BREEDING BIRDS OF YOUNG FLOODPLAIN FORESTS GROWING ON ABANDONED AGRICULTURAL 
LAND.

Melinda G. Knutson, and Laura E. McColl.
U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, 
WI  54603. 

The floodplain forests of the Upper Mississippi River are less diverse in tree 
species and age structure than they were prior to European settlement.  Land 
managers are concerned about habitat quality for migratory birds and other 
wildlife that depend on the forests.  Management agencies responsible for the 
Upper Mississippi River floodplain are particularly interested in the habitat 
values of young floodplain forests because cottonwood (Populus deltoides) and 
willow (Salix spp.)-dominated floodplain forests are currently scarce.  In 2001 
we studied stands of young cottonwood (Populus deltoides) and willow (Salix 
spp.) forest growing on abandoned agricultural land along the Mississippi River.  
The study sites were Harlow and Wilkinson Islands, both owned by the U.S. Fish 
and Wildlife Service, Mark Twain National Wildlife Refuge Complex.  Our 
objectives were to 1) compare the breeding bird community of young cottonwood 
and willow forests with that of adjacent scrub/shrub and mature forest habitats, 
2) describe vegetation characteristics associated with these habitats and, 3) 
place these communities in context with the surrounding landscape.  Forests, 
followed by pasture or grasslands, and row crops are the dominant land uses in 
the region surrounding the study area.  We recorded a total of 69 bird species 
in 2001; the most frequently observed species were the Indigo Bunting (Passerina 
cyanea), Red-winged Blackbird (Agelaius phoeniceus) and Yellow-billed Cuckoo 
(Coccyzus americanus).  Bird species richness differed among the habitat 
classes, with mature forests supporting the largest number of species.  
Ordination plots showed that both the vegetation and bird community differed 
among habitat classes.  The Indigo Bunting, Common Yellowthroat (Geothlypis 
trichas), and Yellow-breasted Chat (Icteria virens) were most indicative of 
scrub/shrub habitats and the Dickcissel (Spiza americana) and Wood Duck (Aix 
sponsa) were of high management concern to the U.S. Fish and Wildlife Service in 
this habitat type.  The Yellow-billed Cuckoo and Orchard Oriole (Icterus 
spurius) were most indicative of young forests; the Field Sparrow and Orchard 
Oriole were of management concern.  The Northern Cardinal (Cardinalis 
cardinalis), Gray Catbird (Dumetella carolinensis), Downy Woodpecker (Picoides 
pubescens), Red-eyed Vireo (Vireo olivaceus), and Tufted Titmouse (Baeolophus 
bicolor) were most indicative of mature forests and the Red-headed Woodpecker 
(Melanerpes erythrocephalus), Northern Flicker (Colaptes auratus), Kentucky 
Warbler (Oporornis formosus), Prothonotary Warbler (Protonotaria citrea), 
Acadian Flycatcher (Empidonax virescens), and Wood Thrush (Hylocichla mustelina) 
were of high management concern in mature forests.  Mature floodplain forests 
provided habitat for many cavity-nesting species because of the abundance of 
standing dead snags.  The mosaic of habitat types that developed on these sites 
post-flooding supported a diverse bird community.  Long-term management that 
speeds the establishment of mature woody wetlands is most compatible with 
patterns of natural vegetation succession and regional bird conservation 
objectives.

Keywords:  Mississippi River, young forest, bottomland forest, cottonwood, 
willow, bird community, floodplain forest, Missouri, Illinois.