1. Avian community composition of Langan Park, Japanese Gardens, and Botanical Gardens in Mobile, Alabama
Jared A. Elmore, Clinton S. Major, and Joel A. Borden
Department of Biology, University of South Alabama, Mobile, Alabama
Introduction
With over 10,000 described species, birds are one of the most diverse terrestrial vertebrate groups on the planet. Birds are excellent bio-indicators to assess habitat quality and understanding their response to habitat disturbances and vegetation cover and type is important for their ecology and conservation1,2. These types of studies are critical with many birds experiencing decline due to anthropogenic disturbances such as destruction, fragmentation, and degradation3,4.
Within the city of Mobile, AL, Langan Park, Japanese Gardens, and Botanical Gardens are three adjacent parks showing a variety of different vegetation types and disturbances, representing a good site to carry out studies to (1) determine the differences in abundance, richness, and diversity of avifauna at each site and (2) compare avian abundance, richness, and diversity with site characteristics of vegetation type and proximity to water. The site as a whole is highly disturbed being in the center of an urbanized, major city. The park area is approximately 570 acres and is a diverse area with habitats ranging from longleaf pine forest to wetland areas.
Materials and Methods
A standardized method in avian ecology known as the avian point count method was used to record bird occurrences5. All birds within a 50 meter diameter site were recorded by both visual and auditory methods for five minutes per site. Three sites were surveyed three times per week starting at approximately 45 minutes after sunrise from September to November Nine sites, shown in Map 3, were chosen throughout Langan Park, Botanical Gardens, and Japanese Gardens based on vegetation cover type, distance from water, and distance from each other. Vegetation and proximity to water were estimated by both visual inspection and using ARC GIS.
Avian abundance was calculated by taking the total number of individuals within each point. Avian richness was calculated by taking the total number of different species found within each point. Diversity is an index of the relation between number of species (richness) and individuals. Diversity is a relative term and for this study was calculated by using the Shannon-Wiener index. The Shannon-Weiner equation is H’ = -Sum( pi ln pi) where H’ is Shannon’s diversity index and pi=proportion of richness made up of the ith species. A General Linear Model (GLM) was run separately on abundance, richness and diversity to compare these with each site or vegetation, proximity to water, and the interaction between vegetation and proximity to water.
Conclusions
The results showed that neither vegetation type nor proximity to water strongly influence avian abundance, richness, and diversity in these parks. While the avian composition differed at each site, these results are not included in this study. These findings suggest that in urbanized areas such as these parks, while the species may differ, the abundance, richness, and diversity remain unaffected by vegetation and proximity to water.
One explanation for these results may be that the area of the park was just too small to see a significant difference among sites. Another may be that none of the sites were more than 300 meters from water. Looking at individual species or guilds may lead to trends based on vegetation and proximity to water in future studies.
Table 1 (below) shows the results from the GLM Anova.
Analysis of Variance
Abundance versus vegetation, proximity to water, and interaction
Source DF
Adj SS
Adj MS
F-Value
P-Value
Vegetation 5
0.4789
1.4
0.414
Error 3
0.2045
Total 8
0.6834
Richness versus vegetation, proximity to water, and interaction
1.02
0.529
Diversity versus vegetation, proximity to water, and interaction
0.1121
0.49
0.773
0.1372
0.2494
Proximity to water and interaction could not be estimated and
was removed from the equation.
Table 2 (below) shows the species and abundance of birds recorded at all sites.
