pdf - Firestone Reserve

Transcription

Research Reports of the Firestone Center for Restoration Ecology v2:1-22
Continued Baseline Assessment of Butterfly Biodiversity and
Community Composition at the Firestone Center for
Restoration Ecology, Costa Rica
Emily Haber
Scripps College
Summer 2006
1
I. Introduction
The newly-established Firestone Center for Restoration Ecology (FCRE) is a 60
hectare reserve and field station located on the southwest coast of Costa Rica. The land
was originally lowland moist rainforest before it was cleared for cattle farming in the
1950's and 1960's. Only a few patches of forest in riparian areas remained before
restoration efforts began in the early 1990's. The FCRE is now covered primarily by
secondary tropical moist forest and bamboo, along with smaller patches of pasture land
and a few relatively pristine riparian zones. Through Pitzer College's stewardship, the
long term goal is to restore the land over the future decades to primary rainforest. This
reforestation effort will undoubtedly give rise to marked changes in the center's floral and
faunal biodiversity.
Sensitivity to environmental change, both climatic and ecological disturbances,
make butterflies an important "indicator taxa". With a relatively short life-cycle and
host-plant reliance, butterfly communities show impact quickly and can act as an early
warning of portending shifts in the surrounding flora and fauna (Batra 2005). In this
research project (continued from summer, 2005) fruit-bait traps were used to collect
baseline data on the biodiversity and community composition among the fruit-feeding
subfamilies of Nymphalid butterflies. Research on butterfly biodiversity in June and July
of 2005 established that the FCRE is home to at least 38 species of Nymphalid butterflies
and showed significant differences in the mean number of individuals found in traps
according to habitat type. Butterfly abundance and community composition also changed
across habitats. The research goal for the summer of 2006 was to continue collecting
baseline data on butterfly biodiversity and community composition at the FCRE using the
protocol established in 2005 and to conduct similar data analysis. As reforestation takes
its natural course, this baseline data will serve as a gauge by which future changes and
trends in butterfly biodiversity can be evaluated and monitored. In addition, amendments
were made to the 2005 trap design to make a more durable and functional butterfly trap.
II. Materials and Methods
Trap construction was modeled after the Tropical Ecology, Assessment, and
Monitoring (TEAM) Initiative butterfly monitoring protocol produced by the Center for
Applied Biodiversity Science at Conservation International.
Trap Construction
21 hand-made fruit bait traps were constructed in 2005 using a modified TEAM
protocol design. Due to the extreme tropical environment, several traps molded or tore
irreparably. The mosquito netting used was not ideal and stretched, making the traps
slightly longer and narrower than originally intended. In 2006, 20 new traps were made
using more durable materials, and the dimensions of the traps were changed slightly by
adding 2.5 cm to the diameter and decreasing the length of the trap by 2.5 cm. These
modifications made the trap dimensions closer to the TEAM protocol design. Following
is a general overview of trap construction. See Appendix 1 for specifics on materials
used, dimensions, sewing instructions and diagrams.
2
Each trap consisted of a cloth cylinder made of mosquito netting with a metal ring
frame at the top and bottom. A collar (made from canvas in 2005 and rip-stop nylon in
2006) was sewn to the top and the bottom of the mosquito netting to hold the ring. The
top of the trap was closed-off with mosquito netting while the bottom was left open as the
point of entry. A 25 cm slit down the middle of the cylinder allowed access to trapped
butterflies. A nonflexible plastic plate was attached to the bottom ring of the trap and a
red bait bowl was bolted to the center of the plastic with its lip slightly above the bottom
cylindrical ring. One important trap design change in 2006 was a string suspension
hanging system in both the old and new traps which prevented stretching of the mosquito
