The Seagull is one of the most useful companions in Birb because it lets you automatically catch fish while you continue working on other parts of your progression. But there is a lot more going on behind the scenes than simply sending a Seagull out to fish.
In this guide, we will go through everything you need to know about Seagull fishing, including Luck, fish rarity, routes, Doctrines, Weather Forecasts, rerolls, Expedition Fish, and Shiny Fish. I’ll also explain which setups are worth using depending on whether you want better fish, more XP, or Expedition Fish.
Keep in mind that Birb changes frequently, so some numbers or mechanics may change in future updates. The information below is based on the current mechanics covered by this guide, so use it as a reference when planning your Seagull setup.
Birb Seagull Fishing, Shiny Fish & Weather Forecast Guide
The Seagull lets you send your companion out on fishing routes where it automatically catches fish.
Several different systems affect the results of each catch:
- Luck affects the rarity distribution of normal fish.
- Routes determine the Seagull’s fishing interval.
- Doctrines change fishing speed, XP, weight, Sparrow Share, and rerolls.
- Forecasts provide temporary bonuses to a specific Doctrine.
- Rerolls can create additional chances to catch Expedition Fish.
- Shiny mechanics determine your chance of getting Shiny Fish.
Understanding how these systems work together is important if you want to get the most out of your Seagull.
Luck and Fish Rarity
Luck determines how the game weights fish when it chooses your catch.
Every fish has a base weight, which acts as its relative probability inside its rarity group. Your total Luck then modifies those weights differently depending on the fish’s rarity.
This means increasing Luck does not simply give every fish the same boost. Instead, higher Luck pushes the normal catch pool toward higher rarities while suppressing common fish.
Rod Tiers and Luck
There are currently 23 rods across tiers 0 through 8.
| Tier | Number of Rods | Luck Range | Example Rods |
|---|---|---|---|
| 0 | 1 | 1 | Simple Rod |
| 1 | 3 | 1.5–2.5 | Sturdy, Reinforced, Professional |
| 2 | 3 | 4–7.5 | Fiberglass, Carbon Fiber, Steam |
| 3 | 3 | 10–15 | Coconut, Nature’s Root, Banana |
| 4 | 3 | 20–30 | Lizard, Pirate’s Hook, Bone |
| 5 | 3 | 45–50 | Jade, Sapphire, Apex Predator |
| 6 | 2 | 100–120 | Infernal, Void |
| 7 | 3 | 250–350 | Rune, Ancient Jungle, Abyssal Depth |
| 8 | 2 | 425–500 | Prismatic, Divine |
Higher-tier rods generally provide significantly more Luck and also unlock access to higher-tier fish.
How Total Luck Is Calculated
Your total Luck is calculated by multiplying several different factors together:
Total Luck = Rod Luck × Level × Prismatic Badge × Bait × Lure × Hook × Luck Control
Here is what each factor means:
| Factor | Formula / Value | Description |
|---|---|---|
| Rod | Lrod | Fixed Luck value of your equipped rod |
| Level | 1 + (Level − 1) × 0.02 | Adds 2% per fishing level |
| Prismatic Badge | 1 + 0.5 × highest Rod Tier | Requires the Sunflower upgrade |
| Bait | Bait’s Luck value | Applies when the bait provides Luck |
| Lure | Lure’s Luck value | Applies when the lure provides Luck |
| Hook | Hook’s Luck value | Depends on the hook |
| Luck Control | Slider % / 100 | Cursed Hook only |
For example, hooks can provide different Luck multipliers:
- Bronze: 1.15x
- Iron: 1.30x
- Gold: 1.50x
- Diamond: 1.75x
The Cursed Hook is particularly interesting because its Luck Control slider can reduce your effective Luck all the way to 0%.
That sounds bad for normal fishing, but as we’ll see later, deliberately lowering Luck can actually be extremely useful when farming Expedition Fish.
How Luck Changes Fish Weights
Each fish has a base weight. The game modifies this weight according to its rarity and your total Luck.
| Rarity | Weight Adjustment |
|---|---|
| Legendary | Weight × 0.15 × Luck^1.4 |
| Epic | Weight × Luck^1.2 |
| Rare | Weight × Luck^0.9 |
| Uncommon | Weight × Luck^0.6 |
| Common | Weight ÷ Luck |
This is why increasing Luck has a compounding effect.
Higher rarities receive stronger Luck scaling, while Common fish are actively suppressed as your Luck increases.
The game then uses the adjusted weights to perform a weighted random selection from the available catch pool.
