Karen Francis and Tom Maechtle prepare to send part of Scott's ashes on their way

Results from Earthspan’s 2012 peregrine falcon surveys have been incorporated into our annual reports for both the Assateague and Padre Island surveys. A summary of results and both reports may be found under the Research tab on this site. The life of our colleague and friend Scott Francis was celebrated at the onset of our autumn Padre survey. An immature female was captured and released at Deer Island. She was dusted with some of Scott’s ashes and released by his wife Karen to carry them along on her southward journey. The rest of Scott’s mortal remains were scattered into the south Texas wind at Deer Island per his wishes. Words were said and tears were cried. Thanks and Godspeed, old pal!

Our work in these studies with satellite-received telemetry allows us to continue elucidating previously undescribed aspects of the tundra Peregrine’s wintering biology and continental migration and to identify critical habitats. Given available technologies, Assateague and Padre remain ideal laboratories in which to study and address present and future issues of concern to Peregrines, other Neotropical migrants, and humans. In recent years we have studied emerging infectious pathogens such as West Nile Virus and Avian Influenza in partnership with U.S. Government entities, and currently address contaminants through studies related to the 2010 Gulf oil spill.

In 2008 our database allowed us to provide an Expert Declaration on the Draft Environmental Assessment and Management Plan for Take of Migrant Peregrine Falcons in the United States for Use in Falconry. Among other points, we concluded that the standardized average number of migrating Peregrines we observed at Assateague over the preceding 29 years was essentially the same as that seen more than six decades ago (1939-1944), before DDT had serious adverse effects on the reproductive potential of the Peregrine in North America. Our work at Assateague and Padre Islands represents the bulk of tundra Peregrine Falcons banded within the continental United States since the establishment of the Bird Banding Laboratory by the Department of the Interior.  Furthermore, our overall database constitutes the most significant and longest continuous monitoring study on this falcon in the Americas. Long-term studies such as ours are essential to monitoring the stability of wildlife populations, particularly in light of rapid changes that may occur due to contaminants, infectious diseases, habitat loss, climate change and other factors. By the long-term and standardized nature of our studies, we have established levels of observation in stable populations that will quickly raise future concerns if not achieved over a several year period.

In 2012 at Assateague, our 43rd annual study was conducted on the northern (MD) portion of the island. Observations and captures by unit effort were the 6th highest and 8th highest respectively for this long-term study. Between 28 September and 19 October the survey team expended 215 man-hours in the field, recording 344 sightings of Peregrines and capturing 98 different individuals. Five of the falcons captured were previously banded. The 344 sightings included 78 observations and six recaptures of individuals previously captured during the survey. We also obtained 96 blood samples for collaborative studies. Please see our full report for details on the study. 2012 Assateague Report

During the 2012 Padre spring survey period from 10-24 April, we expended 145 survey hours in the field, recording 301 sightings and capturing 37 individual peregrines.  Of those captured, 7 (18.92 %) were previously banded Padre Returns, one had been originally banded at Assateague Island in 2005, and 29 (78.38 %) were first banded during the survey.

In autumn 2012 at Padre, we surveyed the wind-tidal flats from 25 September to 23 October.  During this period we expended 484 survey hours in the field, recording 1,002 peregrine falcon observations and capturing 228 individuals.  Of those captured 7 (3.07 %) were previously banded and 221 (96.93 %) were first banded this season. Please see our full report for details on the study. 2012 Padre Report

Scott Francis (1954-2010)

As surely as summer turns to fall, Earthspan biologists gravitate to the East and Gulf Coasts to continue our four decades-plus of research on migrating tundra peregrine falcons. In Texas Gregg Doney will again lead a talented and experienced group of volunteers; in Maryland Bill Seegar and Mike Yates will add to their combined totals of 66 yearly Assateague Island surveys. They will also present a program on Earthspan’s peregrine studies to the Assateague Island Alliance on October 14. The first order of business in fall 2012, however, will be a gathering at South Padre Island, TX to honor our friend and colleague Scott Francis (pictured). A long-time participant on the Padre survey and one of the finest falcon trappers who ever lived, Scott lost a courageous battle with cancer two years ago when only 55 years young. His memory and inspiration will always be with us, and his ashes will return to Padre this September as he wished. Thanks, Karen, for sharing him with us. And thanks, Scott, for your friendship and the simple truth that knowing you made each of our lives richer.

The Deepwater Horizon Oil Spill (DWH) released an estimated 5 million barrels of oil into the Gulf of Mexico during April through July 2010. Earthspan and its partners, The Peregrine Fund and the University of Connecticut,  collected and analyzed blood samples from migrating Peregrine Falcons at South Padre Island (TX) and Assateague Island (MD) to measure pre and post-spill concentrations of polycyclic aromatic hydrocarbons (PAH) from 2009-2012.  PAHs are known to cause a variety of adverse eco-toxicological impacts that include acute toxicity, reproductive failures, DNA adducts, and heritable mutagenesis in offspring.

