Arxiu d'etiquetes: bonobos

Nature in times of war

The actual world  is in turmoil. News related to terrorism, drug trafficking, coups d’état,  refugees crisis or the numerous wars still present flood our screens day after day. And, in a completely understandable bias, the focus is almost exclusively on the people and countries involved. But (and it’s something I ask every time I watch the news) what happens to nature in these regions punished by violence? In this entry we review the most important armed conflicts nowadays and their consequences for the nature surrounding them.


Any human action has repercussions on natural life, and even more wars, intrinsically destructive. A series of damages on the wildlife are associated with them such as deforestation, soil degradation, pollution or hunting, among many others. The first time we really became aware of the great impact of the wars on nature was in the Vietnam War. The US army, in its fight against an invisible enemy, threw more than 75 million liters of herbicides into the jungles, in order to defoliate the trees to find their enemies. However, despite partially achieving its objective (we all know how that war ended) nature was seriously damaged. A study carried out in Vietnam in the mid-1980s found that there were only 24 birds and 5 mammals in an area where there were previously between 145 and 170 birds and between 30 and 55 mammals.

A Huey helicopter from the US military overhangs the jungles of Vietnam while ‘bathing’ them with orange agent. Agent Orange was a potent herbicide and defoliant used by the United States during the war to make more visible enemies hidden in the jungle. A single plane could defoliate tens of hectares in a single flight. The US government spent $ 60 million a year on Agent Orange. Source: Zmescience.

Other wars, such as the Civil War in Rwanda, apart from causing more than 500,000 deads and displacing more than 2 million of people, left the nature of the country in a state of absolute crisis. In the Akagera National Park, one of the most emblematic environments in the country, deforestation wreaked havoc: 200,000 of the 300,000 hectares of forest were lost in just 3 years, as well as 90% of large mammals.

But what is happening today? How are the wars of today affecting the survival of nature? Here we review the most important current conflicts and their difficult coexistence with the wildlife of the region.

Israeli-Palestinian Conflict (1948-present)

Although the last war between Israel and Palestine began in 2005, violence between the two countries has been present since the creation of the state of Israel. Thousands of people have been dead for decades, and millions have been displaced against their will. And, of course, nature has not come out unscathed.

One of the most famous cases occurred in 2006. The Israeli army bombarded two oil tanks near a power station in Jieh, Lebanon (where a terrorist group called Hezbollah was emplaced) causing a spill of 10,0000 and 15,000 cubic meters of oil in the Mediterranean sea. This black tide spread along 90 km of the coast of Lebanon, carrying the death with it. In addition, this phenomenon severely affected the habitat of the green turtle (Chelonia mydas) in one of the last well-preserved places that this species still had in the Mediterranean basis.

The bombing of two oil tanks by the Israeli army left 80 km of the Lebanese coast as can be seen in the image. In 2014, the United Nations Assembly urged Israel to compensate Lebanon with $ 856.4 million for this environmental catastrophe. Source: hispantv.

However, in early 2016, images that would call even more international attention came to light: dozens of animals from the Gaza zoo appeared completely mummified after suffering a terrible agony and starving. It happened twice since the zoo opened in 2007, but the strongest famine took place in 2014, following a conflict between Israel and Hamas’s Palestinian forces. It is estimated that about 80 animals died because of famine, including crocodiles, tigers, baboons or porcupines. When rescue services were able to reach the zoo, only 15 animals remained alive, many of them with severe symptoms of malnutrition.

The Gaza zoo became the World’s Worst Zoo due to the shocking images of mummified bodies as a result of the famine that caused the war. According to Abu Diab Oweida, the owner of the zoo, the bodies were mummified so that everyone could see that even the animals were affected by the war. Source: Dailymail.
The continuous bombing in the Gaza Strip cause numerous casualties, such as those of the horses in the picture. Unfortunately, the end of the conflict is still so far. Source: helpinganimalsingaza.

Second Congo War (1998-2003)

This war, also known as the Great War of Africa or the African World War, has caused the death of more than 5 million people since then, which has given it the dubious honor of being the deadliest armed conflict since The Second World War. Although the war officially ended in 2003 and there is an elected government since 2006, the Democratic Republic of the Congo lives in a state of instability typical of a country at war.

The guerrillas use the country’s many natural resources to obtain money so they can continue the war. And ivory is the most precious commodity, the one that produces the most benefits. That is why African elephant populations (Loxodonta africana) have been reduced by 90% since the beginning of the conflicts. Something worse has occurred to the northern white rhinoceros (Ceratotherium simum cottoni) a subspecies of the white rhinoceros. Its last specimens, 2 males and 2 females living in the Garamba National Park, are believed to have died between 2006 and 2008 at the hands of the guerrillas, causing the extinction of this subspecies.

The mountain gorilla (Gorilla beringei beringei), with an estimated population of  only 700 individuals, lives almost exclusively in the Virunga Mountains, a territory shared by the Democratic Republic of Congo, Rwanda and Uganda. In the picture, a mountain gorilla killed by unknown causes in 2007. It is believed that the rangers were involved in his death. Source: The Guardian.

