How To Identify Gulls...A Conundrum

Hint #10:  Don't get discouraged when birding!  Take it from me, I know it can be frustrating when you can't figure out what species of bird you're looking at.  Birding is meant to be fun, enjoyable and exciting, so when you can't figure out the species in that moment, take notes on its color, shape, size, etc and look it up later.

In this post I'm going to identify five common gull species found in San Francisco, California and teach you how to identify them.  I'll also provide tips on what to look for when you are first learning how to identify gull species.  We'll also try to solve a mystery gull species at the end of this post!

Hundreds of gulls (mostly mew gulls) at Crissy Field.  Photo by Kelly Wohlwend (author)

Gulls are incredibly misunderstood birds, in my opinion.  They have a reputation for being lunch snatchers, poop machines, landfill guests and an overall pest.  But in natural settings where people haven't altered their behavior, gulls actually shy away from people and don't accept hand-outs (which is the way it should be).  They are also smart, having learned to get their food out of tough to reach spaces.  I'll tell a story about this in a bit.  I would recommend referring back to my previous post called "Identifying Birds in the Field: The Basics."  This will help with your overall skills in bird identification and is handy to read before continuing on in this post.  It will teach you about field marks, identifiable features on a bird and the basics of bird identification.
 

Gull external anatomy from ibird.com

Anyway, back to the gulls.  The term "seagull(s)" is a generic term applied to all gull species.  The proper way to refer to a gull is merely "gull(s)" or by its species name.  When identifying gulls, there are a few key places on its body you want to look first.  These are the beak, legs and wings.  If you can see them clearly, the eye color and presence or absence of an eye ring are also great features to note.

The reason these body parts are so important when identifying gulls is knowing their shape, color and markings will quickly narrow down the field when you're trying to pinpoint the gull species you're identifying.  

So let's look at our first gull.  Easily one of the most common gull species on the west coast, a frequent picnic crasher and scavenger is the western gull.  In a natural setting, these gulls eat fish and shellfish.  One fantastic adaptation these birds have (like some other gulls, including glaucous-winged gulls) is breaking open shellfish.  On the shores of the San Jaun Islands in Washington state, I have seen these gulls dig clams up on the beach, fly up high, hover in the air for a moment and then drop their clam.  Gravity cracks open the clam on the rocky beach and the gull gets to enjoy a salty, slimy treat.  

Western gull, photo by Kelly Wohlwend (author)

These gulls are easily identified by the key body parts we listed above.  The first thing you want to look at are the feet.  In western gulls they are pink.  Knowing this eliminates half of the gull species found in western North America.  Next, the beak.  It's very large and yellow (minus the red dot on the bottom part of the beak).  The absence of black on the bill further narrows down the candidates.  Thirdly, the wings.  The wings include the gray on the back and the black and white feathers near the tail.  These black and white feathers are called primary feathers and the color of these and the dark gray on the wings is another good indicator of a western gull.  Lastly, the eyes.  This can be tricky but what you're looking at is the eye color.  The iris of the western gull is yellow or considered "pale" in field guides.  A few other things you may notice about this bird is the large, blocky white head and white chest.  The bird overall is rather large, as well, 25 inches long.

California gull, photo by Kelly Wohlwend (author)

The next gull we're going to look at is very similar, which is why I want to do it next.  Take a moment and consider some differences and similarities that you notice before I reveal the species.  

This is a California gull.  A beautiful gull, in my opinion, and very similar to the western gull above.  Let's look at those key body parts.  The feet are yellow!  That feature is the most obvious difference and will allow you to eliminate this as a western gull straight away.  The California gull has a smaller beak and it has different colors than the western gull, it has black markings near the tip and a red mark on the lower half, like the western gull.  The wing color is nearly the same, gray, with black and white primary feathers.   The eyes are different, however, noticeably even.  The California gull has a dark, nearly black iris.  A few more features about this species are the size and head color.  This gull is a bit smaller than the western gull and has a smaller, rounder head.  In breeding season (when this photo was taken) the California gull has an entirely white head, while in nonbreeding season it is streaked brown.

I hope you're doing okay still and encouraged to learn about three more gull species and solve a mystery species at the end!

