Habitat is manipulated through a variety of methods (mostly water and vegetation management) to achieve functional percentages of different habitat types. It is determined, guided, and tracked by an annual Habitat Management Plan. The Plan identifies physical attributes of the unit, habitat objectives; specifies management activities to make any necessary repairs or improvements; emphasizes positive results from previous years; and notes special management considerations (i.e. presence of special status species or other significant wildlife use). Visit our Sacramento NWR Complex Habitats page to find Habitat Management Maps for each refuge.
Water management is considered essential to maintaining high quality wetlands. It is an important tool for vegetation production and control in wetlands. The water management regime, specifically the timing, depth, and duration of inundation, is often the greatest contributor to the resulting wetland vegetation, whether desirable or undesirable. Water level management is also critical to providing available habitat to certain wildlife species at certain times of the year. Flooding regimes are designed to mimic historic wetland patterns as closely as possible, given water availability and statewide wetland losses.
Reasons for vegetation management include maintaining biodiversity, maintaining desirable proportions of emergent vegetation in wetlands, enhancement of desirable species, reduction of undesirable species, preparation for habitat restoration projects, reducing mosquito breeding habitat, and maintenance and safety around facilities including protecting communities and assets at risk to wildfire. A variety of techniques are used depending on the habitat type, plant species, and resource objectives. Techniques include mowing, disking, prescribed burning, spraying, and livestock grazing.
A prescribed burn is a controlled burn pre-planned by refuge management in a specific area for a specific resource objective.
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Monitoring and Research
Bird and plant monitoring and other research activities provide valuable data that helps refuge staff refine habitat management. Bird diseases include avian cholera, avian botulism, and lead poisoning. These diseases cannot be passed to humans. Dying birds are monitored and dead birds removed with airboats to stop the disease cycle.
Avian Influenza (Bird Flu)
There are numerous Web sites with timely information available to the public. These two documents are concise and give a general overview: Avian Influenza Fact Sheet and What Hunters Should Know About Avian Influenza. Below are some Web sites that provide more detailed information at the state, national and international levels.
California Monitoring for Bird Flu
The California Department of Fish and Wildlife; UC Davis Wildlife Health Center; CA Department of Food and Agriculture; U.S. Fish and Wildlife Service; and the CA Department of Health Services are in partnership to monitor for avian influenza viruses in wild birds.
National and International Information about Avian Influenza:
The Service, Division of Migratory Bird Management's (DMBM) Web site brings together in one location some of the more informative Web sites having information specific to avian influenza in wild birds. The DMBM considers National Wildlife Health Center's Avian Influenza Home Page to be the premier on-line source for information on avian influenza in wild birds.
Other Related Links:
Alaska's Avian Flu Web Site
National Centers for Disease Control and Prevention
World Health Organization