Bushmeat, or the food coming from wild animals, is another major problem stemming from the numerous military conflicts in the country. In the wake of extreme poverty, many villagers have been forced to hunt to survive. And the primates has been one of the most harmed groups. The populations of the great primates, once counted by millions, have been drastically reduced. It is believed that there are only 200,000 lowland gorillas, 100,000 chimpanzees and 10,000 bonobos in freedom.

Bonobos (Pan paniscus) are our closest relatives, and one of the most threatened animals in the Congo. It is endemic to this country, but is being heavily hunted for food and, more recently, to serve as a delicacy to the Asian market. Specimens such as it appears in the image can easily be found in the markets of Kinshasa and Brazzaville. Source. National Geographic.

Syrian Civil War (2011-present)

Undoubtedly, the most famous war at the moment. This conflict has killed more than 500,000 people and has caused one of the most important humanitarian crises of our time: it is estimated that there are more than 10 million of refugees because of the war. Those who have remained in Syria, have been displaced from the interior to the coastal zone, becoming a great threat to the forests of the region. According to Aroub Almasri, a Syrian government environmentalist, most people need food, electricity and fuel to cook and warm up, which has lead to clear the area’s forests, mostly in protected areas. Apart from the severe impact of deforestation, there are also a large number of fires that have been spreading throughout the region in recent times. A particularly affected area is the Fronlok forest on the border with Turkey. In these mountains the degree of endemism is high, and many species are at a serious risk of disappearing from the area, especially a type of oak, Quercus cerris, native to the region and which would begin to be threatened.

Due to the fragmentation of the habitat, it is believed that an iconic species of the Mediterranean zone and classified as critically endangered by IUCN has become extinct in Syria. It is the bald ibis (Geronticus eremita), a bird of which only 500 individuals remain and is present only in three countries: Morocco, Turkey and Syria. In spite of Syria‘s enormous effort to maintain a stable population in its territory, the war wiped out the last individuals of this species in the region. Only one individual of the species remains, a female named Zenobia, who was seen for the last time in Palmyra before ISIS troops entered the city.

It seems that the numerous efforts made by the Syrian government in the early years of the twenty-first century have been insufficient to save this iconic species from extinction. Formerly present in large parts of Europe (from Austria to the Iberian Peninsula) the bald ibis has the most important populations in Morocco, its last redoubt in the natural state. Source: New Scientist.

Second Libyan Civil War (2014-present)

After the first Libyan civil war, which ended with the fall of Colonel Gaddafi, the country entered into a spiral of violence sponsored by the numerous armed groups that control the country. The importation of meat from abroad has stopped, and the owners of sheep, goats and camels keep their animals as if they were gold because of shortages. Because of this, armed groups are heading to the south of the country, where anarchy prevails and there are a lot of wild animals to take advantage of.

One of the most harmed species has been the rhim gazelle (Gazella leptoceros), classified as threatened by IUCN and with its populations in decline. Ten years ago the population did not exceed several hundred individuals, and it is believed that today the situation is much worse.

Rhim gazelle is native to North Africa, where there are less than 2,500 individuals. The militias use their meat to feed or sell it in the Libyan market, where it is scarce. Source: Creative Commons.

But the gazelles are not the only ones harmed by the banditry and impunity reigning in Libya. Large numbers of migratory birds, which have to cross the African country on their way to Europe, are slaughtered by hunters. In addition, the oases that they use to rest are being opened by the hunters, which causes that hundreds of cranes, ducks, herons and flamingos are annihilated without anyone can do anything.

In addition, the effect of the Libyan war on nature does not remain within its borders. In 2015, weapons from Libya were found near elephant corpses in Mali, a heavily threatened elephant subspecies. It is believed that the ivory of the Mali elephants is serving to finance the Libyan militias.

A slaughtered elephant is seen in Bambara-Maoude
Mali’s elephants are one of the only two populations of elephants living in the desert. The last air census (2007) revealed the presence of only 350 individuals in the country. In 2015, 80 elephant were hunted, so the forecasts are not at all flattering: scientists believe that the population will die out in 3 years. Source: Reuters.

The Colombian government against the FARC and other guerrillas (1964-2016)

Despite the peace agreement reached few months ago between the Colombian government and the FARC, both social and environmental wounds will take a long time to be closed. For a long time the militias have been financed largely from the money generated by illegal cocaine crops. Placed deep in the Colombian jungle, thousands of hectares of pristine forest have been cleared for the construction of laboratories and coca plantations. In addition, in an attempt to stop this type of illegal crops, the government fumigated extensive forest areas with glyphosate, a herbicide that, despite being considered harmless, caused the death of birds, small mammals and insects, what in turn left without sustenance the people who live on hunt. Another added problem is that illicit crops have spread to protected areas. Thus, according to a report by the National Parks of Colombia, FARC were present in 37 protected areas of the country, and 3791 hectares of coca plantations were also detected in there.

However, the illicit activity that most threatens Colombia’s nature is illegal mining, one of the most lucrative activities for armed groups. Not for less, since while 1 kg of coca is sold at about 4.3 million pesos, 1kg of gold is sold at 85 million pesos, about 20 times more. For this reason, large areas of jungle have been destroyed by backhoes to open gold (60%), coltan (25%), charcoal (10%) and tungsten (5%) mines. Deforestation resulting from illegal mining reaches unimaginable numbers: between 1990 and 2010, an average of 310,349 hectares of forest per year were deforested, that is, 6206.000 hectares in all that time, or what is the same, 5.4% of the Colombian surface.

