SPECIES TRENDS

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Trends by Habitat

Trends by Species

 

 

TRENDS BY HABITAT:
(1997-2004 Trends)

The species classifications listed here are based on designations assigned by Chicago Wilderness.  For our purposes, shrubland birds have also been further separated out and placed into their own category.  Indicator species (species that well represent a designated habitat type) are denoted in the "IND" column.  The "TREND" column lists the average yearly rate of change of a species based on 1997-2004 point count data.

 

* Click on a species below to pull up graphs and detailed information about its trend. *

 

Grasslands | Shrublands | Woodlands | Wetlands

 

GRASSLANDS:

Nationally, grassland birds are facing the most significant declines according to the Audubon 2004 State of the Birds report.  In the Chicago Wilderness region where tallgrass prairie was one of the predominant habitat types, results are similar and many species are decreasing as urban expansion continues to spread through the Chicago area.  At the same time, results from the BCN Census show that some species like the state threat-ened Henslow's Sparrow are doing very well in preserved areas despite declining trends on Breeding Bird Survey routes in Illinois and the Midwest.  In addition to the protection of habitat, active restoration of grasslands by land managers and volunteers has also had a very noticeable and in many cases almost immediate beneficial impact.

 

SPECIES TREND DATA QTY RECORDS RANGE U.B. L.B. IND
Tree Swallow 17 Very Good 330 20 27 7  
Grasshopper Sparrow 14 Mod Good 169 32 30 -2 *
Savannah Sparrow 10 Very Good 336 16 18 2 *
Red-winged Blackbird 9 Very Good 1034 8 13 5  
Henslow's Sparrow 8 Very Good 201 15 15 0 *
Mourning Dove 1 Good 210 23 12 -11  
Field Sparrow 0 Good 383 14 7 -7  
Common Yellowthroat -1 Good 560 13 6 -7  
Song Sparrow -1 Good 869 9 4 -5  
Eastern Meadowlark -3 Good 457 11 3 -8 *
Brown-headed Cowbird -4 Mod Good 511 14 3 -11  
Barn Swallow -6 Good 198 25 6 -19  
Bobolink -6 Good 421 9 -2 -11 *
American Kestrel -27 Poor 10 111 28 -83  
Sedge Wren -29 Very Good 102 25 -17 -42 *
Killdeer -30 Good 58 32 -14 -46  
Dickcissel -46 Very Good 96 25 -34 -59 *

POORLY KNOWN TRENDS

Blue Grosbeak -------- -------- 1 ------- ------- -------  
Northern Bobwhite -------- -------- 3 ------- ------- -------  
Horned Lark -------- -------- 2 ------- ------- ------- *
Lark Sparrow -------- -------- 1 ------- ------- ------- *
Northern Harrier -------- -------- 1 ------- ------- ------- *
Northern Mockingbird -------- -------- 1 ------- ------- -------  
Sandhill Crane -------- -------- 12 ------- ------- -------  
Vesper Sparrow -------- -------- 4 ------- ------- ------- *
Western Meadowlark -------- -------- 1 ------- ------- ------- *

"U.B." & "L.B." represent the upper and lower bounds of the 95% Confidence interval.

 

SHRUBLANDS:

This habitat is often under managed and under researched due to its vague identity as an often transitional habitat between grasslands and woodlands and its relatively less important role for plants and other animals.  Nonetheless, this habitat distinction is very important to birds.  The Audubon State of the Birds report shows that many shrubland species are facing serious declines, second only to grasslands.  As a successional habitat, the long term management of fragmented shrublands in the Chicago Wilderness region is a difficult task that often requires sensitive care.
* Shrublands include any grasslands or open canopy woodlands with at least moderate understory. 

 

SPECIES

TREND DATA QTY RECORDS RANGE U.B. L.B. IND
Orchard Oriole 35 Moderate 35 89 79 -10 *
Blue-winged Warbler 30 Mod Poor 28 78 69 -9 *
Eastern Towhee 16 Mod Good 136 33 32 -1 *
Common Grackle 12 Good 416 19 22 3  
Warbling Vireo 6 Moderate 94 35 24 -11  
Northern Cardinal 3 Very Good 702 11 9