Tuesday, 14 July 2015

Monday, 29 June 2015

GULLS ON THE FORESHORE: T'SIK'WI

A gull cries in protest at not getting his share of a meal

Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. 

The Laridae are known from not-yet-published fossil evidence from the Early Oligocene — 30–33 million years ago. 

Three gull-like species were described by Alphonse Milne-Edwards from the early Miocene of Saint-Gérand-le-Puy, France. 

Another fossil gull from the Middle to Late Miocene of Cherry County, Nebraska, USA, has been placed in the prehistoric genus Gaviota

These fossil gulls, along with undescribed Early Oligocene fossils are all tentatively assigned to the modern genus Larus. Among those of them that have been confirmed as gulls, Milne-Edwards' "Larus" elegans and "L." totanoides from the Late Oligocene/Early Miocene of southeast France have since been separated in Laricola.

Gulls are most closely related to the terns in the family Sternidae and only distantly related to auks, skimmers and distantly to waders. 

A historical name for gulls is mews, which is cognate with the German möwe, Danish måge, Swedish mås, Dutch meeuw, Norwegian måke/måse and French mouette. We still see mews blended into the lexicon of some regional dialects.

In the Kwak̓wala language of the Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest and my family, gulls are known as t̕sik̕wi. Most folk refer to gulls from any number of species as seagulls. This name is a local custom and does not exist in the scientific literature for their official naming. Even so, it is highly probable that it was the name you learned for them growing up.

If you have been to a coastal area nearly everywhere on the planet, you have likely encountered gulls. They are the elegantly plumed but rather noisy bunch on any beach. You will recognize them both by their size and colouring. 

Gulls are typically medium to large birds, usually grey or white, often with black markings on the head or wings. They typically have harsh shrill cries and long, yellow, curved bills. Their webbed feet are perfect for navigating the uneven landscape of the foreshore when they take most of their meals. 

Most gulls are ground-nesting carnivores that take live food or scavenge opportunistically, particularly the Larus species. Live food often includes crab, clams (which they pick up, fly high and drop to crack open), fish and small birds. Gulls have unhinging jaws which allow them to consume large prey which they do with gusto. 

Their preference is to generally live along the bountiful coastal regions where they can find food with relative ease. Some prefer to live more inland and all rarely venture far out to sea, except for the kittiwakes. 

The larger species take up to four years to attain full adult plumage, but two years is typical for small gulls. Large white-headed gulls are typically long-lived birds, with a maximum age of 49 years recorded for the herring gull.

Gulls nest in large, densely packed, noisy colonies. They lay two or three speckled eggs in nests composed of vegetation. The young are precocial, born with dark mottled down and mobile upon hatching. Gulls are resourceful, inquisitive, and intelligent, the larger species in particular, demonstrating complex methods of communication and a highly developed social structure. Many gull colonies display mobbing behaviour, attacking and harassing predators and other intruders. 

Certain species have exhibited tool-use behaviour, such as the herring gull, using pieces of bread as bait with which to catch goldfish. Many species of gulls have learned to coexist successfully with humans and have thrived in human habitats. Others rely on kleptoparasitism to get their food. Gulls have been observed preying on live whales, landing on the whale as it surfaces to peck out pieces of flesh. They are keen, clever and always hungry.

Wednesday, 3 June 2015

Monday, 25 May 2015

Saturday, 23 May 2015

CRETACEOUS CAPILANO RIVER

If you are looking for a wee fossil day trip, then a stroll down to the Capilano River is just the thing.

From downtown Vancouver, drive through Stanley Park heading north over the Lion’s Gate Bridge. Take the North Vancouver exit toward the ferries. Turn right onto Taylor Way and then right again at Clyde Avenue. Look for the Park Royal Hotel. Park anywhere along Clyde Avenue.

From Clyde Avenue walk down the path to your left towards the Capilano River. Watch the water level and tread cautiously as it can be slippery if there has been any recent rain. Look for beds of sandstone about 200 meters north of the private bridge and just south of the Highway bridge. The fossil beds are just below the Whytecliff Apartment high rises.

