Saturday, July 19, 2014

Lab 10 Endangered Species

The Desert Tortoise (Gopherus agassizii)

 



  • State the scientific name and common name of your organism, its
    taxonomic Order, and taxonomic Family.
Kingdom: Animalia. Phylum: Chordata. Class: Reptilia. Order:
Testudines. Family: Testudinidae. Scientific Name: Gopherus agassizii. Common name: Desert Tortoise. 




  •  Include two photos or one video (no more than two minutes in length)
    illustrating the organism in its natural setting. Do not use any material
    showing harm to this organism.




 

  • Explain this organism’s ecosystem role.
Since
the
desert tortoise is a primary
consumer, their pray consists of various mammals, avian (birds), and reptile
predators. Desert tortoises are also  called ecosystem engineers because they make
us of other animals’ hard work like digging burrows that are used as shelters
by snakes (Serpentes), lizards (Sauria), birds (Aves), rodents (Rodentia), javelinas (Pecari tajacu), and insects (Insecta) and other invertebrates. Desert
tortoises themselves take advantage of packrat (Neotoma albigula) houses for shelter. In
one study, desert tortoises were found sheltering with large colonies of
Africanized honeybees (Apis mellifera)--a very effective defense
against predators! Finally, desert tortoises have few external parasites, but
they are host to intestinal pinworms (Oxyurida).(Crozier).




  • Describe at least two ecological services this organism provides
    for humans and other species (at least two ecological services for each, humans
    and other species). This might involve its food web.


In
the past, desert tortoises were used by indigenous peoples of the American
Southwest for food and medicine, and the shells were used to make bowls,
ladles, and shovels. Desert tortoises were also central figures in the folklore
of the region. Desert tortoises are occasionally still used for food in some
parts of Mexico. In addition, many people in Arizona keep desert tortoises as
pets, though the keeping of captive tortoises is strictly regulated: tortoises
must not be collected from the wild, only one tortoise is allowed per family
member.(Crozier).






  • Include and explain in words, a chart or graph showing population of
    this organism over time.


This graph shows data taken from a
25 year study done throughout the Mojave desert. Although recovery rates
increased at times, there is most recently a decline in the amount of The
Desert Tortoise sightings.  (
“Desert tortoise
(Gopherus agassizzi)”).






  • State how the equation I =
    PAT is involved in the threats to this organism.










I = PAT stands for (I) Environmental impact =
population (P), affluence (A) and technology (T) to environmental impact (Santa Barbara
Foundation Family)
.
 As our population grows this animal
becomes more prone to threat. Since our actions as one affects our environment,
it also impacts every organism on the planet in some way shape or form.  As population increases we build more, which
in return results in more roads etc. This is where affluence comes in because
we can’t seem to stop building and humans want more and more. We feel as though
we must make more roads to get places and to build in places that are
necessary. Which bring us into technology, we need the technology to build and develop
these new places. For example,
in 1995, populations in areas of the Mojave and
Colorado deserts with comparatively little human activity were generally stable
or declining more slowly than populations in areas with high levels of human
activity (Santa Barbara Foundation Family).








  • Referring to figure 9-3 in your text book, determine and describe the
    characteristic(s) that endanger(s) your species.
The Desert Tortoise extinction falls
under every part of HIPPCO.
Habitat
degradation from overgrazing, vehicle use, and invasion by nonnative grasses
may have substantial negative impacts on desert tortoises. The impacts of
severe grazing on their habitat suggest that high levels of grazing likely have
negative impacts on desert tortoises. Potential effects of intense grazing that
could negatively impact desert tortoises include soil compaction, decreased
cover of annual plants, introduction of nonnative species, competition for
forage, and the potential for trampling desert tortoises and their burrows. Invasion
of nonnative grasses and the potential for a nonnative grass/fire cycle pose
major threats to desert tortoises. The release of captive desert tortoises with
upper respiratory disease syndrome, which is typically fatal, into the wild may
have resulted in the infection of wild desert tortoises (Santa Barbara
Foundation Family)
.
Although a new species is not being introduced, I feel it is an example that could
fall into introducing a new species that result in destruction to the species. Climate
change may negatively affect the desert tortoise if droughts become more
frequent or severe or if precipitation increases and results in the spread of
nonnative plant species (Santa Barbara Foundation Family).
 



  • Determine if this organism is affected by density dependent and/or
    density independent factors. Explain the situation in some detail.




The Desert Tortoise would be
considered to be affected by density independent because of the main threat of
humans including, but not limited to fire mostly human caused.


  • Describe the feedback loops involved.
A positive
feedback group is involved with the Desert Tortoise especially because of the
invasive plant life. This plant life is burned it causes a decrease in habitat
for the tortoise. Since most of their food comes from plant life this causes a
worse and worse situation for the essential habitat of the tortoise.
 
