Loyal Gyrfalcon

Defender, flying
Whenever you cast a white spell, Loyal Gyrfalcon loses defender until end of turn.

Gustcloak Skirmisher

Flying
Whenever Gustcloak Skirmisher becomes blocked, you may untap it and remove it from combat.

Aven Sentry

Phantom Flock

Flying
Phantom Flock enters with three +1/+1 counters on it.
If damage would be dealt to Phantom Flock, prevent that damage. Remove a +1/+1 counter from Phantom Flock.

Courier Hawk

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.

Castle Raptors

Flying
As long as Castle Raptors is untapped, it gets +0/+2.

When We Were Young

Up to two target creatures each get +2/+2 until end of turn. If you control an artifact and an enchantment, those creatures also gain lifelink until end of turn.

Commanding Presence

Enchant creature
Enchanted creature gets +2/+2 and has first strike and "Whenever this creature deals combat damage to a player, create a 1/1 white Human Soldier creature token."

Dawnfeather Eagle

Flying
When Dawnfeather Eagle enters, creatures you control get +1/+1 and gain vigilance until end of turn.

Scour the Desert

Exile target creature card from your graveyard. Create X 1/1 white Bird creature tokens with flying, where X is the exiled card's toughness.

Territorial Roc

Heron of Hope

Flying
If you would gain life, you gain that much life plus 1 instead.
{1}{W}: Heron of Hope gains lifelink until end of turn.

Gustcloak Savior

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

Sanctuary Raptor

Flying
Whenever Sanctuary Raptor attacks, if you control three or more tokens, Sanctuary Raptor gets +2/+0 and gains first strike until end of turn.

Supply-Line Cranes

Flying
When Supply-Line Cranes enters, put a +1/+1 counter on target creature.

On Serra's Wings

Enchant creature
Enchanted creature is legendary, gets +1/+1, and has flying, vigilance, and lifelink.

Swooping Protector

Flash
Flying
Swooping Protector enters with a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

Sky Crier

Flying, lifelink
{3}{W}: You and target opponent each draw a card.

Lieutenant Kirtar

Flying
{1}{W}, Sacrifice Lieutenant Kirtar: Exile target attacking creature.

Steel-Plume Marshal

Flying
Whenever Steel-Plume Marshal attacks, other attacking creatures you control with flying get +2/+2 until end of turn.

Military Discipline

Flash
Enchant creature
When Military Discipline enters, enchanted creature gains first strike until end of turn.
Enchanted creature gets +1/+0.

Aven Gagglemaster

Flying
When Aven Gagglemaster enters, you gain 2 life for each creature you control with flying.

Anvilwrought Raptor

Flying
First strike (This creature deals combat damage before creatures without first strike.)

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.

Healer's Flock

Rally Maneuver

Target creature gets +2/+0 and gains first strike until end of turn. Up to one other target creature gets +0/+2 and gains lifelink until end of turn.

Aven Skirmisher

Kangee's Lieutenant

Flying
Whenever Kangee's Lieutenant attacks, attacking creatures with flying get +1/+1 until end of turn.
Encore {5}{W} ({5}{W}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Roc Charger

Flying
Whenever Roc Charger attacks, target attacking creature without flying 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.)

Quick-Draw Dagger

Flash
When Quick-Draw Dagger enters, attach it to target creature you control. That creature gains first strike until end of turn.
Equipped creature gets +1/+1.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Ghirapur Osprey

Welkin Guide

Flying
When Welkin Guide enters, target creature gets +2/+2 and gains flying until end of turn.

Speakeasy Server

Flying
When Speakeasy Server enters, you gain 1 life for each other creature you control.

Dauntless Aven

Flying
Whenever Dauntless Aven attacks, untap target creature you control.

Stonerise Spirit

Flying
{4}, Exile a card from your graveyard: Target creature gains flying until end of turn.

Eagle of the Watch

Battlefield Raptor

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.

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.)

Combat Professor

Flying
At the beginning of combat on your turn, target creature you control gets +1/+0 and gains vigilance until end of turn.

Glint Hawk Idol

Whenever another artifact you control enters, you may have Glint Hawk Idol become a 2/2 Bird artifact creature with flying until end of turn.
{W}: Glint Hawk Idol becomes a 2/2 Bird artifact creature with flying until end of turn.

Moment of Heroism

Target creature gets +2/+2 and gains lifelink until end of turn. (Damage dealt by the creature also causes its controller to gain that much life.)

Tenacity

Creatures you control get +1/+1 and gain lifelink until end of turn. Untap those creatures. (Damage dealt by those creatures also causes you to gain that much life.)

Aven Mindcensor

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

Love Song of Night and Day

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)
I — You and target opponent each draw two cards.
II — Create a 1/1 white Bird creature token with flying.
III — Put a +1/+1 counter on each of up to two target creatures.

Rustwing Falcon

Aesthir Glider

Roc Egg

Defender (This creature can't attack.)
When Roc Egg dies, create a 3/3 white Bird creature token with flying.

Suntail Hawk

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.)

Battleflight Eagle

Flying
When Battleflight Eagle enters, target creature gets +2/+2 and gains flying until end of turn.

Landroval, Horizon Witness

Flying
Whenever two or more creatures you control attack a player, target attacking creature without flying gains flying until end of turn.