Binoculars
There is a huge range of binoculars on offer, to fit various budgets. Look for one that does close-focussing (2 meters or less) so you can use them to look at insects such as butterflies and dragonflies. Binoculars commonly have a spec such as 8x32 or 10x42. The first number refers to the magnification (eg. 8 times or 10 times) and the second to the diameter of the objective lens. Whilst x10 magnification sounds better, the downside is that you see a narrower field of view which can make it harder to scan larger areas or find your subject. Larger objective lenses gather more light but the downside here is that they have more glass so weigh more. Ultimately it comes down to personal choice.
Camera
A camera is essential equipment for recording, both to help you identify what you've seen but also to attach to your record as evidence. As most UK wildlife is small, a camera with a good macro function is really helpful. Mobile phones are fine for plants and larger species but less effective for anything small and especially if it flies. However many small and cheap compact cameras have excellent macro abilities, and also have the benefit of easily fitting in your pocket, so you don't have to spend very much.
Higher quality images generally require a better camera (though the photographer is the most important factor!). Serious wildlife recorders and photographers will usually invest in either an SLR or a bridge camera. Raynox lenses are clip on magnifiers that attach to the front of your camera and these are popular as a relatively inexpensive way of adding a much closer focussing ability to your camera.
Hand lens
A hand lens is essential for plant identification, and can be a major asset for invertebrates too. Being light and small you can carry it with you at all times. They aren't expensive but ensure you get a glass (not plastic) lens. x10 is a good starting point. Some have multiple lenses that can be used separately or rotated together to give various magnifications.
Microscope
Whilst most people are familiar with a microscope they probably think of peering down the lens to view prepared slides at magnifications of 100x or higher. However the more useful type of microscope for the naturalist and wildlife recorder is a 'stereo' or 'binocular' microscope. This type has two eyepiece lenses which you view with both eyes together. Think of binoculars - but with the stereo microscope bringing small creatures or samples into an amazing 3-D view. A good basic model starts at around £130 so they are not too expensive.
Microscope Club: a great to learn microscopy skills. The club meets monthly at the Rutland Water Volunteer Centre.
Nets
A pond net is essential for finding aquatic life. A white plastic tray is usually used with the net so you can empty and examine your catch in this.
Sweep nets are useful for catching small invertebrates hiding in vegetation.
Pots and tubes
Most serious recorders will need to bring home specimens to examine (and identify) at home, usually with access to books and keys as well as a microscope. These are sold in every size and shape but keen recyclers can often make their own from small food containers, etc.
Where to buy?
The following are just a few suggestions:
Natural History Book Store - sells just about everything mentioned on this page!
Field Studies Council - excellent range of ID books and leaflets.
Watkins and Doncaster - lepidopterist supplier, plus general entomology equipment.
One-Stop-Nature - a Norfolk-based shop offering a wide range of microscopes, binoculars, etc.
ArthroPods - UK made accessories for entomologists.
Specimens
The ethics of taking specimens
Is it ever acceptable to kill a specimen in order to identify it? Some think not, if you love wildlife how could you then contemplate killing something? This is a legitimate moral stance and in this case you have to accept that some species cannot then be identified. Others will argue that nearly all small invertebrates have a very short life, are found in huge numbers and taking one specimen has no impact on the population. Furthermore, we know so little about most invertebrate species that only by gathering data on distribution and population trends can we make the case for conservation. Ultimately it is up to the individual to decide.
If you do decide to collect a specimen then this must be done with care, only taking the minimum number and avoiding causing any distress. Special consideration needs to be given to avoid collecting specimens, or parts of plants, if it is known to be rare. With experience, it may be possible to examine the live specimen in the field using a hand-lens and be able to see the key characters, thus enabling its release.
Collecting specimens
It is usual to collect invertebrate specimens in the field and put them in small tubes or lidded containers. Plant and fungi specimens can be collected in a similar way and then stored in a fridge to avoid dessication and keep them fresh. Inverts are best euthanised as soon as possible. It is possible to do this in the field with the right equipment, alternatively it should be done as soon as you return home.
Most invertebrates can be euthanised by putting the pot or container in a freezer, which is believed to be a quick and painless method. Various killing fluids can be purchased and a few drops can be put on an absorbent material and placed in the container with the specimen. Crushed Cherry Laurel leaves do this job as a more natural alternative.
Pinning/Carding/Preserving
If your species is rare or particularly hard to identify you may be expected to keep it as a voucher specimen so that it can be checked later if necessary. Most adult insects have a hard exoskeleton so keep their shape (and external features) when dried out. These can be 'pinned' by pushing a thin pin through the specimen and mounting this on a soft base in an airtight box. It is imperative that it has a tight lid to avoid pests or fungus infections. Soft-bodied specimens are usually stored in alcohol - which be purchased from entomological supplies such as Watkins and Doncaster. Plants and mosses can be dried and then stored out of the light in an envelope or bag.