Describe how global climate change is affecting or is predicted to
affect this organism’s habitat.
Climate, like stated above is having a negative effect
on this species because of the plant life. The habitat is in need of native
plant species and thus a drought inclines their habitat to inhabit nonnative
plant species more frequently. 

  • Referring to the three principles of sustainability, why should humans
    care about this organism?
This species is considered ‘keystone’ to the
Mojave – meaning that it plays a significant role in maintaining the integrity
of the desert ecosystem and, if lost, will put other species at risk for
extinction.
(Collaborating for a sustainable future for wildlife). Maintaining our
impact on this species by educating the public of this threatened species will
in return help us a unit to make changes to help our ecosystem survive. The
Desert Tortoise spends about 95% of its time underground in the burrows they
make, which act as a protector for other species as well. This acts as a very
important role for many species living in the desert (Leon).
 

  • Name and give a two or three-sentence description of two individuals
    (not groups) who are champions of this organism.
Roy
Averill-Murray, Gopherus agassizii expert,
is a part of the U.S. Department of Fish and Wildlife Service, of which is working
to protect the Gorpherus agassizii (Richards-Dimitrie).
Roy is the Desert Tortoise Recovery Coordinator that is from the Nevada office
and has been with the U.S. Fish and Wildlife Service since 2004 (Averill-Murray). 

  • Name and give a two or three-sentence description of two individuals
    (not groups) who do not want this organism protected, at least not in their
    “own backyard.”
Cliven
Bundy, who is against preserving the Desert Tortoise. Clive stated that he “will
not willingly sell their grazing privileges to create another preserve”(Fuller).
Unfortunately, after strenuous research, I was unable to find another specific
name associated with another individual against the protection of the Desert
Tortoise. Although, there are many ranchers who are also opposed to the idea
none were publicized by name. However, it was fought that the government is
acting hypocritical in that they will be euthanizing these animals’ dues to
budget cuts.

  • Include a link to one recent scientific article or story about this
    organism that was written or produced in the last year. Suggestions for sources
    include ScienceNews, ScienceDaily, and NPR.  Your article or
    story must include some peer-reviewed material or state the view of scientific
    experts. Introduce the links in your report by giving a one or two-sentence
    summary of each.
      
An article written in April earlier this year,
talks about how the Desert Tortoise will soon be euthanized due to federal
funds. The Desert Tortoise Conservation Center near Las Vegas has been in
operation for decades and now the funds to run the conservation are dwindling.
There has been many laws put into effect to help these critters to stay safe
from human destruction. As a result any new tortoises brought to the center
will now be euthanized as there are no other options (Animalsoul). <
http://ireport.cnn.com/docs/DOC-1119214> 

  • State the Precautionary Principle in your own words.


The
precautionary principal involves taking precautionary measure to prevent
species from being extinct. We can become more aware that our actions are
affecting extinction of every species even if we are lacking scientific knowledge
of this happening for some species.
 



 Works Cited



“Collaborating for a sustainable future for wildlife.” C2S2 Conservation Centers for Species Survival. Web. 2014 July 18
<http://conservationcenters.org/species-conservation-priorties/desert-tortoise/>.

Crozier,
G. 1999. "Gopherus agassizii" (On-line), Animal Diversity Web. July
19, 2014 <http://animaldiversity.ummz.umich.edu/accounts/Gopherus_agassizii/>.

“Desert
tortoise (Gopherus agassizzi).” U.S. Fish
& Wildlife Service Species Profile.”
18 July 2014. Web. 18 July 2014. <http://ecos.fws.gov/speciesProfile/profile/speciesProfile.action?spcode=C04L> 

“Gopherus
agassizii.” The IUCN Red List of
Threatened Species.
Web. 16 July 2014.
<
http://www.iucnredlist.org/details/9400/0>.

Mayer, Rachelle. Gopherus agassizii. 2008. 18 July
2014 <http://www.fs.fed.us/database/feis/animals/reptile/goag/all.html>.

“Mojave
Population of the Desert Tortoise (Gorpherus agassizzi).5-Year Review: Summary
and Evalutation.” U.S. Fish and Wildlife
Service Desert Tortoise Recovery Office Reno, Nevada.”
30 September 2010.
Web. 18 July 2014. Pg18 <http://ecos.fws.gov/docs/five_year_review/doc3572.DT%205Year%20Review_FINAL.pdf>.

“The Sustainable Scale Project.” Santa Barbara Foundation Family. 2003. 18 July 18
<http://www.sustainablescale.org/ConceptualFramework/UnderstandingScale/MeasuringScale/TheIPATEquation.aspx>.

 Tuma, Michael. “Agassiz’s Desert Tortoise Gopherus agassizii.” Reptiles of Arizona. 2008. Photograph.
Web. 15 July 2014. <http://www.reptilesofaz.org/Turtle-Amphibs-Subpages/h-g-agassizii.html>.

Wildertography. Desert Toroise (Gopherus agassizii)
Attacks!
15 April 2012.
<https://www.youtube.com/watch?v=Z4hDadw7HVc>.


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