The Mississippi Flyway: An Essential Migration Route

April 7, 2015 by  
Filed under Features

Starting in central Canada and stretching to the Gulf of Mexico, the Mississippi Flyway is the name given to the route followed by birds migrating from their breeding grounds in North America to their wintering grounds in the south. The flyway includes Canada’s Mackenzie River which flows north through uninhabited forest and tundra into the Arctic Ocean, with tributaries reaching southwards, feeding into and out of a number of lakes, including the Great Slave Lake, Great Bear Lake and Lake Athabasca. As the name suggests, the Mississippi Flyway follows the route of the Mississippi River in the United States – North America’s largest river system. Originating in northern Minnesota, the slow-flowing river travels southwards for a distance of 2,530 miles, cutting through, or forming a border for, the states of Mississippi, Arkansas, Louisiana, Minnesota, Wisconsin, Illinois, Iowa, Missouri, Kentucky and Tennessee to before emptying into the Mississippi River Delta at the Gulf of Mexico.

According to Audubon, nearly half of the bird species and up to forty percent of the waterfowl of North America spend part of their lives in the Mississippi Flyway. With spectacular forests, grasslands and wetlands, the route provides good sources of food and water, with no mountainous areas to navigate along the entire route. The greatest elevation above sea level along the route is below 2,000 feet. The route is used by large numbers of geese, ducks, shorebirds, sparrows, blackbirds, thrushes and warblers, the majority of which cut across the Gulf of Mexico, providing excellent birding opportunities along the coasts of Louisiana and Texas.

Unfortunately, years of exploitation of natural resources by man has taken its toll on the environment, with waterways being diverted for irrigation having an impact on the habitat that birds and other wildlife rely on. A combination of dams, locks and levees have reduced the Mississippi to less than ten percent of its original floodplain with an estimated nineteen square miles of delta wetlands disappearing annually. Thanks to the efforts of Audubon, which has offices in Minnesota, Indiana, Ohio, Missouri, Arkansas, Louisiana and Mississippi, efforts to preserve habitats along the Mississippi Flyway are making a difference to the birds that make use of the route each year. Audubon is currently focusing intensive conservation efforts on twenty-seven bird species along the Mississippi Flyway, namely: Mottled Duck; Greater Prairie-Chicken; Brown Pelican; Little Blue Heron; Reddish Egret; Swallow-tailed Kite; Clapper Rail; Snowy Plover; Wilson’s Plover; Piping Plover; American Oystercatcher; Upland Sandpiper; Ruddy Turnstone; Red Knot; Sanderling; Western Sandpiper; Short-billed Dowitcher; Least Tern; Black Skimmer; Prothonotary Warbler; Swainson’s Warbler; Cerulean Warbler; Grasshopper Sparrow; Henslow’s Sparrow; Seaside Sparrow; Bobolink; and Eastern Meadowlark.

Godwit Days Spring Migration Bird Festival 2015

March 23, 2015 by  
Filed under Events

This celebration of the Marbled Godwit offers the opportunity to explore the spectacular Redwood Coast and observe a host of bird species and wildlife. The program includes, lectures, workshops, field trips and boat excursions with experienced and well-informed local guides. For more information on this popular event, which is celebrating its 20th anniversary, visit godwitdays.org

Dates: 15-21 April 2015
Venue: Arcata
State: California
Country: United States

Irruptive Migration of Bird Species

March 17, 2015 by  
Filed under Features

The main reason birds migrate is to ensure they have access to food all year round. For some bird species this may mean flying half way around the world, and their migration patterns are so predictable that birders arrange special events to welcome the weary travelers to their wintering ground, as well as to see them off when they depart. For centuries, farmers have looked to the departure and arrival of local birds as an indication of what the seasons hold, while mariners judged ocean currents and the nearness of land by the birds they encountered. Some migrating bird species are somewhat less predictable and these are referred to as irruptive migrants, with their migration habits being referred to as irruptive migration.

Some species may have a cycle of irruptive migration where they visit an area every two or four years and are therefore still predictable, while others are completely random. Reasons for irruptive migration are varied, but the most common cause is a lack of food in their normal wintering grounds. Birds that depend on birch, pine, spruce and maple seeds and catkins are known to irrupt when these trees produce poor crops. As their name suggests, crossbills have unique crossed bill-tips designed to pry conifer cones open and extract the seeds. They do not have the luxury of choosing an alternative food source and are obliged to find food they can access. As these seeds are also rodent food, if they fail to appear or produce an insufficient crop for demand, raptors may also leave the area in search of a more readily available food source.

