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The Effect of Hurricane Katrina on the Waterbird Populations of Southern
Louisiana
Carter Dombrowski
Brigham Young University-Hawaii
INTRODUCTION
RESULTS
DISCUSSION
Marshes of coastal Louisiana act as buffers from
hurricane damage and provide vital habitat to many
wetland birds and animals (Stone & McBride 1998,
Hester et al. 2005). The dumping of the excess
water from recent flooding in New Orleans introduced
harmful substances like arsenic and other pesticides
into the sediments (Liebl et al. 2008). Research on
the pre- post-Hurricane Katrina nekton community
populations shows that nekton density increased and
the community shifted from one of tidal
freshwater/resident species to one containing
brackish/migrant species, but this trend only lasted
until spring of 2007 (Piazza & La Peyre 2009).
The Madisonville marsh contained twenty species
observed post-Hurricane Katrina that were not observed in
the pre-Hurricane Katrina data. In addition to different
species present in the marsh, the abundance of those
species found both pre- and post-Hurricane Katrina were
different (Figure 3 and 4). There was a difference in the
number of species present in the marsh located in
Madisonville, LA pre- and post-Hurricane Katrina. There
were 11 species present before and 27 after the hurricane.
The greatest difference in abundance was found in the
Northern Rough-winged Swallow (Stelgidopteryx
serripennis). None were observed before Hurricane
Katrina while an average of 54.5 birds was observed after
(Figure 3). There was also a difference in the number of
species present in the marsh located in Lacombe, LA.
Thirty-three species were present before Hurricane
Katrina and 28 species present after. The greatest
abundance difference observed was the presence of
Purple Martin (Progne subis) before and the absence of
that species after Hurricane Katrina (Figure 4). A chisquare test was preformed on each set of data for birds
with average counts above two individuals for either pre or
post. Data from the Madisonville marsh and from the
Lacombe marsh showed significant differences (p value <
0.0005) in pre- and post-Hurricane Katrina counts for
resident waterbirds.
Hurricane Katrina did effect the variety and
abundance of birds in the two marshed samples in
this study. Both marshes sustained varying levels of
damage due to Hurricane Katrina, which could have
driven some species out of the marshes, allowing
new species to move in. Marsh grasses were ripped
up and salt-water intrusion worsened due to the
storm surge. The Northern Rough-winged Swallow
(Stelgidopteryx serripennis) could have moved into
the Madisonville Louisiana marsh after a niche
opened up with changes of the marsh. The Purple
Martin (Progne subis) which was present before
Hurricane Katrina and not after may be due to habitat
change. Purple Martins are particular about their
nesting habitat which may account for their absence.
These differences could also be due to other factors,
such as differences in count protocol for pre-Katrina
data. If counts were collected by different means,
then there could be some discrepancies in the
analysis of the data. Further studies could be
conducted during the winter months in an effort to
see if migratory birds also were effected by the
hurricane.
After Hurricane Katrina the landbird populations of
the Greater New Orleans area declined (Yaukey
2008). Many of the wetlands in coastal Louisiana
have been altered due to Hurricane Katrina
(Middleton 2009, McKee & Cherry 2009). The
purpose of this study was to assess the present
relative abundance of waterbirds at two specific
wetlands for which pre-Katrina relative abundance
data are available.
METHODS AND MATERIALS
Poster Design & Printing by Genigraphics® - 800.790.4001
I would like to thank Brother Bruner for all of his
guidance and direction during this study. I would also
like to thank the BYU-Hawaii Biology department. I
would also like to express thanks for the
associateship money that I received to help fund my
research. Thanks are also sent to Dr. Brantley, who
with help from others collected the pre-Katrina data.
REFERENCES
Figure 1. The Madisonville, LA marsh
where 41 acres were surveyed.
Figure 2. The Lacombe, LA marsh where
68 acres were surveyed.
60
40
Pre-Katrina
30
Post-Katrina
20
140
120
Piazza, B. & M. La Peyre 2009. The effect of Hurricane Katrina on nekton communities in the tidal freshwater
marshes of Breton Sound, Louisiana, USA. Estuarine Coastal and Shelf Science 83(1): 97-104
100
Pre-Katrina
Post-Katrina
80
60
40
20
Figure 3. The average bird counts for
Madisonville, LA
American Coot
Least Tern
Laughing Gull
Fish Crow
Eurasian
Nutmeg
Barn Swallow
Northern
Killdeer
Black-necked
White Ibis
Mottled Duck
Tricolored
Great Egret
Red-winged
Black Vulture
(Coragypus
Northern
Rough-winged
Avian Species
Yaukey, P. 2008. Effects of Hurricane Katrina on the urban resident landbirds of New
Orleans, Louisiana. Condor 110(1): 158-161
Hester, M., E. Spalding, C. Franze 2005. Biological resources of the Louisiana coast; Part 1. An overview of
coastal plant communities of the Louisiana Gulf shoreline. Journal of Coastal Research (44): 134-145
0
Common
Grackle
Glossy Ibis
(Plegadis
Lesser Bittern
(Ixobrychus
Great Egret
(Ardea alba)
0
Black-necked
Stilt
10
Average Number of Birds
50
Liebl, A., L. Granados, Q. Zhang, G. Wang, H. Mielke, C. Gonzales, D. Ennis, B. Rees 2008. Effects of posthurricane Katrina New Orleans (LA, USA) sediments on early development of the Japanese medaka (Oryzias
latipes). Environmental Toxicology and Chemistry 27(12): 2557-2564
Hou A., E. Laws, R. Gambrell, H. Bae, M. Tan, R. Delaune, Y. Li , H. Roberts 2006. Pathogen indicator microbes
and heavy metals in Lake Pontchartrain following Hurricane Katrina. Environ Science & Technology
40(19):5904-10
160
Red-winged
Blackbird
Average Number of Birds
The study took place in the marshes surrounding
Lake Ponchartrain near the cities of Lacombe and
Madisonville, Louisiana. Assistance in locating and
obtaining authorization to enter the sites and collect
data was coordinated with local state authorities.
Data were collected from 21 June to 5 August 2010.
Point counts were taken from 0600 to 0800 hours
using fifteen-minute intervals at each point. A car
was driven to each point count for both marshes.
There were no clear protocols in the pre-Katrina
data, which was collected from June through August
of 2004. Counts were preformed twice a week at
each site on alternating days. An equal number of
counts were conducted at both sites. An area of 41
acres was surveyed at the Madisonville location
(Figure 1) and 68 acres at the Lacombe location
(Figure 2). When necessary, binoculars were used to
identify birds located within the boundaries of the
point count. The number of bird species and
abundance of each species seen were recorded for
each point count. Data were statistically analyzed
using a chi-square test and compared to pre-Katrina
data, which was collected by Dr. Chris Brantley and
other bird counters.
Acknowledgments
Avain Species
Figure 4. The average bird counts for
Lacombe, LA.
Stone, G. & R. McBride 1998. Louisiana barrier islands and their importance in wetland protection: Forecasting
shoreline change and subsequent response of wave climate. Journal of Coastal Research 14 (3): 900-915
Middleton, B. 2009. Regeneration of Coastal Marsh Vegetation Impacted by Hurricanes Katrina and Rita.
Wetlands 29(1): 54-65
McKee, K. & J. Cherry 2009. Hurricane Katrina Sediment Slowed Elevation Loss in Subsiding Brackish Marshes
of the Mississippi River Delta. Wetlands 29(1): 2-15