Other Fish Weight Modifiers
Luck is not the only thing that changes fish weights.
Several other modifiers can also affect the final catch pool.
Rod-cost fish receive a 6x weight multiplier, or 6.9x with the Precision Cast upgrade, regardless of their rarity. This helps you obtain fish needed for your next rod.
Tier gating also limits which fish can appear. The catch pool only includes fish where:
Minimum Tier ≤ Rod Tier + 1
Fish that are two or more tiers above your rod are completely excluded.
If a fish is exactly one tier above your rod, its weight is reduced to 0.15x.
There are also upgrades that affect junk:
- Junk Filter reduces Common junk weight by 50%.
- Treasure Hunter doubles the weight of non-Common junk.
Seagull Routes
Your Seagull can use different routes, and each route has an interval multiplier that affects how quickly it catches fish.
| Route | Interval Multiplier |
|---|---|
| Bridge | 1.00x |
| Floor 1 | 1.18x |
| Floor 2 | 1.22x |
| Floor 4 | 1.28x |
A lower interval multiplier means faster catches.
So the Bridge has the fastest base interval, while Floor 4 takes longer between catches.
However, you shouldn’t automatically choose the fastest route in every situation. Expedition Fish are tied to specific expedition floors, so Floors 1, 2, and 4 can be important when you are specifically farming those fish.
Seagull Doctrines
Every Seagull can be assigned a Doctrine.
There are three main Doctrines:
| Doctrine | Interval | XP | Sparrow Share | Weight | Rare Reroll | Rare Penalty |
|---|---|---|---|---|---|---|
| Balanced | 1.00x | 1.00x | 1.0x | 1.00x | 0% | 0% |
| Hunter | 1.30x | 0.94x | 0.8x | 1.18x | 72% | 0% |
| Training | 1.02x | 1.45x | 2.0x | 0.92x | 0% | 56% |
Balanced
Balanced is the safe default.
It doesn’t provide major bonuses or penalties, making it a reliable choice when you don’t have a specific farming goal.
Hunter
Hunter makes your Seagull catch more slowly, but it provides significantly better rare-fish mechanics.
You get:
- 1.30x interval
- 0.94x XP
- 0.8x Sparrow Share
- 1.18x fish weight
- 72% Rare Reroll
- No Rare Penalty
Hunter is particularly useful when you care about rare fish or Expedition Fish.
Training
Training focuses heavily on XP and Sparrow Share.
You get:
- 1.02x interval
- 1.45x XP
- 2.0x Sparrow Share
- 0.92x weight
- No Rare Reroll
- 56% Rare Penalty
The major downside is the 56% Rare Penalty, which can cause your good Rare+ catches to be rerolled into something worse.
For that reason, Training is best when your priority is XP or Sparrow progression rather than maximizing fish quality.
Rare Reroll
Rare Reroll gives your Seagull another chance when its initial catch is below Rare.
When a Common or Uncommon fish is caught, the game can perform another roll and keep whichever result has the higher rarity.
There is a baseline 15% reroll chance that happens before the Doctrine-specific reroll.
This means even Balanced gets a small additional chance to improve a low-rarity catch.
Hunter takes this much further with its 72% Rare Reroll.
Forecasts can add even more reroll chance. For example:
- Predator Wake: +25%
- Blood Tide: +38%
These bonuses can stack with Hunter’s Doctrine reroll when the Forecast matches.
Rare Penalty
Rare Penalty works in the opposite direction.
When a Seagull catches a Rare or better fish, the penalty can trigger another roll. Instead of keeping the better result, the game keeps the lower-rarity result.
Training has a 56% Rare Penalty, so more than half of your Rare+ catches can potentially be downgraded when the penalty triggers.
Fortunately, some Forecasts reduce this penalty.
King’s Tide provides a 100% penalty reduction, completely removing Training’s penalty.
Other examples include:
- Study Current: 20% penalty reduction
- Archive Bloom: 38% penalty reduction
This is why Training can become much more attractive when you have a Forecast that reduces or completely removes its penalty.
Weather Forecasts
Forecasts are temporary effects that change the performance of your Seagull.
They rotate every hour of playtime, and the timer does not continue changing while you are offline.
Most importantly, a Forecast’s bonuses only apply when your Seagull’s Doctrine matches the Forecast’s favored Doctrine.
For example, if you have a Hunter Seagull, a Balanced-favored Forecast will not give you its matching bonuses.
