Whether you’re standing at the coastal watchpoints of Tarifa or scrolling through our online updates, watching migration through The Straits of Gibraltar sparks endless fascination—and plenty of online debate!
From questions about starting dates to debates over flight paths, aerodynamic mechanics, species identification, and even skepticism about whether what we film is real, we’ve gathered the most common queries and myths from our community to set the record straight on how this world-famous bottleneck really works.
1. “Isn’t it too early for migration? Doesn’t autumn migration start in September?”
The Short Answer: Not at The Straits!
While September is a fantastic month for species like Booted Eagles and Short-toed Eagles, nature doesn’t operate on standard calendar months. Different species run on completely different biological timetables:
White Storks are the vanguard of the southbound passage. Once nesting duties wrap up across Europe, they gather in massive numbers and begin moving south in early July, reaching their absolute peak in late July and early August.
Black Kites follow the exact same early window, filling the skies alongside the Storks.
By the time September rolls around, the early movers have already made their passage, handing the sky over to the mid- and late-season Raptors!
2. “Why does migration start in July—is climate change pushing dates earlier?”
While climate change is undoubtedly impacting global bird populations and shifting some wintering ranges, early July migration for White Storks and Black Kites is not a climate shift. Decades of long-term field monitoring by our partners at Fundación Migres show that early July has always been the natural departure window for these species once breeding is complete. Staying in Europe offers no evolutionary benefit once chicks are fledged, so they head south right on schedule.
3. “Are these massive flocks real, or is this AI-generated footage?”
It’s sad to admit, but we’ve actually had commenters call us liars on social media, claiming our videos of tens of thousands of birds in the sky were fake or generated by AI (though those comments often get quietly deleted by their authors once the facts come out!).
We can assure you: every frame is 100% real. The spectacle of tens of thousands of Raptors and Storks gathering along the coast is an ancient, natural phenomenon documented long before digital video existed. If you ever doubt what you’re seeing on screen, come stand on the coastal hills above Tarifa in late July—the sound of thousands of wings overhead is something no AI can ever replicate!
4. “How does migration here compare to other world-famous bottlenecks like Georgia or the Bosphorus?”
The Straits of Gibraltar operate on a year-round migratory treadmill that is virtually unique on Earth.
- Batumi (Georgia) & The Bosphorus (Turkey): These incredible bottleneck sites have very defined, ~2-month autumn windows (typically mid-August to October). Over in Georgia, for example, White Storks are a tiny minority—the main push kicks off in late August with European Honey Buzzards, followed by massive numbers of Black Storks, Harriers, and Eagles into late September.
- The Straits of Gibraltar: Our flyway operates as a year-round cycle. Spring migration begins as early as late November with returning White Storks, building from February and running straight through June with late European Honey Buzzards and non-breeding Raptors. With virtually no gap, early July hands off seamlessly to the autumn return. The flyway simply changes gear!
5. “It’s only 14 km across The Straits—isn’t that an easy hop for a soaring bird?”
On a map, 14 km (9 miles) looks like a short distance, but for a broad-winged soaring bird, a sea crossing is a massive physical and technical hurdle.
- The Thermal-Free Zone: Soaring Raptors and Storks rely on rising columns of warm air (thermals) over land for lift. Cold sea water does not generate thermals. The moment a bird leaves the coast, standard thermal updrafts vanish completely.
- Tacking Like a Sailboat: Without thermals, how do they stay airborne? Soaring Raptors must harness the marine wind itself. By judging wind velocity and angles precisely, they use dynamic wind resistance for lift. Though strong head- and cross-winds cut their ground speed to a crawl, the wind provides the vital lift they need to ‘tack’ across the channel like a sailboat.
- Wind Dictates the Spot: Wind doesn’t just dictate how they fly, but where they leave from in autumn or arrive at in spring. Depending on whether the easterly Levante or westerly Poniente is blowing, departure and arrival points shift drastically along the coast—birds might stream out directly over Tarifa, or drift right across to Algeciras or Cazalla. Reading the local weather accurately and knowing where to position yourself is key to staying right in the heart of that flight stream!
