Rainbow of gulls

2 08 2012

If you’ve been following our blog since we started last year, you’ll notice the gulls are getting more colourful as we go.  In order to help keep species and populations distinct, banding and wing-tagging efforts have adopted unique colour combinations for each species and region so that a gull’s banding location can be known even when the letter codes aren’t discernible.  So far on Sable we’ve put three colours in use including PINK for Herring Gulls TURQUOISE for winter banded Great Black-backed Gulls, and YELLOW/LIMEGREEN for summer banded Great Black-backed Gulls.  Check out some sample pictures below.

A colleague of mine working up in Newfoundland has added one more shade to the gull rainbow.  He’s using a BEIGE wing-tag with black letters  Here’s a little message from Alex who would appreciate your reports if you see any of these gulls too.

As part of a larger study, we put wing tags on 37 adult Herring Gulls on Gull Island in the Witless Bay Seabird Ecological Reserve off Newfoundland’s Avalon Peninsula.  The tags are beige with black codes like “X07” or “X29”.  The birds were also fitted with the black-on-orange colour bands that have been used in Newfoundland for many years.  We know from other band returns that Newfoundland’s breeding Herring Gulls range from southern Labrador to the Carolinas.  Any resights can be reported to the Bird Banding Office/Bird Banding Lab (www.reportband.gov), or directly to me at alex.bond@usask.ca.  Photos, anecdotes, and stories of the birds are most welcome!   Alex Bond, University of Saskatchewan

Beige wing-tags were deployed o Herring Gulls from Newfoundland in a study this summer.

Beige tags were deployed on gulls from Gull Island, Newfoundland.

Thanks for your help and keep the sighting reports coming.
Rob Ronconi
Halifax, NS

Yellow wing-tags on an immature Great Black-backed Gull from June on Sable Island

Pink tagged herring gull landing on the water

A turquoise tagged Great Black-backed Gull from Sable Island in the winter.


The science of patience

10 06 2012

Catching gulls on Sable Island requires a lot of patience.  The gulls are shy of human presence and any disturbance within a colony will set all the gulls in a giant mayhem for quite some time.  So typically, when trying to catch Herring gulls on their nest, we have to wait one hour before calm settles down again on the colony and gulls will return to their nest.  During that hour, we are hiding under our “invisible cloak” a.k.a. a sand coloured bed sheet.  While waiting for the gulls to return, there is only so much distraction one can have crouched in an uncomfortable position, in the sand, under a bed sheet.  This is an intense game patience, with the possibility of a reward if a gull gets caught, or the perspective of another hour of waiting if it escapes.  It might not be physically tiring, but this part of the day can be mentally draining… It’s all in the name of science.

Under the “invisibility cloak” Zoe vanishes right before the eyes of the gulls.

Like any work, being in the field has its share of repetitiveness: catching sparrows, breakfast, trying to catch and tag some gulls, lunch, trying to catch and tag more gulls, dinner, sleep, repeat from step one.  Yet, as anyone who has ever done field work knows, field work is not all that monotonous and we experience a fair amount of adventures each and every day.  There is the time Zoe and I were trying to catch sparrows with a mist net and ended up catching a horse!!! Surprisingly, both the net and the horse came out unscathed.  Carrying a 50 pounds battery up 8 flights of ladder style stairs to the top of the light house, now, that’s an adventure.  But today, the gull catching work is officially over and we are getting ready for some new adventures: tomorrow we will be banding our first Ipswich Sparrow nestlings and over the next few days, we will catch our first terns!!! I`m not sure if we are moving up in the world of birds, but we are switching target size, that’s for sure.  It’s been a long 4 weeks for Jess, whose project is on terns, but she can not hold the excitement any longer.

Reporting live from Sable Island, Ingrid Pollet

Team gull set a trap at a Herring Gull nest on a ridge top.

Ingrid and Zoe wait at a mist net for Ipswich Sparrows. Or maybe they’ll catch a horse!