Common Forecasts
| Forecast | Weight | Favored Doctrine | Interval | XP | Share | Weight | Rare Reroll | Penalty Reduction |
|---|---|---|---|---|---|---|---|---|
| Bustling Shoal | 34.0 | Balanced | 0.88x | 1.00x | 1.0x | 1.00x | 0% | 0% |
| Predator Wake | 26.0 | Hunter | 1.00x | 1.00x | 1.0x | 1.12x | 25% | 0% |
| Study Current | 26.0 | Training | 1.00x | 1.12x | 1.2x | 1.00x | 0% | 20% |
Bustling Shoal
Bustling Shoal favors Balanced.
Its main advantage is its 0.88x interval, making Balanced Seagulls catch faster while maintaining the normal Balanced mechanics.
Predator Wake
Predator Wake favors Hunter.
It gives Hunter an additional 25% Rare Reroll and increases fish weight by 1.12x.
This makes it particularly useful for rare-fish and Expedition Fish farming.
Study Current
Study Current favors Training.
It provides:
- 1.12x XP
- 1.2x Sparrow Share
- 20% Rare Penalty reduction
This makes it a strong Forecast when your goal is Seagull XP and Sparrow progression.
Rare Forecasts
| Forecast | Weight | Favored Doctrine | Interval | XP | Share | Weight | Rare Reroll | Penalty Reduction |
|---|---|---|---|---|---|---|---|---|
| Silver Thermals | 6.0 | Balanced | 0.84x | 1.02x | 1.00x | 1.04x | 12% | 10% |
| Blood Tide | 4.5 | Hunter | 0.96x | 1.02x | 1.00x | 1.18x | 38% | 0% |
| Archive Bloom | 4.5 | Training | 0.98x | 1.20x | 1.45x | 1.00x | 0% | 38% |
Silver Thermals is a strong Balanced Forecast because it makes catches faster while also providing a 12% Rare Reroll.
Blood Tide is excellent for Hunter because it gives another 38% Rare Reroll and increases fish weight.
Archive Bloom is one of the better Training Forecasts because it gives 1.20x XP, 1.45x Sparrow Share, and reduces Training’s Rare Penalty by 38%.
Legendary Forecast: King’s Tide
King’s Tide is the only Legendary Forecast listed in this system.
| Forecast | Weight | Favored Doctrine | Interval | XP | Share | Weight | Rare Reroll | Penalty Reduction |
|---|---|---|---|---|---|---|---|---|
| King’s Tide | 1.0 | Rotates | 0.82x | 1.15x | 1.25x | 1.20x | 42% | 100% |
King’s Tide is special because its favored Doctrine changes every hour between Balanced, Hunter, and Training.
It also provides a huge 100% Rare Penalty reduction, which completely removes Training’s 56% penalty.
This makes Training + King’s Tide an extremely powerful combination when the Forecast is currently favoring Training.
You keep Training’s:
- 1.45x XP
- 2.0x Sparrow Share
and gain King’s Tide’s:
- 1.15x XP
- 1.25x Sparrow Share
- 1.20x weight
- 42% Rare Reroll
- 100% Rare Penalty reduction
Forecast Chances
The total Forecast weight is:
34 + 26 + 26 + 6 + 4.5 + 4.5 + 1 = 102
This gives the following approximate chances per hour:
| Forecast Rarity | Combined Weight | Approximate Chance |
|---|---|---|
| Common | 86 | 84.31% |
| Rare | 15 | 14.71% |
| Legendary | 1 | 0.98% |
So Common Forecasts are by far the most frequent, while a Legendary Forecast such as King’s Tide is extremely rare.
Best Forecast Tips
I recommend checking all four routes every hour.
Different routes can have different Forecast offsets, meaning one route may have a Rare or Legendary Forecast while another route is showing a Common Forecast.
You should also match your Doctrine to the Forecast whenever possible. The Forecast bonuses only apply when its favored Doctrine matches the Seagull’s active Doctrine.
If King’s Tide appears, check which Doctrine it currently favors before assigning your Seagull.
Best XP Combination
When King’s Tide favors Training, Training + King’s Tide is one of the strongest XP combinations.
King’s Tide removes Training’s entire Rare Penalty while allowing you to keep Training’s massive XP and Sparrow Share bonuses.
Second-Best XP Combination
Training + Archive Bloom is another excellent XP setup.
Archive Bloom reduces Training’s Rare Penalty by 38% while adding:
- 1.20x XP
- 1.45x Sparrow Share
This makes it a very strong choice when your main goal is leveling and Sparrow progression.