net cylinder and allowed easy access for re-baiting (See Appendix 1). Butterflies feeding
on the bait enter through the bottom and fly up upon attempted exit, getting caught in the
top of the trap. See Figures 1, 2, and 9 for photographs of the traps. Each trap was filled
with a mixture of fermenting banana, beer, and honey.
Trap Placement
Traps were placed in four distinct habitat types: secondary forest, bamboo,
pasture, and riparian forest. Three pairs of traps were placed in the secondary zone, the
bamboo zone, and the riparian zone (six traps per zone). One of each pair was placed in
the understory (mean height 0.84m) while the other was placed directly above it in the
canopy or upper story of vegetation (mean height 6.51 m). (See Figures 1 and 2). To
keep the trap layout design consistent with 2005, the pasture zone did not have paired
traps. Three single, lower-level traps were hung from trees amidst tall grass. However,
trees, grass, and shrubs in the pasture showed remarkable growth over the span of one
year and trees in the pasture are now tall enough to stratify traps in accordance with the
other three habitats.
The trap pairs were connected with nylon cord and a pulley system allowed the
top traps to be lowered daily to release individuals and to refill bait cups. Bait was
replaced on an as-needed-basis (two times per week on average). Elements such as
rainfall, temperature, humidity, and disturbances (foraging animals, spillage while
checking, etc) affected the rate at which fresh bait was necessary.
Procedure
Fieldwork was conducted in June and July, 2006. Each trap was checked and
emptied once per day in the late afternoon. The species and number of individuals found
were recorded before release. Checking all 21 traps took between 2 and 4 hours
depending on weather, the number of individuals trapped, and how much trap
maintenance was needed. Butterflies were not marked, so some individuals may have
been captured more than once. Upon appearance of a new species, the specimen was
collected and taken back to the field station for identification. When a set of traps needed
re-baiting, all traps were re-baited to ensure that all habitats had equally fresh bait.
3
upper trap
Figure 1. A pair of traps in bamboo
habitat, 2005 design
Figure 2. A pair of trap in riparian
habitat, 2006 design
4
III. Results and Discussion
Differences in mean number of individuals captured due to vertical stratification
Comparing the mean number of individuals found in the upper and lower traps
showed a significant difference in the secondary forest, bamboo, and riparian habitats.
There were significantly more butterflies caught in the lower secondary forest traps than
in the upper secondary forest traps (t=1.985, df=95, P<0.001). There were significantly
more butterflies caught in the lower bamboo traps than in the upper bamboo traps
(t=1.985, df=96, P<0.0001). There were significantly more butterflies found in the upper
riparian traps than found in the lower riparian traps (t=1.985, df=96, P=0.010). However,
few individuals were captured in the riparian traps. See Graph 1 for comparisons of
number of individuals captured in upper versus lower traps across all habitats.
Comparing Mean Number of Individuals Found Daily in Upper and Lower Traps
Mean Number of Individuals Found Daily
3
2.51
2.5
2.23
1.95
2
1.5
1
0.8
0.6
0.5
0.14
0.02
0
Pa
r
we
an
ari
Rip
an
ari
Rip
oo
oo
y
y
da r
da r
mb
Ba
re
stu
Lo
er
r
we
b
am
rB
n
eco
con
Se
rS
r
we
p
Up
Lo
pe
Up
Lo
pe
Up
Habitat Type and Trap Level
Graph 1. Comparing mean number of individuals caught in lower and upper traps
5
Differences in mean number of individuals found according to habitat type-lower traps
In the lower traps there was a significant difference in the mean number of
individuals caught according to habitat type (F=29.18, df=3, p<0.0001). There was no
significant difference in the number of butterflies found in the lower secondary forest,
bamboo, or pasture traps (Newman-Keuls’ test, p>0.05). There were significantly more
butterflies caught in the lower secondary forest, bamboo, and pasture traps than in the
lower riparian traps (Newman-Keuls’ test, p<0.05).
Differences in mean number of individuals found according to habitat type-upper traps
In the upper traps there was a significant difference in the mean number of