Mercury and cyanide, highly contaminating metals, are used for the extraction of gold. It is estimated that about 200 tons of mercury go to Colombian rivers each year. This has caused, at least, the contamination oh 90 rivers, affecting the local fauna and flora. Source: Semana.

Finally, FARC actions against oil extraction have caused serious oil spills in areas of high environmental value. This is the case, for example, of the 492-liter oil spill in Puerto Asis, Putumayo, in June 2015. The FARC intercepted a convoy containing tanks with oil and spilled them, affecting 9 wetlands and spreading oil along the Putumayo River.

In 2013, the FARC’s systematic attacks against the oil industry accounted for 132 only in the province of Putumayo. Hydrocarbons contaminate the soil and remain there for years. In water, oil, due to its oxygen consumption, creates anoxic conditions that causes the death of fish. Source: elcolombiano.

War in Afghanistan (2001-2014)

Either the last war and the previous one had a strong impact on the region’s wildlife. It is estimated that between 1990 and 2007, more than one-third of Afghanistan’s forests were cleared, either by refugees to use wood for cooking, fuel or construction, or by logging industries, which cut down the forests of the region with impunity.

Nevertheless, the news are more optimistic than would be expected of a country plunged into war for decades. Between 2006 and 2009, the first censuses since the 1970s were carried out in the province of Nuritán, with the help of trap cameras, the study of faeces and the realization of transects. The results were encouraging: 18 black bears, 280 porcupines and many red foxes, gray wolves, golden jackals, wildcats, palm civets and rhesus macaques were observed, and even the elusive snow leopard (Panthera uncia), concretely 3 distinct individuals.

Photo-trapping cameras captured images of the elusive snow leopard in the rugged Afghan mountains. With no doubt, they are encouraging news for its conservation. Source: James Nava.

However, there are still threats for Afghan wildlife. The large number of bombs thrown during the years made a dent in the abundance of migratory birds. Many birds died directly from the impact of the bombs or poisoned when they came into contact with contaminated water. Others, however, varied their rute due to the bombing and no longer cross the country. This is the case of the Siberian crane (Grus leucogeranus), a species critically endangered by IUCN that has not been seen in Afghanistan since 1999. In addition, due to the war and the incipient Afghan economy, hundreds of hunters Are forced to catch live birds for subsequent smuggling into rich Arab countries. This has led to the fact that, in some regions of Afghanistan, migratory bird watching has declined by 85% since the start of the war.

According to the Afghanistan Environmental Protection director, every year around 5000 birds are hunted for contraband, especially in the regions of Syed Khel and Kohistan. Many of the Houwa bustards (Chlamydotes undulata) and different types of hawks are sent to rich Gulf countries to serve as pets. In the picture, Afghan hunters near their rudimentary cages. Source: focusingonwildlife.

Korean Conflict (1950-present)

The Korean Demilitarized Zone is the proof that even something as tragic as a war can bring positive consequences. In 1953, following the peace agreement by both countries, the Korean Demilitarized Zone, a strip of land 4 km wide and 250 km long that separates both countries, was created. The area, which has a strong military presence of about 2 million soldiers, has remained virtually unchanged and sparsely populated since then.

The Demilitarized Zone of Korea, or DMZ, separates both countries thanks to a buffer zone 4 km wide. In this place, the leaders of both countries usually hold the infrequent and tense meetings. Source: Creative Commons.

The area is characterized by a great topographic richness and high variety of ecosystems, which allows it to contain a great diversity. Some scientific expeditions have documented more than 1,100 species of plants, 80 species of fish, 50 of mammals and hundreds of birds. In addition, it is a frequent stop for many species of migratory birds that head towards Mongolia, the Philippines or Australia.

The area has a great diversity of flora and fauna. Deer, bears, wild boars and large numbers of birds inhabit the territory. It is even believed that it could contain some individuals of the siberian tiger, habitual inhabitant of the zone before the Japanese occupation of Korea. Source: BBC.

Recently, thanks to improved relations between the two countries, the area can be visited for only about 43 euros. In addition, due to its exceptional conservation status and high diversity, some campaigns are under way to turn the area into a protected area. One of these campaigns, the DMZ Forum, proposes to declare the area as World Heritage Site and World Park for Peace, in order to be able to protect it from a possible urban development on the day that peace between the two countries is reached.

The area has received numerous supports to convert it into a nature reserve in order to protect it from a possible future exploitation. Among the personalities who have supported the plan are the former US President Bill Clinton and the CNN founder Ted Turner. Source: BBC.


DeWeerdt, Sarah (January 2008). “War and the Environment”. World Wide Watch. 21
King, Jessie (8 July 2006). “Vietnamese wildlife still paying a high price for chemical warfare”. The Independent.
Kanyamibwa S (1998). Impact of war on conservation: Rwandan environment and wildlife in agony. Biodiversity and Conservation, 7: 1399-1406.
Cover picture: Earth in transition.


