 2009, Australian Government, viewed 24 May, 2014, http://australia.gov.au/about-australia/australian-story/afghan-cameleers

Government of South Australia, 2013, Biosecurity SA, South Australia, viewed 19 May 2014, http://www.pir.sa.gov.au/biosecuritysa/nrm_biosecurity/pest_animal/pest_animal_programs/management_of_feral_camels

Paroz G., 2008, Pest animal risk assessment, Queensland Government, Queensland, viewed 24 May, 2014, http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&ved=0CEoQFjAF&url=http%3A%2F%2Fwww.daff.qld.gov.au%2F__data%2Fassets%2Fpdf_file%2F0009%2F71010%2FIPA-Camel-Risk-Assessment.pdf&ei=iWOBU6e2F8fJkwWL4oGQCA&usg=AFQjCNEjpX2IwpE2I0U0Ip8ghHuDYrjLPA&bvm=bv.67720277,d.dGI

There Can be Pros...

Since I began this blog I have wondered about whether or not all introduced/invasive species have negative impacts on the non-native areas of which they occupy.  Therefore, in my search for new information I have kept my open for something to the contrary.  I have finally come across some research which implies there can be a beneficial presence of an introduced species, especially when taking into consideration the cost and time that would be necessary to eradicate the introduced species.

The research conducted was on introduced honeysuckle found in central Pennsylvania in the United States.  According to Gleditsch A. and Carlo T. (2010) there is a positive correlation between the honeysuckle in the area and the native frugivore birds in the area.  In areas which had a relative high abundance of the honeysuckle, high numbers of fruit eating birds (frugivores) were present as well (Gleditsch A. and Carlo T. 2010).  Frugivores are responsible for pollination dispersal, seed dispersal and play an important role in their ecosystems.  The honeysuckle aided in attracting those important frugivores whom also fed on the native fleshy fruits in the area continuing their dispersal as well (Gleditsch A. and Carlo T. 2010).

Figure 1: Lonicera spp. (honeysuckle)

An important point made in the conclusion of this study is that careful consideration must be taken when considering eradication and management of introduced, non-native species, the cons may not always out way the pros and human involvement in addition to the invasion could potentially cause even more damage than if left alone (Gleditsch A. and Carlo T. 2010).  There are always two sides to every story and it is only fair to take both sides into consideration before making decisions, especially when the future balance of ecosystems are at stake.

Reference:
Gleditsch A. and Carlo T., 2010, 'Fruit quantity of invasive shrubs predicts the abundance of common native avian frugivores in central Pennsylvania', Diversity and Distributions, vol. 17, no. 2, pp 244-253, viewed 7 May 2014, <http://onlinelibrary.wiley.com/doi/10.1111/j.1472-4642.2010.00733.x/pdf>

Picture Credit:
https://www.google.com.au/search?q=Lonicera+spp.&espv=210&es_sm=93&source=lnms&tbm=isch&sa=X&ei=dNRpU9D1KsOKlQWpkIGICQ&ved=0CAgQ_AUoAQ&biw=1920&bih=979#facrc=_&imgdii=_&imgrc=8036IDJNZT5fHM%253A%3Bntg8EvYAR7ISeM%3Bhttp%253A%252F%252Fstatic.panoramio.com%252Fphotos%252Flarge%252F53362390.jpg%3Bhttp%253A%252F%252Fwww.panoramio.com%252Fphoto%252F53362390%3B1024%3B768

"Oink Oink"

Being a guest in this beautiful and interesting country I really enjoy looking up what information I can find about Australia.  This blog provides me with a good excuse to google different species.  One of the frequent animals I have come across when searching for examples of invasive or introduced species into the region is the feral pig so I decided to finally look into the topic a bit more and make it my blog for the week.

The word feral is simply referring to something non-domesticated or wild.   The feral pig found in Australia was originally brought to Australia by early European settlers in the 1800’s and by 1880 had escaped their confinements establishing a wild population that then spread (Environment and Heritage 2011).  According to Environment and Heritage (2011) the feral pig currently covers and estimated 38% of Australia.

                    

Figure 1: Feral Pig                                                      Figure 2: Distribution of feral pig in Australia

As the theme of this blog goes, the introduced feral pig of Australia brings its own effects on the ecosystem affecting native biodiversity and fragile soil among others.  According to NSW Department of Primary Industries (2012) “feral pigs are listed as a Key Threatening Process due to predation, habitat, degradation, competition and disease transmission”. 

