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Ambler, PA, United States

Tomkovich P.S.,Moscow State University | Porter R.R.,800 Quinard Court | Loktionov E.Y.,Moscow State Technical University | Niles L.J.,Conserve Wildlife Foundation of NJ
Wader Study Group Bulletin

Based on ring recoveries and observations of colour-marked individuals, we identify the non-breeding range, migration routes and staging areas used by Red Knots Calidris canutus of the subspecies rogersi from its southernmost sub-arctic breeding population in Chukotka, NE Asia. We also present the first three geolocator tracks of individual rogersi adult males. The non-breeding grounds of rogersi extend from New Zealand to NW Australia, with the majority going to the eastern part of this range (primarily New Zealand and E Australia). Three key staging areas for migrants are indicated by the geolocator data: (1) the NW Yellow Sea, (2) the western Sea of Okhotsk, north of the Amur River delta, and (3) the Gulf of Carpentaria, Australia. The Yellow Sea is extensively used during both north and south migration, whereas the other two sites are only used during south migration. The three birds with geolocators made round trips of 23,000–31,000 km. The two that went to New Zealand made direct flights of about 10,100 km from New Zealand to the NW Yellow Sea, the longest non-stop flight known for Red Knots to date. Mostly the flight paths taken by the three birds between stopovers were not further from the great circle route that the ca. 200 km margin of error associated with geolocator fixes. The only exception was that in most cases they appeared to fly south of the Kamchatka Peninsula when migrating between their breeding grounds and the Yellow Sea (four of five flight paths passed south around Kamchatka). © 2013, International Wader Study Group. All rights reserved. Source

Niles L.J.,Conserve Wildlife Foundation of NJ | Burger J.,Rutgers University | Porter R.R.,800 Quinard Court | Dey A.D.,Fish and Wildlife | And 4 more authors.
Wader Study Group Bulletin

Light-level geolocators were deployed on 37 Red Knots at Monomoy National Wildlife Refuge, Cape Cod, Massachusetts, United States in Sep 2009 and eight were recovered at the same place a year later. Two of the eight geolocators failed halfway through the year, but the other six provided a full year's record of the birds' locations. All eight birds carried out the whole of their large-feather molt at Monomoy, after which they moved south to wintering areas, leaving between 29 Oct and 16 Nov. Four birds wintered on the U.S. Atlantic coast between Virginia and Florida, while four wintered in the Caribbean in areas not previously identified as important for Red Knots. During northward migration all six knots with geolocators still working stopped in the vicinity of the Nelson River estuary in the south-west corner of Hudson Bay, a site not previously identified as an important stopover for Red Knots. Migration speed (defined as the speed achieved between one stopover and the next, assuming the bird travelled along the great circle route) differed significantly between flights affected by headwinds (median 47 kph), those that took place in calm conditions (60 kph) and those affected by tailwinds (72 kph). We discuss the implications of our results for the conservation of the threatened rufa Red Knot population and highlight the need to investigate some of the sites the birds visited. Source

Newstead D.J.,1305 N. Shoreline Blvd. | Niles L.J.,Conserve Wildlife Foundation of New Jersey | Porter R.R.,800 Quinard Court | Dey A.D.,Fish and Wildlife | And 2 more authors.
Wader Study Group Bulletin

Red Knots Calidris canutus are commonly observed along the Texas coast during fall and spring. Although some significant winter records have been reported in Texas, it was previously unknown if birds were using Texas as a wintering area or primarily as a stopover area en route to more southerly wintering destinations. We fitted 69 Red Knots with geolocators on Mustang and Padre Islands between fall 2009 and fall 2010, and recovered eight of them between fall 2010 and spring 2012. The data showed that these knots: 1) spent nearly the entire nonbreeding phase of their annual cycle (78.4%) in the north-west Gulf of Mexico, 2) used the Mid- Continent (or Central) Flyway as a migratory route on both north and southbound migrations, 3) used stopover sites in the Northern Great Plains of the United States and Canada as well as the Nelson River Delta/Hudson Bay area, and 4) exhibited stronger consistency in timing of northbound migratory movements than in southbound movements. For the two birds for which geolocator data included consecutive years of data, one showed consistency in northbound and southbound stopover location between years, while the other showed variability in northbound, but not southbound stopover locations. A geolocator recovered from a bird that was originally captured in the year in which it hatched showed that it also oversummered in Texas. The data further highlights the critical importance of the north-west Gulf of Mexico – particularly the Laguna Madre and Padre Island – for this population of Red Knots, and the need for further investigation to discover specific wintering sites. © 2013, International Wader Study Group. All rights reserved. Source

Burger J.,Rutgers University | Niles L.J.,Conserve Wildlife | Porter R.R.,800 Quinard Court | Dey A.D.,Endangered and Nongame Program
Wader Study Group Bulletin

Shorebirds that nest at low densities in the Arctic are difficult to study. Information on breeding phenology, incubation period, and incubation outcomes can aid an understanding of population dynamics, particularly for species whose populations are declining. We describe a technique for using data from light-archival geolocators placed on Red Knots Calidris canutus rufa to determine information about breeding, and report on the proportion of knots that reached Arctic breeding grounds, attempted incubation, and appeared to incubate to full term, as well as total time spent in the Arctic. We captured 19 knots that were fitted with geolocators in New Jersey, Massachusetts, Florida, Texas, and S Argentina, and reached Arctic breeding areas. The median arrival date in the Arctic was 10 June, the median departure date was 22 July, and the mean time in the Arctic was 44 ±2.3 days (range 28-65 days). Because of 24 hr sunlight in the Arctic summer, prolonged periods of a mainly dark signal indicate that the geolocator was not exposed to light, and we inferred that the bird was incubating. On the basis of this assumption, we found that 85% initiated incubation (N = 20), 65 % (N = 17) incubated for 18-24 days, and one incubated for 30 days. Geolocator output showed that knots rarely entered salt water while in the Arctic. All the knots for which we obtained data reached their Arctic breeding grounds and a high proportion incubated nests. Source

Burger J.,Rutgers University | Niles L.J.,Conserve Wildlife | Porter R.R.,800 Quinard Court | Dey A.D.,Endangered and Nongame Program | And 2 more authors.

Surveys and banding records of Calidris canutus rufa indicate that Red Knots migrate mainly north and south through Massachusetts, Delaware Bay, and Virginia, and winter in Florida and South America. We fitted 40 adult Red Knots with geolocators at Monomoy National Wildlife Refuge, Massachusetts, during fall migration (2009), and in this paper report on the locations of migration and wintering along the Atlantic coast of the United States of eight recaptured knots. The knots' migration patterns varied: four birds wintered along the U.S. Atlantic coast, and the rest went to the Caribbean islands or the northern edge of South America. Knots spent 58 to 75 days in Monomoy Refuge before migrating south in November. Seven of the eight stopped along the U.S. Atlantic coast for relatively long periods. For the six with complete yearly cycles, the total time spent along the Atlantic coast averaged 218 days (range 121-269 days). All eight knots crossed the Atlantic outer continental shelf from two to six times. Areas of use were Monomoy, Long Island, New Jersey, Maryland, the Outer Banks of North Carolina, South Carolina, and Florida. These data indicate that Red Knots moving through Massachusetts in the fall had variable migration patterns, spent considerable periods of their life cycle along the Atlantic coast, and each knot followed a separate and distinct path, which suggests that knots can be at risk along the Atlantic coast for a substantial period of their life cycle. © The Cooper Ornithological Society 2012. Source

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