Milestone Peregrine Falcon Surveys
Earthspan’s 50th annual survey of migrating peregrine falcons at Assateague Island, MD was completed in October, as was our 43rd annual survey at Padre Island, TX. Summaries and reports on our 2019 surveys are now available under the Research tab.
Read More53 Years of Peregrine Falcon Studies
Earthspan principals conduct long-term studies on migrating tundra Peregrine Falcons (Falco peregrinus tundrius) at Assateague Island, MD/VA (autumn since 1970) and Padre Island, TX (autumn and spring since autumn 1977). In 2019 we entered into a partnership with The Peregrine Fund to continue these studies. We have expended 58,160 man-hours of survey time in observing 74,574 peregrines and capturing 16,702. The tundra peregrine has made a significant recovery and has been removed from the list of endangered species yet continued monitoring of populations is imperative. Because of the...
Read MoreTogether at Last: Earthspan and The Peregrine Fund
In 1970 the peregrine falcon was in serious trouble due to the effects of DDT. The eastern U.S. population had been extirpated in the 1950s; western populations were severely reduced and migratory Arctic-breeding populations had also declined. Diverse efforts were undertaken to study, assist and augment remaining stocks. Earthspan principals began our standardized surveys of migratory peregrines at Assateague Island, MD/VA, while The Peregrine Fund (TPF, www.peregrinefund.org) was formed to breed peregrines in captivity...
Read MoreSpring 2019 Padre Island Peregrine Survey
Our spring survey was conducted April 11 – May 4 by Mike Yates, Bill Seegar and Carl Thelander. We expended 230 man-hours in observing 564 peregrines. We recorded 41 new captures, 10 returns of falcons we’d banded during previous surveys, and six recaptures of falcons newly banded during the survey. Peregrines are notoriously difficult to capture in the spring at Padre because most are adults and all have plenty of available natural prey that is easily caught on the wind tidal flats. This spring demonstrates that in spades, as three highly experienced and proficient field...
Read MoreAnalysis of Mercury in Migrating Peregrines Published
With collaborators Joe Barnes of the Nevada Department of Wildlife and Shawn Gerstenberger of The University of Nevada at Las Vegas we have published our most recent assessment of mercury in feathers we collected 2009-2015 from migrating peregrines at Assateague (MD) and South Padre (TX) Islands. We detected mercury in all sampled fourth primary (range = 0.44–37.46 lg/g) and axillary feathers (range = 0.09–62.68 lg/g). The concentration associated with toxic effects in peregrines is unknown; however, peregrines have recently experienced broad population expansion across the presumed...
Read MoreChallenging 2018 Autumn Surveys
The annual autumn peregrine surveys at Assateague (49th) and Padre (42nd) Islands were completed in October. Although we have no indication that breeding success in the Arctic was low, both surveys experienced lower than normal numbers of migrants. Local and continental weather phenomena undoubtedly played a role, and at Padre severe tides and flooding of the survey area. At Assateague we captured 48 individuals and at Padre 74, acquiring the usual invaluable blood and feather samples for archival purposes and current collaborative studies. Final reports have now been completed, and are...
Read More2018 Spring Peregrine Survey Summary
The 2018 spring peregrine falcon survey at South Padre Island, Texas was conducted April 11 through May 2. In 244 man-hours our biologists observed 468 peregrines, capturing 56 and recapturing four. Two adult males, 35 adult females and 19 second-year females were captured; an astonishing 11 of the adult females had been banded during our previous surveys. A female banded during her second year in spring 2004 is now almost 15 years of age, and a female banded in spring 2009 as an adult will be at least 11 this summer. Most notable this spring was our first capture (among over 15,000...
Read MoreEarthspan’s 2017 Autumn Peregrine Surveys Complete
The autumn Assateage and Padre Island Peregrine Falcon Surveys are in the books. At Assateague, the 48th annual survey observed lower numbers than in recent years with only 65 captures. The 41st annual autumn survey at Padre resulted in 135 captures, including the 10,000th peregrine captured in that survey’s history! Reports were completed by year’s end and are available for viewing under the Research tab.
Read MoreSpring Peregrine Survey at South Padre Island Complete
Our 39th annual spring survey at South Padre wrapped last week. The kickoff on April 12 included an expedition to Deer Island, where a few close friends of Earthspan Director Tom Maechtle joined wife Kathy and daughter Ireland to honor his memory. Extensive flooding of the wind tidal flats and several days of dangerously high winds combined to reduce productivity this spring, and our final capture total was 36. Three falcons originally banded during previous autumn surveys were among those captured, and we continued sample collections for collaborative studies.
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