Common Field Grasshopper (Chorthippus brunneus)

I am an amateur trying to learn something about everything living in my garden.

Sunning itself on (appropriately enough !), my garden sunlounger I found the grasshopper seen in photo 1 (click to enlarge).

I am used to hearing the chirp of grasshoppers on warm days when I go for country walks hereabouts. I do not tend to hear them in my garden however. The grasshopper in the photo is one of only two I can recall having seen there.

Prior to this posting I knew essentially nothing about grasshoppers. Thanks to reading the short but scholarly Grasshoppers and Bush-crickets (Andrew Mahon, publ. Shire Natural History) however, I am now a little better informed.

For the amateur, learning to identify all the British grasshoppers is a realistic proposition (arguably unlike mastering the beetles !) as there are only eleven species, together with ten species of bush cricket. (Amateurs from 'the rest of the world' be warned however, elsewhere a further eleven thousand species are there to be encountered!).

Bush-crickets can be distinguished from grasshoppers, in part, by their longer antennae (typically, longer than their bodies).

Grasshoppers are vegetarians (some bush-crickets are carnivorous). They overwinter as eggs, typically laid into soil or at the base of vegetation, and, following hatching and a period spent as a grub-like larva, grow to adult-hood through a series of nymph-stages (instars), moulting their exo-skeleton between each stage.
Using the key in the book above and working from my photographs, I was able to make some progress towards identifying my grasshopper. Based on my grasshopper not having antennae swollen at the ends into clubs, I understand that he (or she) can be neither a Rufous nor a Mottled grasshopper. Furthermore, viewed from above (photo 2 , click to enlarge) you can also make out the raised "shoulder blades" ('the keels of the protonum'). The fact that these are curved, rather than straight, also means we can dismiss the possibilty of my grasshopper being a Lesser Marsh.

Unfortunalty, some other features (such as the wing veination) that would have clinched the identity of my grasshopper, I wasn't able to get from my photos. Luckily however, the photo on the front cover of Dr. Mahon's book seems a very close match for my grasshopper - so on that basis I'm going with the Common Field. I say 'luckily' as the Common Field shows considerable variation in patterning and coloration as the photo's here prove. Without the picture on the front of Dr. Mahon's book I might have struggled for longer...always assuming of course I'm now correct! If you know for certain please do leave a comment.