Treesearch

Isla Alcatraz is a small volcanic island in the Eastern Midriff Island region of the Gulf of California, approximately 1.4 km from the fishing community of Bahía de Kino, Sonora, México. The island falls under the protection of the Gulf Island Reserve system for wildlife and migratory birds. Isla Alcatraz is home to one of the largest Double-crested Cormorant (Phalacrocorax auritus albociliatus) breeding colonies in western North America (Anderson et al. 1976; Carter et al. 1995). A survey in 1975 estimated a total of approximately 1,500 pairs of breeding Double-crested Cormorants on the...

Seabird research in northwestern México has increased in the last 20 years, however many areas remain unexplored and seabird colony inventories are badly needed. Coastal wetlands and adjacent islands from southern Sonora through Nayarit host large colonies of pelecaniforme and other seabirds, but surveys of these areas have been limited and localized. Seabird colonies on islands in the Gulf of California and off the west coast of the Baja California peninsula have been well documented but only for surface nesting species. Population abundance estimates for sub-surface nesting species are...

The North American Wetlands Conservation Act (NAWCA) was passed in 1989, and has been instrumental in restoring, protecting, and enhancing 3.5 million has of wetland and associated habitats across North America. The objective of this study was to assess the extent to which NAWCA projects have addressed the priority habitat needs expressed by the North American Waterfowl Management Plan (NAWMP), Partners in Flight (PIF), and U.S. Shorebird Conservation Plan (USSCP) regional plans in coastal regions of the U.S., by comparing the habitat conservation activities described in approved NAWCA...

The Gulf of Mexico region contains much of the Western Hemisphere’s most important stopover habitat. Long an important region for industry and agriculture, the near-shore maritime and wetland habitats are now highly threatened by habitat degradation and rapid urbanization. Because of the value placed on coastal property, acquisition is not always a viable conservation tool. The development of public and private partnerships has proven to be an excellent method to deliver cost-effective conservation in the maritime habitats of the western gulf coast. Here we describe accomplishments of four...

Trinidad and Tobago, a twin island nation, is the most southerly of the Caribbean islands and lies just 11 km off the coast of Venezuela, near the Orinoco delta. Trinidad, the larger of the two islands, is approximately 5,000 km² and the Nariva Swamp is located on its eastern coast (fig. 1). In 1993, this site was designated as a wetland of international importance under the Ramsar Convention on Wetlands of International Importance (Ramsar Convention Bureau 1996) and received protection under national legislation in 1995.

We advocate adaptive programs of decision making and monitoring for the management of forest birds when responses by populations to management, and particularly management trade-offs among populations, are uncertain. Models are necessary components of adaptive management. Under this approach, uncertainty about the behavior of a managed system is explicitly captured in a set of alternative models. The models generate testable predictions about the response of populations to management, and monitoring data provide the basis for assessing these predictions and informing future management...

Managed forests of North America provide important breeding and wintering habitat for many bird species. It is therefore essential that we understand all aspects of bird-forestry relationships if forest managers are to balance the needs of birds with timber harvest objectives. To help meet this need, here we provide a review of 116 research articles, dating from 1960 to 2002, which have examined bird-forestry relationships in managed forests across North America. We emphasize patterns in response of birds to silviculture, discuss how forestry practices might be used to enhance habitat for...

In order to determine the effects of selective logging on pine-oak forest?s bird communities in central-western Mexico, we gathered information through 10-min point counts in plots without wood extraction and sites logged at different times in the past (1, 4, and 8 years). We did not find evidences to argue for effects of logging on bird communities; the study plots showed very similar diversity values, and similarity index values among them were high. Feeding guild groups showed different patterns after logging, and particular resident species were the most affected. Migrants as a group...

Monitoring can and should be much more than the effort to track population trends; it can be a proactive effort to understand the effects of human activities on bird populations. It should be an integral part of the adaptive management process. With this in mind, the Northern Region Landbird Monitoring Program has a dual focus: (1) to monitor long-term bird population trends, and (2) to study bird-habitat relationships and management effects. By conducting permanent, longterm monitoring transects every other year, we are free to use the intervening years to study the effects of specific...

Bird conservation plans represent one of the pillars of the National Partners in Flight (PIF) bird conservation strategy known as the Flight Plan. The Flight Plan provides the framework for bird conservation plans that, in turn, set conservation priorities and specific objectives for bird populations and habitat for each state or eco-region in the nation. Many of California?s birds and other wildlife depend upon coniferous forests. In 1998, the California PIF partners identified a need for a comprehensive bird conservation plan for the coniferous forests of California. In order to develop...