So why all the bird noises, cat? What are you trying to tell me here?

Is it excitement, does the thought of hunting and catching of the prey cause those cat noises?
Pedigree Petfood's book "Your Guide to Cats & Kittens" observed that a cat’s vocabulary increased as it matured. Initially, newborn kittens only purred (contentment) or mewed (distress). They learned to interpret the wider range of noises made by their mother, and in response they developed the ability to make a wider variety of communicative sounds. In fact this process continues throughout a cat's life - owners who frequently talk to their cats are often rewarded by cats who "talk" back to them.
My cats make an array of other noises that communicate very specific things.
Joe K:
The video in question does not show the CAT-control picket fence noise. It seems to be some other fault causing a "crackling".

In fact it is pretty obvious the CAT cable isn't even connected in that video. (2m28s in)

@Catnoise hasn't Tweeted yet.Whereas my older cat- who is very vocal makes wonderful "Churrup" noises to greet me.For instance, dogs produce 10 different noises, while cats produce about 100.
Research into the myriad of noises that domestic cats (and their wild cat ancestors and cousins) make has yielded some interesting facts and conclusions. Living with three cats for many years has given me a unique opportunity to observe many different cat sounds (often called cat calls) under various behavioral circumstances.A female cat in heat will yowl and meow a lot, sometimes for hours on end. Along with the yowling a female may roll on the floor and display other signs of being in heat. The noise and behavior can last up to ten days at a time.CATS MEOWING LOUDLY - 10 Cats and Kittens Sounds and noises to make your cat go crazy HD Cats Sound Effects
10 dog Breeds barking:
10 sounds to annoy your cat:

Cats meowing loudly non stop to make your cat or dog go crazy or to annoy them. Cats meowing loudly compilation that will make your cat go crazy.
Cute kittens meowing, angry cats, annoying cats, and more. Each cat meowing will make your cat go mad!

Cat meows video and noises to make your cat angry, to scare mice, to attrack dogs and cats, a lot of cat noises.

cats meowing sound effects, cat meowing, cats meowing compilation, cats meowing loudly, cats meowing angry. Loud cat meows!If you listen closely, you’ll notice your cat has an extensive vocabulary of cat noises, and each sound means something different. How chatty your cat is will depend on her personality, but all cats are capable of communicating through this form of feline language.Meows, purrs, hisses, chatters, and trills—your cat’s noises aren’t as random as you think. Hisses and purrs are easy to figure out, but as one of the most vocal of all domesticated pets, cats employ a long list of sounds to communicate their feelings, thoughts, and needs.How do you tell if a cat actually likes a noise? The researchers looked at how much their subjects purred, rubbed against speakers and oriented their head toward the music.When leaving the house for the day, many people flick on their stereo in hopes that the noise might help keep their cat company. But shows that felines probably don’t care for our tunes. Just like your college roommate, cats appear to have very specific preferences when it comes to music—and their tastes have little to do with what you might like.If you’d prefer a less vocal cat, consider a Persian, Russian Blue, Chartreux, Norwegian Forest Cat, or Maine Coon. These breeds tend to be on the quieter side. But breed-specific guidelines are not failsafe; you could end up with a noisy Persian or a silent Siamese!