The Effect of Hurricane Katrina on the Bird Populations of Southern Louisiana

Transcription

1 The Effect of Hurricane Katrina on the Bird Populations of Southern Louisiana By: Carter Dombrowski Mentor: Phil Bruner Brigham Young University-Hawaii Biology June

2 Abstract: This study compares the relative abundance of birds at two marshes surrounding Lake Ponchartrain near the cities of Lacombe and Madisonville, Louisiana before and after Hurricane Katrina. Data were collected using point counts that were taken from 0600 to 0800 hours, twice a week, from 21 June to 5 August These data were compared with bird counts before Hurricane Katrina. Both marshes had differences in species and relative abundances pre- and post-hurricane Katrina. Possible reasons for the changes could be due to the varying levels of damage sustained by each marsh, which caused a shift in the species and their relative abundance. These observed differences could also be due to differences other than the hurricane, such as count protocols. Monitoring wetlands before and after major climate changes are valuable indicators of habitat quality and avian species composition compromised by these events. Introduction: Marshes of coastal Louisiana act as buffers from hurricane damage and provide vital habitat for wetland birds and mammals (Stone & McBride 1998, Hester et al. 2005). Excess water from flooding in New Orleans due to Hurricane Katrina increased harmful substances like arsenic and pesticides into the sediments (Liebl et al. 2008). Pathogen and heavy metal studies were conducted on the water removed from the city of New Orleans and Lake Ponchartrain. Surface water Esherichia coli and Enterococcus counts were high at stations near the mouth of the 17 th Street Canal, but decreased as distance from the mouth of the canal increased (Hou et al. 2006). The levels of priority heavy metal concentrations were nearly undetectable or below the EPA criterion maximum and criterion continuous concentrations (Hou et al. 2006). Research on the nekton community before and after Hurricane Katrina found that density increased and shifted from one of tidal freshwater/resident species to one containing brackish/migrant species. This trend lasted until the spring of 2007 (Piazza & La Peyre 2009). After Hurricane Katrina the landbird populations of the Greater New Orleans area declined (Yaukey 2008). Counts conducted in the Lower Ninth Ward, Arabi, and the site 2

3 of the Murphy Oil spill showed numbers of birds to be extremely low in these heavily affected areas (Yaukey 2008). There has been little research on post-hurricane Katrina effects on the larger wetland wildlife populations. 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 birds at wetlands for which pre-katrina species composition and relative abundance data were available. Methods and Materials: The study took place in the marshes surrounding Lake Ponchartrain near the cities of Lacombe and Madisonville, Louisiana (Figure 1). Assistance in locating and obtaining authorization to enter the sites and collect data was coordinated with local state authorities. Bird data (species/relative abundance) were collected from 21 June to 5 August Point counts were taken from 0600 to 0800 hours using fifteen-minute intervals at each point. Counts were preformed twice a week at each site on alternating days. Fourteen counts were conducted at each site. An area of 41 acres was surveyed at the Madisonville location (Figure 2) and 68 acres at the Lacombe location (Figure 3). When necessary, binoculars were used to identify birds located within the novel boundaries of the point count station. The number of bird species and abundance of each species seen were recorded for each point count. There were no clear protocols in the pre-katrina data collected by Dr. Chris Brantley (U.S. Army Corps of Engineers) from June through August of All data were statistically analyzed using a chi-square test and compared to pre-katrina data. 3

4 Figure 1. An aerial photo of the north shore of Lake Ponchartrain, LA where bird counts were taken. Marsh A locates the Madisonville, LA location. Marsh B delineates the Lacombe, LA location. The marshes are about 25 miles apart, with marsh A more inland than marsh B. 4

5 Figure 2. An aerial photo of Madisonville, LA from which bird data were collected both pre- and post- Hurricane Katrina. An area of 41 acres was surveyed. 5

6 Figure 3. An aerial photo of Lacombe, LA from which bird data were collected both pre- and post- Hurricane Katrina. An area of 68 acres was surveyed. Results: Several species that were present before Hurricane Katrina were not found after the storm (Table 1). The Madisonville marsh contained twenty species observed post- Hurricane Katrina that were not recorded pre-hurricane Katrina (Appendix 1). In addition to different species being present in the marsh, the abundance of those species found both pre- and post-hurricane Katrina were different, with certain species being higher post Hurricane Katrina (Figure 4 and 5). There was a difference in the number of 6

