i got a word of advice recently from an experienced new york city birder: don’t take razorbills for granted.
you see, these seabirds have become a regular winter sight across the northeast. a midwinter visit to the rockaway peninsula or coney island usually nets a handful, if not dozens of razorbills flying around and fishing in the harbor. some birds have snuck up into the protected waters of jamaica bay, gravesend bay, and even sheepshead bay. but new york city razorbills are a newish and irregular thing — and might not be a thing forever, thanks to a mysterious correlation between razorbills and the north atlantic climate.
first, let’s start with the real reason i wanted to write this blog, which is to tell you about the goth puffin, a nickname i think i first heard from purbita saha. razorbills are tubby, white-bellied, black-backed birds that inhabit frigid waters, and in the summer their black head features a snazzy white trim that gives them a siouxsie sioux-meets-cyclops kinda look. they’re adept swimmers, using their wings to fly underwater and pursue schooling fish, which they snatch up with their namesake flat black beaks.
their similarity to puffins is no coincidence: they’re part of the same family, the alcids. plus, they’re the closest living relative of the great auk, the legendary north atlantic seabird which went extinct in the 19th century and whose folk name, the penguin, is the source of the unrelated southern hemisphere penguin’s name. read this post about the great auk’s extinction if you’re trying to get into a misanthropic kind of mood. you should also know that razorbills do little synchronized swimming routines when they arrive at their breeding colonies. so it’s a real treat that i can take the subway to see them.
ok, thanks for indulging me. anyway, razorbills were rarely, if ever observed in waters off the northeastern united states from 1970 to 1990, according to a study from the us department of the interior’s bureau of ocean energy management. numbers have steadily increased since then, but even so, it’s still irregular which years have razorbills and which don’t. a peculiar north atlantic climate phenomenon, called the north atlantic oscillation or nao, could be helping to drive that pattern.
the nao is kinda like the atlantic version of the el niño southern oscillation, but el niño is a climate phase based around water, while the nao is based around differences in the pressure of different air masses. the nao is a measure of the pressure difference between a persisting low-pressure air mass over iceland and a high-pressure air mass over the azores. when there are big differences in the pressure, we say there’s a positive nao index, while small differences mean a negative nao index. positive and negative phases each bring different kinds of weather patterns across the atlantic. the nao can affect everything from the wind and temperature to hurricane tracks to animal populations and more, and has even been blamed as a partial culprit behind an 18th-century drought on the tibetan plateau.
the nao should be of interest to razorbill-loving new yorkers, too. a 2015 paper by dick veit and lisa manne at the college of staten island analyzed 58 years of data taken in massachusetts from 1954 to 2011, tracking six species of north atlantic auks: common murres, thick-billed murres, dovekies, atlantic puffins, black guillemots, and of course, razorbills. the paper found that in the case of all six species, their winter abundance in massachusetts was correlated in some way with the nao index.
this blog is about razorbills, so i’ll just focus on the razorbill part. on the long-term scale, the razorbill increase is correlated with a general positive shift in the nao since the study started. on the short term, razorbills showed up in massachusetts in larger numbers on average during the year after a year with a higher nao index, and in lower numbers on average during the year following a year with a lower nao index. it’s my assumption that years with lots of razorbills in massachussetts would send birds even further south, too, like to nyc.
correlations are cool, but trying to disentangle the broader story is a little harder. the authors suggest that the nao is indirectly responsible for changing prey abundance due to changing sea temperatures, sending razorbills looking for food elsewhere. the nao would also help drive the overall increase in razorbills wintering in massachusetts as it tends toward more positive indices on average.
but correlation isn’t causation, and there are plenty of other factors that could be driving wintering razorbills southward. most notably, the north atlantic herring population collapsed from overfishing, and a different fish, the sand lance, took the herring’s place. sand lance is now the fish razorbills wintering eat most, and they’ll follow sand lance southward if they need to. also, while razorbill populations are quickly declining in iceland and europe, their breeding population has increased on the north american side of the atlantic, which might be responsible for more birds south of the usual range. perhaps the nao has something to do with those factors, too.
what all this means for the future of razorbills in new york city is anyone’s guess. but given that we live in a world whose climate and ecology is rapidly changing on account of human behavior, it makes me wonder what will happen to a climate-sensitive bird like the razorbill. what impact will climate change have on razorbill colonies? will we continue seeing wintering razorbills in nyc as things warm up? what effect will climate change have on the nao index? am i even asking the right questions as someone without a biology degree who’s just blogging about an old paper for fun?
anyway, this is just another cool reason to bear the uncomfortable new york city winter by the coast, staring into the bright sun reflecting off of the water while the wind buffets your back and chills your fingertips and toes beyond the warming abilities of your gloves and boots, all with the hopes of seeing a goth puffin. these razorbills loafing around the harbor are a local manifestation of earth-spanning climatic forces, and i think that’s pretty neat. and while the razorbills may be around now, you never know where they’ll go next year.
postscript
i’m back baby! sorry it’s been a while, i was busy and/or away and/or couldn’t think of anything to write about. but i went on a boat ride into the atlantic last weekend and saw lots of razorbills. that was nice. i also saw razorbills during the new york ornithological association’s winter waterfowl count on monday, where i annually lead a section along the beach in coney island. i was once scolded for asking why razorbills aren’t one of the count’s focus species when a bunch of other non-ducks are on the list, and the count coordinator said something like, this is a census of waterfowl, not a day out looking for rare birds. i guess the coordinator thought there was still a negative nao index.
i’m going to ecuador next week(!), so it’ll be a while before my next post. here’s a great black-backed gull to keep you occupied.
