On July 11th, Darwin was on deck (somewhat reluctantly) watching marine life:
“The day has passed in listless discomfort.— if I had been well several things would have interested me during these latter days.— The vessel has been followed by many sorts of Petrels.—a very elegant one, the Cape-pidgeon, we met as is generally the case on passing the Tropic.— Several Whales have been seen.— I just had a peep at one, but to my jaundiced eyes, it even possessed little interest.” (July 11)
Petrels (which include three taxonomic families) make up most of the species in the order Procellariiforms (the “storm birds”). One additional family belongs to this order (and is therefore closely related to petrels) – the albatrosses. Most petrels and albatrosses are pelagic – staying out at sea for most of their lives and only coming back to their island colonies to breed and raise young.
The Procellariiforms have a few unique features – all of which seem to focus on their nose. They all have (1) a “tubular nasal passage” that allows them to smell, and (2) a nasal gland that allows them to excrete excess salt through the nose (since they drink seawater). As adaptations go – how cool is that? Imagine if we could do that – it would mean no more water shortages!
David Attenborough – one of the great modern naturalists and a personal hero – calling and interacting with Providence Petrels (from the BBC):
Petrels come in several varieties, including the fulmarine petrels (which includes the Cape Petrel mentioned by Darwin), the prions, shearwaters, storm petrels and diving petrels (all in all, about 100 species). They have a wide range of sizes, are distributed around the world (though seem to be more dominant in the Southern Hemisphere) and tend to be found in shades of black and white (probably a form of camouflage).
Earlier I wrote about storm petrels, or as Darwin called them – Mother Carey’s Chickens. Here are a few other species:
Common Diving Petrels by John Gould:
Cape Petrel (from Wikipedia Commons):
Giant Petrel – which can have a 2-meter wingspan (from Wikipedia Commons)
Studies suggest that the Procellariiforms are an ancient order (as birds go). Fossils have been found that go back roughly 60 million years, and DNA evidence suggest that they go back to the late Mesozoic Era – making them contemporary with their “dinosaur ancestors”.
However old they might be, and no mater how many past catastrophes they may have survived, petrels are now being decimated by human activities. Because of the vulnerability of their nesting sites to introduced predators, and the impact of fishing (getting caught in nets) and marine pollution (floating plastic, for example)on adult birds, petrels and albatrosses are some of the most endangered sea birds on the planet. So much so, in fact, that the international community signed an agreement designed specifically to protect these birds – the Agreement on the Conservation of Albatrosses and Petrels (visit the official website of the agreement for more details).
At this time, the following countries have signed the agreement – Argentina, Australia, Brazil, Chile, Ecuador, France, New Zealand, Norway, Peru South Africa, Spain United Kingdom and Uruguay. Look at that list carefully – it includes every single country visited by Darwin’s on the voyage (except for a few small island nations). Interestingly, there are only two countries on this list that Darwin did not visit (directly or as a colony) – coincidence? And fancy that – the United States has not signed. This does not surprise me but sometimes it makes me so ashamed… (RJV)