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.
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.
This Razorbill invasion is out of control. 'Hundreds' seen today off the Atlantic coast of Florida.
ReplyDeleteI saw one off the coast of South Palm Beach yesterday morning. I thought it was a penguin.
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