La homosexualidad es muy animal

Afortunadamente para el colectivo LGTB, cada vez son más los países y sociedades que entienden que la homosexualidad es algo natural y que no es ninguna enfermedad. De todas formas, aunque ésto es cierto, también lo es que aún hace falta mucho trabajo para conseguir la igualdad de derechos de las lesbianas, gays, transexuales y bisexuales y para eliminar la falsa creencia de que la homosexualidad es antinatural. Ya que en las próximas semanas se van a celebrar en ciudades como Barcelona y Madrid las fiestas más reivindicativas de dicho colectivo, este artículo pretende mostrar claros ejemplos de que la homosexualidad no es algo exclusivo de los humanos, sino que muchos animales presentan relaciones de este tipo. Así que ya sabes, ¡ya no hay cabida para el argumento de que la homosexualidad es antinatural!



La homosexualidad es un hecho presente en muchas especies animales. De hecho, se ha documentado en 1.500 de las más de 1 millón de especies animales descritas hasta la fecha (Bagemihl, 1999). Sin ir más lejos, un estudio de la Universidad de California demostró que en todas las especies analizadas había algunos ejemplares (repito, ¡sólo algunos!) con rasgos o comportamientos homosexuales, incluyendo a gusanos, moscas, aves, delfines y chimpancés, entre otros.

En el reino animal, el concepto “homosexualidad” se refiere a cualquier comportamiento sexual entre organismos del mismo sexo, ya sea la cópula, el cortejo, el apareamiento, la estimulación genital o la crianza. En el caso de los humanos, es mucho más complejo que esto, pues hay muchos más factores y no se simplifica sólo a ésto, puesto que también intervienen los sentimientos en medio de todo ésto.

Des del punto de vista biológico, si se supone que el objetivo de toda especie es su perpetuación en el tiempo, ¿de qué sirve la homosexualidad? Hay muchas teorías al respecto, y no son excluyentes ya que para cada especie hay una explicación u otra. Vamos a dar tres de ellas. Marlene Zuk, profesora de biología de la Universidad de California, propone que al no producir su propia descendencia, los homosexuales podrían ayudar a criar y educar sus parientes, lo que contribuye también al pool genético. Para la bióloga y psicóloga Janet Mann de la Universidad Georgetown, es una forma de crear vínculos y alianzas entre individuos. Finalmente, para el caso de la mosca de la fruta y otros insectos, según el biólogo evolutivo Nathan Bailey, se explica por el hecho de que carece el gen que permite discriminar entre los sexos. También cabe la posibilidad de que la homosexualidad no tenga ninguna función concreta. Sea como sea, la conducta homosexual puede tener consecuencias evolutivas, pero se está empezando a estudiar.


En febrero de 2004, en el diario New York Times se informaba de que Roy y Silo, dos pingüinos barbijos (Pygoscelis antarctica) machos del Central Park Zoo, enroscaban sus cuellos, se vocalizaban el uno al otro y tenían sexo entre ellos. Cuando se los expuso a hembras, no mostraban interés alguno por ellas. Además, los cuidadores les dieron un huevo fértil para que incubaran y cuando nació la joven pingüino la alimentaron hasta que pudo valerse por si misma. Pero éste no es un caso aislado, pues ha ocurrido más veces en éste y otros zoos, como por ejemplo en el Bremerhaven Zoo (Alemania), Faunia (Madrid) y Dingle Ocean World (Irlanda).

Pero esto no sólo se produce en animales cautivos. Un estudio realizado en pingüinos adelaida (Pygoscelis adeliae) de la Antártida encontró comportamientos homosexuales en algunos de sus individuos jóvenes. Otro caso es el pingüino reial (Aptenodytes patagonicus), en los cuales se observa flirteo entre el 28,3% de los machos según un estudio, aunque parece ser que las parejas homosexuales son de corta duración. El motivo en éstos últimos parece ser un exceso de machos o altos niveles de testosterona. De todas formas, se encontraron dos parejas (macho-macho y hembra-hembra) en las cuales el otro había aprendido el canto de su pareja.

Los pingüinos son un claro ejemplo de aves con comportamientos homosexuales (Foto de Listverse).
Los pingüinos son un claro ejemplo de aves con comportamientos homosexuales (Foto de Listverse).


Los bonobos (Pan paniscus), primates muy cercanos a los humanos, son también un gran ejemplo de comportamientos homosexuales. Se trata de animales muy sexuales. Se ha observado que, ya sea en libertad o en cautividad, la mitad de sus relaciones sexuales son con especímenes de su mismo sexo. Se ha visto, además, que las hembras de bonobo tienen sexo con otras hembras casi cada hora. Parece ser que la función principal es la de fortalecer los vínculos entre los individuos. Entre los machos, con el fin de reducir la tensión después de una pelea, tiene lugar la lucha de penes, que consiste en frotar los genitales entre sí.

En los bonobos, las relaciones con seres del mismo sexo podrían servir para hacer los vínculos más fuertes (Foto de BBC).
En los bonobos, las relaciones con seres del mismo sexo podrían servir para hacer los vínculos más fuertes (Foto de BBC).


Las interacciones homosexuales entre los machos de orcas (Orcinus orca) son una parte importante de su vida social. Cuando los grupos residentes se unen en verano y otoño para alimentarse, los machos muestran comportamientos de cortejo, cariñosos y sexuales entre ellos. Normalmente, las interacciones se producen uno a uno y tienen una duración de una hora, aunque puede alargarse más. En estas interacciones, se frotan, se persiguen y se empujan cuidadosamente. Un comportamiento a destacar es el conocido como orientación hocico – genital, aunque también se produce entre individuos de distinto sexo. Justo por debajo de la superficie del agua, un macho nada por debajo del otro boca arriba, tocando la zona genital con su hocico. Después, los dos se sumergen conjuntamente formando un espiral de doble hélice. Ésto se repite varias veces intercambiándose las posiciones. No es raro observar sus penes erectos durante esta interacción. A pesar de que tiene lugar en todas las edades, es especialmente abundante entre los jóvenes.

