Martı daha yukarıda uçuyor.

A natural word-by-word breakdown is:

• martı = seagull / gull
• daha = more, further, or in many contexts part of a comparative idea like higher
• yukarıda = up above, higher up, in a higher place
• uçuyor = is flying

So the sentence literally feels like:

• The seagull is flying further up / higher up.

Daha often adds the idea of more or further.

In this sentence, it combines with yukarıda to mean:

• higher up
• further up

So:

• yukarıda = up above
• daha yukarıda = higher up

This is very common in Turkish.
For example:

• daha büyük = bigger
• daha hızlı = faster
• daha yukarıda = higher up

It does not have to mean more in a strictly literal way every time; often it just forms a comparative meaning.

This is a very common learner question.

• yukarı = up, upwards, the upper part
• yukarıda = up above, in a higher place

The ending -da is the locative suffix, which often means in / at / on.

So:

• yukarı has more of a directional or general up idea
• yukarıda describes a location/position: up there, higher up

In this sentence, the bird is being described as flying at a higher position, so yukarıda fits well.

Uçuyor is the present continuous form of uçmak (to fly).

Structure:

• uç- = verb stem
• -uyor = present continuous ending

So uçuyor means:

• is flying
• sometimes also flies in context, but the most direct meaning is is flying

Turkish present continuous is used a lot, often more widely than English is ...-ing.

Because Turkish is usually an SOV language:

• Subject
• Object
• Verb

Even though this sentence has no object, the verb still normally comes last:

• Martı = subject
• daha yukarıda = adverbial phrase
• uçuyor = verb

So the order is very natural.

English prefers:

• The seagull is flying higher up

Turkish prefers:

• Seagull higher up is-flying

That final verb position is one of the most important word-order habits in Turkish.

Yes, Turkish word order is flexible, but the neutral version here is:

• Martı daha yukarıda uçuyor.

You can move things for emphasis, for example:

• Daha yukarıda martı uçuyor.
  = Higher up, a seagull is flying.

This can sound more marked or context-driven.

But for a learner, the given order is the safest and most standard one.

This is due to two rules:

1. Vowel harmony
2. Consonant voicing

The locative suffix has four forms:

• -da
• -de
• -ta
• -te

In yukarıda:

• the last vowel of yukarı is ı, so the suffix takes the a-type vowel
• the word ends in a vowel, so the consonant is d, not t

That gives:

• yukarı + da = yukarıda

So this is exactly what Turkish spelling rules predict.

It can mean either, depending on context.

Turkish does not have direct equivalents of English a/an and the in the same way.

So martı may be understood as:

• a seagull
• the seagull

The broader context tells you which one is intended.

If the meaning has already been shown to the learner, then that probably settles which English translation fits best in that situation.

Not normally in this context.

Yukarıda can sometimes mean upstairs or above, depending on the situation. But with martı (seagull) and uçuyor (is flying), the natural meaning is:

• higher up
• up above

So the image is of the bird flying at a higher altitude or position, not inside a building.

Yes. Depending on nuance, Turkish might also use things like:

• yüksekte = at a high place / high up
• daha yüksekte = higher up
• yukarda = a common spelling variant of yukarıda in some usage, though yukarıda is the standard form

The given sentence is completely natural, but Turkish often has more than one way to express higher up.

Not always.

The Turkish present continuous can describe:

• something happening right now
• something currently in progress
• sometimes a repeated or characteristic action, depending on context

So Martı daha yukarıda uçuyor most directly means:

• The seagull is flying higher up

But in the right context, Turkish present continuous can be slightly broader than English is flying. Context decides how temporary or immediate it feels.