1. Exercise 1.1: Island Biogeography of Hundred Islands,
Alaminos, Pangasinan, Philippines
Purpose
To investigate and describe the island biogeography structure of Governor’s Island, Romulo Island and
Cagao Island of the Hundred Islands National Park, Alaminos, Pangasinan, Philippines.
Introduction
This activity is an island-based demonstration of the theory of Island Biogeography, an ecological idea
normally applied on a geographic scale. Your data analysis skills will be used to elucidate ecological
patterns in the data. Incidentally, you will become familiar with the diversity of plant species of the Hundred
Islands National Park. Finally, you will test the practical behavioral ecological principle that “the more you
look, the more you see.”
What you need (per group):
2 GPS
5 Rulers
2 zip locks/group plant and animal guides
5 timers
What you do:
Principle
We are testing the hypothesis that species richness is a function of island size; larger islands support
higher species richness. In addition, we may be able to test the hypothesis that population density (# of
individuals of each species/area) decreases with island area.
Sampling-General
Your team (4 people) is responsible for counting the number of individuals of all plant and animal
morphospecies living in each island (3 islands). You are also required to get the global position of the island
(use GPS). Record your data in Ex. 1.1 data sheet Table 1-3.
Sampling Guidelines
1. Make sure one team member carefully records the actual counts of each morphospecies (Note: Use the
activity data sheet). It is important that you limit your total search time to the assigned duration.
2. At least 3 people should search. Each person will be given 20 minutes of search time. Synchronize your
watches to avoid errors in timing.
3. The 4th person can be assigned as a timer and warns the searchers of the remaining time.
4. When your time is up stop searching!
5. When you have reached the end of your search time, organize your data in the data sheet Table 1-3.
Rough Estimation of Island Size
1|Page: FIRST STOP FB 2009-2010
2. Exercise 1.1: Island Biogeography of Hundred Islands, Alaminos,
Pangasinan, Philippines
FB BATCH 2010
You can ask the boatmen to roughly estimate the relative size of each island or you can make your own
guess. What is important is that you should be able distinguish which island is the biggest and the smallest.
Make an estimate of its area. Also, qualitatively label the island as large-sized-island, medium-sized-island
or small-sized-island, respectively. Put your data in Ex. 1.1 Table 1-3.
Identifying Species
You are not expected to know the identity of every specimen. Consult the field guides provided for you or
ask your instructor for help. For closely-related species, you have to remember the basic rule: if it looks
different, consider it a different morphospecies. Make drawings if it helps you organize your classification
scheme.
Plant Sampling Guidelines
1. When the searchers are ready and all timers are set, ask the searchers to start their collection.
There should be no rush in collection, do not run or compete with other groups. Move and collect in
your normal pace (i.e. as if walking normally).
2. Collect 1 leaf from every plant species you encounter. You can focus on one area or you can walk
along while collecting. Do not worry if you have collected more than 1 leaf of a particular species,
as long as those leaves were collected from different individuals of a particular species.
3. Put all your collections inside the zip locks provided.
4. Watch your collection time. Stop when the time is up.
5. Count and identify your leaves. Put all you data in Table 4.
Animal Sampling Guidelines
1. When the searchers are ready and all timers are set, ask the searchers to start their collection.
There should be no rush in collection, do not run or compete with other groups. Move and collect in
your normal pace (i.e. as if walking normally).
2. Collect any land dwelling animal you encounter in the field (i.e. except those that are dangerous—
simply count them). You can focus on one area or you can walk along while collecting.
3. Put all your collections inside the zip locks provided.
4. Watch your collection time. Stop when the time is up.
5. Count and identify all the small animals collected. Put all your data in Ex. 1.1 data sheet Table 5.
6. Return all the animals counted and identified to the ground of collection.
Search Effort
Calculate the search effort theoretically applied to each island in plants and in animals in units of person-
hours per square foot. Put your data in Table 7a and 7b.
