Birds
- RSPB Guide to Birds
- Common Garden birds
- BTO Bird Identification
- BTO BirdFacts
- How to identify wildlife in owl pellets
- Bird feathers
- Bird skulls
Mammals
- Mammal Society: British mammals
- UK Whales and Dolphins species guide
- Scottish WIldlife Trust: Introduction to tracks and trails
- How to identify droppings (Wildlife Trusts)
- How to identify wildlife in owl pellets
Flora
- Botanical Society of Scotland
- British Bryological Society
- BSBI Plant Crib
- BSBI – Plant ID: getting started
- Freshwater Diatom Flora of Britain and Ireland
- Tree Identification
- Tree Identification Guide (Natural History Museum)
- Tree identification (Woodland Trust)
- Orchid Observers Identification Guide
- Orchid observers Identification Guide (downloads a pdf)
- British Carex
- Key to Groups of British Grasses
- Vegetative Grasses
- Key to Plant Families
Galls and Gall causation
- Plant parasites – Leafminers, Galls and Fungi Plant Parasites – Leafminers, Galls and Fungi
- Fungal, mite, insect galls Leafminers and plant galls of Europe
- Fungal, mite, insect galls British_galls (Yahoo group)
- Leaf miners Leafminers and plant galls of Europe
- Leaf miners Keys to UK leaf and stem miners
Coastal and Marine
- Seaweed – Big Seaweed Search
- Seaweed identification (NHBS)
- Bivalve shells Marine Bivalve Shells of the British Isles (Mollusca: Bivalvia)
- Sea slugs Nudibranchs British Isles
- Stalked jellyfish Stauromedusae – photographic guide
- Marine, Maritime, Oceanic and similar Lichens
Amphibians and Reptiles
- Amphibians and Reptiles
- Frogs, toads Frogs, Toads and Spawn
- Newts Newts
- Snakes Snakes
- Lizards Lizards
Invertebrates
- Spider and Harvestmen Recording Website British Myriapod and Isopods
- Spiders and Harvestmen Spiders and Harvestmen
- Spiders Spiders North West Europe
- Money spiders UK Linyphiidae
- Harvestmen Harvestmen (Opiliones) in the UK
- Earthworm Identification Earthworm Key
- Land flatworms Update on native and alien land flatworms (2023)
- Molluscs Mollusc Identification Guides
- Sea slugs Nudibranchs British Isles
- Bivalve shells Marine Bivalve Shells of the British Isles (Mollusca: Bivalvia)
- Stalked jellyfish Stauromedusae – photographic guide
Beetles – Coleoptera
- Beetles
- British Beetles
- British Coleoptera
- Key to Beetle Families
- Key to the British Species of Carabus (Ground Beetles)
- Dung Beetles Key to the British Species of Beetles Geotropidae
- Beetles feeding on dead wood Saproxylic Beetles
- Burying Beetles UK Beetles Silphidae
- Ladybirds UK Ladybirds
Flies – Diptera
- Leaf miner flies Agromyzidae of Great Britain and Ireland
- Barkflies Barkflies
- True Flies British Diptera
- Blowflies Blowflies (Calliphoridae)
- Blowflies, Woodlice Flies British Calliphoridae and Rhinophoridae
- Dagger flies Empididae – Diptera
- Dagger flies Empididae – Diptera
- Louse flies, keds Northwestern European Hippoboscidae
- Louse flies, keds Hippoboscidae
- Horse flies, clegs, deer flies Family Tabanidae (Horse flies, clegs & deer flies)
Bugs – Hemiptera
- Bugs British Bugs – Hemiptera
- Froghoppers Froghoppers
- Aphids Aphids
- Aphids Aphid identification and resources
- Leafhoppers, planthoppers, treehoppers, froghoppers and cicadas Key to Families within the Auchenorrhyncha (Hoppers and Cicadas)
- True bugs and aphids Identification Guides to the Hemiptera (true bugs) of Britain
- Waterbugs Waterbugs – Aquatic Heteroptera
Bees, Wasps, Sawflies, Ants – Hymenoptera
- Bumblebees Bumblebees
- Bees, Wasps and Ants Bees, Wasps & Ants
- Bees and Wasps British Hymenoptera
- Sawflies British and Irish Sawflies
- Ichneumonid wasps (Darwin wasps) Beginner’s guide to identifying British ichneumonids
- Social Wasps Social Wasps Part 1
- Social Wasps Social Wasps Part 2
Butterflies, Moths – Lepidoptera
- Butterflies Butterflies
- Butterfly Conservation – Highlands and Islands Branch Butterfly Conservation – Highlands and Islands Branch
- Moths UK Moths
- Moth Flight Times and Maps Scottish Moth flight times and distribution maps
- Scottish Micro Moth Distribution Maps Scottish micro moth distribution maps
- What’s Flying Tonight – guide to Moths that may be flying
Dragonflies, Damselflies, Aphids, Booklice, Caddis Flies, Millipedes, Centipedes, Grasshoppers, Earwigs, Alder Flies, Dobson Flies, Bristletails, Silverfish and Firebrats
- Dragonflies and Damselflies British Dragonflies and Damselfies
- Booklice, Barklice or Barkflies Identification Guides for the British Psocoptera
- Caddis Flies Keys for the identification of British caddis flies (Trichoptera)
- Millipedes Millipedes: British Myriapod & Isopod Group
- Centipedes Centipedes: British Myriapod & Isopod Group
- Woodlice Woodlice and Waterlice: British Myriapod & Isopod Group
- Earwigs Earwigs – Dermaptera
- Grasshoppers Grasshoppers – Orthoptera recording scheme
- Grasshoppers and Crickets (in Dutch, but Google will translate) Grasshoppers Characteristics Guide – Orthoptera identification – grasshopper, crickets, locusts
- Alder Flies and Dobson Flies Alder flies, Dobson flies – Megaloptera
- Bristletails Bristletails – Microcoryphia (Archaeognatha)
- Royal Entomological Society Keys Royal Entomological Society Keys
- Silverfish and Firebrats Silverfish, Firebrats – Zygentoma
Lichens
Fungi
Astronomy/Night Sky
Miscellaneous Guides
Mapping