affects of physical characteristics of bald head island beaches on shorebird diversity and...

Jennie LaRoche Education Intern

Research Ques+ons

� Do the tides, beach location, severity of beach erosion, and amount of human disturbances affect the number of birds present on the beach and the species richness and diversity of the shorebirds?

Why research these ques+ons? �  The groins and beach renourishment are important ecological issues for

the Bald Head Island community. This research will provide information on the shorebird populations, particularly for the groins area and how it compares to untouched beaches and busy beaches of the Island.

�  The coasts are very important and fragile ecosystems. Coastal environments provide many services to the greater public and as such their health is of utmost importance. Birds are important indicators of the health of ecosystems.

�  Habitat loss and degradation seem to continue to be drivers of shorebird declines (Agardy et al 2005). With this loss of habitat, those shorebird populations become “concentrated at fewer sites, increasing the risk of catastrophic nesting failures.” (Grippo et al 2007).

�  Global tourism has been identified as one of the most profitable industries. By determining the characteristics that appear to be correlated with high bird species diversity and populations we can strive to keep the healthy beaches intact as much as possible.

Shorebird Study �  13 observation dates �  Recorded time, weather, beach ID,

erosion level, human disturbance level, bird numbers and species, and water quality data

�  From my data I determined the total number of species present (species richness) and the species diversity index

�  I ran single factor ANOVAs to determine whether or not there was a significant difference in the mean total number of birds, species richness, and species diversity between the different dependent (test) variables.

Tides �  3 classifications of tides

� High/out – When the tide was on its way out �  Low/in – When the tide was on its way in � Out/low/in – When the sampling time included the low tide

** High tide was too high to be able to use the UTV and record observations in a

reasonable amount of time

Results: Tides

SUMMARY

Groups Count Average

High/out 15 169.2667

Out/low/in 6 87.83333

Low/in 18 86.27778

Anova: Single Factor: Total Number of Birds

ANOVA Source of Variation SS df MS F P-‐value F crit Between Groups 62990.21 2 31495.11 3.534767 0.039663 3.259446

Within Groups 320763.4 36 8910.094

Total 383753.6 38

�  The number of birds sighted differs significantly (p = 0.0397) between the tides, but this test is unable to tell us between which tides this significance occurred.

0

20

40

60

80

100

120

140

160

180

high/out out/low/in low/in

169.27

87.83 86.28

Average Number of Birds

Results: Tides Anova: Single Factor:

Species Richness


Within Groups 196.2778 36 5.45216

Total 205.4359 38

�  The Simpson’s diversity index for the different tides did not differ significantly (p=0.141).


Within Groups 0.306008 36 0.0085

Total 0.341195 38

Anova: Single Factor: Simpson’s Diversity Index

�  The species richness for the different tides did not differ significantly (p=0.44).

Beach Loca+on �  3 beach locations were chosen based on physical characteristics

�  1 – East Beach: little human disturbance, less erosion, a type of control (most ‘natural’)

�  2 – Point: high human disturbance, ‘medium’ erosion

�  3 – Groins: ‘medium’ human disturbance, high erosion

Results: Beach Loca+on

SUMMARY


Beach 1 13 210

Beach 2 13 103.1538

Beach 3 13 42.15385


ANOVA Source of Variation SS df MS F P-‐value F crit Between Groups 187674.2 2 93837.1 17.22841 5.63E-‐06 3.259446

Within Groups 196079.4 36 5446.65

Total 383753.6 38

�  The mean number of birds sighted differs significantly (p = 5.63e-‐6) between the beach locations, but this test is unable to tell us between which beaches this significance occurred.

0

50

100

150

200

250

1 2 3

210

103.15

42.15


Results: Beach Loca+on

Anova: Single Factor Species Richness ANOVA Source of Variation SS df MS F P-‐value F crit Between Groups 64.97436 2 32.48718 8.326396 0.001066 3.259446

Within Groups 140.4615 36 3.901709

Total 205.4359 38

Anova: Single Factor Simpson's Diversity Index ANOVA Source of Variation SS df MS F P-‐value F crit Between Groups 0.033463 2 0.016732 1.957336 0.155976 3.259446

Within Groups 0.307732 36 0.008548

Total 0.341195 38

�  The Simpson’s diversity index at the different beach locations did not differ significantly (p=0.156).

�  The species richness of birds sighted differs significantly (p = 0.0011) between the beach locations, but this test is unable to tell us between which beaches this significance occurred.

0

2

4

6

8

10

1 2 3

9.23

6.38 6.62

Average Species Richness

Erosion �  Separated into 3 categories depending on level/intensity of erosion

�  1 – little erosion, slight in comparison to other levels (East beach)

�  2 – ‘medium’ erosion (Point) �  3 – High level of erosion (Groins) ** Erosion was paired with beach location since large changes in level of

erosion did not occur in the few weeks my study was conducted.

