Frequently Asked Questions / Preguntas más frecuentes
Answered by Dr. Frank H. Wadsworth; Updated by Blanca I. Ruiz, December, 2001; Updated by Victor M. Cuevas, March 2018
Some of the are most frequently asked questions about the forest:
- Why is a Forest Called a Rainforest?
- Where are Rainforests located?
- Why is the Forest Green?
- Where is the Dwarf Forest Located?
- Do We Have to Visit East Peak to See the Dwarf or Cloud Forest?
- Where Does All the Water Come From?
- Where Can You Find the Most Rainfall?
- How Much Does it Rain?
- Is it Safe Drinking Water from Streams?
- Can People take a Dip, or go Swimming in the Rivers?
- How cold does it get in El Yunque?
- Where are the Birds?
- Why is the Puerto Rican Parrot almost extinct?
- Why are the parrots seldom seen?
- Are there snakes in the forest?
- Why are there not a lot of Insects?
- When was the road built?
- Is there any Gold left in El Yunque?
- What towns/municipios are part of El Yunque? Why is Rio Grande the Cuidad del Yunque?
- Why are there no large animals in the El Yunque National Forest?
- I have heard that it rains frogs in the El Yunque National Forest. Is this true?
- Have aliens been seen in the forest?
This is a classification based on the amount of rain received in a location. There are many rainforests in the world, not all in the tropic zone. In a tropical forest, trees do not respond well to frost and would not survive a freeze (helada).
In general terms, rainforest applies to almost any forest of the tropics which is evergreen, seldom dry and receives about 60 to 80 inches of rainfall per year. The El Yunque National Forest (EYNF) receives averages of about 200 inches of rain per year and is classified as a rainforest. Rainforests also exist in the lower slopes of the Cordillera Central on the north side of Puerto Rico. The State Forests of Carite, Toro Negro, Guilarte and Maricao are also classified as rainforests. Learn more about Forest Types here.
Fun Fact: The valleys of Río Mameyes has two type of rainforests, the subtropical rainforest and the lower montane rainforest. The subtropical rainforest corresponds to what we call the Tabonuco Forest type. The type of vegetation at Palma de Sierra Visitor Center exemplifies this type. The lower montane rainforest is what we call the Palo Colorado type, which is farther up the slopes in the EYNF. There are areas of Tabonuco which are wet but not considered rainforest, also there are areas of Palo Colorado in the western half of the forest which are wet and considered rainforest. The subtropical rainforest is marked deep green and the lower montane rainforest is marked green.
The green color arises from the chlorophyll substance in the leaves which with the sunlight, acts as a catalyst, manufacturing the food for the tree. This process is called photosynthesis. The food manufactured by the green leaves is transported down throughout the plant and feeds all the cells in its branches, the stems and the roots. Nutrients and water travel up the tree and are prime ingredients in the photosynthetic process.
Fun Fact: There are many different greens in the forest as a result of leave texture. Some are thinner and therefore lighter in color since the light passes through them. Some of the leaves are covered with mold which makes them darker and others are thicker, reflecting more light, while others may be hairy or corrugated, absorbing more light. When you look over the forest from a high point you see many shades of green, each being a different tree species. Trees in the Caribbean lose their leaves, but only the mahogany tree leaves changes color, turning red in April.
The Dwarf, Elfin or Cloud Forest is limited to the high peaks of the EYNF. It begins at about 3,000 feet above sea level on both the windward and leeward slopes. The largest section is on the East and West Peak areas. There is a small amount of the dwarf forest along the El Toro Trail, west of PR 191, on top of El Cacique and a larger area around El Yunque peak and Mt. Britton. The trees in the dwarf or elfin forest range from 3 to 20 feet in height. It is composed of a small number of tree species, all of which have very thick leathery leaves and are capable of withstanding continuous moisture, wind and temperature near 45 degrees. More water runs off the dwarf forest than falls as rain, as water is out competed of the continuous and constant saturation of the clouds involving the forest. With this constant saturation, the trees receive less sunlight and the constant pressure by the strong winds, help create the dwarfed trees which are twisted and covered with mosses and epiphytes. Constantly surrounded by mist, the forest has a dark, haunted, mysterious look.
