Two examples of bird re-introduction programs in Mexico

 Mexico's geography in the Press  Comments Off on Two examples of bird re-introduction programs in Mexico
Dec 222012
 

Assuming that the world did not come to an end yesterday, Geo-Mexico would like to convey best wishes to everyone for the entire duration of the next Long Count Maya calendar cycle, which runs until sometime in 2406. This may allow sufficient time for some real progress to be made in environmental stewardship.

Today’s post looks at two ornithological conservation projects that have made significant advances in 2012. The first is in Maya territory in south-east Mexico, where biologists are trying to stave off the extinction of the colorful Scarlet Macaw, and extend its current range. Researchers believe that between 250 and 400 of the birds now remain in the wild, almost all of them in the area straddling the borders between Mexico, Guatemala and Belize.

Birds raised in the Xcaret Center for the breeding of macaws, located in the state of Quintana Roo, are being gradually prepared for being set free in Aluxes Park, an ecological reserve on the edge of the natural forest in Palenque, in the state of Chiapas. The plan is to release as many as 250 birds over the next five years. The natural range of the Scarlet Macaw, prior to deforestation, habitat loss and wildlife trafficking, once extended all the way along Mexico’s Gulf coast, from Tamaulipas to Campeche.

At the other end of the country, a decade-old multi-institutional project (government, academic and NGO) aims to reintroduce the California Condor into Baja California state. There are believed to be about 30 California Condors now flying free in the Sierra de San Pedro Martir, following the release of six condors there earlier this year.

California Condor

California Condor in flight. Credit: Friends of the California Condors

Specialists say the project has almost reached the point at which the birds are likely to reproduce successfully in the wild. Since 2008, 10 nesting sites have been located. Condors nest in caves making it difficult and time-consuming to locate nests, even when the birds are tagged with transmitting devices. Among the threats to the success of the program is the incidence of lead poisoning in condors resulting from them swallowing bullets left in animal carcasses killed, and then abandoned, by hunters.

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Protecting Mexico’s endangered marine turtles

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Sep 062012
 

Mexico is home to six of the world’s seven species of marine turtles, all of which are on the international Red List of endangered or critically endangered species.

The beaches along Mexico’s Pacific coast, those in the north-east state of Tamaulipas, and those in Quintana Roo on the Caribbean, are among the world’s most important breeding grounds for marine turtles. These turtles spend almost all their life at sea, but mature females come ashore in late summer and fall to burrow into the warm sand and lay their eggs.

On the Pacific coast, it is estimated that about 40% of these eggs will be stolen by wildlife poachers. When the remaining eggs eventually hatch six to eight weeks later, the baby turtles then stagger towards the relative safety of the ocean, hoping to avoid not only human poachers, but also predators such as crabs, iguanas and birds. Less than one in one hundred hatchlings will survive the fifteen or twenty years required to reach maturity.

The three turtle species most commonly found along the Pacific coast are the Olive Ridley or golfina (Lepidochelys olivacea), the Leatherback or laúd (Dermochelys coriacea) and the Green Turtle or tortuga verde (Chelonia mydas).

The Olive Ridley is relatively small in size with a narrow head. Its numbers are now recovering on the Nayarit and Jalisco coasts. Important nesting sites for the Olive Ridley include Caleta de Campos and Ixtapilla (both in Michoacán), and Playa de Escobilla and Morro Ayuta (both in Oaxaca). About 23.3 million baby turtles were born in the 1.2 million Olive Ridley nests recorded in the 2010-2011 turtle nesting season.

Leatherbacks, the world’s largest turtles, undergo amazing migrations, regularly crossing from one side of the Pacific to the other. Their numbers are in serious decliine. In 2010-2011, 15,400 baby Leatherbacks emerged from the 615 nests recorded. (Mexico is thought to have about 1,600 Leatherback nests in total.) Important nesting sites include beaches in Guerrero, Michoacán and Oaxaca. However, in the last-named state, the number of eggs laid has declined by about 20% a year over the last decade.

Selected marine turtle nesting beaches in Mexico.

Selected marine turtle nesting beaches in Mexico. Copyright 2012 Geo-Mexico; all rights reserved.

Green Turtles are an endemic species and their preferred nesting sites include Colola in Michaocán.

The three remaining species are the Kemp’s Ridley or lora (Lepidochelys kempii), the Loggerhead or caguama (Caretta caretta) and the Hawksbill or carey (Eretmochelys imbricata).

The Kemp’s Ridley is an endemic species and the only marine turtle to nest exclusively during daytime. Its most important nesting site is Rancho Nuevo, in Tamaulipas. While the numbers of Kemp’s Ridley at Rancho Nuevo fell from an estimated 40,000 or so in 1947 to about 5,000, this species appears to be well on its way to recovery. In 2010-2011, 20,574 Kemp’s Ridley nests were laid in Tamaulipas and an additional 534 in Veracruz, which produced a combined 18.9 million hatchlings.

The Loggerhead is found on both sides of Mexico, while the Hawksbill, smaller than the other species, is most common on Mexico’s Caribbean coast, though it can also be found, much more rarely, on the Gulf and Pacific coasts.

