 This PowerPoint presentation is owned by the students who created it and is posted here for example purposes only.  - GC team

Where the Birds At? An experiment on the declining populations of bird species in Brazil and their connection to deforestation. By: Tyler Greer, Sean Ratchford, and Seth Welton

Introduction  Why are Bird Populations declining in Brazil?  How is deforestation and the decline of bird populations related?  What implications will this have for the rest of the world?  What must be done about it?

Hypothesis  Deforestation has led to a decrease in Bird populations in Brazil. By decreasing the amount of deforestation that occurs in Brazil annually, the rate of extinction in Brazil will decrease.

Methods  Why is Brazil Important?  Deforestation Effects on Brazil  By using graphs and Stella models a correlation can be shown that will link deforestation to decreasing bird populations and species extinction.

Why is Brazil Important?  Amazon Rainforest  Over 1600 bird species live in Brazil, including 121 threatened species (Noon & Young).  Massive deforestation occurring in Brazil httpwww.votawphotography.com/photo/Birds/birds2.htm://

Rate of Deforestation In Brazil

Deforestation in Brazil (continued) Image of a Fragmented Forest over several years. The further away a forest fragment is from other patches of forest, the more susceptible it is to local extinction, and thus the species in these forest fragments are even more vulnerable to extinction (Christiansen and Pitter 1997).

Deforestation in Brazil

The Effects of Deforestation  Habitat loss  Concentration of Species  Increases Competition between bird species.  1.5 acres of rainforest are lost every second worldwide. ( This graph shows the remaining Atlantic Forests left on the Eastern Coast of Brazil. Over 90% of the primary forest has been destroyed. (Harris and Pimm 2004) (Harris and Pimm 2004)

Impacts of Deforestation  In a study by G. M. Harris and Pimm, it was discovered that even bird species who are adapted to secondary rainforests, are just as susceptible to extinction as birds who survive in primary rainforests. (Harris & Pimm 2004).

Relating Avian Species Loss to Amount of Deforestation  Amount of Forest Cover Left in Brazil as of 2005 = 2,966,060 km^2  (  Estimated Remaining Bird Species in Brazil = 1685 (  Average Amount of Deforestation in Brazil from = 18,501 km^2/yr (

A Relationship Detailing how Bird Species are Affected by Habitat Loss is Needed  In a study by Brooks, Pimm, and Oyugi, a mathematical relationship was developed that predicted the number of bird species for a certain amount of habitat. (Brooks et al 1999)  Mathematical relationship was shown to work accurately in Kenya, Brazil, and parts of North America  Relationship is S=cA^z (Brooks et al 1999)  S = # of species, A is the amount of forest area, and z is a constant shown to be 0.15 (Brooks et al 1999)  c must be calculated by starting with an initial # of species and amount of area

Solving for c  In 2005, the relationship would look like:  1685 birds = c*( km^2)^.15  Solving for c gives a value of  => S = 180.2*(A^.15)

Predicting Bird Loss  This relationship was first explored with Excel  Results showed that Brazilian bird species would be reduced from 1685 species to 1473 species by  Loss of 212 bird species

Future Effects of Deforestation of Bird Populations

Using Stella  Next, this relationship was explored using a Stella Model  The logical flow of the modeling system in Stella allows for more understanding of how habitat loss influences the number of bird species.

Stella Model

Stella Graph Showing Number of Brazilian Bird Species Lost with Average Deforestation Rate of km^2/yr By simply reducing the average deforestation rate to 10,000 km^2 a year, bird species will be reduced from 1685 to 1591, a loss of 94 species by 2100.

For the Birds  What keeps bird biodiversity high?  Moisture in the ecosystem (Christiansen & Pitter 1997)  Spacious ecosystem  Concentrated environment, avoid boundaries  Avoid isolation

Conclusion  How to stop the declining bird populations in Brazil  Research is currently underway to determine ways to use secondary forest in order to house bird populations.  However, as shown from our model deforestation must be reduced in order to reduce the amount of bird species that will be lost due to deforestation.

Work Cited  Brooks, Pimm & Oyugi “Time Lag between Deforestation and Bird Extinction in Tropical Forest Fragments.” Conservation Biology, 13:  Butler, Rhett A. "Deforestation in the Amazon." Mongabay Nov  Christiansen M.B., Pitter E Species loss in a forest bird community near Lagoa Santa in southeastern Brazil. Biological Conservation, 80 (1):  Harris, G. M. & Pimm Bird Species' Tolerance of Secondary Forest Habitats and Its Effects on Extinction. Conservation Biology, 18 (6):  Noon & Young Evidence of Continuing Worldwide Declines In Bird Populations: Insights from an International Conference in New Zealand. Conservation Biology, 5 (2)  "Rainforest Facts." Raintree Raintree Nutrition Inc. 28 Nov  Stouffer, Bierregaard, Strong & Lovejoy Long-Term Landscape Change and Bird Abundance in Amazonian Rainforest Fragments. Conservation Biology, 20 (4):  "The Process of Habitat Fragmentation." Chesapeake Bay and Mid-Atlantic From Space. 30 Nov  Votaw, Melanie. "Birds 2." Votaw Photography. Bomoco. 30 Nov