Results: Erosion

SUMMARY


1 13 210

2 13 103.1538

3 13 42.15385


ANOVA Source of Variation SS df MS F P-‐value F crit Between Groups 187674.2 2 93837.1 17.22841 5.63E-‐06 3.259446

Within Groups 196079.4 36 5446.65

Total 383753.6 38

�  The mean number of birds sighted differs significantly (p = 5.63e-‐6) between erosion levels, but this test is unable to tell us between which erosion levels this significance occurred.

0

50

100

150

200

250

1 2 3

210

103.15

42.15


Results: Erosion

Anova: Single Factor Species Richness ANOVA Source of Variation SS df MS F P-‐value F crit Between Groups 64.97436 2 32.48718 8.326396 0.001066 3.259446

Within Groups 140.4615 36 3.901709

Total 205.4359 38

Anova: Single Factor Simpson's Diversity Index ANOVA

Source of Variation SS df MS F P-‐value F crit Between Groups 0.033463 2 0.016732 1.957336 0.155976 3.259446

Within Groups 0.307732 36 0.008548

Total 0.341195 38

�  The Simpson’s diversity index for different levels of erosion did not differ significantly (p=0.156).

�  The species richness of birds sighted differs significantly (p = 0.0011) between the erosion levels, but this test is unable to tell us between which levels this significance occurred.

0

2

4

6

8

10

1 2 3

9.23

6.38 6.62

Average Species Richness

Human Disturbances �  3 levels of human disturbances

�  1 – little/no humans , no buildings/houses �  2 – ‘medium’ level of human activity, houses/buildings present

�  3 – high level of disturbance, houses/buildings present

** This varied day to day, time of day often played a large role in the differences

seen between days at the same beach

Results: Human Disturbances

SUMMARY

Groups Count Average 1 19 155.7895

2 11 44.72727

3 9 129.6667

Anova: Single Factor Total Number of Birds


Within Groups 296345.3 36 8231.815

Total 383753.6 38

�  The mean number of birds sighted differs significantly (p = 0.0095) between the different levels of human disturbance, but this test is unable to tell us between which levels this significance occurred.

0

20

40

60

80

100

120

140

160

1 2 3

155.79

44.73

129.67


Results: Human Disturbances Anova: Single Factor Species Richness


Within Groups 174.8729 36 4.857582

Total 205.4359 38

�  The species richness for the different disturbance levels did not differ significantly (p=0.055).

Anova: Single Factor Simpson's Diversity Index


Within Groups 0.305781 36 0.008494

Total 0.341195 38

�  The Simpson’s diversity index for the different disturbance levels did not differ significantly (p=0.139).

Discussion: Limita+ons and Future Studies � Limitations

�  Small sample size �  Confined to low tide so I could get around the beaches �  Large flocks of birds sometimes difficult to get an exact count �  UTV in high demand

�  Future Studies �  Time of day �  Water Quality �  Bird Behavior �  Interacting affects of multiple dependent variables �  Individual Species: are certain species better to focus on, can they tell us

specific things about the health of the environment? �  More sampling sites (smaller sections of beach)

Acknowledgements � Bald Head Island Conservancy

�  Staff �  Board of Directors

�  Fellow Interns � The Public

Literature Cited �  Agardy,T., J. Alder, P. Dayton, S. Curran, A. Kitchingman, M. Wilson, A. Catenazzi, J. Testrepo, C.

Birkeland, S. Blaber, S. Saifullah, G. Branch, D. Boersma, S. Nixon, P. Dugan, N. Davidson, C. Vorosmarty. 2005. Ecosystems and Human Well-‐Being: Current State and Trends. Millennium Assessment Report Series: Global Assessment Reports. Washington, DC: Island Press, 513–549.

�  Grippo, M., S. Cooper, A. Massey. 2007. Effect of beach replenishment projects on waterbird and shorebird communities. Journal of Coastal Research (23), 5, 1088-‐1096.

�  “Groins”. An Educator’s Guide to Folly Beach, South Carolina. <http://oceanica.cofc.edu/an%20educator'sl%20guide%20to%20folly%20beach/guide/process3.htm>. accessed June 15, 2012.

�  Leonard, L., T. Clayton, O. Pilkey. 1990. An analysis of replenished beach design parameters on U.S. east coast barrier islands. Journal of Coastal Research, 6, 15-‐36.

�  Recher, H. F. 1966. Some aspects of the ecology of migrant shorebirds. Ecological Society of America (47), 3, 393-‐407.

�  U.S. NABCI Committee. 2000. The north American bird conservation initiative in the united states: a vision of American bird conservation. U.S. North American Bird Conservation Initiative, Washington, D.C.

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affects of physical characteristics of bald head island beaches on shorebird diversity and...

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