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The Merlin App by The Cornell Lab : Free Bird App Review Part 2

Updated: Nov 13, 2020

The aim of this series of reviews is to provide an overview of the free applications available to birders. There are a number of excellent paid for applications available which we have run a podcast series on previously (, however we believe that some birders may not have the resources to access these apps. The review process will be conducted as objectively as possible as there is clearly a great divide between paid for and free applications in this genre. The rating system will only be judged on criteria consistent across all apps namely search functionality, text, photographs and ease of use. Additional points will be added to the total score for extras such as location settings, calls, offline access, distribution maps and listing settings. This is the second blog in this review series.

As I am an Android user the applications reviewed will be found on Android and hopefully IOS too.

The Merlin application has been published by ‘The Cornell Lab’ which is short for the Cornell Lab of Ornithology which is a member supported unit of the Cornell University in Ithaca, New York, USA. This unit studies birds and wildlife in general.

Description of the app found on the Google Play Store: “What's that bird? Answer 5 questions or upload a photo and Merlin Bird ID will help you solve the mystery.

Merlin is more than just a field assistant to help you identify birds, Merlin is a customizable field guide for birds around the world. Get identification help and discover what birds to look for near you with Merlin Bird ID.

First, Merlin asks you a few simple questions. Then, almost like magic, Merlin reveals a list of birds that best match your description. Pick your bird, then delve into more photos, sounds, and ID tips about your bird! Merlin is fun and easy to use—whether you’re curious about a bird you’ve seen once or you’re hoping to identify every bird that comes to your feeder. The answers are waiting for you with this free field guide app from the renowned Cornell Lab of Ornithology.

If you have a photo of a bird, Merlin can help. Take a photo, choose from your camera roll, or snap a photo of the viewfinder on your camera, and Merlin's powerful AI will suggest an identification almost instantly.”

The language of the app only appears to be available in a very wide variety of languages from English to Spanish, Mandarin etc.

Android and iOs – this app can be found on both platforms as per the below links.

Has adverts: No

Current rating on the Android Playstore: 4.6 stars with over 9000 ratings and more than 1 million downloads

In order to show consistency, I will search for a relatively well-known species on each app.

Search Functionality:

Upon opening the app for the first time, you are prompted to download your relevant country’s bird pack (list of birds). Interestingly the app didn’t pick up that I am in South Africa, but this could have been a slight glitch from my mobile’s GPS. Most other bird apps allow for the Southern African region, however in this case, each country’s pack must be downloaded individually in the region. The South African bird pack contains 705 species whereas two paid for apps show 864 and 877 birds respectively. Be sure to have a stable internet connection when downloading the bird packs as I had some trouble with the download crashing. A quick search of other bird packs revealed many countries of the world which is promising for use outside of our region.

When starting your search for a bird you’ve seen, you are presented with a screen giving three options: Start Bird ID (smart search), Get photo ID (AI search) and Explore birds (manual search). The search functionality is what this app seems to boast about. For the purposes of this review series, I will stick to the manual search functionality (Explore birds) as I will cover the two other options later in this article.

After typing three letters (V-I-O), the app immediately drew me towards Violet-backed Starling as expected.

This app’s major claim to fame is its smart search functionality. On the home screen in bold green colorations is the option ‘Start Bird ID’. This takes the user to a 5-step smart search tool namely location, date of observation, size of the bird, main colouration and behaviour of the bird observed. Interestingly, having seemingly completed the smart search correctly. Violet-backed Starling was not a bird suggested. When this occurs, you are asked to report a ‘no ID’ which I assume helps the app learn that it can improve its suggestions.

Rating: 3.5/5


The text about each species, although original, only covers the main points needed for identification, distribution, behaviour, food items etc. The text is clearly meant to be supplementary to the photographs and identification features. The text offered is adequate without having to go too fate in depth as this is a free application after all.

Rating 3.5/5


The photographs on offer (for Violet-backed Starling) are actual photographs and have a healthy mix of sexual dimorphism and the subject in a variety of habitats. The photographs are high quality, original and are expandable. By expandable I mean you can click on an image as well as zoom in on each image for greater clarity. There are no images of nests or eggs, but again these would just be a nice to have rather than a necessity.

Rating: 4/5

Available offline:

Yes. As the bird packs are downloaded natively to your mobile device, the application works perfectly without data or wifi access as displayed in flight mode here.

User Interface (UI):

The UI is clean and simple to use. This app would be easy for people of all ages. The text is bold, but I couldn’t seems to find any option to enlarge the text for greater ease of reading. You are able to change how birds are displayed by common or scientific names etc. The application links with eBird and with the new to market Swarovski Optik dG smart monocular.

Value adds:

  • Distribution maps: Yes, detailed and display global distribution based on up to date information gleaned from eBird. (1)

  • Calls available in app: Yes, with a variety of calls per species (1)

  • Location settings: Yes, you are able to use your mobile’s inbuilt GPS to assist with species found in your current location (1)

  • Listing settings: Yes, there is a life list setting in the smart search (Smart Bird ID) feature. This list is backed up to the app when you log in with the same email account. (1)

  • Available offline: Yes (1)

  • Smart ID: Yes (1)

Conclusion: This is truly a comprehensive Bird app that competes not only with free apps, but the paid for apps too. The Cornell Lab have gone to great lengths to make birding accessible to larger audience not only locally but the world with this product. I am astonished that all this value is free of charge, and the developers have committed to updating and expanding its reach going forward.

Overall rating: 17/20 *The birds of Southern Africa app was rated out of 18, but was not available offline so still does not qualify for the addition point.


2 commentaires

Tyron Dall
Tyron Dall
14 oct. 2020

Nick Burnett, The biggest asset of Merlin is the artificial intelligence algorithm they have for identifying birds from photos. We have tried it on a number of very tricky species, including juvenile raptors and it got it bang on correct everytime. We were actually truly shocked at how good it was. Also as far as I know only BirdPro get their distribution maps from SABAP2.


Nick Burnett
Nick Burnett
14 oct. 2020

The biggest issue I have with Merlin is the bird names, many are not the recognized South African names e.g. Hadada instead of Hadeda and Piping Cisticola instead of Neddicky. Yellow Billed Kite is listed as Black Kite as they consider it a subspecies, which is true of quite a few others and can cause some frustration.

The distribution maps are very rough and don’t offer the same as what you get from the other apps which use SA bird atlas project data.

It’s ok as a free app but doesn’t offer the kind of focus you get from the paid apps.

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