Island leaving…Island living

Gulls – check!

Terns are tagged, gulls are geared, sparrows are spreading… our job is done, yet we are still here.  This is part of the hazards of working on a somewhat remote island:  you never know when you are getting on and certainly never know when you are getting off.  Up until a few days ago, there were 8 of us (human that is) on the entire island.  That’s about 0.23 people /km2, or the equivalent density of the Falkland Islands.  Five horse-loving tourists arrived on the island a few days ago.  The island is suddenly over populated, it’s time to go, yet we are still here.   As we see it, we are sharing our accommodation with them.  In their eyes, it’s probably more them who are sharing their accommodation with us as we were supposed to leave on the same day as they arrived.  But the weather decided otherwise.  After a beautiful month with limited days of rain or fog, the fog arrived earlier this week, in all kinds of shades and thickness, and no plane can land in this weather on the hard packed sandy beach that we familiarly call the “airport”.  It’s now Thursday and we are getting ready to spend another extra day (or is it days?) on the island.  Once the frustration is put aside, it gives us the opportunity to tweak our set-up, to check on the status of our birds, and to catch /band a few more sparrows.  As much as we appreciate being here and would gladly spend more time on the island, we all have plans for the rest of the season, and are getting itchy for the next adventures.  Not knowing if today is going to be the day we are flying home makes for awkward planning…. Island living, there’s nothing like it.

Ingrid Pollet (still on Sable Island)

Sparrows – check!

Terns – check!

 

TERN that frown upside down!

                Before our time on Sable comes to an end I would like to introduce you fellow readers to two additional species that breed here on the island: the Common tern, and the Arctic tern! I am quite proud to say that these feisty little guys are the focus of my study.  These migratory seabirds breed in colonies that vary in size; from fewer than ten pairs to thousands of pairs in a relatively small area. The main component of my project involved capturing terns while they were incubating their eggs, which meant a long wait after we arrived. The terns were definitely worth the wait!

During the two weeks prior to catching terns, I would make a random count of the number of eggs in the first twenty nests I came across in the colony every two-three days.  I quickly learned that the terns are very territorial and protective of their nests. I strongly recommend a jacket with a hood; mine is now completely painted with presents from the defensive birds! One of my favourite things about walking through the tern colony is being able to see the different nests and eggs. Some terns take the time to make beautiful little nests lined with soft vegetation; others are more impatient and pretty much sit in the sand and call the indent their nest.  Eggs also vary in size and colour patterns.

Terns build small nests out of all sorts of vegetation. This nest was made out of still growing sandwort on the east spit of Sable.

In order to catch the terns, we used cages with trap doors and hoop nets that could be triggered from afar. We were really happy to find that it did not take long for the terns to return (they are very dedicated to their future chicks!!) which meant that we were very efficient. Radio tags that will allow us to monitor their movements were attached to thirty-five birds at the two largest colonies on the island. The crew quickly learned to never look up while walking through the tern colony to retrieve the captured birds.

Box traps are set over top of tern nests to catch them. When they walk in, they step on a plate that triggers a door to close behind them.

Jess holds a Common Tern just before releasing it after it’s been measured, weighed and tagged.

We also completed an island-wide census of the breeding terns by visiting the colonies that had been located by past researchers (look for the results in a future blog post). Unfortunately most of the smaller colonies were no longer present on the island. However, while traveling to the eastern tip of the island one day, Zoe and Rob were fortunate enough to come across a group of endangered Roseate terns!! Five were seen together on the beach at a Common and Arctic Tern loafing area near the East Light colony.  Everyone was extremely excited due to continuing decline of the species. I am happy to say that precautions were taken so that they remained undisturbed and photographs were taken from a large distance.

Roseate terns are an endangered species in Canada and the USA. Sable Island is home to a small breeding population of this species. About 5 pairs of Roseates are known to nest among the large Common Tern colony near East Light on Sable. These ones were seen loafing on the beach about 200 meters from the colony.