individuals caught according to habitat type (F=16.44, df=2, p<0.0001). There was no
significant difference in the mean number of individuals found in the secondary forest
and bamboo traps (Newman-Keuls’ test, p>0.05). There were significantly more
individuals found in the secondary forest traps than in the riparian traps (Newman-Keuls’
test, p<0.05) as well as more individuals found in the bamboo traps than found in the
riparian traps (Newman-Keuls’ test, p<0.05).
6
Community Composition and Species Diversity
Graphs 2-8 examine community composition, individual abundance, and diversity.
Photographs of all species and correlation of letters and scientific names follow the
graphs in Appendices 2 and 3.
Overall Species Frequency Across All Habitats
200
Total Number collected
180
160
140
120
100
80
60
40
20
0
other
T2
Q2
P2
N2
M2
L2
J2
E2
Z
T
Q
P
O
N
M
L
J
I
G
F
D
C
B
A
Species
Graph 2. A general overview of the most common species found on the property. The
“Other” category includes a composite of 29 minority species (individuals were caught ≤
3 times).
Community Composition in Upper Secondary
Traps
5%
Species Composition in Lower Secondary
Forest Traps
5%
11%
A
F
29%
7%
3%
10%
N
Q
11%
3%
5%
2%
M2
C
D
F
J
L
N2
18%
A
2%
2%
5%
J2
16%
12%
12%
O
P
other
L2
42%
P2
other
Graphs 3 and 4. The species distribution for upper secondary forest traps (left) and lower
secondary forest traps (right). The “other” category is composed of 22 species in the upper traps
and 23 species in the lower traps (each species collected ≤ to 3 times).
7
Community Composition of Lower Bamboo Traps
Community Composition of Upper
Bamboo Traps
A
C
D
3% 5%
11%
8%
F
32%
2%
8%
G
C
I
5%
F
41%
J
4%
G
16%
Z
O
2%
2%
E2
P
8%
other
Z
24%
20%
7%
Q2
2%
other
Graphs 5 and 6. The species distribution for upper bamboo traps (left) and lower bamboo
traps (right). The “other” category is composed of 14 species in the upper traps and 10
species in the lower traps.
Community Composition of Pasture Traps
Community Composition Across All Riparian
Traps
A
3%
12%
8%
C
10%
3%
1, 7%
1, 7%
Z
D
2%
F
7%
J
5, 37%
2, 14%
P
L
22%
5%
28%
unidentified
N
Z
T
Q
V2
2, 14%
L2
other
3, 21%
Graph 7 (left). The species distribution for the pasture traps. The "other" category is composed of
26 species.
Graph 8 (right). The species distribution for all riparian traps. The number of butterflies caught
is listed, followed by the percent of butterflies caught. The "unidentified" category is individuals
that flew away before they could be identified. All riparian traps were included in one graph
because only 3 individuals were caught in the lower traps.
8
IV. Concluding Comments
In 2006 throughout 32 days of collection, 19 new species and over 780
individuals were captured in the fruit-bait traps. In attempt to better understand the
butterfly community (or lack of) in the riparian zones of the FCRE, a "mini experiment"
was run the last two weeks of the study period. 3 trap pairs were set up next to a stream
in a highly developed area as well as 3 trap pairs in an undeveloped area with more light
gaps than the area previously studied. When looking at the raw data, there does appear to
be a greater Nymphalid population in the highly developed area. This data, however, was
not included in analysis, but may be useful at a later date.
Considering several new species were discovered in 2006, there are undoubtedly
more Nymphalid species at the FCRE not yet caught. Continuing the species inventory
would be valuable. There were changes between 2005 and 2006 in the community
composition and the average number of butterflies found in each habitat. In 2006 there
were remarkably fewer butterflies in the secondary forest than in 2005. Confoundingly
few butterflies were caught in the secondary traps in June, while in July the traps were
packed full. If this butterfly project continues over the span of several years, it will be
very interesting to see the changes in species abundance across habitats as restoration
efforts progress. Other valuable ideas for future study include: how the climatic shifts
(daily and yearly) effect the butterfly population, a floral inventory at the trap sites, and
sampling the butterfly community in higher niches (>25m).
V. Acknowledgments
This project was funded by a grant from the Mellon Foundation to the Joint