Irrespective of what the motivating factors are for irrupting, it is virtually impossible to predict which species will irrupt in any given year and where they will migrate to, however the following species have been noted for regularly irrupting: pine siskins, bohemian waxwings, boreal chickadees, evening grosbeaks, purple finches, pine grosbeaks, common redpolls, red crossbills, white-winged crossbills, northern shrikes, hoary redpolls, red-breasted nuthatches, snowy owls, great grey owls and rough-legged hawks.

While birders generally welcome seeing unfamiliar birds at their backyard feeders, they should be aware that sometimes the unexpected visitors, particularly if they arrive in great numbers, can intimidate the locals in their quest for food. This can be overcome by setting out extra feeders and spacing them as far apart as possible. Also ensure that plenty of water is provided and water sources are cleaned regularly. Then sit back, relax, and enjoy the sight of feathered friends from far away.

Southeastern American Kestrel in Louisiana

March 7, 2015 by  
Filed under Features

The American Kestrel (Falco sparverius) is the smallest member of the family Falconidae in North America. The American Kestrel can be identified by two distinct black streaks on each side of the head that contrast with the white throat and cheeks, and by a blue-gray patch encircling a rufous-colored spot on the top of the head. The males have a prominent rufous coloration on the back and tail. The Southeastern American Kestrel (F.s. paulus), which is one of two subspecies that occurs in the United States, is a local resident of Louisiana. It is approximately the size of a robin, and the female is larger than the male. The Southeastern American Kestrel (SAK) is often seen during the winter months in Louisiana perched on telephone lines located along fields and pastures.

The resident SAK is often confused during the winter with the migratory subspecies F.s. sparverius, although the resident species is smaller. The mean body mass of the SAK is approximately 22 percent lower in males and 26 percent lower in females, as compared to the migratory subspecies. It is very difficult to distinguish the two subspecies in the field. F.s. sparverius may look chunkier, but it takes someone who has spent long hours in the field watching kestrels to determine the difference between the two subspecies.

SAKs form strong pair bonds that tend to remain permanent. Displaying high site fidelity, pairs often remain on or near their nesting territories. SAK territories can range in size from 300 to 700 acres. In Louisiana, the SAK prefers open, park-like pine forest and open areas with scattered mature trees, which are needed for perch and nest sites. It is important that forest stands do not have a dense understory. The SAK prefers the same type of habitat preferred by the endangered Red-cockaded Woodpecker (RCW).

The SAK begins breeding courtship in late winter. The courtship includes aerial displays in which the male performs dives and a flutter-glide to advertise to the female. The SAK nests in cavities located in snags or living trees, usually excavated by woodpeckers. The Pileated Woodpecker often plays on important role in creating cavities suitable for nesting SAKs by enlarging the cavities of smaller woodpecker species. The SAK will also use nest boxes, when they are placed in suitable habitat. On Fort Polk, we usually find our first eggs in early April, and a full clutch usually consists of four to five eggs. The incubation period lasts 29 to 30 days. The young will fledge around the age of 30 days. The adults and young will forage together until dispersal, which occurs in the fall.

The SAK hunts from a perch, on the wing, and hovering. It is a generalized predator, feedings on rodents, insects, reptiles, amphibians, and small birds. The favorite food items on Fort Polk are lizards, including anoles, fence lizards, and skinks.

The U.S. Fish and Wildlife Service formerly considered the SAK a candidate subspecies for listing as threatened or endangered. It is no longer being considered a candidate for listing, but is considered a species of concern. The SAK is listed as threatened in Florida by the state’s game and fish commission. The SAK is a nonmigratory resident of the gulf coast states, now very rare over much of its former range. Current range includes east Texas, Florida, Louisiana, and the southern portions of the states of Mississippi, Alabama, South Carolina, and Georgia. The ranges of the two subspecies overlap during the winter.

Habitat loss is the main factor in the population decline of SAK in parts of its range. Industrial forest lands provide open areas important for the SAK, but they do not provide mature trees for nests sites. When the timber matures, the timber stand is usually too dense to be suitable for the SAK. Lack of prescribed fire is also detrimental to the SAK, because it prefers open, park-like forest stands kept open by regular prescribed burning. Prescribed burning and placing nest boxes in suitable habitat are the quick and feasible ways to improve SAK habitat.

Contributed by: Kenneth Moore

Also by Kenneth Moore: Southeastern Kestrel Management on Fort Polk

Great Louisiana BirdFest 2015

March 5, 2015 by  
Filed under Events

Taking place on 10-12 April 2015, the 19th Great Louisiana Birdfest is sponsored by the Northlake Nature Center offering birding enthusiasts the opportunity to enjoy the spring migration when large numbers of migrant birds of a variety of species pass through the area heading north from South America and Mexico. The program includes birding trips, photo workshops and socializing with like-minded people. Visit www.northlakenature.org for more information.

Date: April 10-12, 2015
Venue: Northlake Nature Center
City: Mandeville
State: Louisiana
Country: United States

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