Anybody know what this wee fella is ?

[JonathanD]

They thought that the grey squirrels released into Regents Park would n't spread either......Many of these introduced species are far more successful & better adapted than the native ones & their ability to overcome barriers is greater too.....time will tell.
As for what humans have done & will continue to do to the bio diversity on this planet I have to refrain from expressing my opinions as this is a family friendly forum.

But squirrels do spread as they are extremely mobile through all terrain and habitat. Reptiles don't have that ability which is why segregation is one of the major causes of their decline and genetic diversity. That's why the Aesculapians have not spread from the two locations they are in even though they have been there for 40 years now, and the Wall lizards are confined to their locations. They lack the natural corridors to spread. Unlike birds, mammals and even amphibians, these are essential to reptiles.

 

[robin wood]

But squirrels do spread as they are extremely mobile through all terrain and habitat. Reptiles don't have that ability which is why segregation is one of the major causes of their decline and genetic diversity. That's why the Aesculapians have not spread from the two locations they are in even though they have been there for 40 years now, and the Wall lizards are confined to their locations. They lack the natural corridors to spread. Unlike birds, mammals and even amphibians, these are essential to reptiles.

Interesting points, always good to expand our knowledge a little, thanks. Out of interest how mobile are they given infinite appropriate territory to spread into? Do young males go off a fair distance like badgers, spiders, deer etc? Or are they limited to say 1km territories even when there is appropriate large habitat, say a large lowland heath.

 

[JonathanD]

Interesting points, always good to expand our knowledge a little, thanks. Out of interest how mobile are they given infinite appropriate territory to spread into? Do young males go off a fair distance like badgers, spiders, deer etc? Or are they limited to say 1km territories even when there is appropriate large habitat, say a large lowland heath.

After mating, they do disperse to areas a fair distance (2km) away if the area permits and has natural wildlife corridors. Unlike deer, spiders and badgers though, they need constant low overhead cover to do so. They will cross paths and bridleways and even quiet roads. But won't do much more than that. Even in areas of forest that have a few pocketed areas of heath, you will find they will stick within their own pockets. Smooth snakes and sand lizards to a great degree. Adders the same, but at least some individuals will travel outside their pockets, Grass snakes travel well, as do Slow worms. Common lizards not so much. They all need natural corridors and will shun concrete and urban spread, even if minimal. Reptiles are anchored to areas by their hibernaculum sites that are used for generations. They won't stray too far from established areas known to them, and will even stay in the area once cover has been destroyed as it is all they have known. If a hiberbnaculum is destroyed during the Summer, upon their return they simply have no way of finding alternate sites to hibernate in time for the colder weather. Adders, Smooth snakes and Sand lizards just won't spread to other areas, as they can't. The other three can and will, but not to the extent that other species do.

 

[British Red]

If I had the Newt I'd call him "Tiny"

....well he would be my newt

 

[Robbi]

oh dear ! where do i find a face palm piccy when i need one !

 

[Spikey DaPikey]

If I had the Newt I'd call him "Tiny"

....well he would be my newt

I was waiting for this !

 

[blacktimberwolf]

Where did the non native species of snake & lizard you mentioned come from Jonathan ? (not their countries of origin but how they happened to be where they are now)
I assume that the wall lizards you refer to are the ones commonly ( ?) found in Europe (pondarcis muralis)