Not necessarily. Visitors can climb the Mount Britton Trail to see the dwarf Forest. You can turn off from the road between Mt. Britton and Route 10, and then climb the tower to get a better view. While hiking up Mt Britton trail, when you come to the intersection with El Yunque Trail there is a patch of Dwarf Forest (it is the one shown in the movie at El Portal). Although there are very large areas of the Cloud Forest along the East Peak road, they are not as visible or as striking from the road. East Peak road is closed, as it serves a specific restricted use and lies along the edge of a natural area, in order to reduce pollution. Walking is permitted.
Rainfall. The easterly breezes push the clouds full of moisture towards the Island. As they approach the Luquillo Mountains and the winds push them upward to the steep slopes, the cloud temperature drops and it starts to rain. It is estimated that the average annual precipitation (120 inches) would yield 100 billion gallons of water annually. The amount that falls in one year will supply San Juan for 2.5 years or, the entire island of Puerto Rico for 8 months. The month that tends to be the driest is March though in some years it might be February or April. The rest of the year the rainfall is at least 4 inches per month. This keeps the vegetation from drying out. The driest period on record was 35 days in 1936 when only 9/100ths. (.90) of an inch fell at La Mina. The heaviest recorded rainfall at La Mina was 16 inches in 24 hours.
The upper areas of the Forest are the wettest. East Peak is probably the wettest spot in Puerto Rico with El Yunque Peak being somewhat drier. La Mina which is near the old ranger station, is between these two points and probably intermediate in moisture with an average of 183 inches of annual rainfall recorded over a 9 year period. The rain comes in as moisture from the clouds pushed east and up the mountain by the prevailing northeast tradewinds. The moisture laden clouds rise as they hit the mountain slopes. Then as they rise, the air becomes cooler and water droplets form in the clouds and resulting in precipitation. The east winds account for the fact that more of the water falls in the eastern half of the forest than in the west.
Rainfall records have been taken in various places throughout the mountains. One of the longest single rainfall record of good quality is at La Mina, by what used to be the old ranger station. Over a period of 9 years the average at La Mina was of 183 inches, with a maximum of 253 inches and a minimum of 125 inches.
The area that receives the most amount of rainfall is found at East Peak. The readings on East Peak for 1979 are probably one of the highest on record for Puerto Rico. The readings were provided by the Federal Aviation Agency who has a permit for an electronic installation in the Forest. At the lowest end of the Forest, like in El Portal, the rainfall is around 70 to 90 inches. The wettest sections of the Forest include the East Peak area, the upper Mameyes and Fajardo valleys. In comparison with the east, the west side of the Forest receives a significantly lower amount of rain.
Fun Fact: Records at La Mina indicate that it rains three days out of four. Because it does not rain consistently throughout the day, the actual rain percentage of rain received is about 6% of the time, compared to about 3% in San Juan. On a four year survey, La Mina recorded an average of 1,600 showers a year. The average length of the shower was 19 minutes. The maximum intensive 5 minute period was recorded at the rate of 7.5 inches per hour. For a full hour the highest rate was 2.5 inches. About 55% of the rainfall occurs during the day.
The surface water of the forest is not suitable for public consumption. Campers are encouraged to bring their own water or purifying device. Water in the recreational areas is tested regularly and the system is shut off if it is unsafe.
There are no streams with large swimming holes in the rainforest, although most rivers do have small areas where it is possible to submerge. The Forest does not recommend swimming or wading in the rivers and streams. Visitors can proceed at their own risk but must be aware of flash floods, even when it may not be currently raining in the area. You can find options HERE.
