Seabirds look for a share of the caplin
‘Without caplin there would be an adverse domino effect reaching all areas of life in the sea’
The caplin have landed. They hit the beaches at many locations on the Avalon Peninsula this past weekend. No huge amount but it is at least a fairly widespread event to start. No two caplin years are alike. Codfish eat caplin. Whales eat caplin. People eat caplin. And birds eat caplin. We do not even want think about what would happen if the caplin disappeared. There would be an adverse domino effect reaching all areas of life in the sea.
Birdwatchers excitedly anticipate the arrival of the caplin. It draws offshore seabirds in to shore. There is an added allure to seabirds when you can view them from shore. In addition the concentrations are sometimes spectacular, unlike anything you would see in the offshore zone.
The beaches and headlands along the southern edge of the Avalon Peninsula from Cape Race to Cape St. Mary’s offer some of the best of caplin-related seabird birdwatching, though it can happen in other parts of the south and east coast. Nothing is completely predictable with the caplin. No two years are the same. One beach may be hot one year and poor for the next two years. If caplin numbers are low, seabird and whales may feed extremely close to shore desperately searching for their lunch.
During the record-poor caplin years of the early 1990s, humpback whales were feeding just one wave away off from the beach at St.vincents. Shearwaters were getting thrown around in the surf trying to reach for a share of the limited caplin supply. The number of shearwater corpses along the beaches at the end of that summer went mostly unnoticed and was never scientifically recorded. It was probably the result of mass starvation.
In those same years there was nearly complete failure of kittiwake reproduction on the seabird island on the Avalon Peninsula. Murres and puffins were able to switch to other food items to feed the young. It was hard times that no one wants to see again. An unusually cold water temperature was the blame. Bird species with large populations can survive famine years. Fortunately for all the life in our sea that depends on the summer caplin for part of their annual survival, caplin spawning activity has been fairly good for the last couple of decades.
The caplin-enhanced seabirding lasts about a month. The first sign of the impending seabird fiesta appeared this past weekend. The vanguard of shearwaters was noted at the southern extremities of the Avalon Peninsula. At St. Shotts, about 600 sooty shearwaters were seen resting on the water.
On the next day great shearwaters arrived at Cape Race. The shearwaters are ready. They are here for one thing only, the caplin smorgasbord. At St. Vincent’s beach humpback whales have been putting on a good show for a couple of weeks. It was thought to be sand lance at first, but there is definitely caplin in the mix now. On the weekend the kittiwakes and terns were wheeling about along the shoreline diving down on any caplin that came too close to the surface. Jaegers were chasing down the kittiwakes and terns that were too slow to swallow the fish down.
Jaegers are like the hawks of the sea. They do not kill other seabirds but act as though they will. They chase smaller birds like the kittiwakes and terns with such intensity it causes them to drop whatever fish they just caught or even regurgitate the contents of their stomachs to get the jaeger off their back.
Caplin are big for a kittiwake, and especially a tern, to swallow down quickly. This is the break a jaeger is looking for. A jaeger turns on the turbocharger and beelines it toward the bird with the fish. The powerful jaeger with lightning quick reflexes shadows every evasive manoeuvre a fleeing bird can make. Eventually the fierceness of the bullying causes the bird give up its fish to shake off the determined jaeger. The jaeger usually catches the fish before it hits the water and swallows it down quickly. Oddly jaegers rarely hunt for their own food even when it is plentiful but prefer to steal it.
The jaeger watching was particularly good at St. Vincent’s beach on the weekend. The kittiwakes and terns were finding caplin next to the beach. A loose group of 10 parasitic jaegers loafed a couple hundred meters offshore making forays into the beach to harass the birds. Spectacular chases over the surf and even over the beach thrilled the few birders who were lucky enough to be there. The chases were so fast it was difficult to follow with them camera. Even the whale watchers could not help but notice the reckless aerials overhead.
This is only the start of one of the best birding shows in the province.
“Jaegers are like the hawks of the sea. They do not kill other seabirds but act as though they will. They chase smaller birds like the kittiwakes and terns with such intensity it causes them to drop whatever fish they just caught or even regurgitate the contents of their stomachs to get the jaeger off their back.”