Las orcas (Orcinus orca) son cetáceos con comportamientos homosexuales habituales (Foto de WorldPolicy)
Las orcas (Orcinus orca) son cetáceos con comportamientos homosexuales habituales (Foto de WorldPolicy)

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En un estudio realizado en guppies (Poecilia reticulata) se demostró que la falta de hembras en el ambiente durante largos periodos de tiempo produce que los machos prefieran otros machos incluso cuando después hay hembras en el ambiente. No sólo esto. Cuando los machos que habían estado con hembras durante un largo periodo de tiempo fueron privados de ellas por un corto periodo (dos semanas) estos preferían a los machos en lugar de las hembras.

Los machos de guppy preferían otros machos cuando no había hembras en su ambiente durante largos períodos de tiempo (Foto de GuppyFish).
Los machos de guppy preferían otros machos cuando no había hembras en su ambiente durante largos períodos de tiempo (Foto de GuppyFish).


Varias investigaciones han puesto de manifiesto que hay una tasa muy alta de apareamientos entre individuos del mismo sexo en las libélulas. Los motivos podrían ser la falta de disponibilidad de individuos del sexo opuesto o que los engaños de las hembras para evitar las insinuciones sexuales de los machos podría causar que éstos busquen individuos de su mismo sexo. Las hembras de cola azul común (Ischnura elegans) presentan tres tipos de coloraciones y formas. Cuando los machos eran alojados sólo con machos, preferían a los individuos de su mismo sexo cuando se exponían a las hembras, mientras que si estaban alojados en grupos mixtos luego tenían preferencia por los tres tipos de hembra. Por lo tanto, la falta de hembras hacía que las libélulas macho prefiriesen a otros machos. De todas formas, el 17% de los machos de las poblaciones salvajes prefieren a los individuos de su mismo sexo.

Los machos del cola azul (Ischnura elegans) prefieren a otros machos cuando son alojados en ausencia de hembras (Foto: L. B. Tettenborn, Creative Commons).
Los machos del cola azul común (Ischnura elegans) prefieren a otros machos cuando son alojados en ausencia de hembras (Foto: L. B. Tettenborn, Creative Commons).


  • Estudios en gaviota occidental (Larus occidentalis) en estado salvaje muestran que entre el 10 y el 15% de las hembras son homosexuales. Se ha visto que muestran rituales de cortejo entre ellas y que montan los nidos juntas. Sólo puntualmente copulan con machos para producir huevos fértiles, pero luego vuelven con su pareja inicial.
  • En ovejas domesticadas, el 8% de los machos de un rebaño prefiere a otro macho de por vida a pesar de que haya disponibilidad de hembras. Esto podría beneficiar a los otros machos (que pueden tener los mismos genes que los homosexuales) y pueden pasarlos a la siguiente generación. Pero también hace que las hembras sean más fértiles.
  • El rey de la sabana, el león, también presenta comportamientos homosexuales. Se han observado tanto leones como leonas salvajes con comportamientos de este tipo, llegándose a montar.

  • En algunas especies de caballitos de mar, sobre todo entre hembras, las relaciones sexuales homosexuales pueden llegar a ser mucho más frecuentes que las heterosexuales.


Como has podido leer, los comportamientos homosexuales no son exclusivos del ser humano, aunque son mucho más complejos en éstos últimos. Los motivos que conducen al desarrollo de conductas homosexuales en animales pueden ser varias: la poca disponibilidad de hembras, fortalecer vínculos… aunque hemos podido ver que en algunos el comportamiento es permanente. Además se ha visto que no es algo artificial debido a la cautividad de los animales, como podría suceder en humanos en prisiones, sino que ésto también tiene lugar en los animales libres. Así pues, la homosexualidad tiene lugar en muchos animales, por lo que debería hacer plantear a los que van en contra de ella si no se trata de algo muy natural. Además, si no es un elección sino el resultado de fuerzas naturales, el debate sobre si es inmoral debería de ser abandonado. 




Homosexuality is so animal

Fortunately for LGTB collective, greater and greater countries and societies understood that homosexuality is something natural and that it is not an illness. Anyway, despite this is true, it is also true that it is necessary to work hard to achieve equality on lesbian, gay, transexual and bisexual rights and to eradicate the false belief that homosexuality is unnatural. In the next weeks, in cities all over the world like Barcelona and Madrid will take place LGTB Pride parties. For this reason, this article hope to show clear examples that homosexuality is not exclusive of human, but present in many animals. So, there is no reason to continue believing in the argument that homosexuality is unnatural! 



Homosexuality is a fact present in many animal species. In fact, it has been documented in 1,500 of the more than 1 million described animal species (Bagemihl, 1999). Without going any further, a study of the California University demonstrated that in all the analysed species there were some individuals with homosexual traits or behaviours, including worms, flies, birds, dolphins and chimpanzees, among others.