The high peaks in the Forest are slightly cooler than the La Mina station, where a thermometer was kept for 9 years, from 1935 to 1943. The mean temperature was 70 degrees, with the maximum of 90 degrees, and minimum of 52. Temperature can decrease in the lower peaks, and around East Peak, with the lowest temperature recorded was 44 degrees in February 1980. More recent measures tend to indicate that the construction and consequent deforestation in this part of the Island has been affecting the temperatures at the forest and causing the increase in the average temperature. Changes of temperature affect the type of vegetation that is found at different altitudes in the forest. Thus, the Tabonuco type would be found at higher elevations than in previous years and that the actual area for the Palo Colorado type would be decreasing as the interphase between these two types is “pushed-up” by the changing climatic conditions.
There are 97 bird species found within the Forest, of which 45 are migratory. Most of them are well hidden in the trees and many live away from the roads. You will probably be able to hear them, but it would be more difficult to actually see them. A good place to see birds is at Angelito’s Trail, as this is a transition zone between two ecosystems and therefore a better place for them to find food and shelter. It is also easier to spot them early in the morning and later in the afternoon. In Puerto Rico, there are approximately 269 bird species of which 106 are breeding species and 153 are migratory. Learn more HERE.
The Puerto Rican Parrot was common over most of the Island when Christopher Columbus arrived to the island. The Tainos tribe used them as pets and as food. It lives in the Forest, requiring large hollow cavities for nesting. As the trees were being cut to clear land for farming and development, the parrot retreated into the remaining virgin forest. At one time, 85% of the Island was completely deforested, leaving only a few small isolated patches on the south coast with smaller trees unsuitable for parrot habitat. Only in the El Yunque National Forest could parrots find large trees suitable for nesting. From time to time, the parrot flies outside the forest looking for food resources not available under the dense tree canopy. They eat mostly fruits and seeds.
After being declared endangered on the Federal Listing of Threatened and Endangered Species, a recovery program was started. Today, the success of the recovery program have increased their population with the addition of a second aviary and wild population in the Rio Abajo State Forest Untuado, and another wild population in the Maricao National Forest. The effects of hurricanes Irma and Maria have severely affected the parrot recovery program. Parrots in the wild didn’t not fare well from the storm (3 out of 56 survived), captive parrots all survived and are doing well. Breeding season is currently underway (January- July) and 8 babies were born in mid-March. Thirty parrots were released into the forest in January 2020. Learn more about the parrots.
The Pearly–eyed thrasher (Zorzal Pardo) has invaded the Palo Colorado Forest, the parrot’s prime habitat. The bird is a very aggressive competitor for nesting trees and disturb the parrot’s nests by laying its eggs inside them. Thrasher chicks are larger than the parrot’s, giving them the advantage of food availability that result in the parrot’s chick’s deaths.
Honeybees also pose a big problem for the parrot. Although not native in Puerto Rico, honeybees have taken many hollow trees which are suitable for parrot nests. There is no one problem causing the demise of the parrot. The ongoing research and recovery program is making some strides, not only to identify the causes of decline, but to attempt to increase the parrot population.
They are so few in numbers and they nest at long distances from the roads. In the past they could be occasionally seen around El Yunque Restaurant or flying over the Sierra Palm or Palo Colorado Visitor Information Centers or heard squawking loudly in the tree tops around the recreation area in El Yunque. The increase in visitors to these areas, have forced the parrots to retreat and are rarely seen today.
Yes, there are snakes in the forest but they are not poisonous, they are infrequently found and they do not constitute a problem to visitors.
Snakes in the Forest are not poisonous or aggressive, they are rather shy and don’t constitute a hazard to the public. The only large snake found in the Forest is the Puerto Rican Boa (culebrón). Some have been seen measuring about 5 to 6 feet in length. They are generally found at lower elevations. Sightings are uncommon, forest personnel who are in the field each day rarely see them.
There are 4 other species of snakes which are much smaller and non-poisonous. These, unlike the Boa, do not climb trees and are even harder to find.
The lack of insects is common in wet forests. The 12 species of coquís and 8 of lizards in the forest eat millions of mosquitos and other smaller insects daily. There are several biting insects and very large beetles found in the forest. If one looks hard, many insects can be found in the lower parts of the forest. Many are very brightly colored and more varied in colors, sizes and shapes than those in temperate climates.