You will see some exposed shale in the area. It does not contain fossil material. The fossils occur only in the sandstone. Interesting, but again, not fossiliferous are the many granitic boulders and large boulders of limestone which may have been brought down by glaciers from as far away as Texada Island. Cretaceous plant material (and modern material) found here include Poplar (cottonwood) Populus sp. Bigleaf Maple, Acer machphyllum, Alder, Alnus rubra, Buttercup Ranvuculus sp., Epilobrium, Red cedar, Blackberry and Sword fern.

Monday, 11 May 2015

LINGULA ANATINA: PRIMATIVE BRACHIOPOD

Lingula anatina — a primitive brachiopod 
One of the most primitive brachiopods is this caramel and cream fellow, Lingula anatina

Brachiopods are marine invertebrates with a stalk and two shells connected along a hinge. They are often confused with bivalves such as clams. 

Bivalves have shells on the sides of their bodies. Brachiopods have shells on the top and bottom. As a result, the plane of symmetry in a bivalve runs along the hinge while it runs perpendicular to the hinge in brachiopods. 

Lingula forms are regarded as the most primitive brachiopods and represent the first certain appearance of brachiopods in the fossil records dating back 530 million years. 

Their shells do not have any locking mechanisms. Instead, they rely on complex musculature to move their shells. They are the first known examples of animal biomineralisation — a process whereby living organisms stiffen or harden tissues with minerals. Their shells are composed of calcium phosphate and collagen fibres, characters shared only by evolutionarily distant vertebrates.

Lingulid brachiopods had changed so little in appearance since the Silurian, 443-419 million years ago, they are referred to as living fossils — a term bestowed upon them by Charles Darwin himself.

Photo: Wilson44691 - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=8624418

Tuesday, 5 May 2015

PLANNING YOUR NEXT STAYCATION: HORNBY ISLAND

Hornby is so many things to so many people. I have avid pottery afficianato friends who go to look through the talented work of local potters. Others swear by the pie. It is off the beaten track and pure heaven.

Sunday, 19 April 2015

TAKING IN THE VIEW

One of the most satisfying moments is taking in a sunset after a long days hike. Pure visual poetry. Peaceful, meditative and well-earned. It is a time for reflection on the day, your world, fresh blisters - the gamut!

Have you ever wondered about the colors you see in these moments? What sunlight actually is? Yes, it's light from the Sun but so much more than that. Sunlight is both light and energy. Once it reaches Earth, we call this energy, "insolation," a fancy term for solar radiation. The amount of energy the Sun gives off changes over time in a never ending cycle. Solar flares (hotter) and sunspots (cooler) on the Sun's surface impact the amount of radiation headed to Earth. These periods of extra heat or extra cold (well, colder by Sun standards...) can last for weeks, sometimes months.

The beams that reach us and warm our skin are electromagnetic waves that bring with them heat and radiation, by-products of the nuclear fusion happening as hydrogen nuclei shift form to helium. Our bodies convert the ultraviolet rays to Vitamin D. Plants use the rays for photosynthesis, a process of converting carbon dioxide to sugar and using it to power their growth (and clean our atmosphere!) That process looks something like this: carbon dioxide + water + light energy -->glucose + oxygen = 6 CO2(g) + 6 H2O + photons → C6H12O6(aq) + 6 O2(g) Photosynthetic organisms convert about 100–115 thousand million metric tonnes of carbon to biomass each year, about six times more power than used my us hoomins.

We've yet to truly get a handle on the duality between light as waves and light as photons. Light fills not just our wee bit of the Universe but the cosmos as well, bathing it in the form of cosmic background radiation that is the signature of the Big Bang.

Once those electromagnetic waves leave the Sun headed for Earth, they reach us in a surprising eight minutes. We experience them as light mixed with the prism of beautiful colors. But what we see is actually a trick of the light. As rays of white sunlight travel through the atmosphere they collide with airborne particles and water droplets causing the rays to scatter. We see mostly the yellow, orange and red hues (the longer wavelengths) as the blues and greens (the shorter wavelengths) scatter more easily and get bounced out of the game rather early.

Tuesday, 14 April 2015

Monday, 16 March 2015

Sunday, 15 March 2015

Sunday, 22 February 2015