In the animal kingdom, the concept “homosexuality” refers to any sexual behaviour between same sex animals, like copulation, flirt, mating, genital stimulation and young breeding. In the case of humans, it is more complex than this because there is much more factors and feelings are involved in this.

From the biological point of view, it is supposed that the goal of any species is its perpetuation. So, which is the function of homosexuality? There are many theories about it and they are not particular because for each species there is one explanation or another. Let’s explain three of them! Marelen Zuk, professor in biology at the University of California, propose that not producing their own offspring, homosexuals could help to breed and take care of their relatives, what also contributes to genetic pool. According to the biologist and phsycologist Janet Mann from the Georgetown University, it is a way of creating links and alliances between individuals. Finally, in the case of fruit fly and other insects, the evolutionary biologist Nathan Bailey suggest that the reason of their homosexuality is the lack of the gene that let them to distinguish between both sex. There is also the possibility that homosexuality doesn’t have any function. At any rate, homosexual behaviour may have evolutionary consequences, but it is still being studied.


On February 2004, New York Times published that Roy and Silo, two male chinstrap penguins (Pygoscelis antarctica) from the Central Park Zoo, coiled their necks, vocalized one to other and had sex. When they were exposed to females, they rejected them. Moreover, zookeepers gave them a fertile egg in order they incubate them and when the little penguin was born they feed her until she was able to live by herself. This is not an isolated case because it have happened more in this and other zoos, like in Bremerhaven Zoo (Germany), Faunia (Spain) and Dingle Ocean World (Ireland).

But this is not exclusive of captive animals. A research done on Adélie penguin (Pygoscelis adeliae) found homosexual behaviours in some of their young individuals. Another research was carried on king penguin (Aptenodytes patagonicus), in which it was observed that 28.3% of males flirted with other males. The reason in this case seems to be an excess of males or high testosterone levels. Anyway, it was found two partners (male-male and female-female) in which one knew the vocalization of the other.

Los pingüinos son un claro ejemplo de aves con comportamientos homosexuales (Foto de Listverse).
Penguins are a good example of birds with homosexual behaviours (Picture from Listverse).


The bonobo (Pan paniscus), apes very close to humans, are a good example of homosexual behaviours. They are so sexual. It has been observed that, in captivity or free, half of their sexual relationships are with same sex animals. In addition, females have sex with other females almost every hour. The main function of this is to strengthen links between animals. In the case of males, in order to reduce the stress after a fight, a penis fight takes place, that consists on rubbing their genitals together.

En los bonobos, las relaciones con seres del mismo sexo podrían servir para hacer los vínculos más fuertes (Foto de BBC).
In bonobos, same sex relationships may be done to strengthen social links (Picture from BBC).


Homosexual interactions between male killer whales (Orcinus orca) are an important part of their social life. When resident groups join together during summer and autumn to feed, males show flirting, affectionate and sexual behaviours between them. Normally, interactions take place one to one and lasts for an hour, but it can be longer. In this interactions, they caress, chase and carefully push one to the other. Another amazing behaviour is the beak – genital orientation, but it also take place between males and females. Just under the water surface, one male swims in an upside down position, touching the genital zone of the beak. Then, they dive together in a double helix spiral. This happens several times, but they interchange their positions. It is not strange to see them with the erected penis during this interaction. Despite it happens in all ages, it is specially abundant in young animals.

Las orcas (Orcinus orca) son cetáceos con comportamientos homosexuales habituales (Foto de WorldPolicy)
Killer whales (Orcinus orca) are cetaceans with homosexual behaviours (Picture from WorldPolicy)


A research made on guppies (Poecilia reticulata) demonstrated that the lack of females in the environment during a long period of time produce that males prefer other males even when there are females in the environment. Not only this. When males that had been with females during a long period of time are deprived from females for a short time (two weeks) they prefer males instead of females.

Los machos de guppy preferían otros machos cuando no había hembras en su ambiente durante largos períodos de tiempo (Foto de GuppyFish).
Male guppies prefer other males when there is no females in the environment during a long period of time (Picture from GuppyFish).


Some studies lay bare that there is a high rate of mating between same sex individuals in dragonflies. The reasons could be the lack of individuals of the other sex or that female tricks to avoid sexual advances of males could produce that males look for same sex individuals. One specific example is blue-tailed damselfly (Ischnura elegans), in which 17% of males of wild populations prefer male partners.

Los machos del cola azul (Ischnura elegans) prefieren a otros machos cuando son alojados en ausencia de hembras (Foto: L. B. Tettenborn, Creative Commons).
17% of male blue-tailed damselfly (Ischnura elegans) prefer other males (Picture: L. B. Tettenborn, Creative Commons).


  • Studies on wild occidental gull (Larus occidentalis) show that between 10 and 15% of females are homosexual. It has been seen that they show flirting rituals between them and that they set nets together. They only copulate with males to produce fertile eggs, but then go with their initial partner.
  • On domestic sheep, 8% of males from a flock prefer other males despite the presence of females. But this could benefit other males because they can present the same genes and pass to next generation. But this also benefits females by doing them more fertile.
  • The king of savannah, the lion, also have homosexual behaviours. It has been observed wild male and female lions with this behaviour, include mating.