A study conducted by Doupé et al. in 2008 provided an example of how the presence of feral pigs can alter habitat and drive away species such as freshwater turtles who depend on that habitat.  Feral pigs are dependent on areas with water, shelter from the heat and abundant food source (NSW Department of Primary Industries 2012).  The area studied provided all these resources for the pigs making the location ideal for foraging.  Once the feral pigs were in the area they uprooted soil systems, damaged macrophyte communities, altered the water chemistry and clarity, created areas of more bare ground and contributed to the enrichment of nutrients via their waste (Doupé et. al 2008).  After tracking the turtles, feral pigs, and the changes taking place they found that two of the turtles in the study had relocated to a nearby river, one of the turtles had joined another solo turtle in the other lagoon being monitored while the rest disappeared and assumed to have either relocated beyond the parameters of the study or were predated upon either by the feral pigs themselves or another predator (Doupé et. al 2008).  This is just one example of how the presence of this feral species can affect the communities in which they choose to roam.

Below is an example of how easily they can uproot soil and alter habitat.

 

Figure 3: Mud holes created by feral pigs

Being that the “feral pigs are declared pest animals under the Rural Lands Protection Act 1988” it is illegal to keep or transport these animals and is required of land owners to take action (NSW Department of Primary Industries 2012).  Methods for control and removal of these animals are shooting the pigs, fencing, and/or bait traps and the method chosen depends on the situation and location keeping in mind general safety and care to not harm any native species in the process (Animal Control Technologies 2013).

References:

Animal Control Technologies, 2014, Animal Control Technologies, Victoria, viewed 2 May 2014, < http://www.animalcontrol.com.au/pig.htm>

Doupé, R.G. et. Al, 2008, An example of freshwater turtle habitat destruction by foraging feral pigs in tropical north-eastern Australia, Australian Centre for Tropical Freshwater Research, Townsville, viewed 2 May 2014, < http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCoQFjAA&url=http%3A%2F%2Fresearch.jcu.edu.au%2Fresearch%2Ftropwater%2Fresources%2F08%252021%2520An%2520Example%2520of%2520Freshwater%2520Turtle%2520Habitat%2520Destruction%2520by%2520Foraging%2520Feral%2520Pigs%2520in%2520Tropical%2520North%2520Eastern%2520Australia%2520.pdf&ei=4_JkU9W0IIGGkAXUvIFY&usg=AFQjCNEOfq4HvN-mWSr6BfCJlu2hZeO5fg&sig2=03g-S9b4Gs0KHF0alm_zOA&bvm=bv.65788261,d.dGI>

Environment & Heritage, 2011, NSW Government, NSW, viewed 2 May 2014, < http://www.environment.nsw.gov.au/pestsweeds/FeralPigFactsheet.htm>

Primary Industries Agriculture, 2012, NSW Department of Primary Industries, viewed 2 May 2014, < http://www.dpi.nsw.gov.au/agriculture/pests-weeds/vertebrate-pests/pest-animals-in-nsw/feral-pig-biology>

Picture Credit:

Figure 1: https://www.google.com.au/search?q=australian+feral+pig&source=lnms&tbm=isch&sa=X&ei=4P1kU8CpN4iUkgWrsoGADA&ved=0CAYQ_AUoAQ&biw=1366&bih=753#facrc=_&imgdii=_&imgrc=Cs7NXkdDdhz3zM%253A%3BQ7rnQ-dD2SqbkM%3Bhttp%253A%252F%252Fwww.dpi.nsw.gov.au%252F__data%252Fassets%252Fimage%252F0005%252F444173%252FVanessa-Macdonald_feral-pig-web.jpg%3Bhttp%253A%252F%252Fwww.dpi.nsw.gov.au%252Fagriculture%252Fpests-weeds%252Fvertebrate-pests%252Fpest-animals-in-nsw%252Fferal-pig-biology%3B640%3B495

Figure 2: http://commons.wikimedia.org/wiki/File:Feral_Pig.jpg

Figure 3: https://www.google.com.au/search?q=feral+pig+in+australia&source=lnms&tbm=isch&sa=X&ei=2QBlU4z1JcPnkAWHyYCwAQ&ved=0CAYQ_AUoAQ&biw=1366&bih=753#q=habitat+degradation+due+to+feral+pig+in+australia&tbm=isch&facrc=_&imgdii=_&imgrc=LniJrAqAsxAfRM%253A%3BnBNROMUc6Nrh7M%3Bhttp%253A%252F%252Fwww.lrm.nt.gov.au%252F__data%252Fassets%252Fimage%252F0018%252F17334%252FBoarDamage2.jpg%3Bhttp%253A%252F%252Fwww.lrm.nt.gov.au%252Fferal%252Fboar%3B1024%3B681