Modern Threats to Biodiversity: Habitat Loss & Fragmentation, Invasive Species
Tuesday & Thursday  Week 10

Announcements:

• News Item:

• Mini-Exam 1 Key posted on Moodle

• Advising week - sign up with your advisor!!

• More Current News: from the Union of Concerned Scientists - GOOD News!!!

• In the next few weeks, Brazil is expected to release its final figures on Amazon deforestation for the past year. The data from Brazil’s National Institute for Space Research will likely show that the loss of forest has reached a record low level, approximately a 45 percent drop from the previous year and 80 percent below the average for the baseline decade of 1996-2005. This billion-ton reduction in deforestation means a reduction in heat-trapping emissions almost equal to the total reduction that the United States has promised to make in its own global warming emissions—but from 2005 to 2020. Thus, a developing country has already achieved what one of the world’s wealthiest countries has simply promised to do over the next decade.

Assignments:

• Reading for Thursday: Niles Eldredge article, "The Sixth Extinction" available online here: http://www.actionbioscience.org/newfrontiers/eldredge2.html

  • Read the article; some of it is review, some of it introduces our next new topics

  • Be able to address/discuss the 5 bold-heading questions/topics addressed in the article
     

Tuesday - Question of the Day: What happens to biodiversity when the size of a habitat declines?

Q1) What is the evidence of habitat loss? 

• Deforestation maps

Q2) How does species abundance relate to habitat size? 

• Evidence from various habitats

Q3) What are the impacts of decreasing habitat size (fragmentation)?

• Habitat Fragmentation and Edge Effects

Q4) What are other ways that habitat may be lost (other than direct reduction of size)?

• Impacts of pollutants

Powerpoint

Announcements:

• News Item: Josh Parkhurst

·  DUE next TUESDAY:  Hawaii Birds group assignment (hypothesis, conclusion, data summary/figure)  - Please put in the folder provided up front

• ALSO DUE next TUESDAY: Hawaii Birds individual assignment  on the Hawaii birds case study .  See the Moodle site for details.

• Attend a lecture or presentation - do this soon!! Turn in summaries if you haven't

• Extra credit: up to 10 pts for attending an additional event & submitting written summary

Thursday - Issue of the Day-
Threats to Biodiversity: A Case Study of Hawaiian Birds
modified from an exercise by
Sarah K. Huber, Organismic and Evolutionary Biology, University of Massachusetts at Amherst
Paula P. Lemons, Biology Department, Duke University

Read this essay on invasive species & their economic impacts (if this link is broken, I have a copy of the article saved from Common Dreams)

Powerpoint for Case Study

Biological Diversity of the Hawaiian Islands - Why are the islands so unique, and so diverse?

Biological Diversity of the Hawaiian Islands - Why are the native species so threatened?

• http://www.jackjeffreyphoto.com/hawaii.html

Case Study Questions:

1. Examine the data presented in Table 1.  How many of these species are currently extinct?  What other trends do you notice?  What factors might contribute to these trends?

Table 1 modified from Scott, J.M., C.B. Kepler, C. van Riper III, and S.I. Fefer.  (1988).  Conservation of Hawaii's vanishing avifauna.  Bioscience 38(4):238-253.

2. One factor that leads to a decline in biodiversity is the introduction of non-native species.  However, most species that are introduced to an area do not become established.  What are some characteristics of species that might make them more likely to thrive in a new habitat?
    

3.  Several species of large rats arrived to Hawaii as stowaways on ships.  These rats live in a variety of habitats and eat a variety of foods, both plants and animals.  Speculate about how these introduced rats could directly and indirectly affect native bird species.
 
 

4.  Researchers hypothesize that several factors may affect the extent of predation by rats on birds.  These factors include bird size, nesting site, and the amount of time young spend in the nest (duration of egg incubation and nestling period).  Formulate hypotheses about how these factors might affect predation.
 

1. Bird size:
    
   • H1 (hypothesis):
      
2. Nesting site:
    
   • H1 (hypothesis):
      
3. Incubation and nestling period:
    
   • H1 (hypothesis):
    

5.  Examine the data given to you (Table 2a, 2b, or 2c). Do the data support or refute your hypothesis?

Table 2a modified from:
° Atkinson, I. A. E. 1985.  The spread of commensal species of Rattus to oceanic islands and their effects on island avifaunas.  In P. J. Moors (ed.), Conservation of Island Birds.  pp. 35-81.  ICBP Technical Publication No. 3.
° Pratt, D. H., Bruner, P. L., and Berrett, D. G. 1987.  A Field Guide to the Birds of Hawaii and the Tropical Pacific.  Princeton, NJ: Princeton University Press.

Table 2b modified from Atkinson, I. A. E. 1985.  The spread of commensal species of Rattus to oceanic islands and their effects on island avifaunas.  In P. J. Moors (ed.), Conservation of Island Birds.  pp. 35-81.  ICBP Technical Publication No. 3.

Table 2c modified from Atkinson, I.A.E. 1985.  The spread of commensal species of Rattus to oceanic islands and their effects on island avifaunas.  In P. J. Moors (ed.), Conservation of Island Birds.  pp. 35-81.  ICBP Technical Publication No. 3.
¹Berger, A.J. 1972. Hawaiian Birdlife. Honolulu: The University Press of Hawaii.
²Grant, G.S., J. Warham, T.N. Pettit, and G.C. Whittow. 1983. Reproductive behavior and vocalizations of the Bonin Petrel (Pterodroma hypoleuca). Wilson Bulletin 95(4):522-539.
³Harrison, C.S. 1990. Seabirds of Hawaii: Natural History and Conservation. Ithaca, NY: Cornell University Press.
⁴Niethammer, K.R., J.I. Megyesi, and D. Hu. 1992. Incubation periods for 12 seabird species at French Frigate Shoals, Hawaii. Colonial Waterbirds 15(1):124-127.

More information on exotic species interactions & how they impact native birds:

http://www.jackjeffreyphoto.com/env_concerns.html