The main varieties in the park are silver birch, downy birch and Himalayan birch (though I'm wondering if at least one of these is a Chinese Red birch).
Most are single specimens. But there's a group of tall, skeletal old silver birch on the north side of Bruntsfield Links, facing the end of Leamington Walk, and another group of three at the foot of Marchmont Road.
Here's a blue tit among the winter catkins of a solitary silver birch at the west side of the Links:
A new downy birch stands in a tree guard on Townswomen's Guild Walk (see the photos at the start of this page), and the beautiful bark of a Himalayan birch (or Chinese Red?) can be seen on this young tree in the small park on the corner of Hope Park Crescent.
And these leaves belong to a new silver birch planting on Leamington Walk:
In spring, the new birch leaves attract insects, visible here if you click on the photo below to enlarge it. Several species of aphid love silver birches, and don't necessarily harm them.
From a distance at this time of year, the birches look pretty dead, but they're full of life. Late in April 2016 I saw my first ladybird of the year (a Two-Spot Ladybird, at that) on one of the row on Bruntsfield Links, near the main road.
It was a dull sky so I couldn't get a sharp photo, but you can just about make out two other bugs too: both are on the new leaf growth at the bottom of the pic.
Two-Spot Ladybirds are native to the UK and popular with gardeners: they scoff down aphid eggs and larvae. I don't know if the big translucent-looking bug is an aphid: if so, surely there must be an almighty struggle between the ladybird and the parent of its lunch?
By May, some silver birches are covered in hosts of interesting insects.
Here on another day in May are two ladybirds mating on a birch leaf. (Both are native 2-spot ladybirds, even though the black has four spots: it's a melanic form of the two-spot.)
As spring progresses, the branches of birches are soon thick with catkins.
The bark of silver birches sometimes acquires dark diamonds.
(By the way, if you're in Edinburgh and particularly love silver birch, I recommend visiting the simple but still really beautiful little memorial grove of birches for Robert Louis Stevenson in Princes Street Gardens.)
Others become stained a deep red around their branches
Many peel, particularly the Himalayan birch
Even in full autumn colour the park's birches have an ethereal silhouette among the other trees
The papery leaves and spindly twigs endure through some grim weather
And through the odd autumn storm, here behind the sunshine
But they make it through. Here's a tall one dusted in snow a few winters ago, in a Marchmont back green.