Professional Field Guide (Bird Identifier) for 515 bird species inhabiting Europe - from the Atlantic Ocean to the Urals, and from the Arctic Ocean to the Mediterranean Sea. The list of bird species included in the app can be viewed at https://ecosystema.ru/eng/apps/21birds_eu.htm

BIRDS IDENTIFIER
The application has a built-in polytomic Bird Identifier (Identification Filter), which helps to determine the unknown bird by 24 different features. You can select the region of Europe, the size of the bird, plumage coloration, streaks, beak and feet shape and color, distinctive features of appearance, behavior, habitats, location of a sitting bird, song and calls, daily activity, nest size, shape, construction material and location, eggs size and color. The Identifier will help you to narrow down the range of species for unknown bird.

TERRITORY OF USE
The application covers most of the territory of Europe and can be successfully used in the most part of Northern, Western, Central, Southern and Eastern Europe, including Scandinavia, Baltic States, France, Spain, Balkan countries, Transcaucasia, Northern Kazakhstan and other adjacent territories.

22 EUROPEAN LANGUAGES
The app is composed on 22 European languages, including English, German, French, Spanish, Italian, Hellenic and others. The user can choose any of these languages.

BIRDS CALLS
For each of 515 bird species, the app provides one combined recording, including male songs and several most typical calls – alarm, aggression, interaction, contact and flight calls, etc. Each of the recordings can be played in four different ways: 1) once, 2) in a loop without interval, 3) in a loop with an interval of 10 seconds, 4) in a loop with an interval of 20 seconds.

PHOTOS AND DESCRIPTIONS
For each species, a several photos of the bird in nature (male, female or immature, bird in flight), distribution maps and eggs are given, as well as a text description of the appearance, behavior, features of reproduction and feeding, distribution and migrations.

QUIZ
The app has a built-in Quiz, which can train you to recognize birds by their voices and appearance. You can play the quiz repeatedly – the questions for recognizing species alternate in random order and are never repeated! The difficulty of the Quiz can be adjusted – change the number of questions, change the number of answers to choose from, turn on and off bird images.

PURCHASES AND SUBSCRIPTIONS
* the application is downloaded from the Store in the format of a free demo version, valid indefinitely (forever);
* in the free (demo) version, you can test all sections of the application no more than three times a day.
* you can access all the features of the app by purchasing or subscribing to any groups in any ratio;
* PURCHASE is made once and gives access to the purchased content for your account forever; the purchase prices are as follows: the "All Birds" group is $12.00, any geographical region - $7.50, any systematic or ecological group of birds is $2.50;
* SUBSCRIPTION gives access to the purchased content for a period of 1 year; the subscription costs are as follows: the "All Birds" group is $5.00, any geographical region - $3.50, any systematic or ecological group of birds is $1.50;
* plus sales tax applicable in your country.

THE VOICES OF BIRDS CAN BE PLAYED IN NATURE!
In the presence of the Internet, the voices of birds can be played directly in nature. After paying for in-app purchases, all functions can be used offline, including in the areas without the Internet - on ornithological excursions, walks in the country, on expeditions, hunting or fishing.

THE APPLICATION IS DESIGNED FOR:
* bird watchers and professional ornithologists;
* university students and faculty at on-site seminars;
* teachers of secondary schools and additional (out-of school) education;
* forestry workers and hunters;
* employees of nature reserves, national parks and other nature protected areas;
* all other nature lovers.