Science Department, Scripps College.
Thanks to Professor McFarlane, Keith Christenson, and FCRE summer research
students for assistance.
Works Cited
Batra, Puja. Tropical Ecology, Assessment Butterfly Monitoring Protocol. The Center
for Applied Biodiversity Science ant Conservation International. 1 August. 2005.
<http://www.teaminitiative.org/application/resources/pdf/butterfly_3_13_03.pdf.>
Haber, Emily. Baseline Assessment of Butterfly Biodiversity and Community
Composition at the Firestone Center for Restoration Ecology, Costa Rica. 2005.
Research reports of the Firestone Center for Restoration Ecology v. 1.
<http://costarica.jsd.claremont.edu/pdf/Haber%2005.pdf>
DeVries, P.J. 1987. The Butterflies of Costa Rica and Their Natural History. New
Jersey: Princeton University Press.
Reserve and Field Station, la Isla del Cielo. Home Page. 22 Feb. 2005. Joint Sciences
Department, Claremont colleges.
<http://costarica.jsd.claremont.edu/index.shtml.>
9
Appendix 1: Trap Materials and Construction Instructions
________________________________________________________________________
Raw Materials Per Trap
Traps
•
•
•
•
•
•
thread–polyester or nylon
polyester horse-hair seam braiding (0.67 yards)
grommets for collar and grommet tool (8 grommets)
"no-see-um" mosquito netting–100% polyester, gray or white (1.5 yards)
waterproof coated ripstop nylon–light or medium weight (0.5 yards per trap)
heavy duty sewing machine needles
Rain Caps
• clear plastic vinyl (0.67 yards)
• thread
• fiber glass kite rods for support (1.37 m rod cut into 4 pieces 33 cm long)
Support Ring
• rust-proof fencing wire to make top and bottom support ring (each ring 29 cm in
diameter , quantity: 2)
• 5 cm of 3/16 inch diameter aluminum tubing to link ends of wire–same gage as
wire (quantity: 2)
• "zip-a-grip glue" (purchased at kite-making store)
Base
•
•
•
•
1 plexiglass square (51 cm by 51 cm)
1 stainless steel eyebolt and nut
1 stainless steel fender washer
1 red plastic bait bowl
Net Suspension System
• dacron or nylon string (6.7 m)
• 1 top hanging ring
• 4 plastic toggle cord locks
• 2 straws
• Tangle Foot
• utility cord for hanging traps from trees and anchoring to ground–nylon or
polyester
Equipment Suppliers
Seattle Fabrics: www.seattlefabrics.com
Home Depot
Ace Hardware
Kite making supplier
10
Trap Construction–Trap Pattern Layout and Dimensions
C. Trap Top
33 cm diameter
B. Trap Center
Figure 3. Trap pattern pieces and dimensions
11
Trap Construction–Sewing and Assembly Instructions
See Figure 3. for dimensions and pattern pieces
Sew along dotted line, all seams 01.27 cm
Step 1
Place A1 and A2 on top of B
with edges matching
Sew A1 to B along top 96.5 cm side
Sew A2 to B along bottom 96.5 cm side
Step 2
Flip open out A1 and A2
A1
A1
B
B
B
B
A
A2
A2
Step 3
Fold in half along 111.5 cm side (with fabric inside out)
Pin two edges together
Sew seam down edge, leave 25 cm opening in middle
A1
Step 4
Sew braiding into both sides
of the opening for stiffness
\
B
A2
Step 5
Turn tube rightside out (all seams on inside)
Step 6
Fold top collar (A1) in half (towards inside of cylinder)
Insert D1 (top support ring) into folded collar, pushing to the top of the
crease
Step 7
Tuck C (trap top) into A1 and pin into entire cylinder
Step 8
Match unsewn edge of A1 to already sewn hem of A1 and top stitch around
entire cylinder
Step 9
Fold A2 in half (towards inside of cylinder)
Insert D2 into folded collar, pushing to the crease
Match unsewn edge of A2 to already sewn hem of A2 and top stitch around
entire cylinder
Step 10
A. Hammer four evenly spaced grommet holes into top collar
B. Hammer four grommet holes into bottom collar. Make sure top and
bottom holes line up. These holes must also line up with holes drilled in
platform.
12
Rain Cap
•
Cut out 51 cm by 51 cm square of clear
vinyl
Sew a channel from each corner to the
center point large enough to slip bendable
fiber-glass or metal rod through
Insert 33 cm support rods and sew off ends
Cut 7.6 cm slits at the midpoint of each
side
Attach a piece of sticky-back velcro on
either side of slit (for closure around
strings)
•
•
•
•
Figure 4. Rain hat diagram
Figure 5. Photograph of rain hat on trap
Plexiglass Platform and Bait Bowl
•
•
•
•
•
Start with 38 cm by 38 cm square piece of plexiglass
