And The Action Continues...

That's right. We didn't stop after the Santa Fe fieldtrip. Instead, we headed south to the Azuero Peninsula and stayed in the town of Pedasí (hometown of the first woman president of Panama). We wake up early on monday morning and meet our captain at El Ciruelo port (with an adult Bare-throated Tiger-Heron close to the beach). Our destination: the Frailes islands and its colony of seabirds. The last time I visited the islands, there were no terns on it (you can read a narrative of that trip here). The only other occasion I visited the islands was more than ten years ago and back then I did not notice any Sooty Tern, despite the fact that the islands were full of breeding birds (maybe simply I was unable to separate them from the Bridled Terns). This time I was prepared and, after reading some fieldguides and seeing many plates, I printed in my mind the following differences to look in the Sooties:

1. Heavier look with broader wings

2. Less white in the underwing
3. Less contrast between crown and mantle

4. Lack of complete white nape collar

5. Bigger white forehead patch not extending behind the eye

Maybe you can pick apart the Sooty Tern from these pics:

As you can see, we saw both of them, the Bridleds being commoner, and the Sooties restricted to south Frailes Islands, where we noticed another thing: the low pitched voice of the Sooties, quite different from the high nasal calls of the Bridleds. Other birds seen breeding in the islands were the Brown Noddies (the commonest) and the Brown and Blue-footed Boobies. There were also Brown Pelicans and Magnificent Frigatebirds, but none seemed to be breeding in the islands. On the way back, between Frailes north and south, we saw a lonely Galapagos Shearwater close to the boat. The sea and the clouds cooperated and gave us a calm return to mainland, where we prepared ourselves for the next journey.