Mexico’s first turtle management program was launched in 1962. In 1990, the government enacted a total ban on the trafficking of all turtles, turtle products and byproducts. Even so, illegal poaching  (for meat, eggs or shell) continues to be a problem, especially since successful convictions relating to the capture or trafficking of turtles are rare. It is still possible to buy baby turtles (for pets) and turtle eggs (thought to be an aphrodisiac) on the black market.

The most successful strategy to date has been the establishment (since the early 1970s) of turtle protection camps on key beaches. During the egg-laying and hatching season conservation groups led by biologists, with the assistance of volunteers, local fishermen and Mexican navy personnel, guard the nesting sites, sometimes moving nests to better protected areas. This strategy has definitely been successful. For example, over the past few years, the conservation group patrolling San Francisco beach has seen the number of active Olive Ridley nests increase tenfold to 700. However, not all beaches can be protected. In Jalisco, for example, only about 80 km of the state’s 200 km of sandy shores are closely monitored.

Protection efforts at 33 nesting beaches are overseen by the National Commission on Natural Protected Areas (Conanp). Of these 33 beaches, 10 are natural protected areas, 3 are in biosphere reserves and 15 are internationally-designated Ramsar wetlands; the remaining 5 have no formal protection status.

Besides the threat from wildlife poachers and predators, marine turtles face numerous other long-term threats, including:

  • habitat destruction, when beaches are cleared for tourist development
  • the installation of coastal infrastructure, designed to prevent erosion, which may limit turtle access to beaches
  • hurricane damage destroying nests
  • the accidental bycatch of turtles by commercial fishermen
  • artificial lighting which may disorientate hatchlings who head towards the light assuming it is reflected off the ocean
  • ocean contamination by items as mundane as plastic bags, which may be mistaken for jelly fish, a favorite food of Leatherbacks

Further reading (Spanish language):

  • Programa de acción para la conservación de la especie Tortuga Laúd (Dermochelys coriacea)
  • Programa de Monitoreo de la Tortuga Golfina (Lepidochelys olivacea) en el Parque Nacional Lagunas de Chacahua

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Jul 052012
 

By virtue of its geography, the Gulf coast state of Veracruz is one of the best places in the world to see the annual migration of birds of prey (raptors) from North America to Central and South America.

Between 4 and 6 million birds (eagles, hawks, vultures, falcons, and kites) make this trip each way each year to trade the harsh winter and scarce food in one hemisphere for better conditions in the other hemisphere. The migration south takes place September-November, and the return migration passes overhead in March-April.

Since most raptors are relatively large birds, and they are accompanied by other species such as storks, white pelicans and anhingas, this annual migration is one of the most awesome birding spectacles anywhere in the world. Each passing flock contains tens of thousands, in some cases hundreds of thousands, of individuals.

The raptors fly during daylight and rest overnight. Their New World songbird cousins, who also migrate in vast numbers, prefer to feed and rest during the day and then fly at night. Most songbirds take a direct migration route from the eastern USA to Central and South America, flying directly over the Gulf of Mexico in a “single, epic 18-hour flight”. Raptors, on the other hand, prefer a more leisurely approach, leap-frogging along the coastal plain.

Why do they fly through Veracruz?

The main reasons are:

1. Relief: Mexico’s mountain ranges, especially the Sierra Madre Oriental {Eastern Sierra Madre) and Volcanic Axis, funnel the birds towards the east coast, but the Gulf of Mexico provides a natural barrier preventing the birds from attempting routes further to the east. At its narrowest, this funnel is only 25 km (15 miles) wide.

2. Climate: The wide coastal plain warms up sufficiently to provide ascending thermal “bubbles” which help keep these large birds aloft and minimize  the energy expenditure required to soar and fly large distances. Raptors use the thermals to soar to about 1000 meters (3000 feet) above the ground, before gliding in their desired direction of travel gradually losing height until they pick up another thermal at a height of about 300 meters (1000 feet), repeating the process as often as needed. On a good day, they will cover more than 320 km (200 miles) in this fashion before resting for the night.

3. Biogeography: The varied landscape, vegetation and animal life in habitats ranging from tropical wetlands to temperature forests, offers plenty of potential food sources for the raptors.

This massive migration has been studied since the early 1990s and scientists continue to tag birds today in order to update their estimates of bird populations and of the precise timing and routes involved. An official counts is held each year from 20 August to 20 November, organized by Pronatura Veracruz. The count is held in two locations: Cardel and Chichicaxtle (see map).

The counts have confirmed that Veracruz hosts the most concentrated raptor migration in the world.

This short video clip highlights Mexico’s leading role in studying the population and routes of these annual international raptor migrations:

One of the major long-term threats to this migration is habitat change in central Veracruz. Pronatura Veracruz sponsors an environmental education program known as “Rivers of Raptors” which tries to address this issue, helping local landowners appreciate the need for watershed protection and for an end to deforestation.

Pronatura’s work with raptors and the local communities is partially funded by ecotourism, and hawk-watching has become an important component of Mexico’s fledgling “ornithological tourism” market. Other key sites in Mexico for birding tourism include the tropical forests of the Yucatán Peninsula and Chiapas, and the San Blas wetlands in the western state of Nayarit.

