Sunday, December 16, 2012

The Razorbill Invasion of Florida



                     A Razorbill on a North Sea outcropping.  Photo from Orca's Weblog

Every so often and for whatever ecological reason, populations of some birds irrupt. Actually the population does not irrupt; birds in the population irrupt.  When they irrupt, birds leave their usual range and move to different areas usually seeking food.  Some of these irruptions are cyclical and can almost be predicted on a calendar. Others are more random occurring irregularly every few years.  Still others may have never occurred before in recent times.

The highly predictable 10-year cycle of Ruffed Grouse is one example.  This cycle has been researched for as long as people have known about Ruffed Grouse and entire books have been written on the subject.  Their numbers build and build and suddenly when numbers are at their apex the numbers of individuals in the population collapses.  Reasons for the collapse can be legion. With Ruffed Grouse there are generally two factors at work.  One is the spread of disease among densely packed animals.  The other is not enough food (especially catkins which are essential winter food) available to support the burgeoning population.  Ruffed Grouse literally eat themselves out of house and home and when they do their population crashes.

Snowy Owls also function on a nearly predictable cycle.  Theirs is a four-year cycle that closely mimics the ups and downs of numbers of North American Brown Lemmings, a major food item for Snowy Owls.  Lots of lemmings results in more young owls surviving and that means that the owl population can increase.  A sudden drop in the lemming population means that Snowy Owls suddenly have to search anywhere and everywhere for food.  In these situations the owls leave the High Arctic and pour south in large numbers looking for food.  Occasionally they have been recorded as far south as Alabama and Florida when food resources are scarce in their normal range.

For other bird species the irruptions are not as predictable but they are still based on the availability of food.  Red-breasted Nuthatch is one example. Some years in my native northern Wisconsin you are hard pressed to see or hear even a single Red-breasted Nuthatch all winter long.  Other years you almost need a shovel to clear them out of your way.  Results of a Christmas Bird Count I used to conduct in Barron County Wisconsin are illustrative.  From 1972 through 1975 we recorded one single Red-breasted Nuthatch in the Cedar Lake Christmas Bird Count circle.  That was an average of 0.25 Red-breasted Nuthatches per year.  However in 1976 there was a massive failure of the cone crop among spruce trees in the boreal forest and Red-breasted Nuthatches swarmed south.  That year we recorded 139 Red-breasted Nuthatches in our count circle.  In 1977 and 1978 there were none.

During the fall and winter of 1977 – 1978 there was a huge incursion of Common Redpoll and Purple Finch in northern Wisconsin.  My former wife and I surmised that we had at least 20 Common Redpoll’s and 7 or 8 Purple Finches at our backyard bird feeders that winter.  We put up mist nets to capture and band the birds and by the end of March 1978 we had banded more than 3,000 Common Redpolls and more than 1,000 Purple Finch.  The following year we did not see a single individual of either species.  It was likely all food related. 

The same phenomenon is occurring in the 2012-2013 fall/winter in Florida and Razorbill is grabbing the birding headlines.  This Arctic-nesting seabird, a relative of the extinct Great Auk and the common and often comical Atlantic Puffin, generally nests on rocky islands and inaccessible promontories from easternmost Maine north to the High Arctic of Canada.  They are generally associated with cold water throughout the year where they eat a variety of marine life including fish and crustaceans.  In most years they rarely migrate south of New York/New Jersey in winter.  The first one I ever saw was on the coast of New Hampshire on November 22, 1984.  The furthest south I had ever seen a Razorbill was on the coast of Delaware on March 1, 1995.  That was until this year.

The first indication of an impending invasion happened two weeks ago when a single Razorbill was taken to a rehabilitation center on Florida’s east coast.  Soon another one showed up and then someone found a healthy bird floating around near Ponce Inlet in Volusia County.  That seemed to be the opening of the flood gates and now Razorbills are being seen in sizeable numbers as far south as Fort Myers and Miami.  Someone recently went offshore from Miami and reported multiple flocks of 150 to 200 individual Razorbills.  This is totally unheard of this far south.

Last week I made a day trip to Palm Beach County to look for a Razorbill that had been observed there.  I wanted to get it for my Florida state list and add it to my meager Palm Beach County list.  I did not have to work hard and easily found the bird.  The following day I received an email from the local bird sighting group with the astonishing news that a Razorbill was just seen that morning on Anna Maria Island west of Bradenton about 25 minutes from my dining room table.  What made this news astonishing was that the bird was on the Gulf side of the state meaning that it likely flew across the peninsula to get here.  Given this species’ breeding range, you would expect them on the Atlantic Coast.  However to get to the Gulf side took real effort.