Back to the Beach

8 06 2012

At 40km long with only five year-round (human) residents, Sable Island is probably Canada’s biggest and most fantastic beach.  That is if you like pounding surf, blowing sand, horizontal rain, fog (and more fog) and a few hundred thousand seals that leave “gifts” on the shores.  Donning mitts, touques, full rain/wind gear, and “invisibility cloaks” (see the upcoming blog entry by Ingrid), our research team has assembled on Sable for the 2012 field season.  The team has doubled this year to account for quadruple the work load planned.  Ingrid and Rob have returned for another season of gull wrangling and brought Zoe and Jess, two Masters students from Acadia University.  Both are starting new projects tied in with the gull study but they seem to have a preference for the smaller birds that don’t draw blood when they bite.  Jess will be studying the foraging habitats and diets of terns around the island and Zoe is tracking the migration of the Ipswich Sparrow, Sable’s endemic sub-species of Savannah sparrow.

The new gull crew from Acadia University providing navigational aid to passing traffic on North Beach, Sable Island. From left to right: Rob, Zoe, Ingrid, and Jess.

Admittedly we’re a little behind in blog entries since we’ve been here 3 weeks already.  We arrived May 15th, earlier than last year, so we could catch Great Black-backed Gulls, a task most easily done when they are incubating their eggs.  Too late for that, the chicks were already hatching during our first few days on the island so we had to switch tactics.  We started catching Black-backs by setting traps around dead seals that they forage on (illustrated guide below… “how to catch a Black-backed Gull in 4 easy steps”).  No guts, no glory!

Building on last year’s project with Herring Gulls, this year’s mission is to deploy VHF tracking tags on Herring Gulls, Great Black-backed Gulls, terns, and Ipswich Sparrows to study their movements around the island, interactions with offshore gas platforms, and migrations to the main land.  Full speed ahead since day one, we’ve deployed 50 tags on gulls, colour banded almost 100 Ipswich, and nearly caught a horse (unintentionally of course) that walked through and dragged down one of our mist nets.  A special technological treat for this year are the 6 solar-powered satellite tags that will allow us to track Herring Gull movements year-round for 2 years (stay tuned for maps in future blog entries).

Since I’m bad at keeping the blog entries up to date I’ll be sure to get the rest of the crew to write a few words over the coming week before we finish up.

Rob Ronconi

Main Station, Sable Island

Step 1 – The Bait.   Jess and Ingrid hide traps (leg-loop carpets) in the sand around a dead seal. Black-back Gulls can’t resist!

Step 2 – The Wait. The intrepid researchers wait and watch until the black-backs get caught.

Step 3 – The Catch (and watch out for the horses). Horses pass by as Zoe and Jess run to grab the gull caught in the trap.

Step 4 – and Release. After tags are attached a black-back springs free.

Black-backed Blizzard: winter tagging on Sable

24 01 2012

During December and January, Sable's shorelines and dunes get crowded with resident grey seals that come ashore to give birth, feed their pups, and mate. Gulls mill about the seal colony in search of food like placentas from seal births, dead pups, and carcases of seals washed ashore.

The Sable landscape is completely changed in the winter.  The waves are bigger, the wind is stronger, dunes become sand storms, the lush vegetation dies back and the resident population explodes!  Not the human population but the population of native wildlife that migrate to the island.  By mid December, this island is crowded with grey seals that come to Sable to give birth, nurse and fatten up their pups, and mate.  With thousands of seals on the beaches and dunes, it’s a spectacle to behold … the sights and sounds are reminiscent of a zombie movie with seals crawling every which way, moans, groans, snarling and snapping at your feet as the females protect their pups, the young learn to crawl and the big males compete for mates.  They are wonderful, adorable (the pups), powerful, and assertive creatures.  Recent estimates showed that more than 65,000 seal pups are born here annually making Sable the largest grey seal colony in the world – learn more about research that’s been conducted here by the Department of Fisheries and Oceans (DFO) for several decades now.

Along with the seals come the gulls that “flock” to the island to feed.  The winter medley of Sable gulls is much different from the summer breeding population.  In the summer, Herring Gulls outnumber Great Black-backed Gulls by about 4 to 1.  In winter, Great Black-backed Gulls are the dominant species probably numbering in the thousands (2000-5000 would probably be my best guess).  For every 200 Black-backs there’s maybe 20 Iceland Gulls, 1 Glaucous Gull, the occasional Herring Gull, and other rarities like the Lesser Black-backed Gull.

Why so many gulls on this remote sandbar?  They come here to feed and fatten up for the winter.  In winter, food resources are often scarce for wildlife, but Sable offers a smorgasbord for gulls.  The large seal population presents rich and nutritious meals of protein and fat from placentas left over from births, dead pups that are weaned too young, and seal carcases that are washed ashore after being killed by sharks.

