Monday, February 7, 2011


Natureblog  February 2011

Mallard duck eggs

I do an egg unit with schools – oology it’s called. There are oologists throughout the world who study eggs, but the term is also used for egg collectors. Birds’ egg collections used to be a big thing and as a youngster I did my share of bird-nesting although I never collected any from protected birds unless the nest was abandoned. Finches, blackbird, sparrow, thrush, dunnock, magpie, skylark and starling were fair game. Duck, swan and goose eggs were commonly found and I chanced across the odd ones discarded from gull nests or from abandoned nests such as the oystercatcher and stilt where the owners had been disturbed and decamped. These open-ground nesting species have camouflaged eggs, often a very effective disguise against predators. Unfortunately the stoat has a keen sense of smell and an egg has a scent attractive to it. In fact, unbroken eggs are used as bait in stoat traps. Hedgehogs are predators of eggs also and more of a problem than we thought in the past. Mrs Tiggywinkle gave the world an unrealistically favourable impression of the spiny tribe.

Can you spot the two Banded dotterel eggs?

Egg-collecting has been illegal since 1954 in the UK, the home of oology. What started as a schoolboy hobby became an obsession for Victorian and Edwardian gentlemen with money and time on their hands, and rare eggs changed hands – carefully – for thousands of pounds.

In Tom Brown’s Schooldays (1857), Tom and cronies go birdnesting in Caldicott’s Spinney, and come to grief if I remember correctly.

Egg collecting led to the loss of a number of breeding species in Britain – eagles, ospreys, some owls and others – and may have contributed to the demise of the Great auk, although that fowl, the Garefowl of The Waterbabies, was also harvested for food and for its feathers which were used in stuffing mattresses.
Here is a White-fronted tern egg, matching the cockle shells on which it is laid

In earlier days kids were paid for sparrow eggs or ‘spugs’ eggs’ as my parents generation used to call them. The birds were a pest amongst the crops and local authorities paid a penny a dozen or suchlike for the eggs. A futile gesture but profitable for children, especially if they knew where the eggs were discarded after purchase as they could be recycled.

Here is a White-fronted tern egg,
matching the cockle shells on which it is laid

Blowing eggs can be a problem but must be done or the contents will rot. I have had some crack or explode, the worst being a gull’s egg which went with a bang when I made a hole in one end. You have to get new clothes and avoid polite company for a week.

I found an abandoned swan nest and decided to break one egg to see if the others were fresh enough to blow. I threw it, intending for it to fall to the ground but by mischance executed a girlie-throw that sent the egg straight up. A very long time later it came straight down and hit me. Fortunately it wasn’t addled.

My largest egg is a cast of the Elephant bird egg, from that extinct native of Madagascar; It’s the largest egg of any bird. Possibly the only larger eggs are were some of the dinosaurs and maybe the Whale shark. I have moa eggshell fragments as well. They can be found quite readily in some places. Moas were the largest New Zealand species to leave eggshell and you can find fragments readily in sand dunes, sometimes with New Zealand’s tiniest eggs. These minute eggs, a few millimetres long, were laid by long-extinct landsnails.