Richard Rathe<p><span class="h-card" translate="no"><a href="https://mastodon.social/@JKrotkov" class="u-url mention" rel="nofollow noopener noreferrer" target="_blank">@<span>JKrotkov</span></a></span> </p><p>It is interesting that this is *not* mentioned on the allaboutbirds site as far as I can tell?!</p><p>One mention I can find on the related ebird.org is "Gray body, sometimes with intense rusty staining."</p><p><Staining> implies external pigment.</p><p>I cannot vouch for the org, but this site has a very detailed write-up...</p><p><a href="https://enviroliteracy.org/why-do-sandhill-cranes-preen-with-mud/" rel="nofollow noopener noreferrer" translate="no" target="_blank"><span class="invisible">https://</span><span class="ellipsis">enviroliteracy.org/why-do-sand</span><span class="invisible">hill-cranes-preen-with-mud/</span></a></p><p><a href="https://c.im/tags/Birds" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>Birds</span></a> <a href="https://c.im/tags/SandhillCranes" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>SandhillCranes</span></a> <a href="https://c.im/tags/Mud" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>Mud</span></a> <a href="https://c.im/tags/Behavior" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>Behavior</span></a></p>