The four spoons and four plates on the blanket.

As one of them is cooking, it is likely that he has got out enough cutlery for all of them and no more or less.

The four names on the on-duty list (or at least the four days on the duty list).

It is not likely that a scout has agreed to do two duties.

There are some oars leaning against the tree on the right.

Scouts cannot drive, and they are camping alone it would seem, and it is not likely they would have simply carried the oars with them.

There is a spider’s web on the tent.

Spiders tend to build their webs at night (although not always the case); so, the tent is likely to have been there overnight.

Also, the spider must take time decide where to put its web (they tend to choose places where lots of insects fly); so, it is unlikely the spider will have decided this on the day of their arrival with all the activity going on to set up camp.

Finally, it takes a spider about 30 to 60 minutes to spin a web, so again, they will need some time and peace to do this; which overnight is going to offer better than during the first day of arrival.

There is also another reason I note further below. See if you can spot it as you answer the other questions.

You can see a butterfly net behind the tent and bush.

You are told in the question that Alex is not visible (that is new information).

There are only four scouts (we confidently believe based on question 1).

Three scouts are visible.

Therefore, the person holding the net is likely to be Alex.

The rucksack has the letter "C" written on it.

We know from the roster that three of the scouts are called "Colin, Peter and James".

We know from the previous question that the fourth scout (whose name is hidden on the roster) is called "Alex".

If a "C" is written one rucksack, and a "J" on another, then it is likely that it means the scout's initial, rather than a logo.

We also know that each of the scouts has a different name, because the "On Duty" roster tells us that and we know that Alex is the fourth scout on the roster.

It is unlikely that someone other than Colin would be looking into Colin's rucksack.

Because there is a tripod sticking out of his rucksack.

We have decided that Colin is the scout looking in is rucksack and Alex is butterfly catching.

That leaves us with James and Peter.

There is a "J" on one of the rucksacks.

That rucksack has what looks like a tripod sticking out of it (hard to tell, but what else could it realistically be)?

A tripod is a stand for a camera.

There is a scout standing up taking a picture, and as they have a camera, it is likely it is their tripod, as no one else has a camera in view.

We have identified James, Colin, and Alex, so the only scout remaining is likely to be Peter.

We have decided that Peter is cooking, and the on-duty roster shows Peter down for the 8th.

This also confirms our deduction for question 3 (did they arrive on the day of the picture?). It is likely to be day 2 (not the day of arrival) because Peter is cooking, we have decided, and he cooks on the second day.

He is next on the roster after peter

There is a chicken in the bottom left-hand corner.

By "nearby" we assume a few minutes' walk.

Chickens tend to be kept on farms.

Chickens also tend to keep within about 200 feet of their roost (e.g., their chicken coop), so the farm is likely to be nearby.

How far chickens wander depends on if they find something interesting to eat, which a camp will offer.

They always tend to return to their roost at night.

The flag on the tent is taut and not slack.

The flames on the fire are also leaning in the same direction.

The branches on the trees are bigger on the LEFT side.

The SOUTH facing side of a tree tends to get more sunshine} in the Northern Hemisphere of the Earth.

Science.com | North and South Facing (LINK)

We know we are in the Northern Hemisphere, because we are told the scouts are in Derbyshire.

The flag is pointing the opposite way, so the wind must be going from South to North.

We know that the South side of a tree gets more sunlight. We know that James is facing the same direction.

We also established that the wind is blowing FROM THE SOUTH (known as a SOUTHERLY wind). We therefore (for interest only) know that the Flag is pointing North. James is facing in the opposite direction.

We know that James is facing SOUTH (to the LEFT), the flag is pointing NORTH (to the RIGHT), so looking at the compass points, Peter must be facing EAST (towards us).

Peter is facing EAST and Peter has a long shadow is behind him.

Peter must be facing into the sun because his shadow is behind him.

From our own knowledge, we know that the sun rises in the East, and sets in the West.

We know that Peter is facing EAST, so the sun must be rising.

From our own knowledge, we also know that early in the morning shadows are longer, because the sun is low on the horizon, and at noon there are no shadows because the sun is overhead.

Therefore, because Peter's shadow is long, so we can deduce that it is early in the morning.

What meal do you eat early in the morning? BREAKFAST!

Melons typically ripen in August.

See Melons (LINK).

They would not take an unripe melon with them.

The scouts would be at school in September.

The scouts are not wearing coats, so it must be warm; especially as it is breakfast time.