Breeding in the Canadian Artic and wintering in Argentina and Chile, red knots undertake an epic migration journey of around 9,300 miles (15,000 km) twice every year. In order to complete the voyage successfully, red knots (Calidris canutus) require top quality food sources, and previously they have found this in abundance in the shape of horseshoe crab eggs in Delaware Bay. However, it’s been noted that red knot numbers have declined drastically since the turn of the century, with one of the main reasons being the decline in horseshoe crabs that have been harvested for commercial gain. Without sufficient fuel, these medium-sized shorebirds may not make it back to their Arctic breeding grounds, or if they do, they may be too weak to breed successfully, and considering that nearly 90 percent of the red knot population use Delaware Bay on their migration route, the lack of food could result in the species becoming endangered, or extinct.
Recognizing this problem, the US Fish and Wildlife Service (FWS) have proposed that red knots be classified as ‘threatened’ under the Endangered Species Act (ESA). Data reveals that there has been about a 75 percent decline in red knot numbers since the 1980s, with the rate of decline increasing sharply after the year 2000, coinciding with the decline in horseshoe crab populations. Red knots arrive at Delaware Bay just as horseshoe crabs arrive on the beaches to lay their eggs in shallow holes they dig in the sand. Each female lays up to 120,000 eggs in batches, which are then fertilized by the male that hitched a ride on her back to the beach. Shorebirds, including the red knot, eat many thousands of these protein rich eggs in the two week period before they hatch.
When red knots arrive at Delaware Bay, they are quite exhausted and emaciated. They need to rebuild their strength and stock up on fat reserves for the arduous journey ahead. As they feast on the eggs, they undergo a number of interesting physiological changes. As documented by the FWS, these include an increase in fat stores, and an increase in size of the chest (pectoral) muscles and heart, while the gizzard, stomach, intestines, liver and leg muscles of the birds decrease in size, all in preparation for the last leg of their migration.
While the decline of horseshoe crab eggs as a food source is a serious problem for red knots, it is not the only problem they face. The FWS notes that climate change is altering the terrain they breed in and impacting their diets on their home turf. Rising sea-levels and coastal development are other issues. But these are beyond the control of conservationists concerned with the plight of migratory birds. What can (and likely will) change is when harvesting of horseshoe crabs takes place, so that when the red knots arrive they have first choice of the horseshoe crabs’ eggs to fuel up for the last leg of their journey.
The Kachemak Bay Shorebird Festival will be celebrating its 20th Anniversary in 2012. Keynote speaker for the event will be Dr. George Archibald, who is the Senior Conservationist and Co-founder of the International Crane Foundation. Festival events will include backyard birding presentations, ornithology workshops, field trips, art events, boat tours and children’s activities.
Dates: 10 to 13 May 2012
Location: Kachemak Bay
Country: United States of America
Beginning this fall, and continuing through to 2014, rice farmers participating in the Migratory Bird Habitat Initiative (MBHI) will work with the Natural Resources Conservation Services (NRCS) of the US Department of Agriculture on a pilot project aimed at benefiting waterfowl and shorebirds by adapting certain rice production practices. Seventy farmers in Colusa and Glenn County, California, have signed contracts to support the MBHI in a project which is the culmination of many years of research and cooperation between rice farmers and conservationists, represented by Audubon California, PRBO Conservation Science, the NRCS and the California Rice Commission.
Speaking on behalf of the California Rice Commission, Paul Buttner noted that they have worked together in testing practices that appear to make a difference to the birds, while at the same time being acceptable to rice farmers. Under the new agreement, rice farmers will extend the time period that their fields are flooded, either starting earlier or draining the fields later, thereby accommodating the birds’ breeding and migratory needs. Also the depth of the water will be adjusted, specifically at agreed upon times in the season. NRCS Assist State Conservationist, Alan Forkey, explained that generally shorebirds and waterfowl prefer a habitat of between 2 and 6 inches deep, but rice fields are usually flooded deeper than that. This will be adjusted, and instead of draining the fields in January, farmers have agreed to keep them flooded for longer and drop the water levels more gradually.
To accommodate the nesting requirements of the birds, levees between fields will be modified, with sloped levees being flattened to provide a better nesting surface and allow easier access to the water for chicks. Some farmers have also agreed to provide artificial nesting structures. A number of the proposed changes will not only benefit the birds, but will be to the farmers’ benefit as well. For the farmers who have agreed to use portions of their fields as wetlands, incoming water will have the opportunity to warm up a bit before running on to the young rice plants which will be beneficial for them, plus longer periods of flooding the fields will help to degrade the rice plants after harvesting, making it easier to clear the fields.
The cooperation of farmers in implementing the pilot project has been very encouraging, and the Migratory Bird Conservation Partnership will be measuring the results of the MBHI with a view to extending the project to other areas of importance to migratory birds.
Whimbrel birds stand a height of 1.5 feet and are known to be migrating birds, referred to as long haul fliers, as they are able to travel distances of up to three thousand five hundred miles without resting in between and can maintain speeds of fifty miles per hour. Before they migrate they ready themselves by packing on weight, and will weigh approximately double their usual weight before migrating. What is truly amazing is a bird named Chinquapin that took on Hurricane Irene.
Chinquapin is a Whimbrel that was tagged with satellite tracking, enabling researchers and biologists, such as Fletcher Smith (College of William and Mary’s Centre for Conservation Biology), to track Chinquapin’s movements. Whimbrels are shorebirds but move to the high Arctic regions for breeding, with most birds remaining in Brazil during the winter months. To learn more about the migratory patterns of the whimbrels, tracking devices were fitted to a few birds.
Panic erupted as Chinquapin’s device transmitted that he was on a one way collision course with Hurricane Irene. As he entered the hurricane, his tracking device lost signal, leaving researchers expecting the worst and nervously watching their monitors to try and find him. Eventually his transmitter confirmed that he had made it through and was safely resting in the Bahamas. Smith said that it was incredible that some birds are able to increase their energy levels to fly through such horrific conditions. Even though Chinquapin survived, researchers are still no closer to finding out how he managed to survive.
Many birds are either thrown off course, or worst case scenario, killed, while trying to fly through these weather conditions, but it is not the first time for Chinquapin, who made the decision to fly around the 2010 Tropical Storm Colin. Another bird tried flying though the storm and was killed, while Chinquapin’s decision saved his life. Chinquapin is most definitely a very brave and special bird, and researchers will continue their efforts to track Whimbrels to learn more about them and their habits.
The 2011 Kachemak Bay Shorebird Festival has the theme “Wild Birds, Wild Places”. The keynote speaker for the event will be Carl Safina. Carl has a doctorate in Ecology from Rutgers University and has been studying the ocean for twenty-five years.
The Kachemak Bay Shorebird Festival began in 1993 when a number of Homer residents decided to create an event that would help to educate the public about weblands and shorebirds. Be sure to take part in this fantastic festival.
Date: 5-8 May 2011
Venue: Kachemak Bay
Country: United States of America