A quick check of the Avisys database reveals that there are no records of Razorbill from Alabama, Louisiana, Mississippi or Texas.  Thus unless there had been Razorbills somewhere on the Gulf Coast of Florida in past years, this bird was likely the first one ever seen on the Gulf of Mexico!

Surprised by its presence and always looking for a new bird for my Manatee County list, I flew out the door headed for Anna Maria Island.  Enroute I called my friend Sue Paschall, a fledgling birder from Bradenton and picked her up on the way to the island.  This would be a life bird for Sue and an entirely new bird family she had never seen before.

We drove to Longboat Pass and walked the seawall toward the bridge.  Someone there pointed us toward the bird as it floated in the water maybe five feet from shore.  We walked up to the bird and were so close we could see it blink its eyes.  It was actively hunting for food with its face submerged beneath the water's surface.  Occasionally it would dive giving us great views of it “flying” underwater.  Sue made a comment about it acting like a penguin which was a very astute observation because its behavior was very much like the Humboldt Penguins I have watched foraging off the coasts of Chile and Peru.


 The Manatee County Razorbill photographed off Anna Maria Island by Claire Herzog   Image used with Claire's permission.

We watched the bird for maybe ten minutes and then left it still actively foraging along the shore.  In my haste to get to the island I failed to bring along my camera.  This picture, of the same individual, was taken the following day by local enthusiastic birder Claire Herzog.  Coincidentally the bridge over Longboat Pass plays an important role in my new novel "Minor League Heckler."  However you will have to buy the book to find out why and how.

Since the Anna Maria Island bird there have been additional Gulf Coast observations in Florida including one at Fort DeSoto Park in Pinellas County, the Venice jetty in southernmost Sarasota County, Stump Pass Beach State Park in Charlotte County, and Bunchie Beach near Fort Myers in Lee County.  At one point it was possible to keep track of how many Razorbill’s had been seen in Florida.  Now the number is out of control and is anyone’s guess.

Adding to the excitement, on Friday someone found a Thick-billed Murre at Fort Clinch State Park in northernmost Nassau County.  The curious thing about Thick-billed Murre is that their normal range is at a latitude even higher than the Razorbill.  Something clearly has happened to the food resource further north to bring so many Arctic seabirds down to the subtropics. 

Someone recently posted a comment on the Florida bird list serve pondering whether the invasion was related to the failure of nesting habitat or if something had happened to the nesting habitat.  That seems highly unlikely given the rocky areas they nest in on remote uninhabited islands and the even more remote sea stacks and cliff faces in Arctic Canada.  No doubt what happened is that some important item or items in the natural prey base of Razorbill has crashed.  It must be just one or two prey species because we have not witnessed a huge increase in numbers of Northern Gannet, or Red-throated Loon or even Common Loon; all species from a similar winter habitat and prey item suite.  Just like with the Red-breasted Nuthatches back in northern Wisconsin the abundance and presence of some food tem fell off the charts and the Razorbill’s have headed south

Now I am wondering if this invasion extends to the West Indies.  There are no records of Razorbill from any country in the West Indies including both Cuba and the Bahama Islands.  With 519 species on my West Indies list it has become increasingly difficult to get a new bird for that list.  My hunch, given the large numbers of Razorbill offshore from Miami and all the birds that have been found in Palm Beach County, is that there are at least a few Razorbill’s somewhere in Bahamian waters.  If Razorbill’s turn up in Key West then the question becomes – will they make the 90 mile hop over to Cuba since they are in the neighborhood?

Oh to be back again sitting on the beach of North Bimini with my spotting scope pointed toward the open ocean.  Now that I mentioned it I think I’m going to call an airline to see if they have any space available on the next flight to Bimini.  I can’t think of a better Christmas present for myself than looking for and maybe finding in the West Indies an Arctic seabird that just like me, had its fill of the cold and headed south to the subtropics.  If they are wise the Razorbill’s, like me, won’t go back.

4 comments:

  1. This Razorbill invasion is out of control. 'Hundreds' seen today off the Atlantic coast of Florida.

    ReplyDelete
  2. I saw one off the coast of South Palm Beach yesterday morning. I thought it was a penguin.

    ReplyDelete
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