Map of Central Veracruz

Map of Central Veracruz; all rights reserved. Click map to enlarge

In fact, Mexico is one of the world’s most important countries for birds, home to 1054 species of birds, 98 of them endemic, including 55 globally threatened species. Mexico has no fewer than 145 recognized “Important Bird Areas” (IBAs) of global significance, which between them cover 12% of the national land area (see summary map below).

Important Bird Areas in Mexico [Birdlife.org]

Important Bird Areas in Mexico [Birdlife.org]

Want to read more about the raptors?

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Drug war impacts extend to child arrests, border tunnels and stressed zoos

 Mexico's geography in the Press  Comments Off on Drug war impacts extend to child arrests, border tunnels and stressed zoos
Feb 252012
 

More children being arrested

One extremely unwelcome development in the war on drugs is that an increasing number of young adolescents (aged 11 to 17) are involved in drug smuggling and related activities, according to U.S. Drug Enforcement Administration and U.S. Immigration and Customs Enforcement (ICE). Most of the children are Hispanic, and many hold US citizenship. They are enticed by the lure of “easy” money and know they that, if caught, they can be tried only as juveniles. The Gulf cartel and the Zetas reportedly pay adolescents an average of $500 to smuggle drugs, and $1,000 to guard a kidnap victim for a month. In southern California, the number of arrests of adolescents has risen sharply, with charges ranging from drug trafficking to extortion and kidnapping.

Where are most drug tunnels?

Several major cross-border drug tunnels have been unearthed in the past few months, including one linking warehouses in Tijuana and San Diego which contained 32 tons of marijuana. This tunnel, 600 meters long, was particularly sophisticated and used electric rail cars. More than 70 cross-border tunnels have been found since October 2008.

Significant clusters of tunnels have been found in three main areas:

  • San Diego,
  • California’s Imperial Valley, where the clay soil makes for easy excavation
  • Nogales (Arizona), a city underlain by a network of existing underground drainage canals

Mexico’s zoos struggle to cope with unexpected influx of exotic animals

Press reports such as Captured Drug Kingpin’s Pets Strain Mexican Zoos have highlighted the problems resulting when rare and dangerous animals are confiscated from drugs cartel leaders. Several major cartel figures have amassed extensive private collections of exotic animals, from ostriches and parrots to monkeys, tigers, lions and giraffes. For example, when Jesús “The King” Zambada, a powerful member of the Sinaloa drug cartel, was arrested in mid-2011, authorities had to find new homes for several hundred animals, many of them exotic species. The nation’s zoos are struggling to cope with the influx of so many unexpected new arrivals.

Drug capos do not view animals only as a status symbol. They are also a means to hide drug shipments. Animals have also regularly been used in drugs trafficking. In recent years, grisly finds have included frozen sharks stuffed with cocaine, cocaine-fed snakes, and even liquid cocaine in shipping containers used for tropical fish.

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Feb 132012
 

No one doubts the need for reforestation in Mexico. Since colonial times, huge swatches of the country have been denuded of their native vegetation. Recent figures from INEGI suggest that Mexico has lost almost 50% of its native forests due to logging and clearance for farming and settlement. The majority of this loss is in the Volcanic Axis belt that stretches west-east across the center of Mexico at an average height of 3000 m above sea level, but tropical rainforest areas much further south have also been decimated.

There is, however, some encouraging news.

Data released by the UN Environment Programme (UNEP) puts Mexico in a lofty 4th place worldwide for the number of trees planted since UNEP began its “Billion Trees Campaign”  in 2007. According to the UNEP figures, only China, India and Ethiopia have planted more trees than Mexico.

The “Billion Trees Campaign, inspired by the work of the late Nobel Peace Prize Laureate Wangari Maathai, recognizes that trees bring multiple benefits to people, ranging from carbon sequestration and the provision of timber to soil erosion control, enhanced aesthetic value and opportunities for recreation. UNEP claims that 12 billion trees have been planted worldwide since the program began.

The short Youtube video – Taking Root The Vision of Wangari Maathai –”tells the dramatic story of Kenyan Nobel Peace Prize Laureate Wangari Maathai whose simple act of planting trees grew into a nationwide movement to safeguard the environment, protect human rights, and defend democracy—a movement for which this charismatic woman became an iconic inspiration.” (http://takingrootfilm.com)

Poster prepared by Reforestamos México A.C.

Poster prepared by Reforestamos México A.C. (Mexican NGO) Visit www.reforestamosmexico.org for more information

But are the UNEP figures all they appear to be? Certainly, Mexico’s Environment Secretariat has organized, for many years, on-going programs of reforestation and conservation designed to stem the tide of logging that decimated Mexico’s natural forests over the past century. Official figures show that the pace of this effort has accelerated in the past few years. For example, between 2007 and 2011, Mexico’s National Forestry Commission protected, restored or reforested 21,000 square kilometers  (8100 sq. mi) across the country, an area equivalent to the state of Hidalgo. The total area reforested in those five years amounts to more than 3500 square kilometers  (1350 sq. mi).

On the other hand, critics of Mexico’s forestry policies, such as Greenpeace claim that up to 70% of all lumber sold in Mexico has been illegally harvested, and that less than 60% of trees planted in national campaigns survive their first few critical years.