I think I speak for the entire crew when I say that our experience here on Sable has been one that we will never forget. From dealing with charismatic birds to spending time with some really great people, it has been quite the month! Even though we will be leaving soon, we hope to return sometime in the future to continue our research and gain even more experience! So make sure you all tern-your frowns upside down because there will be more Sable posts to come!

Cheers,

Jess Stephens

Carefully walking among tern nests to catch terns in traps, terns take direct aim at intruders.

Ipswich-aroo

Although this is a blog about the magnificent Sable Island gulls, I think there is a bit of leeway to (Ip)switch species for a moment and talk about some of the other feathered friends that live on the island.  We are also working on Ipswich Sparrows while we’re out here.

The Ipswich work has been a lot of fun so far and we’ve even started banding chicks.  We catch them using mist nets and call playbacks so we all know the Ipswich song very well by now.  It’s hard not to hear them all around you while you sit and wait for the much larger gulls to be trapped.  It’s once you have a sparrow interested in the speaker that the action starts.  The best way to catch them seems to be to run at them and flush them into the net.  Sometimes they outsmart us and escape the net at the last moment, but we don’t give up!  We’ve managed to catch most of the sparrows we’ve set our eyes on with one or two exceptions of some particularly wiley individuals.  No one likes being outsmarted by a sparrow.

Jess sets up a mist-net just out of reach of a passing horse.

 

We’ve caught a few surprises too; magnolia warbler, cedar waxwing, northern waterthrush, and a blackpoll warbler.  It can also be a challenge working around wild horses, one has run through our net (both the net and the horse made it out in one piece), but they have also managed to chase sparrows into our nets which has been a huge help.

 

Zoe delicately removes an Ipswich Sparrow from a mist net.

A male Ipswich Sparrow with a red leg bad and metal (numbered) band. Females get blue bands. During the breeding season it’s easy to determine the sex of birds (females have a brood patch and male don’t). We’re banding sparrows now with colour bands so it will make it easier to tell apart the males and females in late August when we return to tag them.

 

Getting the chicks is a bit trickier at first, since the nests are so small and well hidden in the dense ground cover.  Once you find one you just have to wait until they are big enough to band but not old enough to be forced out of the nest too early.  Then you can just reach in and get them.  They start out with just a bit of down along their head and back which looks like a little Mohawk, and the rest of the feathers grow in after that.  After waiting 6 days for the first set of chicks we were finally able to band our first nest yesterday.   We should have a couple more ready in the next few days and we’re all very excited to band more little Ipswich chicks!

Zoe Crysler

Ipswich conceal their nests among grass and shrubs on Sable. Each summer pairs raise up to three clutches of 3 to 5 eggs.

After only 12 days of incubation, these hungry little mouths emerge.

 

 

The science of patience

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

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 15^th, 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.

BlackOutSpeakOut

Back to Sable

After a year of traveling on the eastern seaboard, the Sable Island gulls are making preparations for their upcoming breeding season.  A pink-tagged gull was spotted back on Sable Island on April 14.  Al Wilson, Sable Island Supervisor with Environment Canada’s Meteorological Service, saw this bird about 7km west of Main Station.

On Sable most Herring Gulls don’t lay eggs until mid to late May.  Although it’s a bit early for nesting, there is still plenty to do before hand.  Herring gulls are typically monogamous and form life-long pair bonds.  When they arrive at colonies in April the males are busy establishing and defending the best territories for nesting.  Courtship involves a song and dance between males and females with crouching, head-tossing, upright posturing, and calling.  This display sometimes ends with males regurgitating meals for females, often leading to copulation soon after…very romantic!   This feeding by regurgitation is thought to help females replenish body reserves for egg formation.

Us researchers too will be back on Sable Island soon.  Stay tuned for posts about the fieldwork we’ll be doing once the gulls are nesting in May and June.

Rob Ronconi

Halifax, NS