<?xml version='1.0' encoding='utf-8'?>
<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>J.M. Eadie</dc:contributor>
  <dc:contributor>D.L. Loughman</dc:contributor>
  <dc:contributor>G.S. Yarris</dc:contributor>
  <dc:contributor>M.R. McLandress</dc:contributor>
  <dc:creator>Joshua T. Ackerman</dc:creator>
  <dc:date>2003</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Nest&amp;nbsp;&lt;/span&gt;depredation&lt;span&gt;&amp;nbsp;is the foremost cause of reproductive failure in waterfowl. Management strategies typically have focused on reducing predator contact with nests, yet the late of nests after predators have found them has received little attention. Although nest&amp;nbsp;&lt;/span&gt;depredation&lt;span&gt;&amp;nbsp;can result in complete&amp;nbsp;&lt;/span&gt;clutch&lt;span&gt;&amp;nbsp;loss, nests often are only partially depredated and the remaining&amp;nbsp;&lt;/span&gt;clutch&lt;span&gt;&amp;nbsp;may be successful. We investigated the prevalence of&amp;nbsp;&lt;/span&gt;partial&lt;span&gt;&amp;nbsp;&lt;/span&gt;clutch&lt;span&gt;&amp;nbsp;&lt;/span&gt;depredation&lt;span&gt;&amp;nbsp;in dabbling ducks and assessed its&amp;nbsp;&lt;/span&gt;influence&lt;span&gt;&amp;nbsp;on&amp;nbsp;&lt;/span&gt;duckling&lt;span&gt;&amp;nbsp;&lt;/span&gt;production&lt;span&gt;&amp;nbsp;in the Suisun Marsh of California, USA, from 1998 to 2000.&amp;nbsp;&lt;/span&gt;Partial&lt;span&gt;&amp;nbsp;&lt;/span&gt;clutch&lt;span&gt;&amp;nbsp;&lt;/span&gt;depredation&lt;span&gt;&amp;nbsp;by predators was common in all duck species and in all years. Overall, 37% of mallard (Anas platyrhynchos; n = 803), 37% of gadwall (A. strepera; n = 340), 22% of northern pintail (A. acuta; n = 46), 31% of cinnamon teal (A. cyanoptera; n = 16), and 1 of 2 northern shoveler nests (A. clypeata) were partially depredated. Of those nests experiencing a&amp;nbsp;&lt;/span&gt;depredation&lt;span&gt;&amp;nbsp;event, 53% of mallard and 50% of gadwall nests were only partially depredated rather than completely destroyed. As a result of&amp;nbsp;&lt;/span&gt;partial&lt;span&gt;&amp;nbsp;&lt;/span&gt;clutch&lt;span&gt;&amp;nbsp;&lt;/span&gt;depredation&lt;span&gt;, total&amp;nbsp;&lt;/span&gt;duckling&lt;span&gt;&amp;nbsp;&lt;/span&gt;production&lt;span&gt;&amp;nbsp;was reduced by 10% for mallards and 9% for gadwalls. The female's decision to stay with or abandon the reduced&amp;nbsp;&lt;/span&gt;clutch&lt;span&gt;&amp;nbsp;had an important&amp;nbsp;&lt;/span&gt;influence&lt;span&gt;&amp;nbsp;on nest success. Mallard and gadwall females abandoned the nesting attempt after&amp;nbsp;&lt;/span&gt;partial&lt;span&gt;&amp;nbsp;&lt;/span&gt;clutch&lt;span&gt;&amp;nbsp;&lt;/span&gt;depredation&lt;span&gt;&amp;nbsp;37% and 32% of the time, respectively. However, 27% of partially depredated mallard nests and 23% of partially depredated gadwall nests were successful. Egg success was 0.60±0.24 (mean±SD) for mallards and 0.53±0.23 for gadwall. From 1998 to 2000, 22% of mallard and 21% of gadwall ducklings produced in our study area carne from partially depredated nests. Although many duck nests experienced&amp;nbsp;&lt;/span&gt;partial&lt;span&gt;&amp;nbsp;&lt;/span&gt;clutch&lt;span&gt;&amp;nbsp;loss, they nevertheless contributed substantially to overall&amp;nbsp;&lt;/span&gt;duckling&lt;span&gt;&amp;nbsp;&lt;/span&gt;production&lt;span&gt;. Incorporating an estimate of egg success, in addition to nest success, may provide a more accurate assessment of waterfowl management strategies.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.2307/3802715</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Wildlife Society</dc:publisher>
  <dc:title>The influence of partial clutch depredation on duckling production</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>