Deforestation in the Monarch Butterfly Biosphere Reserve

One of the most critical areas, one where continued deforestation could be a real “game-changer”, is the Monarch Butterfly Biosphere Reserve which straddles the boundary between Michoacán and the state of Mexico. This is where millions of Monarch butterflies arrive each year from as far north as Canada to spend their winter. The butterfly itself is not endangered (there are non-migratory populations in many countries, and a year-round resident population in Mexico) but what assuredly is endangered is the “migratory phenomenon” of the Monarchs. Adequate forest cover at an altitude where winter weather is consistently within a narrow temperature band is absolutely crucial to the survival of this spectacular annual migration.

According to the National University (UNAM)’s Environmental Geography Research Center, at current rates of deforestation, the area of overwintering sites for the Monarch butterflies could be reduced by 75% in the next 18 years, leaving just 12,000 ha of suitable habitat. The protected area, established in 2000, covers 560 square kilometers (56,000 ha. or 216 sq. mi) but includes land cleared for pasture, settlement and cultivation. Researcher José López García claims the reserve is losing 3% of its forest each year. He blames clearance and changes of land use more than illegal logging. The rate of forest clearance has been exacerbated by a rapid rise in the population of the El Rosario ejido. El Rosario is the gateway to the most-visited part of the reserve, attracting thousands of tourists annually. The ejido’s population rose by an average of 5.65%/year between 2005 and 2010.

How will climate change affect Mexico’s forests?

Climate change is predicted to have several effects on Mexico’s forests. These include:

  • tropical rainforests (in both Mexico and Brazil) will gradually decline in extent, rainforest soils will have reduced fertility and some parts will become tropical grasslands.
  • the semi-arid areas in central and northern Mexico will become drier, and the total area of arid areas will increase

Globally, deforestation is believed to account for 17.4% of greenhouse gas emissions, so forest protection and reforestation are key strategies in efforts to mitigate the effects of further cliamte change.

The geography of wildfires in Mexico: the disastrous wildfire season of 2011

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Jan 212012
 

In the past 20 years, wildfires have destroyed 47,000 square kilometers (18,000 sq. mi) in Mexico, equivalent to five times the area of all sections of Mexico City’s Chapultepec Park, the largest urban park in Latin America. The average fire in Mexico affects 32 hectares (80 acres); this figure has not changed significantly in recent years, even though the incidence of fires has increased somewhat due to a combination of climate change and an increase in the number of people living on the margins of forested areas. The National Forestry Commission (Conafor) says that 99% of Mexico’s forest fires are caused by human error, and only 1% are due to natural causes such as lightning strikes.

It generally takes about 30 years to rehabilitate forest areas ravaged by fire, with reforestation costing up to $2400/ha.

Wildfires are not entirely bad. For example, they help regenerate grassland areas, especially, with fresh young plants. On the other hand, in addition to protecting the existing vegetation, stopping wildfires when they occur helps to preserve soil structure and prevents additional emissions of CO2 from the burning of more plant material. At a national level, it is estimated that fires result in the erosion of 86 million metric tons of soil a year.

In a 2009 study, Conafor used 17 variables to identify the areas of the county with the highest risk of wildfires. Three broad areas accounted for the 900,000 square kilometers identified as having either a “medium” or “high risk” for wildfires:

  • i. Yucatán Peninsula, Chiapas, Oaxaca and Guerrero
  • ii. Central Mexico – Veracruz, Tlaxcala, Puebla, México, Michoacán, Jalisco and the Federal District. This area has more fires than any other because local populations often use fire to clear fields before planting.
  • iii. Baja California. This is the only area where the main fire season is in summer, from March to November. This is the rainy season in the remainder of Mexico, where the fire season corresponds with the winter dry season.

The first half of 2011 was an especially bad period for wildfires in Mexico, the worst for at least 30 years.

Coahuila wildfire, April 9, 2011 (Earth Observatory, Landsat-5)

Coahuila wildfire, April 9, 2011 (Earth Observatory, Landsat-5)

During the first half of 2011, serious wildfires devastated several areas of northern Mexico, with the states of Coahuila and Nuevo León being hardest hit. Other states badly affected included Durango, Chihuahua, Quintana Roo, Oaxaca, Puebla and Guerrero. More than 7,800 fires occurred, severely damaging a total area of 4100 square kilometers. 30 of Mexico’s 32 states were affected; only Tabasco and Baja California Sur escaped unscathed.

Conafor’s annual fire-fighting budget for the entire country is only 650 million pesos ($50 million dollars); the average annual area damaged by wildfires is only 2600 square kilometers, of which 500 square kilometers are forest. At the height of the 2011 fire season, more than 60 new fires were being reported each day, according to Conafor.

Coahuila

In the state of Coahuila, fires damaged 250 square kilometers in four weeks. It is believed that 50% of these fires were due to farmers losing control of deliberate burns. Farmers are supposed to have an adequate fire-suppression plan in place before setting a deliberate burn, but in practice this requirement is not enforced.

The main locations were La Sabina and El Bonito. Authorities were very slow to respond. Diana Doan-Crider, a wildlife biologist at Texas A&M University, has spent the past 25 years studying the Mexican black bear in the Serranía del Burro in Coahuila, an ecological corridor that runs parallel to the Eastern Sierra Madre. The area includes a large population of Mexican black bears. Doan-Crider claims that authorities completely ignored the first warnings and that their eventual response (two weeks after the first fires started) lacked adequate coordination. Many mother bears and their young cubs perished in the fires.

