Reproductive Behavior

The way in which gulls mate is actually quite similar to humans in that monogamy is the accepted way to go! Most seagulls began the reproduction process of selecting a mate at around the age of 4. During this time, male seagulls work to show off in a variety of ways so they will be selected by the females as reproductive mates. Below is an image of two male seagulls taking part in this behavior.

Once a seagull has found her mate, however, their behavior remains pretty calm because all courtship behaviors are complete. Although gulls do settle in colonies or groups, each couple has their own personal plot of land (check out the last post for more information on that!). Divorce does happen on occasion with gulls; however, it is not often and the cost of the break up can persist for a few years after it occurs. The majority of gulls will breed once a year, producing a clutch size of three eggs. After the eggs are born, they being about a month long incubation process. At this point having a reliable mate is essential for seagulls. The parents will take turns incubating the eggs, allowing the their mate to feed.

An interesting fact regarding gulls and their courting behavior is they take part in homosexual mate selection. Similar to elephants and the very familiar Homo sapian, some gulls will select same sex mates. There was a particularly high instance of this off the coast of Santa Barbara. Although it is unclear why exactly gulls take part in this behavior, it possibly has to do with the high female to male ratio on the islands. Studies regarding this behavior continue to find out more about the lesbian seagulls that have caused quite the ruckus in both homosexual and conservative groups.

http://en.wikipedia.org/wiki/Gull

http://www.spwickstrom.com/seagull/

http://www.flickr.com/photos/goingslo/4527336492/ (image)

http://articles.latimes.com/1993-06-20/local/me-5238_1_channel-island

Territorial Behavior

Because seagulls nest in large colonies, they are also incredibly territorial in that they are protective of their homes. As a protection mechanism, many gull colonies use mobbing behavior, in which they attack and harass possible predators or intruders. Particularly during nesting and mating behaviors, the Gull can be very territorial. Many bird mates secure only a few meters worth of land by verbalizing their presence with specific calls or demonstrating it with a variety of displays. If other gulls decide to ignore such calls, the birds tend to become violent in their attempts to keep their area. Specific calls used by gulls are the “long call” as a threat, a “mew” used as a support call from a fellow mate, a “kek kek” is used when a colony as a whole is disturbed, a “yeow” is also used for the two previous functions. Specific postures are also used to communicate with other gulls. For examples of the previous calls and for posure examples, you can watch the movie attached!

But what happens when this protective territorial behavior is applied to an urban setting according to National Geographic News, urban Britain has really faced these problems. All across Britain there have been issues with swarming, attacking, and defecating on pedestrians. Even an 80-year-old Welshman suffered a fatal heart attack after being swooped by the gulls. Why exactly are these issues happening though? According to the Royal Society for the Protection of Birds, it is because of the loss of cliff top breeding sites due to coastal development.

http://en.wikipedia.org/wiki/Gull

http://www.youtube.com/watch?v=zF8Jl2oBf5I

http://news.nationalgeographic.com/news/2003/01/0107_030107_seagulls.html

Eating Habits Foraging Behavior

Most gulls, including the common Larus species I referred to in the taxonomy post, are carnivores and like to eat live food like crabs and small fish. Their jaws unhinge, making it very easy for them to eat prey larger than expected. Some species of the gull (the Herring Gull) have really tricky ways of getting food. They use tools such as bread as bait to catch small fish. As many of us also know, the gull has gotten very good at cohabiting with humans and indulging in our food. Other gulls use “kleptoparasitism” to obtain food. In short, they steal food from other animals rather than catching their own. Gulls have even been seen landing on whales and picking off flesh from their backs… who would have thought a seagull would be so aggressive it would take on a whale??

One gull that has an interesting method of foraging is the California Gull. Like many other gulls, it is commonly seen scavenging at garbage dumps or docks, but the way it forages for flies is different! It starts at one end of a large swarm of flied and runs through the swarm with its mouth open snapping up flies. Sometimes seagulls’ attraction to human food has caused some ruckus in the human world. In 2009 at a Kansas City vs. Indians baseball game, a pack of seagulls arrived toward the end of an extra inning and camped in the outfield. When a hit ball struck one of the birds it was very alarmed and deflected the ball away from the outfielder, allowing the Indians to score the winning run!

http://www.ehow.com/about_6618858_seagull_s-diet.html

http://en.wikipedia.org/wiki/Gull

http://www.spwickstrom.com/seagull/

Top 50 Animal Images 2011 (honestly has nothing to do with Seagulls...)

On a very random side note that has nothing to do with Seagulls... I thought I would share this link with my Animal Behavior classmates. It is the top 50 animal pictures of 2011, and has some great images! Enjoy!!

http://www.stumbleupon.com/su/9liDjF/www.buzzfeed.com/mjs538/incredible-photos-of-animals-from-2011/

Evolutionary Background and Taxonomy

First things first, my blog is slightly deceiving… the “Seagull” depicted’s name isn’t actually seagull, but Larus occidentalis, or a Western Gull. This is the species name, or the most specific way of categorizing a creature. Taxonomy can be a very confusing so as a little review, the different aspects of categorization are: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species (want an easy way to remember this? Just remember “Dumb kids playing chicken on freeways get squished!”). When applying this to the seagull we all see on the beach, the taxonomy is:

- Domain: Eukaryota

- Kingdom: Animalia

- Phylum: Chordata

- Class: Aves

- Order: Charadriformes

- Family: Laridae

- Genus: Larus

- Species: Larus occidentalis

Other gulls are part of the Laridae Family: Genus Ichthyaetus, Leucophaeus, Chroicocephalus, and others, making them all very close relatives. Although some posts in this blog (like this one!) will focus on either larger or more specific aspects of gulls, it will primarily focus on the Larus genus of the Laridae family.

The evolutionary background of the Aves Class is actually very interesting in that it highlights their evolutionary similarities to reptiles and dinosaurs. One of the most important finding that caused this bird-dinosaur hypothesis was that of the 150-million year old Archaeopteryx (check out the picture below!). This oldest bird on record had one essential characteristic that identified it as a bird: feathers. This clinching characteristic of a bird was found alongside reptilian jaw bones and an extended boney tail just like a reptile. In addition to this ancient bird’s similarities with reptilian dinosaurs, other similarities between the first birds and dinosaurs include (but are not limited to): eggshell microstructure, ankle held above the ground (you might think a bird’s knee is backwards, but that is actually because it isn’t it’s knee, but it’s ankle!), hollow bones, large eye openings in the skull and s-shaped curved neck. From these incredibly early beginnings, the bird evolved into an extremely diverse group with a variety of features that evolved dependent on naturally selected capabilities to succeed.

Think it looks anything like a Seagull??

References

- http://www.ucmp.berkeley.edu/diapsids/avians.html

- http://www.pbs.org/lifeofbirds/evolution/

- http://en.wikipedia.org/wiki/Gulls#Taxonomy

Photo Credit

- http://www.guardian.co.uk/science/2011/oct/26/archaeopteryx-bird-family-tree

After their famous appearance in Disney's Finding Nemo, seagulls have been labeled as selfish and annoying birds. Especially now that I live on Mission Beach, these birds are seriously everywhere and their behavior can be less than appealing to most. But why do they do the things that they do? What explains their behavior? I hope to answer questions like these in my blog about seagulls and their behavior! Based out of my Psychology 344 class, Animal Behavior, this blog will include both structured and open ended posts regarding this bird's actions and the psychological explanation behind this behavior.