- The High-Stakes Calculation: Deprived of thermal altitude, birds enter a prolonged, energy-draining powered glide. Coastal winds push them sideways off course, turning a 14 km straight line into a 20 to 30 km grueling crossing. Judging these marine wind conditions before leaving land is literally essential to their survival.
6. “What is La Milanada?”
La Milanada is the evocative local term used to describe the breathtaking gathering of Black Kites along The Straits in mid-summer.
Because open-water crossings are so physically demanding, tens of thousands of Black Kites funnel down to the coast, building up in immense numbers while waiting for optimal wind conditions. When favourable winds arrive, thousands of Kites lift into the sky simultaneously, literally darkening the sky above Tarifa before taking the leap across to Africa.
7. “Is illegal bird shooting still a threat along this flyway?”
Wildlife crime remains a tragic reality along several sections of the Mediterranean flyway, but The Straits is a massive conservation success story.
Thanks to decades of dedicated monitoring by local organisations like our partners at Fundación Migres, strict legal protection, and active enforcement by SEPRONA (Spain’s environmental protection police), illegal shooting of birds of prey around The Straits of Gibraltar has been virtually eliminated. Unlike ongoing persecution issues elsewhere—such as the plight of Hen Harriers in the UK—The Straits stands out as a genuine safe haven where hundreds of thousands of soaring migrants can wait out strong winds in peace.
The Straits Migration Calendar: Species Timetable
Nature doesn’t follow rigid deadlines! The dates below are not absolute start and end cut-offs, but rather expected windows of movement based on decades of census data with Fundación Migres.
A Note on Early Eagles: You might spot species like Booted Eagles and Short-toed Eagles crossing southbound as early as July! These early movers are typically sub-adult non-breeders. Even though 2nd and 3rd-year birds have zero intention of nesting that season, spending the summer wandering across Spain, Portugal, or France allows them to map out prime woodland/open-country feeding territories, assess local competition, and establish range familiarity for when they are ready to breed. Crucially, these non-breeders—just like the adults—are utilising the extended daylight hours of the northern summer to maximise foraging and development time, rather than relying solely on prey abundance.
Autumn Migration (Southbound: Europe to Africa)
| Species / Family | Expected Start | Peak Window | Expected End |
|---|---|---|---|
| White Stork | Early July (Jul 1) | Late July (Jul 20–31) | Mid-August |
| Black Kite | Early July (Jul 1) | Late July – Mid-August | October |
| Short-toed Eagle | July (Sub-adults early) | Mid-September – Early October | Late October |
| Booted Eagle | July (Sub-adults early) | Mid-September – Early October | Late October |
| Montagu’s Harrier | Late July | Mid – Late August | Mid-September |
| European Honey Buzzard | Early / mid August | Late August – Early September (Peak ~Aug 28–Sep 3) | Mid-September |
| Egyptian Vulture | Late July | Late August – Early September | November |
| Black Stork | Early August | Mid – Late September | Mid-October |
| Griffon Vulture | Mid-September | Late October – Early November | December |
Spring Migration (Northbound: Africa to Europe)
| Species / Family | Expected Start | Peak Window | Expected End |
|---|---|---|---|
| White Stork | Late November | January – February | March |
| Black Kite | Late January | February – March | Mid-April |
| Short-toed Eagle | Early February | Mid-March – Early April | May |
| Booted Eagle | Early February | Mid-March – April | May |
| Egyptian Vulture | Mid-February | March – April | May |
| Montagu’s Harrier | Late February | April | Early May |
| European Honey Buzzard | Late April | First week of May (Peak ~May 1–10) | June (stragglers) |
| Griffon Vulture | April | May – June | Late July |
Experience #FlywayBirding with the Specialists!
At Inglorious Bustards, we are dedicated specialists in #FlywayBirding, living and breathing this year-round migratory phenomenon. There is simply nothing like standing at The Straits watchpoints in person to experience the raw power of avian migration.
Want to witness the sky dark with thousands of European Honey Buzzards, Eagles, and Kites tackling the ocean leap?
Check out our prime-season migration tours and join us on the frontlines of one of the greatest wildlife spectacles on planet Earth—no filter or AI required!