7 species present in the marsh located in Madisonville, LA pre- and post-hurricane Katrina. Eleven species were present before and 27 after the hurricane (Appendix 1). The Northern Rough-winged Swallow (Stelgidopteryx serripennis) was not recorded before Hurricane Katrina while an average of 54.5 birds per-visit was observed on this study (Figure 4). 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 (Appendix 2). The greatest difference in average abundance was observed in the Purple Martin (Progne subis) with an average of 145 birds per-visit before and the absence of that species after Hurricane Katrina (Figure 5). A chi-square test was preformed on each set of data for birds with average counts above two individuals for either pre or post Katrina. Data from both marshes showed that there were significant differences (p value < ) in pre- and post-hurricane Katrina counts. Table 1: The avian species that were present at both marshes before Hurricane Katrina, but not after. Bird Species Black-necked Stilt (Himantopus mexicanus) Common Moorhen (Gallinula chloropus) Red-bellied Woodpecker (Melanerpes carolinus) Common Yellowthroat (Geothlypis trichas) Wood Duck (Aix sponsa) Black-bellied Whistling Duck (Dendrocygna autumnalis) Barn Swallow (Hirundo rustica) Seaside Sparrow (Ammodramus maritimus) Ruby Throated Hummingbird (Archilochus colubris) Mourning Dove (Zenaida macroura) Blue Jay (Cyanocitta cristata) American Crow (Corvus brachyrhynchos) Purple Martin (Progne subis) Eastern Kingbird (Tyrannus tyrannus) Least Tern (Sterna antillarum) 7

8 Figure 4. The pre-visit average counts for some of the avian fauna present with a pre-visit average count of at least three individuals in the Madisonville, Louisiana marsh both pre- and post-hurricane Katrina. 8

9 Figure 5. The pre-visit average counts for the avian fauna present with a pre-visit average count of at least three individuals in the Lacombe, Louisiana marsh both pre- and post-hurricane Katrina. Discussion: Hurricane Katrina caused changes in the number and kinds of birds at both marshes investigated in this study. These sites sustained varying levels of damage due to Hurricane Katrina. Marsh grasses were ripped up and salt-water intrusion increased due to the storm surge. The Northern Rough-winged Swallow (Stelgidopteryx serripennis) may have moved into the Madisonville Louisiana marsh due to ecological changes in the marsh. The Purple Martin (Progne subis), which was present before Hurricane Katrina, but not after may also be due to habitat change. Further studies could be conducted during the winter months check for the storm s effect on the abundance and diversity of migratory birds in these marshes. 9

10 Acknowledgements: 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 for all their assistance and guidance throughout this study. I would also like to express thanks for the associateship money I received to help fund my research. Finally this project would not have been possible without the assistance of Dr. Chris Brantley. 10

11 Apendix 1: The average waterbird counts for the Madisonville, Louisiana marsh for both pre- and post- Hurricane Katrina. Pre-Hurricane Katrina data were collected from June through August of Post- Hurricane Katrina data were collected from June through August of Species Pre-Katrina Post-Katrina Red-winged Blackbird (Agelaius phoeniceus) Great Blue Heron (Ardea herodias) 5 2 Great Egret (Ardea alba) Snowy Egret (Egretta thula) Little Blue Heron (Egretta caerulea) 0 2 Tricolored Heron (Egretta tricolor) 0 2 American Bittern (Botaurus lentiginosus) Lesser Bittern (Ixobrychus exilis) Mottled Duck (Anas fulvigula) Gadwall (Anas strepera) 0 13 Glossy Ibis (Plegadis falcinellus) White Ibis (Eudocimus albus) Common Loon (Gavia immer) 1 1 Double-crested Cormorant (Phalacrocorax auritus) 0 2 Black-necked Stilt (Himantopus mexicanus) White Pelican (Pelecanus erythrorhynchos) Common Moorhen (Gallinula chloropus) 1 0 Killdeer (Charadrius vociferus) Lark Bunting (Calamospiza melanocorys) 0 1 Common Grackle (Quiscalus quiscula) Brown-headed Cowbird (Molothrus ater) 0 4 Northern Rough-winged Swallow (Stelgidopteryx serripennis) Louisiana Waterthrush (Seiurus motacilla) 0 1 Northern Cardinal (Cardinalis cardinalis) Mourning Dove (Zenaida macroura) Fish Crow (Corvus ossifragus) 1 1 Laughing Gull (Larus atricilla) 0 2 Black Vulture (Coragypus atratus) Red Tailed Hawk (Buteo jamaicensis) Red-bellied Woodpecker (Melanerpes carolinus) 2 0 Common Yellowthroat (Geothlypis trichas)