Firefighters in Coahuila had to cope with a spectacular but terrifying fire whorl or fire tornado

Nuevo León

In the neighboring state of Nuevo León, large swathes of ranching land were ravaged by fire. One rancher who lost more than 10,000 ha of cattleland was equally critical of the slow response time of firefighters who took more than two weeks to appear on the scene, by which time the fires had taken hold.

David Garza Lagüera had converted his 14,000 ha ranch into the Cumbres de Monterrey National Park, one of the key areas of bear habitat. The largest pines on his land were more than 150 years old. All were totally destroyed.

The worst damage was in Galeana, Montemorelos, Zaragoza, Aramberri and Mina. The area burned in Nuevo León in May 2011 was almost ten times the total area affected in the state for the whole of 2010.

Why was the 2011 fire season so bad?

To quote the Earth Observatory, “Lack of winter rain and frost left the plants dry and prone to fire. On top of that, the area has not burned for more than 20 years, during which time fuel built up. Thunderstorms and steady strong winds with gusts up to 110 km/h (70 mph) completed the formula for a dangerous, fast-moving wildfire.”

Ironically, the passage of Hurricane Alex in July 2010, which brought 1500 mm (60″) of rain to the Serranía del Burro, actually worsened the fire damage the following year. The rain from Hurricane Alex encouraged so much new growth in the final months of the rainy season that when it died back in the dry season, there was far more fuel available than usual for any wildfire that was sparked.

By the time the federal government declared a state of emergency, it was too late; the fires had already destroyed large areas of grassland, scrubland and forest. The emergency response when it finally arrived included help from the USA and Canada such as the specialist aerial Mars water-bombers stationed on Vancouver Island. The fires were only fully extinguished once the annual rainy season arrived.

As we now know, the disastrous fires of April-May 2011 were an early sign of Mexico’s worst drought for 70 years:

The diffusion of the Africanized honey bee in North America: a bio-geographical case study

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Oct 082011
 

Africanized honey bees, sometimes popularly called “killer” bees, resulted from the crossing (hybridization) of European honey bees and African honey bees. They combine the best and the worst of both sets of relatives. Africanized honey bees are slightly smaller than European honey bees, but more aggressive and less inclined to remain in one place. They can swarm and attack even if unprovoked, even though they can sting only once before dying shortly afterward.

Their “killer bee” label is because they have killed 1,000 people in the Americas since their ancestors escaped from a laboratory in Brazil. Africanized bees react ten times faster to disturbances than European bees and can pursue a hapless human victim for 300-400 meters.

The mixing of genes that created Africanized honey bees occurred in the 1950s. In 1956, Dr. Warwick Kerr, a bee researcher in Brazil, hoped to develop a bee that would thrive in Brazil’s tropical climate. He decided to cross European bees with African bees. Unfortunately, in March of the following year, some of his experimental bees escaped into the wild. The Africanized bees soon began to multiply and expand their range. They proved to be very adaptable, and have since spread, at a rate of up to 350 km/year through most of South and Central America, as well as into Mexico and the USA. They arrived in Peru by 1985 and Panama by 1982. Their spread northwards continued, and they crossed from Guatemala into Mexico, near Tapachula, in October 1986.

The map shows the gradual northward spread of Africanized bees in Mexico. Up to 1987, the progression looks fairly regular, but in the following year, Africanized bees’ northward movement was restricted to a zone along Mexico’s Gulf Coast. This remained true even through 1989. By 1990, the “front” of the bees advance once again stretched right across the country.

Q. What factors may have caused the unusual (anomalous) geographic spread of Africanized bees in 1988 and 1989?

Map of africanized bees spread across Mexico

Africanized bees spread across Mexico (adapted from Kunzmann et al)

Why are Africanized bees more migratory than European bees?

Scientists believe that Africanized bees are uniquely equipped to cope with the unpredictability of suitable food sources in the tropics. They are more opportunistic, changing their foraging habits to suit local conditions, including short-term supplies of pollen, which they will collect and store to ensure their survival. When a new resource presents itself, Africanized bees will swarm rapidly to maximize their use of the new pollen source.

In bio-geographical terms, Africanized bees are an example of an opportunistic or r-species, perfectly equipped to move to new or changing habitats. They reproduce rapidly, and use available resources efficiently. This makes them far less stable than European bees which thrive in a more predictable environment and adapt to changing circumstances far less quickly.

Africanized bees can survive on limited food supplies, will explore and move to new locations frequently and are aggressive in defending their resources. When they come into contact with other less aggressive bees, such as Mexico’s native bees, Africanized bees may out-compete them for pollen and eventually replace them as that area’s dominant bees.

In Mexico, the speed of diffusion of Africanized bees slowed down

When Africanized bees were reported from southern Mexico, US beekeepers began to fret. The US honey industry is worth 150 million dollars a year. Fear spread that Africanized bees might jeopardize the entire industry, mainly because they are prone to migrate, and would be hard to control.

