This week, we're celebrating gulls! There are about 55 widely recognized species of gull in the world. We'd like to share some of the extreme facts and interesting statistics found within this diverse family.

Smallest Gull Species
The Little Gull, weighing in at around 4.2 ounces (120 grams), is the smallest species of gull. Its length is  9.8 to 12 inches (25 to 30 cm).

Largest Gull Species
The largest gull species in the world is the Great Black-backed Gull, which weighs in at around 62 ounces (1750 grams), almost 15 times as heavy as the Little Gull. It's length is 2.1 to 2.6 feet (64 to 79 cm). 

The Longest Living Gulls
Gulls, particularly the large "white-headed" gulls, can be long-lived. The longevity record for the European Herring Gull is 49 years! The longest-lived wild Great Black-backed Gull was over 27 years old.

Cross-Species Parenting
The Black-headed Duck of South America is known to be a brood parasite of the Brown-hooded Gull. The duck lays eggs in nests of other birds (including other ducks and other gulls) and lets the nest-owners do the incubating! The ducklings are able to leave the nest just hours after hatching, making their escape without otherwise disturbing the nest. The Brown-hooded Gull or other nesting adult will continue to care for its own eggs and chicks.

Tale of the Tails
Most species of gull have a rounded tail. There are only three exceptions: the Sabine's Gull and Swallow-tailed Gull have forked tails, and the Ross's Gull has a wedge-shaped tail.

Longest Migration
Many species of gull are migratory. The Franklin's Gull may have the longest migration of all the gulls. They breed as far north as central Canada, and spend the winter as far south as Chile and Argentina.

Rare Gulls & Threatened Species
The Lava Gull of the Galapagos Islands is considered to be Vulnerable to extinction. The small population of less than 400 pairs is relatively stable but the species is probably the rarest of all the gulls.

The Black-billed Gull of New Zealand is considered to be Endangered. The population has been on a rapid decline since the introduction of invasive predators to New Zealand, like weasels and cats.

Other species considered to be Vulnerable to extinction are the Relict Gull of central Asia, the Saunders's Gull of eastern Asia, and the both the Red-legged Kittiwake and the Black-legged Kittiwake.

Most Abundant
The Ring-billed Gull was once hunted for its feathers. With protection the species has rebounded and is likely the most common species of gull in North America.

Night Vision
The Swallow-tailed Gull is a "black-headed" gull found in the Galapagos Islands. They are the only completely nocturnal gulls in the world! They feed on squid and fish that only come to the water's surface at night. In order to be able to see in the dark, the Swallow-tailed Gull has very large eyes -- larger than any other gull species!

Join us in the following days as we celebrate all things gulls with our second Gull Week! Our first Gull Week was back in 2015. Gulls are part of a widespread family of social and intelligent seabirds.

Birdorable has 23 species of gull so far, out of the approximately 55 recognized species of gull in the world. We'll add a couple more this week to make it a cool 25!

To kick off the week, let's take a look back at how we've featured gulls here at Birdorable in the past:

• We shared a Gull Glossary of terms and keywords related to gulls. Read more
   
• We told readers about Gulls Named for People, like Bonaparte's Gull and Heermann's Gull. This week we'll add another one of these named gulls to Birdorable! Read more
   
• We shared the story of a particular individual Lesser Black-backed Gull named Pierre. Read more
   
• We added three species to our collection of free downloadable bird coloring pages. Read more

• We answered some Frequently Asked Questions About Gulls. We'll have another batch of Gull FAQs for this Gull Week. Read more
   
• We laughed at some silly Gull Jokes, complete with accompanying goofy gull photos. Read more

Since our first Gull Week, we've added a couple of new species to the family. Check out our Grey-hooded Gull and Iceland Gull. We hope you'll join us this week as we celebrate gulls on the Birdorable blog!

If you think our Birdorable birds are cute as adults, what about when they are babies? Below are some baby photos (shared via Flickr Creative Commons) of the Horned Lark.

Female Horned Larks build the nest alone. A natural depression is found, or a cavity is dug by loosening soil and flipping it away with beak and feet. Woven plant material is formed into a nest inside the cavity, which is then lined with soft material like fur and feathers. Once the eggs are laid, incubation, performed only by the female Horned Lark, takes around 11 days. Chicks are fed a diet of mostly insects while growing in the nest.

Baby Horned Larks typically leave the nest 8-10 days after hatching. It takes another two weeks before they are able to walk and fly as well as adults.

This adorable t-shirt design features four of our Birdorable birds that are common in back yards across the United States and Canada. The birds that are perched together in this original cartoon design are: American Goldfinch, Northern Cardinal, American Robin and Black-capped Chickadee.

Cute Backyard Birds is available on many different t-shirt styles and colors for men, women and children. The shirt shown above is a Girls' Fine Jersey T-Shirt, a super-soft ribbed collar shirt made of 100% combed ringspun cotton.