  • In some species of seahorse, homosexual behaviours between females are frequent, more than heterosexual.


Homosexual behaviours are no only in humans, but they are more complex in people. The reason that lead to the development of these behaviours in animals are several: lack of females, to stablish harder links… but there are some examples in which the behaviour is permanent. Moreover, it has been seen that this behaviours are not artificial due to the captivity of animals, like humans in prison, but they haven in wild animals too. So, homosexuality happens in many animals and cannot be considered unnatural. In addition, if it is the result of natural forces it cannot be considered immoral. 




La homosexualitat és molt animal

Afortunadament pel col·lectiu LGTB, cada vegada són més el països i societats que entenen que la homosexualitat és quelcom natural i que no és cap malaltia. De totes maneres, tot i que això és cert, també ho és que encara falta molta feina per aconseguir la igualtat de drets de les lesbianes, gais, transexuals i bisexuals i per eliminar la falsa creença de que la homosexualitat és antinatural. Ja que en les properes setmanes es celebraran en ciutat com Barcelona i Madrid les festes més reivindicatives d’aquest col·lectiu, aquest article pretén mostrar clars exemples de que la homosexualitat no és quelcom exclusiu dels humans, sinó que molts animals presenten relacions d’aquest tipus. Així que ja saps, ja no hi ha cabuda per l’argument de que la homosexualitat és antinatural! 



La homosexualitat és un fet present en moltes espècies animals. De fet, s’ha documentat en 1.500 de les més d’un milió d’espècies animals descrites fins a la data (Bagemihl, 1999). Sense anar més lluny, un estudi de la Universitat de Califòrnia va demostrar que en totes les espècies analitzades hi havia alguns exemplars (repeteixo, només alguns!) amb trets o comportaments homosexuals, incloent a cucs, mosques, aus, dofins i ximpanzés, entre altres.

Al regne animal, el concepte “homosexualitat” es refereix a qualsevol comportament sexual entre organismes del mateix sexe, ja sigui la còpula, el flirteig, l’aparellament, l’estimulació genital o la cria dels joves. En el cas dels humans, és molt més complex que això, doncs hi ha molts més factors i no es simplifica només a això, ja que també hi intervenen els sentiments en mig de tot plegat.

Des del punt de vista biològic, si se suposa que l’objectiu de tota espècie és la seva perpetuació en el temps, de què serveix la homosexualitat? Hi ha moltes teories al respecte, i no són excloents ja que per cada espècie hi ha una explicació o altra. Anem a veure’n tres. Marlene Zuk, professora de biologia de la Universitat de Califòrnia, proposa que al no produir la seva pròpia descendència, els homosexuals podrien ajudar a criar i educar als seus parents, el que contribueix també al pool genètic. Per a la biòloga i psicòloga Janet Mann de la Universitat Georgetown, és una forma de crear vincles i aliances entre individus. Finalment, pel cas de la mosca de la fruita i altres insectes, segons el biòleg evolutiu Nathan Bailey, s’explica pel fet de que els manca el gen que permet discriminar entre els sexes. També hi ha la possibilitat de que la homosexualitat no tingui cap funció concreta. Sigui com sigui, la conducta homosexual pot tenir conseqüències evolutives, però s’està començant a estudiar.


Al febrer de 2004, el diari New York Times informava de que Roy i Silo, dos pingüins de cara blanca (Pygoscelis antarctica) mascles del Central Park Zoo, enroscaven els seus colls, es vocalitzaven l’un a l’altre i tenien sexe entre ells. Quan se’ls va exposar a femelles, no mostraven cap interès per elles. A més, els cuidadors els van donar un ou fèrtil perquè l’incubessin i quan va néixer la jove pingüí la van alimentar fins que va poder valdre’s per ella mateixa. Però aquest no és un cas aïllat, doncs ha tingut lloc més vegades en aquest i altres zoos, com per exemple al Bremerhaven Zoo (Alemanya), Faunia (Madrid) i Dingle Ocean World (Irlanda).

Però això no només es produeix en animals captius. Un estudi realitzat en pingüins d’Adèlia (Pygoscelis adeliae) de l’Antàrtidava trobar comportaments homosexuals en alguns dels seus individus joves. Un altre cas és el pingüí reial (Aptenodytes patagonicus), en els quals s’observa flirteig entre el 28,3% dels mascles segons un estudi, tot i que sembla ser que les parelles homosexuals són de curta durada. El motiu en aquests últims sembla ser un excés de mascles o alts nivells de testosterona. De totes maneres, es van trobar dues parelles (mascle-mascle i femella-femella) en les quals l’altre havia après la vocalització de la seva parella.

Los pingüinos son un claro ejemplo de aves con comportamientos homosexuales (Foto de Listverse).
Els pingüins són un clar exemple d’aus amb comportaments homosexuals (Foto de Listverse).


Els bonobos (Pan paniscus), primats molt propers als humans, són també un gran exemple de comportaments homosexuals. Es tracta d’animals molt sexuals. S’ha observat que, ja sigui en llibertat o en captivitat, la meitat de les seves relacions sexuals són amb espècimens del seu mateix sexe. S’ha vist, a més, que les femelles de bonobo tenen sexe amb altres femelles quasi cada hora. Sembla ser que la funció principal és la d’enfortir les vincles entre els individus. Entre els mascles, amb la finalitat de reduir la tensió després d’una baralla, té lloc la lluita de penis, que consisteix en fregar els genitals entre si.