Site Species List
Common Name
Species Name
Total Abundance
American Coot
Fulica americana 1
American Robin
Turdus migratorius 42
Belted Kingfisher
Megaceryle alcyon 3
Blue Jay
Cyanocitta cristata 31
Brown Headed Nuthatch
Sitta pusilla
Brown Thrasher
Toxostoma rufum
Canada Goose
Branta canadensis 65
Carolina Chickadee
Poecile carolinensis 5
Carolina Wren
Thryothorus ludovicianus
Chimney Swift
Chaetura pelagica 19
Common Grackle
Quiscalus quiscula 12
Domestic Duck
Anas platyrhynchos x Cairina moschata 32
Double Crested Cormorant
Phalacrocorax auritus 11
Downy Woodpecker
Picoides pubescens
Eastern Bluebird
Sialia sialis 49
Eastern Towhee
Pipilo erythrophthalmus 10
Great Blue Heron
Ardea herodias
Great Egret
Ardea alba 7
Killdeer
Charadrius vociferus 2
Lesser Yellowlegs
Ringa flavipes
Loggerhead Shrike
Lanius ludovicianus
Mallard Duck
Anas platyrhynchos 18
Mourning Dove
Zenaida macroura
Mourning Warbler
Geothlypis philadelphia
Muscovy Duck
Cairina moschata
Northern Cardinal
Cardinalis cardinalis 14
Northern Flicker
Colaptes auratus
Northern Mockingbird
Mimus polyglottos 13
Pied Billed Grebe
Podilymbus podiceps
Pine Warbler
Setophaga pinus 6
Red Bellied Woodpecker
Melanerpes carolinus
Red Headed Woodpecker
Melanerpes erythrocephalus
Ruby Throated Hummingbird
Archilochus colubris
Snowy Egret
Egretta thula
Solitary Sandpiper
Tringa solitaria
Tufted Titmouse
Baeolophus bicolor
Wilsons Snipe
Gallinago delicata
Wood Duck
Aix sponsa 15
Yellow Warbler
Setophaga petechia
Figure 1 (above) shows the total species richness at each site within the parks.
Map 1 (above) shows the location of Mobile, AL within the southeastern U.S.
Map 2 (above) shows the location of the park study sites within the city of Mobile, AL. 7 1 2 3 4 5 6 8 9
Figure 2 (above) shows the Shannon-Wiener index for site diversity within the parks.
Results
A total of 2,436 individual birds were recorded during the study with 407 of these occurring at sites and the other 2,029 occurring along transects. 50 individual species were recorded during the study with 39 species occurring at sites, shown in Table 2. Only the results for the sites are shown on this poster.
Site 1 was mixed lowland forests. Site 2 was open grassland on an island. Sites 3 and 4 were open mixed forests. Sites 5 and 6 were wetland marsh. Sites 7 and 8 were longleaf pine upland. Site 9 was upland mixed forest.
Figure 1 shows the species richness by site. Sites 5 and 6 had the highest richness with with 17 and 13 different species respectively. Sites 1, 2, 3, 4, and 8 all had the same species richness with 9 different species. Sites 7 and 9 were slightly lower with 8 and 7 different species respectively.
Figure 2 shows the diversity by site. Site 5 had the highest diversity with an index number of Sites 1, 6, 7, and 9 all fell between 0.8 and 1. Sites 2 and 3 fell between 0.6 and 0.8. Sites 4 and 8 had the lowest diversity with an index number less than 0.6.
The anova, shown in Table 1, showed no significant relationship between site abundance, richness, or diversity with vegetation type, proximity to water, or the interaction between these two variables. Table 2 shows the overall abundance of species at all sites.
Map 3 (above) shows the location of the sites (plots) and transects within the parks.
Sources
1Etterson, M.A., Niemi, G.J., and Danz, N.P Estimating the effects of detection heterogeneity and overdispertion on trends estimated from avian point counts. Ecological Applications, 19,
2Padoa-Schioppa, E., et al Bird communities as bioindicators: The focal species concept in agricultural landscapes. Ecological Indicators, 170, 1-11
3Cartwright, S.J., et al Anthropogenic Natal Environmental Effects on Life Histories in a Wild Bird Population. Current Biology, 24,
4Kuussaari, M., et al Extinction debt: a challenge for biodiversity conservation. Trends in Ecology and Evolution, 24,
5Ralph, J.C., et al Managing and Monitoring Birds Using Point Counts: Standards and Applications. USDA Forest Service Gen. Tech. Rep. PSW-GTR-149,
Acknowledgements
I would like to thank Dr. Ylenia Chiari for guidance and support, Dr. John McCreadie for help with statistical analyses, and Mr. Sam Stutsman for instruction with ARC GIS. I would like to thank the University of South Alabama Biology Department for the opportunity to complete this study and the Earth Sciences Department for use of the GIS program and lab. I would lastly like to thank the ASB for the Support Award.