I had the great pleasure to spend New Years on Sable where I worked for 2 weeks in December/January helping colleagues from DFO with their long-term seal research program.  We were conducting seal population census, monitoring pup production, and and recovering tags from seals involved with the Ocean Tracking Network project.

During our “spare” time, three of us that were staying at the East Light Field Camp (Sarah, Damian and myself) were busy trying to catch gulls.  Since they were already cued in on dead seals, we took advantage to set leg-noose carpets around seal carcasses.  While feasting on the open carcases their legs would get caught in the nooses and we were on standby right as this happened.  Winter gull catching is not for the faint of heart… frozen fingers, blowing sand, blood and guts (from the seal carcases and also from the gulls regurgitating on us once they were captured), and aggressive seals.  During our last capture session a snow storm set in just as we were finishing up with our last bird.

Just after sunset, as a snow storm sets in, Sarah and Damian release an adult Great Black-backed Gull after tagging it during our last day on Sable Island.

We measured, weighted and tagged 12 Great Black-backed Gulls this winter with turquoise wing-tags and green leg bands.  With some vigilance this summer, hopefully we’ll discover where these gulls came from (Maine? New Brunswick? Newfoundland?) to forage on this rich bounty of Sable seal flesh!

Rob Ronconi, Halifax, NS

P.S. Special thanks to Simon who cut out all the tags for me back in Halifax!

Damian holds a young Great Black-backed Gull ready for release after tagging. Maybe Damian is contemplating a career change now from seal biologist and photographer (lidgardphotography.com) to ornithologist.

East Light field camp where we stayed for 2.5 weeks in December and January. This field camp is run by the Department of Fisheries and Oceans at the Bedford Institute of Oceanography.

Blue/Turquoise wing-tagged adult Great Black-backed Gull flies by mother grey seal with her pup.

Chick round-up

16 06 2011

By the time we arrived on the island on June 6th, the Great Black-backed Gulls had already hatched their chicks.  By mid June the chicks were getting big and running around while being guarded and fed by their diligent parents.  This is a great opportunity to catch young gulls, before they can fly, and outfit them with their own colour bands.

Chicks lay calmly on their backs as they await their turn for banding.

When their not hiding in the vegetation, chicks are running fast.  We were often outsmarted by these 20-day old birds who evaded capture by disappearing in the grass, running down and over steep dunes, and, most effective of all, swimming off into the surf.    We succeed in banding 28 chicks but they were too small to be fitted with wing-tags.

Ingrid, Susan, and Damian round up three chicks for banding.

A Great Black-backed Gull chick runs off with its new green band.

Catching gulls on Sable

13 06 2011

Sable Island is sand bar – approximately 40 km long and 1.5 km wide – located about 200 km offshore from mainland Nova Scotia.  Despite its isolation, Sable is home to a diversity of fauna including grey seals, harbour seals, wild horses (that were introduced to the island in the 1700’s), and a wide variety of bird species.  Gulls, terns, and occasionally Leach’s storm-petrels, are the only seabirds which nest on this island.  Both Herring Gulls and Great Black-backed Gulls breed on Sable, but detailed studies of these species have not been made here since 1971 when it was estimated that ~2000 pairs of Herring Gulls and ~600 pairs of Great Black-backed Gulls were nesting on the island.

Ingrid climbs the ridge of a sand dune to reach a Herring Gull nest on top. Gulls on Sable nest in small colonies often on dune ridges and slopes.

In June of 2011, a small team of keen biologists set out to Sable Island to initiate a new study of the gulls that nest on Sable.  Rob Ronconi and Ingrid Pollet, from Acadia University, worked on Sable for 2 weeks catching and tagging gulls.  We stayed at “BIO House” with grey seal biologists from the Department of Fisheries and Oceans who helped immensely with the logistics of working in this remote place.

Eggs are temporarily swapped with "dummy" eggs to protect the real eggs during captures of nesting adults.

At this time of year Herring Gulls were still incubating their eggs which allowed us catch them by setting traps over their nests.  Catching gulls on Sable was easier said than done – the uneven and shifting sands made it difficult to set traps and the gulls were more skittish than on other islands where I’ve worked before.  Many times we were duped by these crafty birds…gulls are much smarter than people give them credit for.

Rob releases Herring Gull fitted with pink wing-tag "AAR"