1.0Swiss Ornithological Institutehttps://www.vogelwarte.ch/en/rich600338<blockquote class="wp-embedded-content" data-secret="MxxomvM0lK"><a href="https://www.vogelwarte.ch/en/birds-of-switzerland/caspian-tern/">Caspian Tern</a></blockquote><iframe sandbox="allow-scripts" security="restricted" src="https://www.vogelwarte.ch/en/birds-of-switzerland/caspian-tern/embed/#?secret=MxxomvM0lK" width="600" height="338" title="“Caspian Tern” — Swiss Ornithological Institute" data-secret="MxxomvM0lK" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" class="wp-embedded-content"></iframe><script> /*! This file is auto-generated */ !function(d,l){"use strict";l.querySelector&&d.addEventListener&&"undefined"!=typeof URL&&(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&&!/[^a-zA-Z0-9]/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret="'+t.secret+'"]'),o=l.querySelectorAll('blockquote[data-secret="'+t.secret+'"]'),c=new RegExp("^https?:$","i"),i=0;i<o.length;i++)o[i].style.display="none";for(i=0;i<a.length;i++)s=a[i],e.source===s.contentWindow&&(s.removeAttribute("style"),"height"===t.message?(1e3<(r=parseInt(t.value,10))?r=1e3:~~r<200&&(r=200),s.height=r):"link"===t.message&&(r=new URL(s.getAttribute("src")),n=new URL(t.value),c.test(n.protocol))&&n.host===r.host&&l.activeElement===s&&(d.top.location.href=t.value))}},d.addEventListener("message",d.wp.receiveEmbedMessage,!1),l.addEventListener("DOMContentLoaded",function(){for(var e,t,s=l.querySelectorAll("iframe.wp-embedded-content"),r=0;r<s.length;r++)(t=(e=s[r]).getAttribute("data-secret"))||(t=Math.random().toString(36).substring(2,12),e.src+="#?secret="+t,e.setAttribute("data-secret",t)),e.contentWindow.postMessage({message:"ready",secret:t},"*")},!1)))}(window,document); //# sourceURL=https://www.vogelwarte.ch/wp-includes/js/wp-embed.min.js </script> https://www.vogelwarte.ch/wp-content/uploads/2026/03/2740_1.jpg16001200The Caspian Tern is the largest tern: its wingspan exceeds that of the Mew Gull and its very large red bill is almost as long as the Yellow-legged Gull’s. On its way from the West African wintering areas to the breeding sites on the Baltic Sea, the Caspian Tern migrates through European inland areas sometimes following rivers. Arriving birds often announce themselves with their loud heron-like calls that sound like sheet metal being pulled over a rough concrete floor.