Our Aspen woodland on a sunny early Spring day is glorious to behold. The first of our spring flora are carpeting the woodland floor here and mingle to create a throng of cheerful nodding blooms. These spring flowers are delicate yet hardy and provide a vital early nectar source for our emerging pollinators such as bumblebees and butterflies. They include Snowdrop, Primrose , Lesser Celandine, Spring Crocus and coming up right now Daffodil.
The symbolism of the Primrose was used to great effect by Shakespeare and he references this flower 7 times in his work. They often have melancholic associations as he links their paleness to early death, especially of young maidens.
In another use he coins the phrase the “primrose path”. This literally stands for a path strewn with flowers and means taking the path of pleasure, indulgence, or the easy route in life.
The joy and optimism of lengthening days and the return of the sun easily make it my favourite season by a country mile. Unbelievably in early February we began to enjoy some glorious warm spring like days. I keep finding myself furiously willing things to grow – but everything has it’s ideal time and place.
In reaction some of our hibernating and dormant species began to wake up – a trifle too early for the awaiting conditions to be honest.
Butterflies such as Peacock and small Tortoiseshell butterfly are on the wing – too early for many of the flowers theses butterflies feed on.
I came in to find a somewhat confused small tortoiseshell butterfly fluttering around the visitor center where it has been hibernating under our giant jigsaw.
It is often a problem of how best to help these poor butterflies unwittingly tricked into thinking spring has come early. While the weather has been warm and spring-like the flowers that it nectars on are not out yet!
Releasing a butterfly into the winter is usually dooming it. The butterfly rapidly loses the ability to fly when its body temperature plummets in the cold and is picked off by birds or mammals. The other problem is starvation. The butterfly built up vital fats by gorging on nectar in our gardens and countryside before switching off for winter and long periods of unseasonable activity reduces these reserves.
Strange as this sounds if you come across a butterfly awake in winter you can place it in a dry, transparent container lined with a folded section of kitchen roll to absorb moisture and place it in the salad drawer in the fridge, where the temperature is around four Celsius. The butterfly will soon settle and can be kept there until warm, sunny weather arrives in March or April. Alternatively, remove the butterfly from the container when it is quiet and place in an unheated shed or room to complete its winter rest.
We have encountered our 1st frog of the year and we think a gravid female full of eggs from her rotund look. Between late summer and early spring, a female frog develops thousands of eggs – up to a whopping 4,000 – inside her body.
Around the month of March, the female will release those eggs – to be fertilised by an awaiting male – – into their breeding ponds – to create frog spawn. Our toads are generally a bit later in the year.
Unbelievably our reptiles are awake – so we can put winter to bed right. Maybe hold that thought for another month! We spied this common lizard on the 8th of February – the joint second earliest we have seen them and staying within the warm shelter of this dry stane dyke.
So how might Scotland’s terrestrial reptiles be affected by climate change?
To begin to answer this, we have to consider the direct effects of climate change on reptile adaptation and behaviour, and the indirect impacts from changing populations and dynamics of predators and prey.
Our reptiles are more or less at the northernmost edge of the range for their species, although the adder, common lizard and slow worm have Scandinavian populations at higher latitudes. These three species are viviparous, meaning embryos develop within the body of the adult and born live.
All UK reptiles however, have cousins residing in the warmer southerly climes of Iberia and Central Europe and the Balkans. So, we could assume that warmer climate here will improve survival in existing reptile populations, while enabling a northward shift of their distributions.
Under various warming scenarios modelled for 2050 and 2080 it is however, unfortunately not great news.
Slow worms, here in good numbers, show a mixed northward shift with a contraction of southern populations. For adder and common lizard species modelling predicted widespread population decline, greater under higher warming scenario’s.
Being ectothermic, reptiles are highly sensitive to their environment, with a tight set of requirements to achieve their optimal climatic conditions.
Temperature and rainfall strongly influence reptile behaviour, and a changing climate has great potential to create mismatches – for example if temperature and rainfall is less than the ideal either for reptiles or their prey species, especially at key points in the year such as hibernation emergence. If our retiles emerge into a cooler baseline temperature it takes them longer to gain energy from the sun and they remain basking out in the open – lethargic – for longer. This leaves them more vulnerable to predators such as Pheasant and Buzzard.
Interestingly warming could accelerate reptile growth and time to sexual maturity, due to longer periods of activity. Milder winters will likely reduce hibernation lengths for our reptiles. Earlier spring emergence, and activity extending further into the autumn and winter months would likely bring reproduction forward in the year, as length of pregnancy is generally shorter in warmer climates. Larger body sizes in warmer climates may result in greater reproductive success .
This has been subject to experiment by placing common lizards in climate-controlled chambers subject to current average temperatures and future climate predictions. Warming did increase growth rates, bring mating forward and resulted in more broods per season. However, this was coupled with a reduction in adult survival rates. Perhaps the greater energy requirement required by larger individuals can’t be matched by foraging opportunities, especially across hot summers. It can be too hot.
Out on the water our birds have ranched up their courtship displays with the goldeneye sheering off into smaller groups of breeding males and females.
For these breeding birds we have been racing around trying to replace our more dilapidated goldeneye nest boxes in time for them to start nest prospecting.
A huge highlight of the week – on Saturday I was joined by a small team to place Goldeneye nest boxes onto Castle Island – the 1st time I have stepped foot on the island.
A massive thanks to Jeremy and Simon from Loch Leven and their expert boat handling, trailer driving skills and to Judy CNPA ranger and Carey. An especial thanks to Jeremy for his rope with a stick trick which meant an easy way of maneuvering these heavy and bulky boxes onto the tree.
Just to leave you with a mystery offering from a visitor which frankly confused me until Butterfly Conservation recorder Helen Rowe identified it (immediately) as a Northern Eggar moth cocoon.
Muir of Dinnet National Nature Reserve 