Expedition Fish
Expedition Fish are special fish that can only be caught on expedition floors.
They are found on:
- Floor 1
- Floor 2
- Floor 4
Each floor has its own unique Expedition Fish.
You also need the Divine Rod to catch them.
The important thing about Expedition Fish is that their catch chance is normally fixed and is not affected by Luck, rod tier, bait, or lure.
The game checks for Expedition Fish before moving to the normal weighted fish pool.
However, rerolls create additional Expedition Fish checks.
This is where things get interesting.
How Rerolls Affect Expedition Fish
Every reroll is essentially another fresh catch attempt, meaning the game checks the Expedition Fish chances again.
| Mechanic | Trigger | Extra Roll |
|---|---|---|
| Base catch | Every catch | 1 |
| Baseline reroll | Below Rare, 15% chance | +1 |
| Doctrine reroll | Below Rare, Hunter 72% | +1 |
| Forecast reroll | Below Rare | +1 |
| Rare penalty | Rare+, Training 56% | +1 |
| Specialist Seagull | Initial catch | Up to +50 |
| Desert upgrade | Dispatched catch below Rare | +1 |
This means maximizing the number of rerolls can dramatically increase the number of times the game checks for an Expedition Fish.
Why Low Luck Is Better for Expedition Fish
This is one of the most unusual mechanics in Seagull fishing.
Normally, you would think that higher Luck is always better. But for Expedition Fish farming, low Luck can actually be better.
Expedition Fish themselves are not affected by Luck.
However, Luck affects the normal fish pool.
With high Luck, the normal pool is more likely to produce Rare+ fish. When that happens, you may not trigger the reroll mechanics.
With very low Luck, the normal pool produces sub-Rare fish much more frequently. That means your rerolls trigger more often, giving you additional Expedition Fish checks.
The Cursed Hook is extremely useful here because its Luck Control slider can be set to 0%.
By reducing your Luck, you can intentionally increase the frequency of sub-Rare results and therefore maximize your reroll opportunities.
Best Expedition Fish Farming Setup
If you’re specifically farming Expedition Fish, I recommend this setup:
| Slot | Recommended Choice | Reason |
|---|---|---|
| Doctrine | Hunter | 72% Rare Reroll |
| Hook | Cursed Hook with minimum Luck | Forces more sub-Rare catches |
| Forecast | Blood Tide / Predator Wake | +38% / +25% reroll |
| Seagull | Specialist | Can produce up to 50 checks |
| Upgrade | Rare Routes | Adds baseline 15% reroll |
| Upgrade | Tackle Crate | Adds another reroll for dispatched Seagulls |
With the right combination of rerolls, you can potentially get many Expedition Fish checks from a single catch.
The Specialist Seagull is especially powerful because it can perform up to 50 checks on its initial catch.
Hunter vs Balanced for Expedition Fish
A common question is whether Hunter is actually better than Balanced for Expedition Fish.
Hunter catches more slowly because of its 1.30x interval, while Balanced has no Doctrine reroll.
Once the shared upgrades and Forecasts are included, the difference becomes much closer.
Expedition Checks Per Catch
With low Luck, almost every normal catch is sub-Rare, so the reroll mechanics can trigger frequently.
| Source | Balanced | Hunter |
|---|---|---|
| Base catch | 1 | 1 |
| Rare Routes | 0.15 | 0.15 |
| Doctrine reroll | 0 | 0.72 |
| Tackle Crate | 1 | 1 |
| Total | 2.15 | 2.87 |
Hunter therefore gets more Expedition Fish checks per catch.
But Hunter’s slower interval needs to be considered when comparing the two.
Expedition Checks Per Cycle
Some useful combinations are:
| Setup | Approx. Checks/Cycle |
|---|---|
| Hunter + Blood Tide | 2.60 |
| Balanced + Silver Thermals | 2.70 |
| Hunter + Predator Wake | 2.40 |
| Balanced + King’s Tide | 3.13 |
| Hunter + King’s Tide | 3.09 |
| Balanced, unmatched | 2.15 |
| Hunter, unmatched | 2.21 |
Interestingly, Balanced can slightly outperform Hunter when both are using their ideal matched Forecast.
However, Forecast availability changes the overall result.
Overall Hunter vs Balanced
When all Forecast probabilities are considered, Hunter comes out slightly ahead for Expedition Fish farming.
The estimated results are:
- Hunter: 2.28 checks per cycle
- Balanced: 2.19 checks per cycle
That means Hunter has approximately a 4.1% overall advantage.