US experts helped finance a joint program in Mexico which aimed to slow down the bees’ progress northwards. The original idea was to stop bees from crossing the narrowest part of Mexico, the Isthmus of Tehuantepec, preventing them from reaching central Mexico. However, by the time funding was approved, some bees had already crossed the Isthmus. The focus of the bee-control plan was changed to trying to slow down their seemingly inexorable progress north. Even if scientists could only delay the bees’ progress, it would give US farmers more time to plan for their eventual arrival.

The plan was relatively simple. Hang sufficient bee traps in trees throughout the region to attract wild swarms while banning Mexican beekeepers from moving any hives from southern Mexico into central or northern Mexico. Thousands of distinctive blue boxes appeared in orchards and forests across a broad belt of Mexico, from the Pacific to the Gulf.

The combined Mexico-US program is credited with having slowed the bees’ entry into the USA down by about two years. Even so, by 1990, Africanized bees were spotted in Texas; they reached Arizona by 1993 and California by 1995. By this time, they were also found throughout Mexico.

In a later post, we will look at honey production in Mexico and see whether or not it was permanently affected by the influx of Africanized bees.

Sources:

(a) “Africanized Bees in North America” by Michael R. Kunzmann et al, in Non-native Species by Hiram W. Li (biology.usgs.gov)

(b) Introduced Species Summary Project: Africanized Honey Bee by Christina Ojar, 2002.

(c) Alejandro Martínez Velasco. Las andanzas de la Abeja Africana Informador (Guadalajara daily), 1 September 1991.

Aug 082011
 

Durango has long been considered the scorpion capital of Mexico (even the local soccer team became known as Los Alacranes, the Scorpions). At one point in the past, the city paid a bounty for each scorpion killed. Some historical accounts suggest that the scorpion catch rose dramatically, until the local authorities realized that some families had started their own financially lucrative scorpion-breeding programs.

These days, few scorpion stings are reported in Durango, partly because Durango’s scorpion hunters (alacraneros) catch and kill thousands each rainy season; prime specimens are encased in souvenir key rings and wall clocks sold in the local market. They also supply medical research labs.  Research in one lab at the University of California has isolated several peptides that appear to suppress the immune system, promising another way to prevent transplant rejection.

Lourival Possani, and his colleagues at Mexico’s National University (UNAM) have discovered a toxin (named scorpine) in scorpion venom that slows down the growth of malaria parasites in fruit flies; if similar techniques work in malarial mosquitoes, it may be possible to dramatically reduce the spread of malaria.

About 250,000 people in Mexico are stung by scorpions each year—more people than in any other country. Several dozen people die each year. Indeed, for the past 20 years, scorpion stings have been the leading reason in Mexico for  deaths due to adverse reactions and poisoning caused by venomous plants and animals. There are more than 200 different species of scorpions in Mexico, of which only 8, all belonging to the genus Centruroides are a significant public health risk. The map shows the areas defined by Mexico’s Health Secretariat as being of High, Medium and Low risk for dangerous scorpions.

Mortality remains higher in the smallest settlements, and is greatly reduced in mid-sized and large settlements. This is a function of both the reduced proximity of medical care in small settlements and of the higher numbers of scorpions/10,000 people in less urbanized settings. The highest mortality rates by age occur in the 0-1 years group (7 deaths/million), followed by the 1-4 age group (3.8/million) and the 60+ years group (0.8/million) (all data from http://www.scielo.br/pdf/rpsp/v21n6/05.pdf)

Scorpion risk in Mexico

Scorpion risk in Mexico (Secretaria de Salud)

Fortunately, progress is being made. The number of recorded deaths from scorpion stings [1] has fallen from more than 1,000/year in the 1950s to 285 in 1995, about 80 in 2003, and 57 in 2005. This improvement is the result of public health campaigns stressing the importance of seeking emergency treatment and of the development of antivenin serum (known as Alacramyn in Mexico and Anascorp in the USA). Mexico’s antivenin industry, led by the Bioclon Institute, is world class, exporting serum to the USA and Australia as well as throughout Latin America. The biggest threat from scorpions comes from central and northern states in Mexico, including several along the Pacific Coast: Nayarit, Jalisco, Colima, Michoacán and Guerrero.

According to UNAM’s Biomedical Investigation Institute, 277,977 people in Mexico reported scorpion stings in 2010. In the first five and a half months of 2011, 98,818 people in Mexico have been stung. The five states with the highest incidence of reported scorpion stings are: Jalisco (19,995), Guerrero (15,769), Morelos (13,123), Guanajuato (12,326) and Michoacán (10,597).

The incidence of scorpion stings rises sharply in summer when higher temperatures encourage scorpions to leave their lairs and go exploring.

Q. What other factors, besides the ones mentioned in this post, might help explain the pattern of risk shown on the map? Hint – can you think of things that the states shown as “high risk” — or the “low risk” ones — have in common?

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[1] A Google search using the terms “scorpion”, “deaths” and “Mexico” finds dozens of websites all claiming that “In Mexico, 1000 deaths from scorpion stings occur per year.” This includes the two highest ranking sites in the results here and here, for articles dated 14 April 2011 and 20 August 2009 respectively. Given that 1000 deaths/year from scorpions has not been true for 20+ years, perhaps it’s time for these sites  to update their data by referring to Geo-Mexico!