Road PR 191 from Mameyes to Río Grande was started in 1929 with prison labor and finished in Río Blanco in 1937. The construction took eight years, and about two thirds of the road was built with Civilian Conservation Corps (CCC or “la PRERA”) after prison labor discontinued its efforts. Built almost completely by hand, wheel and barrow, it is a legacy that has endured all these years.
Fun Fact: The CCC was a program that provide work for unemployed youth during the Depression era in construction of infrastructure. CCC structures, like all of the Forests trails, pools, bridges, houses, shelters, “honeymoon cottages” and the old restaurant (El Yunque Pavillion) are still present in El Yunque as a testimony to the great work of these young men. Similar structures are also present in all of the state forests.
In the early days gold was removed from the sands in rivers, particularly in Río Mameyes. As labor became more expensive it was no longer practical to pan for gold. The actual source of gold was never found. Downstream from Puente Roto there was a very large area operated by the French Mining Co. during the 19th Century. Learn more about the history of gold in El Yunque.
There are 7 towns that have a portion of El Yunque, with Rio Grande having the largest portion, as well as containing the main entrance to the national forest.
The island of Puerto Rico was formed by volcanic activity during the Triassic period. Thrusting out of the Caribbean sea it had no land bridge to any continent. Consequently, the animals of Puerto Rico (and the El Yunque National Forest) originally arrived on the island by either swimming, floating or flying, and thus were smaller in size than those found on large continents. The largest mammalian animals in the forest are the rats, bats and the mongoose (see EYNF Wildlife Facts). A reptile, the Puerto Rican Boa can grow to a length of 6 feet but poses no threat to humans. None of the animals of the forest, large or small (including insects) are poisonous. The tarantulas, scorpions and centipedes found in the forest can provide a venomous bite (similar to a bee sting) but are only dangerous to those who are allergic.
This interesting forest legend involving Puerto Rico's indigenous Coqui frog (Eleutherodactylus coqui) is actually based on scientific fact. During those times of the year when the humidity is high, the tiny Coqui frogs will climb to the forest canopy, sometimes as high as 100 feet (30 meters). Predators such as the tarantula anticipating this behavior, lay in wait for the frogs. Many frogs are caught by the predators during their ascent. Instead of returning to the ground by the same dangerous path, the surviving frogs prefer to launch themselves into the air, thus bypassing their predators on the way down. The tiny frogs are almost weightless so that they float to the forest floor unharmed. If you are lucky enough to be sitting under a tree when this is happening, you will indeed be rained upon by tiny frogs! To read more about the Coqui frog check-out EYNF Wildlife Facts
There is no scientific evidence that aliens have visited the El Yunque National Forest, however local folklore has kept this story alive for years. The most reasonable explanation for any alien sightings in the forest is easily explained. From the early 1960s until quite recently the US Navy maintained an Electronic Tracking Facility on Pico del Este (East Peak) a part of the El Yunque National Forest that overlooks many of Puerto Ricos major northeastern roadways and towns. At night the lights of the facility, seen from below during military exercises cast an eerie glow over the mountain peak, which most probably added fuel to the legend.
Preguntas que más hacen nuestros visitantes:
- ¿Cuánta lluvia cae en el bosque pluvial?
- ¿De donde proviene tanta agua?
- ¿Hay culebras en el Bosque Nacional El Yunque?
- ¿Aún se puede encontrar oro en los ríos del Bosque Nacional El Yunque?
- ¿Por qué no hay animales grandes en el Bosque Nacional El Yunque?
- He oído que "llueven ranas" en el Bosque Nacional El Yunque. ¿Es cierto?
- ¿Por qué la Cotorra Puertorriqueña esta prácticamente extinta?
- ¿Se han visto "extraterrestres" en el bosque?