En los bonobos, las relaciones con seres del mismo sexo podrían servir para hacer los vínculos más fuertes (Foto de BBC).
En els bonobos, les relacions amb individus del mateix sexe podrien servir per fer els vincles més forts (Foto de BBC).


Les interaccions homosexuals entre els mascles d’orques (Orcinus orca) són una part important de la seva vida social. Quan els grups residents s’uneix a l’estiu i tardor per alimentar-se, els mascles mostren comportaments de flirteig, carinyosos i sexuals entre ells. Normalment, les interaccions es produeixen un a un i tenen una duració d’una hora, tot i que poden allargar-se més. En aquestes interaccions, es freguen, es persegueixen i s’empenyen amb cura. Un comportament a destacar és el conegut com a orientació morro – genital, tot i que també es produeix entre individus de diferent sexe. Just per sota de la superfície de l’aigua, un mascle neda per sota de l’alta amb la panxa amunt, tocant la zona genital amb el seu morro. Després, els dos es submergeixen conjuntament formant una espiral de doble hèlix. Això es repeteix vàries vegades intercanviant-se les posicions. No és rar observar els seus penis erectes durant aquesta interacció. Malgrat té lloc en totes les edats, és especialment abundant entre els joves.

Las orcas (Orcinus orca) son cetáceos con comportamientos homosexuales habituales (Foto de WorldPolicy)
Les orques (Orcinus orca) són cetacis amb comportaments homosexuals (Foto de WorldPolicy)

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En un estudi realitzat en guppis Poecilia reticulata) es va demostrar que la manca de femelles en l’ambient durant llargs períodes de temps produeix que els mascles prefereixin altres mascles fins i tot quan després hi ha femelles a l’ambient. No només això. Quan els mascles que havien estat amb femelles durant un període llarg de temps van ser privats d’elles per un temps curt (dues setmanes) aquests preferien als mascles enlloc de les femelles.

Los machos de guppy preferían otros machos cuando no había hembras en su ambiente durante largos períodos de tiempo (Foto de GuppyFish).
Els mascles de guppi preferien altres maslces quan no hi havia femelles al seu ambient durant períodes llargs de temps (Foto de GuppyFish).


Vàries investigacions han posat de manifest que hi ha una taxa molt alta d’aparellaments entre individus del mateix sexe en les libèl·lules. Els motius podrien ser la manca de disponibilitat d’individus del sexe oposat o que els enganys de les femelles per evitar les insinuacions sexuals dels mascles podrien causar que aquests busquin individus del seu mateix sexe. Les femelles del cua blau comú (Ischnura elegans) presenten tres tipus de coloracions i formes. Quan els mascles eren allotjats només amb mascles, preferien els individus del seu mateix sexe quan s’exposaven a les femelles, mentre que si eren allotjats en grups mixts després tenien preferència pels tres tipus de femella. Per tant, la manca de femelles feia que les libèl·lules mascle preferissin a altres mascles. De totes maneres, el 17% dels mascles de les poblacions salvatges prefereixen als individus del seu mateix sexe.

Los machos del cola azul (Ischnura elegans) prefieren a otros machos cuando son alojados en ausencia de hembras (Foto: L. B. Tettenborn, Creative Commons).
Els mascles del cua blau comú (Ischnura elegans) prefereixen a altres mascles quan són allotjats en absència de femelles (Foto: L. B. Tettenborn, Creative Commons).


  • Estudis en gavina occidental (Larus occidentalis) en estat salvatge mostren que entre el 10 i el 15% de les femelles són homosexuals. S’ha vist que mostren rituals de flirteig entre elles i que munten els nius juntes. Només puntualment copulen amb mascles per produir ous fèrtils, però després tornen amb la seva parella inicial.
  • En ovelles domesticades, el 8% dels mascles d’un remat prefereix a un altre mascle de per vida malgrat que hi hagi disponibilitat de femelles. Això podria beneficiar als altres mascles (que poden tenir els mateixos gens que els homosexuals) i poden passar-los a la següent generació. Però també fa que les femelles siguin més fèrtils.
  • El rei de la sabana, el lleó, també presenta comportaments homosexuals. S’han observat tant lleons com lleones salvatges amb comportaments d’aquest tipus, arribant a muntar-se.

  • En algunes espècies de cavallet de mar, sobretot entre femelles, les relacions sexuals homosexuals poden arribar a ser molt més freqüents que les heterosexuals.


Com has pogut llegir, els comportaments homosexuals no són exclusius de l’ésser humà, tot i que són molt més complexos en aquests últims. Els motius que condueixen al desenvolupament de conductes homosexuals en animals poden ser vàries: la poca disponibilitat de femelles, enfortir vincles… tot i que hem pogut veure que en alguns el comportament és permanent. A més, s’ha vist que no és quelcom artificial degut a la captivitat dels animals, com podria passar en humans en presons, sinó que això també té lloc en animals lliures. Així doncs, la homosexualitat té lloc en molts animals, pel que hauria de fer plantejar a aquells que hi van en contra si no es tracta de quelcom molt natural. A més, si no és una elecció sinó el resultat de forces naturals, el debat sobre si és immoral hauria de ser abandonat.