Friday, June 29, 2007

Population of Aplomado Falcon threatened in the Chihuahuan Desert

Please take a moment to read the following. I consider Angel Montoya to be a friend and a hard-working scientist for the Peregrine Fund. The following deserves our attention.
-David McCauley
Tlacotalpan, Veracruz

Friends and colleagues,*
*Over the years you have all either been directly involved with
or interested in the Aplomado Falcons of Chihuahua, Mexico. I am now writing
because although you may not know it there is currently a clear and imminent
threat to the grasslands, grassland birds, pronghorn, and Aplomado Falcon in
Chihuahua as we know them today. Unfortunately, the aforementioned threat is
happening at an alarming rate and there does not seem to be an end to it.*
*Please read the attached article by Duarte, Rodriguez, Montoya, Cade, and
Hunt on the destruction of Chihuahuan Desert grasslands and its consequences
to the survival of the last known Aplomado Falcon population in the
Chihuahuan Desert. As you all know this not only affects Aplomado Falcons
but other species ( pronghorn, grassland birds, etc..) as well. Please feel
free to forward this information to others. For more information or
suggestions you may either contact Grainger Hunt at, Alberto Macias at, Tom
Cade at, Roberto Rodriguez at or myself Angle Montoya at . For additional articles on the Aplomado Falcons in
Chihuahua please visit the website: . You may also post this
on any list servers you see as appropriate. *
*If you respond please do so individually. Thanks and I apologize if you
have received this in duplicate.*
*Angel Montoya*
*The Peregrine Fund*
*100 East Hadley Ave.*
*Las Cruces, NM 88001

Here is the text of the pdf. file

Alberto Macías-Duarte, Roberto Rodríguez-Salazar, Angel Montoya, Tom Cade,
and Grainger
The last known desert-dwelling Aplomado Falcon population (Falco femoralis
septentrionalis) in North America may be extirpated within the near future.
We have studied and worked to
conserve this relict population in Chihuahua for the last fifteen years, and
we feel a responsibility
to inform the international community of the recent and ongoing destruction
of the falcon's
breeding habitat through the plowing of native grasslands.

The Aplomado Falcon is a strikingly beautiful, endangered species that once
occurred throughout
the grasslands of the Chihuahuan Desert. In the 1800s, the population
extended northward into
the southwestern United States, but it disappeared there entirely by the
1950s and has since been
reintroduced in Texas. This is one of only two areas in Mexico where this
endangered species is
known to breed, one along the eastern coastal savannas from southern
Tamaulipas southward and
the other in the desert grasslands of Chihuahua. The distance between those
populations is about
one thousand kilometers.

When we began studying the Chihuahua population in 1992, there were
thirty-five known pairs, but the long drought of the 1990s and early 2000s
reduced the population to about twenty-five
pairs. At that time, we identified grassland desertification as the major
threat to the long-term
survival of the species (Macias-Duarte et al. 2004. The Auk 121:1081-1093).
We could not
foresee, however, that in the next few years, the species would face the
destruction of its breeding
habitat by the sudden conversion of desert grassland into croplands.

Native grasslands in Tarabillas valley

Just as the remnant falcon population in Chihuahua began to respond to the
recent increase in
rainfall, Mennonite farmers began buying the grassland portions of the
ranches inhabited by
falcons within Tarabillas valley, north and east of Sierra El Gallego, in
the municipality of
Ahumada. At a recent meeting with government authorities, we discussed the
loss of seven
Aplomado Falcon breeding territories to plowing. Officials informed us that
farmers are buying
"…every available hectare of native grassland in the area," including
additional known
Aplomado Falcon territories. The farmers continue negotiations with
landowners to buy all the
grasslands within that valley including communal lands (ejidos), and if left
unchecked they will
eventually own and farm the entire Tarabillas valley. These purchases are
facilitated by the fact
that most grasslands are in poor condition following the drought and its
consequences on
livestock production, tempting many landowners to sell their land to

The Mexican Institute of Water Technology measured aquifer recharge rates at
37 million
m3/year from which CONAGUA (the agency responsible for
monitoring/controlling water
utilization) determined that ground water pumping could support 5,300
hectares of crop
production in the Tarabillas Valley on a sustainable basis. About 10,200 ha
are already under
ground-water irrigated crop production, and 20,400 hectares have been
ploughed in preparation
for crop production. In all, 59,900 hectares of grassland have been sold for
conversion to crop
production in just the last four years. Ground water pumping at current and
projected rates is
clearly not sustainable. Meanwhile, a substantial portion of the last
remnants of desert grasslands
known to support Aplomado Falcons in Chihuahua are being destroyed for
short-term profit from
unsustainable agriculture.

Today we know of only 18 Aplomado Falcon pairs remaining in Chihuahua, a
trend that suggests
the possibility of extirpation within a few years unless immediate action is
taken to stop the rapid
conversion of native grassland to cropland. In the last year alone, the
breeding territories of seven
pairs have been lost to the plow. We have found no evidence of Aplomado
Falcons in other
regions of Chihuahua, and surveys in Durango and Coahuilla have also been

The Aplomado Falcon is not the only species risking extirpation from this
portion of Mexico. The
endangered Mexican pronghorn (Antilocapra americana mexicana) lives only in
Chihuahuan grasslands and will share the same fate as the Aplomado Falcon if
conversion continues in Tarabillas valley during the coming months. Both
Aplomado Falcons
and Mexican pronghorns are closely associated with open grassland.
Pronghorns move along
grassland corridors, and the farming of these grasslands will further
fragment their already
diminished populations. Tarabillas valley is an internationally important
wintering ground for
migratory grassland birds from the northern United States and Canada; the
density of grassland
birds during the winter far exceeds that observed in other grasslands in
Chihuahua (Mendez-
Gonzalez 2000, Master's Thesis, Universidad Autonoma de Chihuahua).

Farms in the northern half of Tarabillas Valley have thus far destroyed
seven Aplomado Falcon
breeding territories.

Pronghorn antelope in native Chihuahua grassland

For further information, contact Alberto Macias-Duarte
( );
see for details about the Aplomado
Falcon population
in Chihuahua. Directors of the Mexican federal agencies involved in
environmental protection
include Juan Rafael Elvira Quesada, Secretary of Environment and Natural
( ) and Ignacio Loyola Vera, Federal Attorney
for Environmental
Protection (