12 Appendix 2: The average waterbird counts for the Lacombe, Louisiana marsh. Pre-Hurricane Katrina data were collected from June through August of Post-Hurricane Katrina data were collected from June through August of Species Pre-Katrina Post-Katrina Red-winged Blackbird (Agelaius phoeniceus) Great Blue Heron (Ardea herodias) 4 2 Great Egret (Ardea alba) 17 7 Snowy Egret (Egretta thula) Little Blue Heron (Egretta caerulea) 2 2 Tricolored Heron (Egretta tricolor) Green Heron (Butorides virescens) American Bittern (Botaurus lentiginosus) Lesser Bittern (Ixobrychus exilis) Mottled Duck (Anas fulvigula) Wood Duck (Aix sponsa) Black-bellied Whistling Duck (Dendrocygna autumnalis) 2 0 Glossy Ibis (Plegadis falcinellus) White Ibis (Eudocimus albus) 10 1 Double-crested Cormorant (Phalacrocorax auritus) Black-necked Stilt (Himantopus mexicanus) White Pelican (Pelecanus erythrorhynchos) Brown Pelican (Pelecanus occidentalis) Purple Gallinule (Porphyrio martinica) 0 2 Killdeer (Charadrius vociferus) Common Grackle (Quiscalus quiscula) Northern Rough-winged Swallow (Stelgidopteryx serripennis) Northern Cardinal (Cardinalis cardinalis) Barn Swallow (Hirundo rustica) Seaside Sparrow (Ammodramus maritimus) 6 0 Nutmeg Mannikin (Lonchura punctulata) Ruby Throated Hummingbird (Archilochus colubris) 1 0 Mourning Dove (Zenaida macroura) 13 0 Eurasian Collard Dove (Streptopelia decaocto) Blue Jay (Cyanocitta cristata) American Crow (Corvus brachyrhynchos) 2 0 Fish Crow (Corvus ossifragus) Purple Martin (Progne subis) Red Tailed Hawk (Buteo jamaicensis) 1 1 Laughing Gull (Larus atricilla) Eastern Kingbird (Tyrannus tyrannus) 4 0 Least Tern (Sterna antillarum) 3 0 Forster's Tern (Sterna forsteri) American Coot (Fulica Americana)

13 Works Cited: Liebl, A., L. Granados, Q. Zhang, G. Wang, H. Mielke, C. Gonzales, D. Ennis, B. Rees Effects of post- Hurricane Katrina New Orleans (LA, USA) sediments on early development of the Japanese medaka (Oryzias latipes). Environmental Toxicology and Chemistry 27(12): Hou A., E. Laws, R. Gambrell, H. Bae, M. Tan, R. Delaune, Y. Li, H. Roberts Pathogen indicator microbes and heavy metals in Lake Pontchartrain following Hurricane Katrina. Environ Science & Technology 40(19): Piazza, B. & M. La Peyre 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): Yaukey, P Effects of Hurricane Katrina on the urban resident landbirds of New Orleans, Louisiana. Condor 110(1): Hester, M., E. Spalding, C. Franze Biological resources of the Louisiana coast; Part 1. An overview of coastal plant communities of the Louisiana Gulf shoreline. Journal of Coastal Research (44): Stone, G. & R. McBride Louisiana barrier islands and their importance in wetland protection: Forecasting shoreline change and subsequent response of wave climate. Journal of Coastal Research 14 (3): Middleton, B Regeneration of Coastal Marsh Vegetation Impacted by Hurricanes Katrina and Rita. Wetlands 29(1): McKee, K. & J. Cherry Hurricane Katrina Sediment Slowed Elevation Loss in Subsiding Brackish Marshes of the Mississippi River Delta. Wetlands 29(1):