Migratory Route

Create four 1/1 white Bird creature tokens with flying.
Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Plains

Rootborn Defenses

Populate. Creatures you control gain indestructible until end of turn. (To populate, create a token that's a copy of a creature token you control.)

Sejiri Refuge

Sejiri Refuge enters tapped.
When Sejiri Refuge enters, you gain 1 life.
{T}: Add {W} or {U}.

Wing Shards

Target player sacrifices an attacking creature.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Augury Owl

Flying
When Augury Owl enters, scry 3. (Look at the top three cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Crookclaw Elder

Flying
Tap two untapped Birds you control: Draw a card.
Tap two untapped Wizards you control: Target creature gains flying until end of turn.

Battle Screech

Create two 1/1 white Bird creature tokens with flying.
Flashback—Tap three untapped white creatures you control. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Bower Passage

Creatures with flying can't block creatures you control.

Messenger Falcons

Flying
When Messenger Falcons enters, draw a card.

Selesnya Locket

{T}: Add {G} or {W}.
{G/W}{G/W}{G/W}{G/W}, {T}, Sacrifice Selesnya Locket: Draw two cards.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Soulcatcher

Flying
Whenever a creature with flying dies, put a +1/+1 counter on Soulcatcher.

Sage Owl

Flying
When Sage Owl enters, look at the top four cards of your library, then put them back in any order.

Seaside Citadel

Seaside Citadel enters tapped.
{T}: Add {G}, {W}, or {U}.

Soulcatchers' Aerie

Whenever a Bird is put into your graveyard from the battlefield, put a feather counter on Soulcatchers' Aerie.
Bird creatures get +1/+1 for each feather counter on Soulcatchers' Aerie.

Aven Mindcensor

Flash
Flying
If an opponent would search a library, that player searches the top four cards of that library instead.

Seaside Haven

{T}: Add {C}.
{W}{U}, {T}, Sacrifice a Bird: Draw a card.

Selesnya Sanctuary

Selesnya Sanctuary enters tapped.
When Selesnya Sanctuary enters, return a land you control to its owner's hand.
{T}: Add {G}{W}.

Keeper of the Nine Gales

Flying
{T}, Tap two untapped Birds you control: Return target permanent to its owner's hand.

High Sentinels of Arashin

Flying
High Sentinels of Arashin gets +1/+1 for each other creature you control with a +1/+1 counter on it.
{3}{W}: Put a +1/+1 counter on target creature.

Arctic Aven

Flying
Arctic Aven gets +1/+1 as long as you control a Plains.
{W}: Arctic Aven gains lifelink until end of turn. (Damage dealt by this creature also causes you to gain that much life.)

Grow from the Ashes

Kicker {2} (You may pay an additional {2} as you cast this spell.)
Search your library for a basic land card, put it onto the battlefield, then shuffle. If this spell was kicked, instead search your library for two basic land cards, put them onto the battlefield, then shuffle.

Teshar, Ancestor's Apostle

Flying
Whenever you cast a historic spell, return target creature card with mana value 3 or less from your graveyard to the battlefield. (Artifacts, legendaries, and Sagas are historic.)

Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

River Hoopoe

Flying
{3}{G}{U}: You gain 2 life and draw a card.

Azorius Guildgate

Azorius Guildgate enters tapped.
{T}: Add {W} or {U}.

Derevi, Empyrial Tactician

Flying
When Derevi, Empyrial Tactician enters and whenever a creature you control deals combat damage to a player, you may tap or untap target permanent.
{1}{G}{W}{U}: Put Derevi onto the battlefield from the command zone.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Emeria Angel

Flying
Landfall — Whenever a land you control enters, you may create a 1/1 white Bird creature token with flying.

Tah-Crop Elite

Flying
You may exert Tah-Crop Elite as it attacks. When you do, creatures you control get +1/+1 until end of turn. (An exerted creature won't untap during your next untap step.)

Kangee, Aerie Keeper

Kicker {X}{2} (You may pay an additional {X}{2} as you cast this spell.)
Flying
When Kangee, Aerie Keeper enters, if it was kicked, put X feather counters on it.
Other Bird creatures get +1/+1 for each feather counter on Kangee, Aerie Keeper.

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

Dismantling Blow

Kicker {2}{U} (You may pay an additional {2}{U} as you cast this spell.)
Destroy target artifact or enchantment. If this spell was kicked, draw two cards.

Icefeather Aven

Flying
Morph {1}{G}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Icefeather Aven is turned face up, you may return another target creature to its owner's hand.

Fertile Ground

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Simic Locket

{T}: Add {G} or {U}.
{G/U}{G/U}{G/U}{G/U}, {T}, Sacrifice Simic Locket: Draw two cards.

Forest

Aerie Mystics

Flying
{1}{G}{U}: Creatures you control gain shroud until end of turn. (They can't be the targets of spells or abilities.)