Esto depende de la parte del bosque donde se encuentre. Por lo general, mientras más alto está en el bosque, mas lluvia caerá. La cantidad máxima de lluvia que ha caído en las partes más elevadas del bosque es de más de 250 pulgadas (635 centímetros) al año, mientras que en las elevaciones más bajas solo cae entre 50 y 60 pulgadas (120-150 centímetros). Para ver las lecturas de lluvia actuales para áreas especificas del bosque, refiérase a nuestro Mapa de Precipitación.
El agua proviene de la lluvia, llega al bosque traída por los vientos alisios. Los Vientos Alisios, con su aire húmedo, soplan desde África hacia el oeste, por encima del Océano Atlántico y del Mar Caribe. Estas corrientes de aire constantes eran las que llenaban las velas de los barcos que llevaban carga entre Europa y África y el Nuevo Mundo. Cuando las nubes de los vientos alisios alcanzan las montañas, como las del Bosque Nacional El Yunque, se ven obligadas a subir por la pendiente. Mientras el aire húmedo sube, se enfría y se condensa formando gotas de lluvia que caen sobre el bosque. Este fenómeno se conoce como lluvia "orográfica" y produce gran parte de la lluvia que recibe el bosque cada año. Se estima que el índice de precipitación promedio (120 pulgadas-304 centímetros al año) produciría 160,000 millones de galones (605,000 millones de litros) al año, lo suficiente para proveer de agua por dos años al municipio de San Juan, cuya población es de medio millón de personas.
Sí, existen 5 ó 6 especies de culebras que viven en el bosque. Por lo general, no se ven, no son venenosas, ni resultan peligrosas para los humanos. La más grande de éstas es la Boa de Puerto Rico que puede alcanzar hasta 6 pies (casi dos metros) de largo. Es un depredador que trepa árboles y que caza por las noches animales pequeños y huevos de aves. A veces, se le puede ver durante el día en las elevaciones más bajas, enrollado y dormido. Las otras especies de culebras que se encuentran en el bosque son mucho más pequeñas y no trepan árboles, por lo que son más difíciles de encontrar. Para leer más sobre la Boa de Puerto Rico vea Vida Silvestre .
Sí, pero no espere hacerse rico buscándolo. Los estimados varían, pero a lo sumo, no espere recoger más de US $2.00 por todo un día de trabajo arduo. En otra época, se extraña el oro de las arenas de ríos como el Mameyes que cursa paralelo a la carretera PR 191 camino hacia el Bosque Nacional El Yunque, pero nunca se pudo descubrir la fuente del oro por lo que, con el tiempo, se descontinuaron los trabajos. Aprende mas sobre el oro en El Yunque.
La isla de Puerto Rico se formó por actividad volcánica durante el periodo Triásico. Emergiendo del Mar Caribe, no tenía un puente de tierra con ningún continente. Por consiguiente, los animales de Puerto Rico (y los del Bosque Nacional El Yunque) originalmente llegaron a la isla nadando, flotando o volando, por cual eran de tamaños más pequeños que los que se encuentran en los grandes continentes. Los mamíferos más grandes del bosque son las ratas, los murciélagos y las mangostas (véase Vida Silvestre del BNEY). Hay un reptil, la Boa de Puerto Rico, que puede alcanzar hasta 6 pies (casi 2 metros) de largo, pero no presenta ningún peligro para los humanos. Ninguno de los animales del bosque, grandes o pequeños (incluyendo los insectos) son venenosos. Las picada de las tarántulas, los escorpiones y los ciempiés que se encuentran el bosque pueden ser venenosas (similares a una picada de abeja) pero tan sólo son peligrosas para las personas alérgicas a éstas.
De hecho, esta leyenda interesante sobre el bosque que involucra al coquí puertorriqueño (Eleutherodactylus coqui) está basada en hechos científicos. En las temporadas del año que la humedad es alta, el pequeño coquí se trepa al dosel del bosque, a veces subiendo hasta 100 pies de altura (30 metros). Los depredadores, como la tarántula, prevén esta conducta y se quedan quietos esperando a las ranas. Los depredadores capturan muchas de las ranas cuando éstas están subiendo. En vez de regresar a la superficie por el mimo camino peligroso, los coquíes sobrevivientes prefieren tirarse al aire. De esta manera evitan a sus depredadores en la caída. Las pequeñas ranas son muy livianas, así que llegan intactos hasta el piso del bosque. Si tiene la suerte de sentarse bajo un árbol en el que esto esté pasando, en efecto, "caerá una lluvia" de pequeñas ranas sobre su cabeza. Para leer más sobre el coquí, ojee la sección Vida Silvestre del BNEY.