Mexico has forty UNESCO-designated biosphere reserves

 Other  Comments Off on Mexico has forty UNESCO-designated biosphere reserves
Jul 232011
 

A surprising percentage of Mexico’s land area is protected in one form or another. A very large number of sites of archaeological or historical importance are managed by the National Institute of Anthropology and History, more commonly known by its acronym INAH. In theory, all buildings more than 100 years old have some degree of protection (under INAH), but in practice this protection is often ignored by developers with other ideas.

Sites considered significant for their natural beauty are protected in a variety of ways, ranging from nature sanctuaries of local importance to protected areas, national parks and internationally recognized biosphere reserves. In total, more than 11.5% of Mexico’s land area is now protected. This percentage has risen steadily for more than a century.

The designation of biosphere reserve can only be made by UNESCO (U.N. Educational, Scientific and Cultural Organization), in a manner somewhat similar to the designation that some major historical sites enjoy as World Heritage Sites. One of the benefits of attaining Biosphere Reserve status is that it allows access to more sources of funding for conservation programs.

Mexico currently has 40 biosphere reserves. Only the USA (48), the Russian Federation (41) and Spain (41) have more. Worldwide, there are now (July 2011) 580 biosphere reserves in 114 countries. The guiding principle of biosphere reserves is that the local populace is not displaced, but actively involved in all aspects of management, research and monitoring.

Biosphere Reserve Zonation

Biosphere reserves have a research-intensive core area or areas at their heart, surrounded by a buffer zone, where sustainable development is fostered, before gradually transitioning into the surrounding region. Many reserves have innovative systems of governance designed to ensure that the views of local people are fully respected. The idea of biosphere reserves was first proposed in 1968 at the UNESCO “Biosphere Conference”, the first international attempt to reconcile the need for conservation with the use of natural resources for development.

No system is perfect. The challenges for biosphere reserves include strengthening the worldwide network by establishing new reserves in areas where few currently exist, as well as helping meet the on-going funding needs for all the reserves. One of the most significant future threats to biosphere reserves is likely to be the habitat changes wrought by global warming.

One of the more startling surprises in the existing network of reserves is the almost total lack of protection afforded to such an amazing part of Mexico as the Copper Canyon region, with its indigenous Tarahumara people and world-class scenery. But perhaps one day this region, too, will become part of Mexico’s extensive system of protected areas.

Mexico’s Biosphere Reserves, as of July 2011:

Baja California Peninsula:

  • El Vizcaíno (Baja California Sur): desert, mountain and coastal/marine ecosystems, petroglyphs, wall paintings, birds and Grey whales.
  • Sierra La Laguna (Baja California Sur): contrasting ecosystems, woodlands and scrub, with high degree of endemism.
  • Alto Golfo de California (Baja California and Sonora): extraordinary geological formations with volcanic craters, dunes, oasis and beaches, and a diversity of plant associations.
  • Islas del Golfo de California (Baja California Sur and Sonora): series of over 240 islands with high number of endemic species; ornithological paradise.

Northern Mexico:

  • Mapimí (Durango, Chihuahua and Coahuila): fragile warm desert and semi-desert ecosystems.
  • La Michilía (Durango): mountainous area of pine-oak forest; habitat for the now rare black bear (Ursus americanus) and wolf (Canis lupus).
  • El Cielo (Tamaulipas): one of the most ecologically rich and diverse parts of Mexico; numerous endangered animal species; ecotourism area.
  • Laguna Madre and Río Bravo Delta (Tamaulipas): a migratory bird haven on coastal wetlands.
  • Cumbres de Monterrey (Nuevo León): the landmark mountains that ensure the water supply for the state capital.
  • Maderas del Carmen (Coahuila): encompassing parts of the Chihuahuan Desert in Coahuila state adjacent to the U.S. biosphere reserve of Big Bend National Park.
  • Cuatrociénegas (Coahuila): an oasis with 500 pools that preserve species found only in the Coahuila state part of the Chihuahua desert.
  • Sierra de Alamos–Rio Cuchujaqui (Sonora): endangered tropical deciduous forest.

Central and Western Mexico:

  • Sierra de Manantlán (Jalisco and Colima): transition of the Nearctic and Neotropical biological realms; cloud forest and wild perennial corn (Zea diploperennis).
  • Chamela-Cuixmala (Jalisco): a Pacific Coast dry tropical forest harboring iguanas and crocodiles in lagoons and marshes.
  • Islas Marietas (Nayarit): a biodiverse archipelago of islands with a rich mix of marine species, corals and landforms.
  • La Primavera (Jalisco): pine and oak forest in a caldera close to Guadalajara, Mexico’s second city.
  • Sierra Gorda (Querétaro): ecologically diverse area with 14 vegetation types, historic missions and Huastec Indians.
  • Monarch butterfly migration sites (Michoacán and State of México): unique annual migration links Mexico to Canada and the U.S.
  • Sierra de Huautla (Morelos): woods full of endemic species.
  • Barranca de Metztitlán (Hidalgo): home of Otomí Indians and large variety of wildlife.
  • Los Volcanes (State of México/Puebla) is the volcanic landscape of significant aesthetic and touristic value that surrounds the twin volcanoes of Popocatépetl and Ixtaccíhuatl.
  • Islas Marías (Nayarit), a group of four islands, perhaps best known for its federal penitentiary, with considerable diversity of ecosystems and many
    endemic species.