Hunter benefits from having more Forecasts that provide reroll bonuses, including the common Predator Wake, while its 72% Doctrine reroll remains useful even when the Forecast does not match.
So if Expedition Fish are your main goal, I would use Hunter.
What About Training?
Training isn’t recommended for Expedition Fish farming.
Its Rare Penalty does create another Expedition Fish check, but the penalty keeps the lower-rarity result. That means it can potentially downgrade a good catch.
Training is better saved for XP and Sparrow Share rather than Expedition Fish.
Shiny Fish Chance
Shiny Fish work differently depending on where the fish comes from.
The most important thing to remember is:
Luck does not affect Shiny Fish chance.
So stacking Luck will not increase your Shiny chance.
Manual Fishing Shiny Chance
When fishing manually, the Shiny chance is:
| Fish Type | Shiny Chance |
|---|---|
| Legendary | 0.001% — 1 in 100,000 |
| Other non-junk fish | 0.002% — 1 in 50,000 |
| Junk | 0% |
Junk can never be Shiny.
These are flat chances, so there are no additional Luck modifiers to increase them.
Seagull Normal Catch Shiny Chance
Normal Seagull catches have their own Shiny chance.
| Condition | Shiny Chance |
|---|---|
| No Moonlit Scales | 0.001% — 1 in 100,000 |
| Moonlit Scales, recently resolved | 0.001% |
| Moonlit Scales, 250 hours since last resolve | 0.0015% |
| Moonlit Scales, 500+ hours since last resolve | 0.002% — 1 in 50,000 |
The Moonlit Scales milestone is unlocked at Migration 75.
It increases Shiny chance based on the amount of time between resolves.
A resolve happens when you collect your offline earnings summary after opening the game.
The effective multiplier is:
1 + min(2, hours / 1000 × 2)
The Shiny chance is capped at 0.002%, meaning the maximum is 2x the base chance.
That cap is reached after approximately 500 hours.
Seagull Daily Legendary Shiny Chance
The Seagull’s Daily Legendary Catch has by far the highest Shiny chance.
| Upgrade | Shiny Chance | Cooldown |
|---|---|---|
| Base, Migration 50+ | 1% — 1 in 100 | 24 hours |
| Legend Beacon | 3% — 1 in 33 | 16 hours |
The Daily Legendary Catch guarantees a Legendary fish on the Bridge.
If you have the Legend Beacon, the Shiny chance increases from 1% to 3%, while the cooldown drops from 24 hours to 16 hours.
So if you’re specifically hunting for Shiny Fish, the Daily Legendary Catch is easily the most important mechanic to take advantage of.
Best Seagull Setup for Different Goals
Best for Normal Fishing
For general-purpose fishing, Balanced is the safest choice.
It doesn’t have the major penalties of Training or the slower catch rate of Hunter.
Best for Rare Fish
Use Hunter when you want better rare-fish chances.
Its 72% Rare Reroll combined with Forecast bonuses makes it very strong for chasing higher-rarity catches.
Best for XP
Use Training when your main goal is Seagull XP or Sparrow Share.
If you get King’s Tide while it favors Training, this becomes especially powerful because the Legendary Forecast completely removes Training’s Rare Penalty.
Best for Expedition Fish
For Expedition Fish, use:
Hunter + Cursed Hook with Luck Control at 0%
Then look for Blood Tide or Predator Wake.
If you have a Specialist Seagull and the relevant upgrades, the number of Expedition Fish checks can become extremely high.
Best for Shiny Fish
Luck isn’t what you should focus on for Shiny hunting.
Instead, take advantage of the Daily Legendary Catch, especially if you have the Legend Beacon.
The 3% Shiny chance with the Beacon is dramatically higher than the normal manual or Seagull Shiny rates.
The Seagull has a lot of hidden depth, so I recommend changing your setup depending on what you’re currently farming rather than keeping one Doctrine permanently.
For general use, Balanced is the easiest option.
For rare fish and Expedition Fish, Hunter is generally the better choice, especially when you can take advantage of rerolls and low Luck.
For XP and Sparrow progression, Training is the way to go, especially when a Forecast such as Archive Bloom or King’s Tide reduces its Rare Penalty.
Always check the Forecasts before committing to a route. A rare or Legendary Forecast can completely change which Doctrine is worth using.
And if you’re farming Expedition Fish, remember the unusual rule: more Luck isn’t always better. Lowering Luck with the Cursed Hook can produce more sub-Rare catches, which means more rerolls and therefore more Expedition Fish checks.