Ring-billed gull, photo by Kelly Wohlwend (author)

This gull is a bit tricky to identify in the photo.  This is a ring-billed gull.  I hope the reason it was named this is obvious when you look at the photo.  This gull is rather small, nearly 4 inches shorter than the California gull.  It has a small beak with a distinct black ring and NO red.  The legs are yellow (not visible in the water).  When you can't see the legs, the ring on the bill alone would allow you to identify this species.  The wings are a lighter gray than the California gull and the primary feathers (wing tips) are black (not really visible).  The white spots on the wing are smaller than the California or western gull's.  The eyes are pale in color with a red eye ring.  This photo was taken in nonbreeding season, which is why the head has light, brown streaking.  In breeding season it is entirely white.  

Mew gull, photo by Kelly Wohlwend (author)

Our next gull is small, cute and quint and one of my favorites.  It is the mew gull.  It is smaller yet than the ring-billed gull by a little over an inch and has a tiny, yellow beak with a faint ring around it (visible in the photo).  The legs are yellow and the wings are a slightly darker gray than the ring-billed gull with black and white primary feathers (wing tips).  The white spots on the wings are a bit bigger than the ring-billed.  The iris of the eyes are clearly dark with no visible eye ring, similar to the California gull.  The head is small and round and in nonbreeding season (when this photo was taken) is covered in a gray streaking.  In breeding season it is white.  I really like the small size of this gull and it is generally rather shy and lights to congregate in huge flocks, as seen in the picture of Crissy Field above.  

Adult Heermann's gull, photo by Kelly Wohlwend (author)

Juvenile Heermann's, photo by Kelly W.

Our next gull looks completely different than the ones we have just identified.  When I first saw it as a juvenile I had no clue what it was.  For a moment I thought it was a jaeger (type of gull species) but it is a rather common gull, perched on roof tops at Fisherman's Wharf, watching for a french fry or piece of deep-fried fish to fall from someone's plate.   It didn't help that the juvenile (left) looks completely different than the adult (right).  I thought they were different species!  Having never encountered this gull back in Washington state (since their range doesn't extend much north of the bay area) I had to take photos and check my field guide later.  This is a Heermann's gull.  A striking gull with a blood red, beak tipped in black and jet, black legs (which are also seen in jaegers, hence my initial confusion).  The iris of eyes is also dark and in this photo it appears to have a red eye ring, however, this isn't too obvious in my field guide.  The wings are dark gray with nearly all black wing tips.  The white spots in the wing primaries (apparent in the nonbreeding season) disappear and leave them completely black for breeding season.  The adult was photographed in this species breeding season so it has an entirely white head.  The gray prevalent on the rest of the body would spread and cover the head in nonbreeding season.  This gull is also relatively small compared to the western gull we looked at first, measuring 6 inches smaller.  

It's time to use our new gull identification skills to figure out our mystery gull! 

Our mystery gull, photo by Kelly Wohlwend (author)

This gull, to this day, makes me second guess myself.  It was absolutely monstrous looking in person.  Let's start at the beginning.  The beak is large and very thick and yellow with a red spot on the bottom.  The legs are clearly pink.  Okay...starting to look like our first gull, a western gull.  The wings are dark gray and the wing tips are black with obvious white spots.  Hmm...still resembling a western gull.  The eyes are a bit off...they appear dark in the photo and when I saw this bird in person (mind you it was only about 10 feet away) the eyes were not obviously pale like in the photo of the western gull above.  It could just be the evening lighting shading the eye.  Now the head and neck coloring.  There is more gray streaking on this bird than is normally seen in western gulls sporting their nonbreeding season plumage.  It is generally far more subtle and less prominent on the face.  The outstretched, long neck is also strange.  I realize a bird can merely stretch it's neck but it just seemed unusually long and the head doesn't seem as blocky as a western gull's.  Going back to the size of the bird.  It was huge.  It made me go, woah, that's a big bird!  It didn't appear to look like your average western gull.  So what gull species is this?  Honestly, I'm not 100% sure. 

Gulls are tricky.  They hybridize, which means, different species interbreed where their ranges overlap, making gull identification even more difficult.  This could be a glaucous-winged gull x western gull hybrid, which may explain the heavier streaking on the head and perhaps larger body size.  The wings are a big too dark, however.  But it's possible.  It is most likely a western gull that threw me off.   

This is a perfect example as to why gull identification can be frustrating but an exciting challenge, nonetheless.  Remember don't get discouraged, have fun, enjoy yourself and remember to...

Keep Your Eyes On The Sky!