In iBird the illustration and all the data about it are accessed by a sliding array of 14 buttons at the bottom of the page.

Each button opens a large scrolling screen full of information about each topic.

There are over 14 full pages of data per species.

A single tap opens the illustration in full screen.

The details displayed with the image are crisp, comprehensive and easy to read.

At a glance you will see the Latin name, family name, order, bandcode and overview of the species.

In addition to beautiful hand drawn illustrations iBird also provides several thousand photos.

In this case we see a detailed flight view of the Peregrine falcon. iBird is the only app that offers BOTH illustrations and photographs.

In Sibley the only detail is provided in a short paragraph under the drawing.

Range map and audio are accessed by two buttons.

This lack of information is somewhat compensated by the larger number of drawings of each species.

However the drawings are the same tiny size as those in his book.

Here is the Sibley drawing after tapping it once to make it full screen.

Note how small the image is and that it can’t be zoomed any larger.

Other than it being an adult of the Pacific variety no additional information is provided.

To read about the bird you need to close the screen and scroll the tiny half devoted to text.

Audubon has a static menu of 8 buttons at the bottom of the screen.

To read about the species you close the photo and tap the section called Description.

The quality of the information in the app is very good.

The app uses only photos, there are no illustrations like are found in Sibley and iBird.

Here is the Audubon photo after tapping it once to make it full screen.

Note the image does not use entire screen of the iPhone.

While the photo can be zoomed it becomes fuzzy.

The National Geographic app has a single scrolling page.

To access the remaining information about the bird you scroll down to 5 categories for describing the bird.

The information is adequare but not as extensive as other apps. Suprisingly the company that produces the finest printed field guide on the market did not put the same effort into their app.

To see the larger version of the illustration you tap the Images menu.

Unfortunately when the image is zoomed it pixelates and becomes fuzyy as you can see here.

The National Geographic app is also one of the smallest with only about 83 MB while the others are all around 500 MB.

Peterson can be a perplexing app to navigate. There is no single isolated image of the species, instead its part of a collage of other drawings.

It’s the only app that has no search box where you can access the bird by typing its name. Instead you must manually scroll though “pages” of drawings until you find the composite containing the species you want, tap it, then tap an icon to see the illustration full size.

Here we see the largest view of the species.

Unfortunately Roger Peterson drew a collection of birds which overlap so its not possible to isolate just a single view of any species.

As you can see the head of the female is cut off. There is no way to pan the drawing to bring it into view nor can it be zoomed to see more detail.