Archive for the ‘Sea Birds’ Category

Bright Lights Kauai Hawaii

On the island of Kauai, Hawaii, the bright lights are endangering the seabirds by distracting and disorientating them.  Often on their maiden flight the young seabirds are caught in the glare of very bright light, rather than being guided by the light of the moon and are killed or injured when they crash into objects.

They will also circle around and around until they are exhausted and fall to the ground where they are killed by cats, dogs and other human activities.  Or, they die of starvation and dehydration.

With the growing popularity for windfarms birds are having to deal with yet another great hazard.   The location of windfarms close to breeding grounds and the annual migrations when huge numbers of birds fly across the seas, mostly at low altitudes and at night, greatly increase the potential for collisions with the turbine blades. Poor visibility during adverse weather conditions adds to this potential.

Finally, windfarms act as barriers to migrating birds and if they are rerouted from their favourite flight paths, the result could be an increase in the distances they must travel as well as lowering their survival rates due to fatigue and the survival of their offspring because on the new routes, food could become more difficult to find.

Oil Rig

Global warming is having a huge effect on the North Sea.  This sea is warming and the plankton upon which everything else depends is dying and as a consequence the whole eco system of the North Sea is changing, leaving the seabirds with not enough to eat.

In June of 2004, scientists were baffled by hundreds of seabirds, seemingly healthy, washing up dead on the Norfolk coast.  The post mortem reports showed that almost all of the birds found on coasts around the North Sea, were adult females.  The cause of death of each of these birds was acute starvation.  What was happening out there that was causing the birds to starve?

Data from over 70 years of studying plankton around the British coast shows that the North Sea is warming and that the cold-water plankton has already migrated up to 1000 kilometers north. The loss of this vital food supply – plankton – affects the whole eco system.  It is the building block of the food chain and as it disappears fish, birds and other animals that feed on both the fish and the plankton will starve to death.

As the temperatures warm, conditions and the creatures we see in much warmer waters, such as red mullet, squid and pilchards, are becoming more common in the North Sea.

And the North Sea isn’t the only place this is happening.  In 2006 the Pacific coastline of North America started seeing similar warming of the water with similar results – dead seabirds, failure of breeding colonies, starving chicks, emaciated gray whales and the appearance of creatures normally found much farther south.

Squid, normally found south of San Francisco, has arrived on the coastline of Washington and a bloom along Oregon’s beaches of a type of plankton usually found around San Diego, are cause for real concern.  So is the fact that the top 300 feet of the Pacific Ocean has become warmer and much more dense in the last 30 years.  Since the 1970’s, the number of seabirds in Puget Sound has dropped by nearly 50% and there has been a significant die-off of kelp off the coast of southern California.

The scientists are warning us that there are some really important changes occurring in both the Pacific coastal system and the North Sea and of course, elsewhere as well.  So as weather patterns alter and the planet warms further, will we see ever fewer of the seabirds and other animals that currently inhabit these seas?

First of all, what is a sea bird?

California Gull

These are birds that have evolved to live, feed and breed on or near the oceans, on or near the shore line, in land but still feeding from the seas and those who live on or near rivers, lakes and waterways of all sorts.

For the millennia, birds have adapted to living in and on fresh and salt water.

They have developed webbed feet that assist them with diving and swimming underwater as well as moving along the surface of the water.

Another adaptation has been the development of salt glands by which sea birds eliminate the salt they take in by drinking the ocean’s water and feeding on other creatures living in the oceans.

Sea birds have many more feathers than land birds partly because the denser the plumage, the better the protection from the cold, from getting wet and water logged.  Feathers are hollow so the birds gain both buoyancy and insulation from them, keeping them dry and warm.

Sea birds have a very different life spans than land birds, they often live between 20 and 60 years.  Because of the conditions in which they live, they often delay the start of their breeding for up to 10 years and have fewer young per breeding period.  Their breeding may also be spread over two years rather than happening every year.  Again because of the conditions at sea, the scarcity of available food or the distances the parents have to fly to get food, sea bird young are looked after by their parents for far longer than land birds.  Sea birds will also often mate for life or at least will be monogamous for a breeding season.

While there are some land birds that also migrate great distances, sea birds are known for their phenomenal travels, for instance the Arctic Tern will be born in the Arctic but flies to the Antarctic to over winter.  Another great traveller is the Sooty Shearwater who flies 40,000 miles or 64,000 km in their annual migration!

Damaging Smoke and Fires

So far we’ve discussed the impact that man-made hazards can have on seabirds but what about natural events such as fires, floods, hurricanes, volcanoes, algal blooms etc. that could spell disaster for them?

Severe weather events, fires, floods, tsunami and volcanoes actually have little impact on seabirds primarily because birds and other animals are so much better tuned into the vagaries of nature.  They generally don’t get caught in severe storms because they leave before the storms come or they take shelter wherever they can if they can’t fly away quickly enough.  Sometimes migrating birds crossing open sea, may get caught by hurricane winds but even here because the birds are tuned in, they make alterations in their flights paths to avoid the severe weather.

Coastal habitats are vital to birds for shelter as well as for food and resting places.  Man can do quite a lot to help by not cutting down sheltering trees, not building right up the shoreline and making sure that supplementary food is put out for the birds after severe weather in which the food they normally eat – berries, nuts and fruits – may have been stripped from trees and bushes.

Algal blooms are becoming a more well-known phenomena around all of our coast lines and something birds can not outrun (outfly!).  Tens of thousands of seabirds died in October 2009 off the coast of Washington and Oregon because of the bloom created by Akashiwo sanguinea, a single-cell algae or phytoplankton.

These algal blooms can spell disaster for seabirds because when two specific conditions combine – low salinity and warm water – the algae’s reproduction explodes.  Winds then blow the algal bloom onshore where the surf whips it up into a sticky foam.  The foam sticks to the seabirds and strips the waterproofing from their feathers.  Once stripped of this critical element, the birds die of hypothermia or drown.

Algal blooms are happening more often and in more places.  Is this as many scientists think, part of global warming and climate change?  Can humans do anything about this?