Organization | • | Illinois Natural History Survey Library | [X] |
| | 1: | | Title: | | | | | Volume/Number: | 37 2005 3-4 August | | | | Issuing Agency: | | | | | Description: | Irregularly published technical series. This volume consists of two issues: 37 3 , entitled "Nesting Ecology of Black-crowned Night-Herons at Lake Calumet Wetlands" and 37 4 , entitled "Population Trends in a Black-crowned Night-Heron Colony at Lake Calumet Wetlands" Volume 37 3 Partial Abstract: We examined the nesting ecology of a Blackcrowned Night-Heron Nycticorax nycticorax colony located at wetlands associated with Lake Calumet in south Cook County, Illinois,during the 2002 and 2003 nesting seasons. This area of southeastern Chicago has been greatly impacted by heavy industry, solid and chemical waste disposal, urbanization, and altered hydrology. Volume 37 4 Abstract: The number of active Black-crowned Night-Heron Nycticorax nycticorax nesting colonies in Illinois has declined significantly over the past century. Habitat loss/degradation and other factors such as exposure to environmental contaminants and competition for nest sites at established colonies may have contributed to this decline. In this study, we examined recent trends in population levels of Black-crowned Night-Herons nesting at wetlands associated with Lake Calumet in southeastern Chicago, Illinois. The number of Black-crowned Night-Herons nesting annually at these wetlands has fluctuated widely over the last two decades. Immigration of herons from riverine colonies may have driven population increases during the mid-1980s and early 1990s. However, this population has remained relatively stable at between 300 and 400 pairs during 19972003. | | | | Date Created: | 09 13 2005 | | | | Agency ID: | | | | | ISL ID: | 000000010478 Original UID: 5765 FIRST WORD: Black | |
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