To date, a total of 189 red blood cell (RBC) samples have been analyzed at for parent PAHs.  These include 52 pre-DWH and 137 post-DWH samples.  In addition, we conducted exploratory analyses of four alkyl PAH compounds on the Padre 2011 samples.  Our analyses support, in many instances, the petrogenic (associated with crude oil) sourcing of PAHs after DWH.  Results to date demonstrate that there was an increased incidence of PAH contamination and in PAH blood concentrations in Peregrine Falcons sampled along the Texas Gulf coast after the DWH oil spill. As well, these data demonstrate a significant shift in PAH composition.  Through comparisons with similar studies, the source of increased PAH contamination in 2010 and 2011 was likely due to crude oil, which was not present the year prior to the spill.  Percent occurrence and blood concentrations of PAH burdens decreased in 2011. However, blood concentrations remained above pre-DWH levels and PAH profiles suggest a petrogenic origin, differing from Pre- DWH sampling periods.  These factors warrant the need for continued monitoring of blood PAH concentrations.

To our knowledge, this is the first field study in which levels of PAHs were measured nondestructively in Peregrine Falcons with the purpose of monitoring oil pollution in the coastal environment after a large oil spill. The analysis of PAHs in Peregrine Falcon blood provides a convenient and relatively rapid method, with little disturbance to birds, for monitoring PAH contamination in their avian food chain. Overall, our study demonstrates the use of peregrine blood as a monitoring tool for oil exposure. Working with our partners, we intend to continue monitoring blood PAHs in migratory Peregrine Falcons.

White-faced ibis with PTT package

Earthspan principals led a cooperative study to identify the source(s) of DDT-related contamination still plaguing a northern Nevada population of white-faced ibis many years after use of the pesticide was banned in the United States.

The white-faced ibis (Plegadis chihi) is a long-legged wading bird that feeds primarily on invertebrates in wetlands and irrigated croplands. It is a highly social colonial nester and often forages in large aggregations. Due to restricted nesting habitat and potential vulnerability to pesticides, the species is listed by the U.S. Fish and Wildlife Service as a migratory non-game bird of management concern.

Dr. Charles Henny (U.S. Geological Survey; USGS) documented continued troubling levels of DDE (the principal metabolite of the organochlorine pesticide DDT) in a large segment of the white-faced ibis population nesting at Carson Lake in western Nevada. Of twenty eggs collected in 1996, 45% contained >4 ppm DDE, and eggshells averaged 18.3% thinner than normal. This represented no improvement from DDE levels documented in 1985-86, which is contrary to patterns shown for most other avian species in the USA. Analyses of upper digestive tract contents in 18 Carson Lake ibis revealed no organochlorine insecticides; the conclusion was that contamination is not occurring on the Nevada breeding grounds. Identification of contaminant sources was highly desirable because it is likely that different regional cohorts of ibis and other wildlife species are frequenting those same areas.

We captured and blood sampled ibis, then tracked them to wintering locales via satellite-received telemetry. We visited wintering sites to collect earthworms, and analyzed them and the original ibis blood samples for DDE. Birds with highest contamination wintered in the Mexicali Valley of Baja Norte, Mexico, and highest DDE levels were also found in earthworms collected at those corresponding wintering areas. Our findings were published in 2010.Yates etal WFIB DDE 2010 Ecotoxicology

The broad-winged hawk is a neotropical migrant that breeds in eastern and central North American forests and winters primarily from Southern Mexico south through Central America to northern South America (Bolivia and Northern Brazil), with small numbers wintering in southern Florida. Its population status is of concern due to the decline in numbers of birds encountered at some migration observation points since the 1970’s and in some areas of its breeding range in the Eastern United States. Information is available on the natural history of the broad-winged hawk in North America, but little is known of its wintering ecology. Within the continental United States, breeding numbers appear to be stable in some areas but decreasing in others. The Puerto Rican population is classified as Endangered, and these declines are attributed to habitat alterations. Similarly, in the Eastern United States, some areas have reported declines in BWHA associated with human development and alteration of woodlands.

Broad-winged hawk integrated radio tracking

Approach/Objectives
Earthspan’s broad-winged hawk research focused on identifying critical habitat during the breeding season, along migration pathways, and during the boreal winter period. The approach integrated radio tracking via satellite, field monitoring, remote sensing, and a geographical information system (GIS) to identify locations and important landscape and nest site features used by the species. This study filled gaps in knowledge concerning aspects of broad-winged hawk migration and wintering biology and provided data critical for the development of a management plan for broad-winged hawks on federal, state, and private lands throughout its annual range.

Broad-winged hawk

Results
Because broad-winged hawks tend to travel in large flocks that are easily identified on NEXRAD radar imagery, Earthspan and the Clemson University Radar Ornithology Laboratory are attempting – for the first time ever – to correlate migration data of individual BWHAs with flock activity. Results from this study will be useful in the development of an effective resource management strategy for this species that can be applied throughout the Americas. Additionally, information collected about land use practices and environmental contaminant uses will be relevant to the conservation of a variety of other wildlife species.

Earthspan tracked (via satellite) broad-winged hawks from North America to their wintering areas and described important land cover types at the hawks’ destinations (both breeding and wintering). Our research provided information on the extent to which North American nesting populations associate with natural and modified habitats across the non-breeding range. Additionally, information may be acquired to describe their exposure to habitat alteration and environmental contaminants in their wintering areas. The breeding habitat, migratory pathways, and wintering range of broad-winged hawks are also shared by a number of other neotropical migrant species, including several that are species of major conservation concern. This project will set the standard for other research projects to study the movements, migration, and wintering habitats of other neotropical migratory species.

Resulsts from this project were published in The Wilson Quarterly.

Broa-winged hawk tracking map