La Cotorra Puertorriqueña (Amazona vittata) es nativa de la isla. Cuando Cristóbal Colón llegó a la isla en su segundo viaje de exploración en 1493, estas aves eran muy comunes a través de toda la isla. Esta cotorra es un ave de bosque que requiere de grandes troncos de árboles huecos para anidar. Como los conquistadores originales cortaron muchos árboles para hacer espacio para fincas, las cotorras se retiraron gradualmente a los bosques que restaban. Durante los siglos siguientes, se cree que el 85% de la isla se ha deforestado. Las cotorras solo encontraban los grandes árboles que necesitaban para anidar en el protegido Bosque Nacional El Yunque. La población de cotorras disminuyó considerablemente hasta que se pasaron leyes que prohibían la caza de éstas en el bosque. En 1968, la Cotorra Puertorriqueña se incluyó en la Lista Federal de Especies en Peligro de Extinción, comenzando un esfuerzo colaborativo para recuperar esta importante especie entre el Servicio Forestal del Departamento de Agricultura de Estados Unidos, el Servicio Federal de Pesca y Vida Silvestre, el Departamento de Recursos Naturales y Ambientales del Estado Libre Asociado de Puerto Rico y el Fondo Mundial para la Naturaleza. La continua disminución de la población de cotorras se debe a varios factores: la competencia por nidos con el Zorzal Pardo, un ave agresiva que ha invadido el hábitat principal de las cotorras, una aumento de abejas de miel que se han establecido en muchos de los árboles de Palo Colorado que son idóneos para que las cotorras aniden y por varias otras razones. En el Bosque Nacional El Yunque se ha creado un aviario de cotorras administrada por el Servicio de Pesca y Vida Silvestre federal. En ésta, se incuban huevos de cotorra, se preparan los pichones que se crían en cautiverio para que puedan vivir en el bosque y, posteriormente se liberan. La población actual en el bosque es de menos de 50 aves, pero, cada año, se liberan individuos y parejas criados en cautiverio y su índice de supervivencia es alentador. Para más información sobre la cotorra de Puerto Rico, refiérase a Vida Silvestre en el BNEY-Agosto 2004.
No existe prueba científica de que "extraterrestres" hayan "visitado" el Bosque Nacional El Yunque. Sin embargo, el folclor local ha mantenido esta historia viva durante años. Los "extraterrestres" que visitan el bosque se pueden explicar de una forma muy razonable. Desde comienzos de la década de 1960 hasta no hace mucho tiempo atrás, la Marina de Estados Unidos mantuvo una Estación de Seguimiento Electrónico en el Pico del Este, una parte del Bosque Nacional El Yunque con vista a mucho de las carreteras y los pueblos del noreste de Puerto Rico. Durante la noche, las luces de la estación que se ven desde abajo durante los ejercicios militares, arrojan un resplandor misterioso sobre la cima de la montaña, lo que, probablemente, alimentó la leyenda. Sin embargo, sólo los animales del bosque saben toda la historia detrás de estas supuestas visitas nocturnas de extraterrestres y, hasta el momento, lo han guardado en secreto.
Alerts & Warnings
- Rd 9938 Repairs - Closed to Vehicles / Pedestrian Access to Mt. Britton Trail
- Reparaciones en Rd 9938 - Cerrado a vehículos / Acceso peatonal a Mt Britton
- Main Recreation Area Open by Reservation
- Principal Área Recreativa Abierta Por Reservación
- Un tramo de la vereda El Yunque permanecerá cerrado al público por reparaciones
- A section of El Yunque Trail to El Yunque Peak Closed for Repairs