A North American Conservation Success

The Peregrine Return

From zero breeding pairs east of the Mississippi in 1964 to tens of thousands across the continent today — the peregrine falcon's recovery is the conservation story that falconers, biologists, and The Peregrine Fund wrote together. The science now shows the population is normalized. The policy is catching up.

See the Recovery → Read the Science
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1999
ESA Delisted
6,000+
Captive Released
~40k
N. Am. Birds
<1%
Current Take
25+ yr
Since Recovery
Where We Stand in 2026

The recovery is complete. The science says it's time to update the rules.

When DDT collapsed peregrine populations in the mid-20th century, North American falconers and a small group of biologists — led by Dr. Tom Cade at Cornell — built the world's most successful raptor restoration effort from the ground up. Today, peregrines breed on skyscrapers in every major U.S. city, occupy more historic eyries than pre-DDT in some regions, and are monitored by the same scientists who helped bring them back. A new Environmental Assessment from the U.S. Fish and Wildlife Service proposes to finally normalize the regulations around falconry take to match the robust populations modern science has documented.

Adult peregrine perched on a tree branch
Adult peregrine in classic profile — slate-grey back, barred underbelly, the silhouette that has returned to every region it was lost from. Photo: USFWS / Wikimedia Commons.
The Recovery Arc

From collapse to continental comeback

Over seventy years, the peregrine went from the poster species of the pesticide crisis to the most successful raptor recovery in North American history. Falconers were present at every stage.

1946 – 1962
DDT enters the food chain
Widespread post-war DDT use bioaccumulates in birds of prey. Peregrine eggshells thin by up to 20%, causing catastrophic reproductive failure. Population begins vertical decline.
1964
Extirpation east of the Mississippi
Dr. Joseph Hickey's landmark 1964 survey documents zero successful peregrine nests east of the Mississippi River. What was once a common sight on every Appalachian cliff is gone.
1970
The Peregrine Fund is founded
Cornell raptor biologist and falconer Dr. Tom Cade launches The Peregrine Fund with a single mission: breed and release peregrines back into the wild. North American falconers donate their personal birds to start the captive population.
1972
DDT banned in the United States
EPA bans agricultural use of DDT. The reproductive trap that crashed the species is finally removed — but the birds themselves are still missing from most of their range.
1974 – 1997
The great release program
The Peregrine Fund and state partners release more than 6,000 captive-bred peregrines into historic range using hacking — a 4,000-year-old falconry technique. Falconers supply expertise, volunteer labor, and tower construction across the country.
August 1999
Delisted from the Endangered Species Act
The U.S. Fish and Wildlife Service declares the peregrine fully recovered. Estimated breeding pairs in the U.S. and Canada: ~1,650 — well above the delisting target.
2003 – 2015
Post-delisting monitoring confirms stability
Federally mandated 15-year monitoring finds populations continuing to grow. By 2015, survey-based estimates for North America approach 6,000+ breeding pairs, with many regions exceeding pre-DDT baselines.
2018 – Present
Robust, stable, expanding
Modern survey data from Partners in Flight, eBird, and agency counts place the North American peregrine population around 40,000 individuals. Urban colonies now span every major U.S. metro.
2024 – 2026
USFWS proposes normalized take
New Environmental Assessment developed using the Millsap prescribed-take framework proposes to normalize falconry take to reflect population health. Public comment and final rulemaking expected in 2026.
The Peregrine Fund

Built by falconers. Backed by science.

Founded at Cornell University in 1970 and now headquartered at the World Center for Birds of Prey in Boise, Idaho, The Peregrine Fund pioneered captive propagation of raptors at a scale no one thought possible. Every major technique — artificial insemination, double-clutching, hack tower design — came out of a community that refused to accept extinction.

The organization has since carried that model to 65 countries and more than 100 species, from California condors to Philippine eagles. But the peregrine remains its founding story — and the one its founders, nearly all falconers themselves, staked their careers on.

1970
Founded
6,000+
Peregrines Released
65
Countries
100+
Species Programs

From zero breeding pairs east of the Mississippi in 1964 — to every major U.S. city, continent-wide, within a single human lifetime.

This is not a species on the way back. This is a species that came back. The apparatus that handled the emergency is still in place; it's time for regulation to reflect the result.

Photo: Wikimedia Commons
The Falconer Contribution

Why the comeback would not have happened without falconry

Falconers are the only group in North America with the combined husbandry, training, and field experience to rebuild a raptor species from captive stock. They brought 4,000 years of practice to a 20th-century emergency.

🥚

Donated founder birds

When the Peregrine Fund had nothing, falconers turned over their personal peregrines — the only genetically viable North American stock remaining in captivity — to start the breeding program.

🏗️

Hacking expertise

Hack-tower releases rely on a centuries-old falconry method. Falconers designed, built, and staffed the hack sites that launched more than 6,000 birds back into the wild.

🧬

Captive propagation know-how

Imprinting, artificial insemination, and chamber design were all adapted from falconry husbandry. Tom Cade, Heinz Meng, Bob Berry, and Jim Weaver were falconers first.

🔭

Volunteer monitoring

State peregrine monitoring crews across the East and Midwest were disproportionately staffed by volunteer falconers — climbing eyries, banding chicks, and reporting productivity data.

📜

Political coalition

The North American Falconers Association and state clubs provided the sustained political energy to fund recovery across four administrations and two decades.

🦅

Ongoing stewardship

Today, falconers continue as the largest volunteer workforce for raptor banding, rehab intake, and population monitoring — a living partnership with state and federal biologists.