These shirts will make a great gift for anyone that loves their backyard birds! Click through to Zazzle to customize and order yours today!

Did you know that some species of bird feed their chicks milk? It's true, but it's not the same kind of milk that mammal mothers feed their young.

This baby bird food is secreted from the lining of the parent bird's crop and then regurgitated to the baby birds. It is high in protein and fat as well as other components important for their growing chicks to consume, like anti-oxidants, ("good") bacteria, and substances to improve the immune system.

All species of pigeons and doves feed crop milk to their young -- for these species the substance is called pigeon milk. Flamingos also feed their young a type of milk, though production occurs in more of the upper digestive tract than just the crop. Male Emperor Penguins produce a similar substance to feed their chicks when the mother bird is away at the time of hatching.

In pigeons and doves, parent birds begin to produce the milk days before their eggs hatch. The chicks, called squabs, eat only crop milk for the first week after hatching. Afterwards other foods are introduced, after being softened inside the parent bird's crop.

This week's featured t-shirt design is our Birdorable Kakapo in BOOOOOM!!! which is shown here on a Kids' Basic Long Sleeve T-shirt from Zazzle. The model shown above is 4'7" and is wearing a small.

The critically endangered Kakapo parrot (or Owl Parrot) of New Zealand is the only flightless species of bird to use a lek breeding system for mating. During part of the lekking process, males compete for females by displaying and making a "booming" sound. Boom! Males position themselves kilometers apart to signal to potential mates.

This fun and original Birdorable design is inspired by the booms of the lekking Kakapo. Pick this up for the Kakapo lover on your list! Only true Kakapo fans will "get" this unique and cute cartoon design.

Earlier this month, the Iiwi ('I'iwi), a beautiful Hawaiian finch, was introduced as the American Birding Association's Bird of the Year for 2018. We think it's an interesting and excellent choice!

In 2016 Hawaii was added the ABA Birding area by popular vote, and the process of adding species to the official checklist was completed last year. So it makes sense to feature a Hawaiian species in 2018.

The Iiwi is a type of finch, part of a group of Hawaiian honeycreepers. More than 50 species of honeycreeper used to call Hawaii home. Today less than half of those species still exist. They face threats including predation by introduced species and competition from invasive birds, as well as habitat loss and disease.

Of the native birds of Hawaii, the Iiwi is the most common.

The beautiful Iiwi can be recognized by its bold scarlet and black plumage, and by its long curved bill. In many ways the Iiwi behaves like a hummingbird, hovering in flight and drinking flower nectar.

Be sure to visit the ABA's Bird of the Year page to learn more about the Iiwi!

Today our 2017 Birdorable Bonanza concludes with a superb species: the Superb Lyrbird!

The Superb Lyrebird is a large species of songbird native to Australia. Several facts make this amazing bird a very interesting study.

It belongs in the passerine bird order, which makes it a songbird. But it is the size of a pheasant, and weighs in at 2lb or more, making it one of the most heavy species of songbird, rivalled only by ravens.

The Superb Lyrebird is one of two species of lyrebird. They get their common name from the shape of the spectacular tail of adult males, part of which forms the shape of a lyre (a musical instrument).

Superb Lyrebirds are known for their amazing ability to mimic a wide variety of sounds. Watch this short clip from BBC Wildlife featuring a singing male lyrebird.

Pretty amazing, right? With this awesome bird we conclude our 2017 Birdorable Bonanza! Thanks for following along.

Our 2017 Birdorable Bonanza is winding down! Just one more bird to go after today's newbie: the African Spoonbill!

The African Spoonbill is one of six species of spoonbill found in the world. They are all long-legged wading birds with the uniquely shaped bill that gives them their name. The African Spoonbill joins the Roseate and the Eurasian here at Birdorable.

Male and female African Spoonbills look alike. As chicks, they have small and stubby beaks which gradually grow into the spoon-tipped shape.

African Spoonbills do well in captivity and are found in zoos around the world. They are abundant throughout their native range and the population is considered to be stable. They may live up to 15 years in the wild.

Tomorrow our Bonanza wraps up with our 677th bird, a species known for its ability to mimic sounds. And check out that tail! Can you guess the bird?

Today's new Birdorable is the White-winged Guan!

The White-winged Guan is a critically endangered species found in a small area of Peru. They live around ravines and feed on things like seeds, fruit, leaves, and other plant matter.

White-winged Guans were thought to be extinct for about one hundred years, the time between recorded sightings of the species. When it was rediscovered in the late 1970s, a captive breeding program was introduced in an effort to save the species.

The current wild population of the White-winged Guan is very small, with a likely count of 250 individual birds or fewer. There are two distinct populations, a northern group and a southern group. Threats facing survival of the species include hunting and habitat destruction.

Tomorrow we'll add a species of spoonbill to Birdorable. There are six species of spoonbill in the world, and we already have the Roseate Spoonbill and the Eurasian Spoonbill. Our new bird does not have a black face, a yellow bill, or a royal name. That just leaves one...