Mist Raven

Flying
When Mist Raven enters, return target creature to its owner's hand.

Secluded Steppe

Secluded Steppe enters tapped.
{T}: Add {W}.
Cycling {W} ({W}, Discard this card: Draw a card.)

Thieving Magpie

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Thieving Magpie deals damage to an opponent, draw a card.

Stormscape Familiar

Flying
White spells and black spells you cast cost {1} less to cast.

Eyes in the Skies

Create a 1/1 white Bird creature token with flying, then populate. (Create a token that's a copy of a creature token you control.)

Selesnya Guildgate

Selesnya Guildgate enters tapped.
{T}: Add {G} or {W}.

Archetype of Imagination

Creatures you control have flying.
Creatures your opponents control lose flying and can't have or gain flying.

Urban Evolution

Draw three cards. You may play an additional land this turn.

Aven Cloudchaser

Flying (This creature can't be blocked except by creatures with flying or reach.)
When Aven Cloudchaser enters, destroy target enchantment.

Aetherstorm Roc

Flying
Whenever Aetherstorm Roc or another creature you control enters, you get {E} (an energy counter).
Whenever Aetherstorm Roc attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it and tap up to one target creature defending player controls.

Bronzebeak Moa

Whenever another creature you control enters, Bronzebeak Moa gets +3/+3 until end of turn.

Rupture Spire

Rupture Spire enters tapped.
When Rupture Spire enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Opal Palace

{T}: Add {C}.
{1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

Negate

Call

Create four 1/1 white Bird creature tokens with flying.
Fuse (You may cast one or both halves of this card from your hand.)

Beck

Whenever a creature enters this turn, you may draw a card.
Fuse (You may cast one or both halves of this card from your hand.)

Beck // Call

Aven Sunstriker

Flying
Double strike (This creature deals both first-strike and regular combat damage.)
Megamorph {4}{W} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Wingmate Roc

Flying
Raid — When Wingmate Roc enters, if you attacked this turn, create a 3/4 white Bird creature token with flying.
Whenever Wingmate Roc attacks, you gain 1 life for each attacking creature.

Aven Mimeomancer

Flying
At the beginning of your upkeep, you may put a feather counter on target creature. If you do, that creature has base power and toughness 3/1 and has flying for as long as it has a feather counter on it.

Airborne Aid

Draw a card for each Bird on the battlefield.

Raven Familiar

Flying
Echo {2}{U} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Raven Familiar enters, look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Mana Geode

When Mana Geode enters, scry 1.
{T}: Add one mana of any color.

Palace Familiar

Flying
When Palace Familiar dies, draw a card.

Thrummingbird

Flying
Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Murmuring Mystic

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.

Healer's Hawk

Murder of Crows

Flying
Whenever another creature dies, you may draw a card. If you do, discard a card.

Cloudchaser Kestrel

Flying
When Cloudchaser Kestrel enters, destroy target enchantment.
{W}: Target permanent becomes white until end of turn.

Aven Wind Guide

Flying, vigilance
Creature tokens you control have flying and vigilance.
Embalm {4}{W}{U} ({4}{W}{U}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a white Zombie Bird Warrior with no mana cost. Embalm only as a sorcery.)

Simic Guildgate

Simic Guildgate enters tapped.
{T}: Add {G} or {U}.

Tidings

Island

Warden of Evos Isle

Flying
Creature spells with flying you cast cost {1} less to cast.

Gustcloak Savior

Flying
Whenever a creature you control becomes blocked, you may untap that creature and remove it from combat.

Azorius Keyrune

{T}: Add {W} or {U}.
{W}{U}: Azorius Keyrune becomes a 2/2 white and blue Bird artifact creature with flying until end of turn.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Transguild Promenade

Transguild Promenade enters tapped.
When Transguild Promenade enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Windreader Sphinx

Flying
Whenever a creature with flying attacks, you may draw a card.

Expedition Raptor

Flying
When Expedition Raptor enters, support 2. (Put a +1/+1 counter on each of up to two other target creatures.)

Judge's Familiar

Flying
Sacrifice Judge's Familiar: Counter target instant or sorcery spell unless its controller pays {1}.

Tempt with Glory

Tempting offer — Put a +1/+1 counter on each creature you control. Each opponent may put a +1/+1 counter on each creature they control. For each opponent who does, put a +1/+1 counter on each creature you control.

Saltcrusted Steppe

{T}: Add {C}.
{1}, {T}: Put a storage counter on Saltcrusted Steppe.
{1}, Remove X storage counters from Saltcrusted Steppe: Add X mana in any combination of {G} and/or {W}.

Azorius Chancery

Azorius Chancery enters tapped.
When Azorius Chancery enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Cloudfin Raptor

Flying
Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)

Flurry of Wings

Create X 1/1 white Bird Soldier creature tokens with flying, where X is the number of attacking creatures.