The Science of Normalization

What the population data actually shows

The North American peregrine population is no longer "recovering." It is recovered, stable, and expanding. The regulations governing take for falconry were written against 1990s numbers — when a few thousand pairs was the whole continent. Modern surveys and demographic models tell a very different story.

North American Breeding Pairs, 1970 – 2025

Reconstructed from USFWS status reviews, Peregrine Fund records, and Partners in Flight estimates
Population climbs from an estimated 324 known pairs at the nadir to over 10,000 breeding pairs across North America today. The gold dashed line marks the 1999 ESA delisting. Data are reconstructed from multiple periods of survey methodology, so individual points have uncertainty — but the trajectory is unambiguous.

Eggshell Thickness Recovery

DDE residue in eggs vs. pre-DDT baseline
Eggshell thickness has fully returned to pre-DDT baseline (set to 100%). The reproductive trap is gone.

Occupied Territories vs. Recovery Goal

As % of regional delisting targets
Every U.S. recovery region now sits well above the threshold that USFWS set for delisting in the 1980s recovery plans.

Current Falconry Take vs. Sustainable Allowable Take (Millsap framework)

Prescribed Take Level analysis — wild passage peregrines, U.S.
The Prescribed Take Level framework, pioneered by Brian Millsap and colleagues at USFWS Migratory Bird Program, calculates how many birds can be removed annually without causing population decline. Actual take by licensed falconers is a small fraction of the sustainable threshold — a gap the new EA is designed to close responsibly.
"For most North American raptor populations, including peregrine falcons, current levels of falconry take are well below the prescribed take level that would allow for stable populations. The framework allows managers to align regulations with the actual demographic capacity of the population."
— Summary of Millsap et al., Journal of Wildlife Management, on the Prescribed Take Level framework
324 → 10k+
Known breeding pairs, 1975 vs. today (N. America)
~40,000
Estimated continental population (Partners in Flight range)
100%
Eggshell thickness recovered to pre-DDT baseline
5%+
Annual λ (population growth rate) in post-delisting monitoring
New USFWS EA · 2026

A new Environmental Assessment proposes to normalize take

The U.S. Fish and Wildlife Service is finalizing an Environmental Assessment that would update falconry take allocations for wild peregrines. The EA rests on the same Prescribed Take Level framework that USFWS uses for all other raptor harvest decisions — a framework developed by the agency's own raptor biologists, including Brian Millsap.

The proposal does not increase risk to the population. It brings the rule-set into line with demographic reality: peregrines have been recovered for 25+ years, monitoring data is mature, and the take framework has been successfully applied to other species for over a decade.

EA at a glance

Lead agencyUSFWS Migratory Bird Program
FrameworkPrescribed Take Level (PTL)
Species statusDelisted (1999) · Stable
Current take~36 E / 60 W / AK quota
Proposed actionNormalize to PTL
Primary authorsUSFWS raptor team (Millsap et al.)
Expected publication2026
Public commentUpon release
Peregrine falcon in flight with coastal cliffs in background
Adult peregrine in flight against a cliff face — the bird and the habitat both back on every coast they were lost from. Photo: Wikimedia Commons.
The Communication Gap

Why the public still thinks peregrines are endangered

The peregrine's role in Silent Spring and the DDT story is one of the most successful pieces of conservation communication in American history. It has also become a ceiling. Public perception is frozen in 1972, even as the actual bird became one of the most common urban raptors in North America.

Normalizing regulations doesn't diminish the story — it completes it. A recovery is only fully written when the rules that governed the emergency are rewritten for the recovered animal.

Every other ESA delisting — bald eagle, brown pelican, grey wolf in the Rockies — eventually brought management authority back to a normal harvest or take framework. The peregrine deserves the same completion of its own success story.

Follow the science. Support the return.

The peregrine is back. The data is clear. When the USFWS Environmental Assessment opens for public comment, the scientific community, falconry community, and informed public need to be ready to support a regulatory framework that reflects the recovered status of the bird.

Visit The Peregrine Fund → Re-read the Science

Sources & Further Reading

  1. Cade, T. J., Enderson, J. H., Thelander, C. G., & White, C. M. (Eds.) (1988). Peregrine Falcon Populations: Their Management and Recovery. The Peregrine Fund.
  2. U.S. Fish & Wildlife Service (1999). Endangered and Threatened Wildlife and Plants; Final Rule to Remove the American Peregrine Falcon From the Federal List of Endangered and Threatened Wildlife. Federal Register 64(164):46541–46558.
  3. U.S. Fish & Wildlife Service (2003, 2006, 2015). Post-Delisting Monitoring of the American Peregrine Falcon. Divisional reports.
  4. Millsap, B. A., Zimmerman, G. S., Sauer, J. R., et al. (2013). "Golden Eagle population trends in the western United States: 1968–2010" and related prescribed-take analyses. Journal of Wildlife Management.
  5. Millsap, B. A., et al. (2022). Demographic framework for assessing the sustainability of raptor harvest. USFWS Migratory Bird Program technical reports.
  6. Partners in Flight (2021). Avian Conservation Assessment Database, population estimates v. 2021.
  7. Hickey, J. J. (Ed.) (1969). Peregrine Falcon Populations: Their Biology and Decline. University of Wisconsin Press — the 1965 Madison conference proceedings that documented the collapse.
  8. North American Falconers Association — recovery volunteer records and state-level peregrine banding summaries.

Population figures on this page are synthesized from the sources above. Exact numbers vary year to year and by survey methodology; all values shown are consistent with published ranges in the sources listed. Chart data is illustrative of documented trajectories. For regulatory decisions consult the USFWS Environmental Assessment directly when published.