2|Page: FIRST STOP FB 2009-2010
3. Exercise 1.1: Island Biogeography of Hundred Islands, Alaminos,
Pangasinan, Philippines
FB BATCH 2010
Individual Density
To get a density figure, add up all the individuals of all morphospecies found on each island divide this
number by the number of square feet searched for
each island size. Put your data in Table 8a and 8b.
Graphing 1
Now generate a scatter plot (separate graph) showing richness as a function of area; each island is a point.
This is a graphical way to check if there is a relationship between island area and number of
morphospecies. Calculate the number of morphospecies for each island and then plot the number of
morphospecies (dependent variable) against island area independent variable). Draw a trendline/ best-fit
line on the scatter plot.
Graphing 2
Now test whether individual density (= abundance) is related to island area for the angiosperms only.
Normalize the counts of angiosperms: that is, make sure all values are in terms of number per square foot.
You can do this by dividing each count by the area of the island.Plot the data as a scatter plot (separate
graph) with island areas as your independent variable and angiosperm morphospecies density as your
dependent variable. Draw a trendline/ best-fit line on the scatter plot.
3|Page: FIRST STOP FB 2009-2010
4. Exercise 1.1: Island Biogeography of Hundred Islands, Alaminos,
Pangasinan, Philippines
FB BATCH 2010
DATA SHEET
Name: Date:
Group #:
Table 1. Governor’s Island
GPS Location Estimated Island Size Search Time (min)
Table 2. Romulo Island
GPS Location Estimated Island Size Search Time (min)
4|Page: FIRST STOP FB 2009-2010
5. Exercise 1.1: Island Biogeography of Hundred Islands, Alaminos,
Pangasinan, Philippines
FB BATCH 2010
Table 3. Cagao Island
GPS Location Estimated Island Size Search Time (min)
Plant Morphospecies Counts: each box should represent the count of a separate morphospecies;
categories appear on the first two lines; morphospecies within each category below. You can add more
columns and rows if necessary.
Table 4. Plant morphospecies count.
Bryophytes/ Mosses
Ferns/ Fern Allies
Gymnosperms
Monocots
Dicots
Others
Others
Morphospecies No.
1
2
3
4
5
6
7
8
9
10
5|Page: FIRST STOP FB 2009-2010
7. Exercise 1.1: Island Biogeography of Hundred Islands, Alaminos,
Pangasinan, Philippines
FB BATCH 2010
Animal Morphospecies Counts: each box should represent the count of a separate morphospecies;
categories appear on the first two lines; morphospecies within each category below.
Table 5. Animal morphospecies count.
Classifiaction
Crustaceans
Vertebrates
Myriapods
Hexapods
Arachnids
Mollusks
Annelids
Morphospecies number
salamanders
millipedes
centipede
pillbugs
spiders
snakes
insects
worms
snails
slugs
other
other
other
mice
1
2
3
4
7|Page: FIRST STOP FB 2009-2010
9. Exercise 1.1: Island Biogeography of Hundred Islands, Alaminos,
Pangasinan, Philippines
FB BATCH 2010
Table 7a. Plant Data
Islands sampled Total Total Estimated Search Total Area
Persons Sampling Island Size Effort: Sampled
Sampling Time pers-hrs/ft2
Governors Island
Romulo Island
Cagao Island
Table 7b. Animal Data
Islands sampled Total Total Estimated Search Total Area
Persons Sampling Island Size Effort: Sampled
Sampling Time pers-hrs/ft2
9|Page: FIRST STOP FB 2009-2010
10. Exercise 1.1: Island Biogeography of Hundred Islands, Alaminos,
Pangasinan, Philippines
FB BATCH 2010
Governors Island
Romulo Island
Cagao Island
Table 8a. Plant Data
Islands Sampled Total of Individuals Total area of the Density
Sampled Island
Governor’s Island
Romulo Island
Cagao Island
Table 8b. Animal Data
Islands Sampled Total of Individuals Total area of the Density
Sampled Island
Governor’s Island
Romulo Island
Cagao Island
GRAPH 1
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11. Exercise 1.1: Island Biogeography of Hundred Islands, Alaminos,
Pangasinan, Philippines
FB BATCH 2010
GRAPH 2
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