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<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>W.A. Link</dc:contributor>
  <dc:contributor>P.C. Osenton</dc:contributor>
  <dc:contributor>Daniel B. Carter</dc:contributor>
  <dc:contributor>R.G. Weber</dc:contributor>
  <dc:contributor>N.A. Clark</dc:contributor>
  <dc:contributor>M.A. Teece</dc:contributor>
  <dc:contributor>D.S. Mizrahi</dc:contributor>
  <dc:creator>G.M. Haramis</dc:creator>
  <dc:date>2007</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;We used stable isotope (SI) methods in combination with pen feeding trials to determine the importance of eggs of the Atlantic horseshoe crab&amp;nbsp;&lt;/span&gt;&lt;i&gt;Limulus polyphemus&lt;/i&gt;&lt;span&gt;&amp;nbsp;to migratory fattening of red knots&amp;nbsp;&lt;/span&gt;&lt;i&gt;Calidris canutus rufa&lt;/i&gt;&lt;span&gt;&amp;nbsp;and ruddy turnstones&amp;nbsp;&lt;/span&gt;&lt;i&gt;Arenaria interpres morinella&lt;/i&gt;&lt;span&gt;&amp;nbsp;during spring stopover in Delaware Bay. By manifesting measurable fractionation (ca +3‰) and rapid turnover, blood plasma δ&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;&amp;nbsp;nitrogen proved a functional marker for SI diet tracking during the short 3-week stopover. Blood samples from free-ranging knots (3 data sets) and turnstones (1 data set) produced similar convergence of plasma δ&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;N signatures with increasing body mass that indicated highly similar diets. Asymptotes deviated slightly (0.3‰ to 0.7‰) from that of captive shorebirds fed a diet of only crab eggs during stopover, thus confirming a strong crab egg-shorebird linkage. The plasma δ&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;N crab-egg diet asymptote was enriched ca +4.5‰ and therefore readily discriminated from that of either blue mussels&amp;nbsp;&lt;/span&gt;&lt;i&gt;Mytilus edulis&lt;/i&gt;&lt;span&gt;&amp;nbsp;or coquina clams&amp;nbsp;&lt;/span&gt;&lt;i&gt;Donax variabilis&lt;/i&gt;&lt;span&gt;, the most likely alternative prey of knots in Delaware Bay. Crab eggs were highly palatable to captive knots and turnstones which achieved rates of mass gain (3–11 g/d) comparable to that of free-ranging birds. Peak consumption rates during hyperphagic events were 23,940 and 19,360 eggs/bird/d, respectively. The empirical conversions of eggs consumed to body mass gained (5,017 eggs/g for knots and 4,320 eggs/g for turnstones) indicate the large quantities of crab eggs required for the maintenance of these shorebird populations during stopover.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1111/j.0908-8857.2007.03898.x</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Wiley Online</dc:publisher>
  <dc:title>Stable isotope and pen feeding trial studies confirm the value of horseshoe crab Limulus polyphemus eggs to spring migrant shorebirds in Delaware Bay</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>