Drill 5 holes ( preferably with drill press):
one in the center, four on corners (15 cm from center)
Break four corners off with scoring blade and flat-nosed
pliers
Holes should be approximately 5 cm from edge
Attach bait bowl to center plexiglass hole using stainless
steel eyebolt/nut/washer combination with eyebolt on
the underside of trap for anchoring trap to ground
Figure 6. Plexiglass
platform diagram
Figure 7. Photograph from below of plexiglass platform and bait bowl attachment
13
Assembly Diagram
Figure 8. Labeled trap diagram.
Assembly Instructions
• Cut 2 strings of 3.3 m length
• Put strings together and fold them in half, creating four strings
• Tie knot at the top, leaving 5 cm loop above knot
• Attach to hanging ring
• Measure 28 cm down from knot and mark on all four strings
• Thread each cord through a grommet hole on the upper collar and tie at the mark
• Let the cords hang freely down the outside of the trap and through the bottom
collar grommet holes (don't tie) and through the holes in the plexiglass
• Put a toggle or bead on the bottom of each string below the plexiglass and tie off
• The opening of the trap should be no greater than 5 cm
14
Trap Photographs
Figure 9. Photograph of fully assembled trap
Figure 10. Photograph of trap entry point
15
Appendix 2: Butterfly Species Collected in 2005
________________________________________________________________________
Species A
Cissia Hesione
Species D
Taygetis andromeda
Species B
Archaeoprepona demophoon gulina
Species E
Siproeta stelenes biplagiata
Species C
Cissia hermes
F
Genus: Hamadryas
Species G (upper corner)
Eryphanis polyxena lycomedonle
Species H (directly above)
Taygetis virgilia rufomarginata
Species I (left)
Manataria maculata
16
Species J (left)
Caligo eurilochus sulanus
Species K (directly below)
Temenis laothoe agatha
Species L (far left)
Opsiphanes cassina fabricci
Species M (left)
Unidentified
Species N (far left)
Historis Odius
Species 0 (left)
Taygetis mermeria excavata
Species P (top left)
Smyrna blomfildia datis
Species Q (top right)
Opsiphanes tamarindi
tamarindi
Species R (bottom left)
Anartia fatima
Species S (bottom mid)
Cissia libye
Species T( bottom right)
Zaretis elleps
17
Species U
Nica flavilla canthara
Species Z
Colobura dirce
Species C2
Consul fabius cercrops
Species V
Prepona gnorima
Species W
Prepona dexamenus
Species A2
Catoblepia orgetorix championi
Species D2
Opsiphanes bogotanus
Species B2
Opsiphanes bogotanus
Species E2
Historis acheronta
Species J2 (far left, male)
Hamadryas laodamia saurites
Species H2 (left)
Catonephele mexicano
18
Species I2
Junonia evarete
Species J2 (FEMALE)
Hamadryas laodamia Saurites
Species K2
Siderone marthesia
Species L2 (left)
Unidentified
Species X (right)
Opsiphanes Cassina Chiriquensis
Species Z2 (left)-Tigridia
acesta
Speceis not photographed:
Species Y-Unidentified
Species G2-Unidentified
19
Appendix 3: New Butterfly Species Collected 2006
________________________________________________________________________
Species M2
Memphis centralis
Species O2
Hamadryas februa ferentina
Specie N2 (female)
Memphis chaeronea indigotica
Species P2
Unidentified
Species N2 (male)
Species Q2
Cissia pseudocofusa
Species R2 (left)
Unidentified
Species T2 (bottom left)
Unidentified
Species U2 (bottom right)
Archaeoprepona meander
amphimachus
20
Species W2
Megeuptychia antonoe
Species X2
Archaeoprepona
demophon centralis
Species A3
Memphis arginussa eubaena
Species D3
Unidentified
Species B3
Unidentified
Species E3
Unidentified
Species Y2
Unidentified
Species C3
Unidentified
Species F3
Catonephele numilia esite
21
Species G3
Hamadryas amphinome
mexicana
Species H3 (female)
Morpho amathonte
Species A2
Catoblepia orgetorix championi
22

pdf - Firestone Reserve

Transcription

Similar documents

Atsena Otie Key - Mosquito Magnet

Color Flyer page 2 - World Manufacturing

John`s John

CUSHCRAFT R7 Rescue and Refurbishment

10 species of sea anemones

2016 Caribbean Classic full page ad copy - NSSA-NSCA

Our LatestNewsletter - Animal Protection League of New Jersey

How to Trap a Leprechaun.pptx - CarrolltonFineArtsFall2013

Best Trapping Practices - Fédération des trappeurs gestionnaires du

Seasonality and daily activity of male and female tabanid flies

Eggfruit Caterpillar [Sceliodes cordalia (Double Day