Eastern Mexico:

  • Los Tuxtlas (Veracruz): a beautiful jungle-covered volcanic region, with vestiges of pre-Hispanic archeology.
  • Sistema Arrecifal Veracruzano (Veracruz): an archipelago off the Caribbean coast.
  • Pantanos de Centla (Tabasco): villages in coastal wetlands.

Southern Mexico:

  • Montes Azules (Chiapas): Lacandon tropical rainforest; 500 species of trees; several indigenous groups (including Tzeltal, Chol and Lacandon Maya).
  • Volcán Tacana (Chiapas): fragile ecosystems in Chiapas, adjacent to Guatamala.
  • El Triunfo (Chiapas): diverse evergreen cloud forest in rugged mountain terrain; a primary Pleistocene refuge for numerous endemic plants and animals; large mobile population.
  • La Encrucijada (Chiapas): shrimping lagoons on the Pacific Coast.
  • La Sepultura (Chiapas): ancestral lands of the Olmec and other pre-Hispanic cultures.
  • Selva El Ocote (Chiapas): rain forests, caves and reserves of underground water.
  • Huatulco (Oaxaca): coastal reserve protecting endangered sea turtles, dolphins and purple snails.
  • Lagunas de Montebello (Chiapas) series of beautiful lakes close to the border with Guatemala, set in upland, wooded terrain, with varied flora and fauna including orchids, butterflies, fish, reptiles, mammals and birds.
  • Naha-Metzabok (Chiapas) northern section of the Lacandon tropical forest, home to several members of the cat family and an important part of the Mayan forest biological corridor

Yucatán Peninsula

  • Ría Celestún (Yucatán and Campeche): coastal region including important wetlands and drowned river valley (ría) with diverse fauna and flora, including flamingos.
  • Región de Calakmul (Yucatán): diverse tropical rainforests; the largest forest reserve in Mexico, with important Maya sites; ecotourism project.
  • Ría Lagartos (Yucatán): coastal estuary with diverse birdlife including more than 18000 pink flamingos as well as some 30,000 migratory birds.
  • Arrecife Alacranes (Yucatán): the largest coral reef in the Gulf of Mexico, and the only one in Yucatán state.
  • Sian Ka’an (Quintana Roo): coastal limestone plain, and extensive barrier reef system on Caribbean coast, with numerous archaeological sites; more than 4,000 plant species.
  • Banco Chinchorro (Quintana Roo): mosaic of open water, sea grass beds, mangroves, sandy beaches and coral reefs; more than 95 species of coral.

Main source: UNESCO: Directory of the World Network of Biosphere Reserves

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How ecological is ecotourism in Mexico?

 Excerpts from Geo-Mexico  Comments Off on How ecological is ecotourism in Mexico?
Jun 162011
 

Ecotourism is often touted as one solution to many of the potential woes associated with conventional resort tourism. It should come as no surprise to find that Mexico has embraced ecotourism: Mexico’s biodiversity is phenomenal. It is one of the five most important countries in the world in terms of biodiversity:

To be ecologically successful, ecotourism probably has to be small-scale. Constructing the infrastructure necessary for large-scale coastal ecotourism projects often involves the destruction of highly productive (in ecological terms) wetlands, including tropical mangroves. These ecosystems play a vital role in helping preserve biodiversity and their destruction has serious long-term economic implications for fishing, port and marina access, coastline preservation and beach-based tourism.

Marine biodiversity

Mangroves (pictured on the right of the image) are especially vulnerable, with an undeserved reputation for being impenetrable thickets harboring noxious insects and reptiles. Mangroves sequester carbon and help reduce the organic content of water. Their roots bind unstable coasts, preventing erosion and acting as a natural barrier against hurricanes. They are important breeding, shelter and feeding places for fish, crustaceans and birds as well as being a source of charcoal, firewood, wood and roofing materials. They offer economic opportunities of fishing for shrimp, mollusk, fish and crustaceans.

In the year 2000, the total area of mangroves along Mexican coasts was estimated at 880,000 hectares (2.2 million acres), approximately two-thirds on the Atlantic and Caribbean coasts, and one-third on the Pacific. The annual loss of mangroves is estimated to be between 2.5% and 5% of this area. Even with the lower rate of loss, by 2025 mangroves will occupy only half of their 2000 area. In 2007 Mexico enacted federal legislation to protect existing mangroves.

The unique habitats of coral reefs are also at risk. Mexico has important zones of coral from the Baja California Peninsula and Sea of Cortés in the north to Cozumel Island and Chinchorro Bank in the south. The latter area is the northernmost extension of the Meso-American Barrier Reef system which is the world’s second largest reef system after Australia’s Barrier Reef. Marine pollution, overfishing and tourism have all hastened the decline of coral reefs,though many areas are now protected.

Even animal migrations are considered at risk. Some studies have shown that the number of tourists viewing the whale migrations off the coast of Baja California, for instance, is already having an adverse effect on the whales’ breeding habits.

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This is an excerpt from chapter 19 of Geo-Mexico: the geography and dynamics of modern Mexico. Buy your copy today, and learn more about Mexico’s fascinating geography. The more knowledge you acquire, the more pleasure you will derive from your next trip to Mexico!