Arxiu d'etiquetes: conservation

Tuatara: reintroduction of a living fossil

There’s a reptile in New Zealand whose lineage arose in the time of the dinosaurs. Even if its external appearance is similar to that of a lizard, the tuatara (whose name means “spiny back” in the Maori language) is an animal with many unique characteristics that classify it in an order different from the other reptiles. In this entry we’ll explain the main characteristics of this relic from the past, as interesting as endangered.

ORIGIN AND EVOLUTION

The tuataras are unusual reptiles whose lineage goes back to 240 million years ago, at the middle Triassic. Tuataras are lepidosaurs, yet they form a different lineage from the squamates, and that’s why they are found in their own order, the rhynchocephalians (order Rhynchocephalia). Lots of species flourished during the Mesozoic, even if almost all of them were replaced by squamates. At the end of the Mesozoic only one family survived, the Sphenodontidae.

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Homoeosaurus fossil, an extinct relative of the tuataras. Photo by Haplochromis.

Of all the existing sphenodontids, only tuataras have survived to the present day. Traditionally it was considered that tuataras included two species: the common tuatara (Sphenodon punctatus) and the Brother’s Island tuatara (Sphenodon guntheri), although recent analyses have popularized the idea that the tuatara is only one species, S. punctatus.

TUATARA ANATOMY

As we have already stated, tuataras look externally like a lizard, having a certain resemblance to iguanas. Male tuataras are larger than females, measuring up to 61 cm in length and one kilogramme of weight, while females only measure 45 cm and weigh half a kilo. Tuataras present a spiny crest on their backs which give them their common name. This crest is bigger in males, and can be erected as display.

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Photo by KeresH of a young male tuatara.

What really distinguishes the tuataras is their internal anatomy. All the other reptiles have modified greatly their skull structure, but tuataras have maintained the original diapsid configuration without most changes. While crocodiles and turtles have developed a sturdy skull, tuataras conserve wide temporal openings, and while squamates have developed flexible skulls and jaws, tuataras keep a rigid cranium. Also, unlike most reptiles, tuataras present no external ears.

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Modified image from the drawing by Nobu Tamura of the tuatara skull. In it we can see the main characteristics that distinguish it: 1. Beak-shaped premaxilla, 2. Acrodont teeth, fused to the jaws, 3. Diapsid-like wide temporal openings and 4. Parietal or pineal opening.

The name Rhynchocephalia means “beak head” and it refers to the beak-like structure of their premaxilla. Tuataras are also one of the few reptiles with acrodont teeth, which are fused to the maxilla and the jaw, and are not renewed. Also, they present a unique saw-like jaw movement, moving it forwards and backwards.

Video by YouOriginal, of some captive tuataras feeding. In this video we can appreciate the singular jaw movement.

Finally, one of the more incredible anatomic characteristics of tuataras is that they conserve their parietal or pineal eye. This is a structure reminiscent from the first tetrapods, which connects with the pineal gland and which is involved in the thermoregulation and circadian rhythms. Even if some other animals also keep it, the tuataras present a real third eye, with complete lens, cornea and retina, even if it gets covered with scales as they age.

HABITAT AND BIOLOGY

Tuataras live in some thirty islets in the Cook Strait, between the two main islands of New Zealand. Also, the previously considered species S. guntheri is found on Brother’s Island, in the northwest of South Island. All populations live in coastal forests or scrublands, with loose soils easy to dig. Also, in most of their distribution area there are colonies of sea birds, whose nests are also used by tuataras.

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Photo by Satoru Kikuchi of a typical humid forest of New Zealand.

Compared with most reptiles, tuataras live in relatively cold habitats, with annual temperatures oscillating between 5 to 28°C. Tuataras are mainly nocturnal, usually coming out of their burrows at night, even if sometimes they can be found basking in the sun during the day (especially in winter).

Tuataras have few natural predators. Apart from some introduced animals, only gulls and some birds of prey represent a danger for these reptiles. In contrast, their diet is fairly varied. Being sit-and-wait predators, tuataras feed mainly on invertebrates like beetles, crickets and spiders, even if they are able to predate on lizards, eggs and bird chicks, and even younger tuataras. As their acrodont teeth don’t renew, these get worn down in time, so older individuals usually feed on softer prey like snails and worms.

Tuataras mate between January and March (summer), when the territorial males compete for the females, which will lay around 18-19 eggs between October and December (spring). The sex of the offspring depends on the incubation temperature (males at higher temperatures and females at lower ones). The eggs will hatch after 11-16 months (one of the longest incubation periods of all reptiles), from which young tuataras will be born, who will avoid the cannibalistic adults being active mainly during the day.

Unique video of the birth of a tuatara at the Victoria University of Wellington. The translucent mark on the little tuatara’s head corresponds to the parietal eye.

As we can see based on their long incubation period, tuataras develop slowly. These reptiles do not reach sexual maturity until the age of 12, and they keep growing. Also, tuataras are extremely long-lived animals, living up to more than 60 years in the wild. In captivity they can live more than 100 years.

CONSERVATION AND THREATS

Before the arrival of man, the tuataras were present in both main islands of New Zealand and many more islets. When the first European settlers arrived, tuataras were already only found in about 32 little islands. It’s believed that the extinction of tuataras from the main islands was due to habitat destruction and to the introduction of foreign mammals like rats. Other threats include the low genetic diversity caused by isolation of the different populations and climate change, which can affect the sex of the offspring.

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Current distribution map of the tuataras. The squares correspond to the old species Sphenodon guntheri, now considered a population of S. punctatus.

When the first human settlers arrived in the isles, it is thought that 80% of New Zealand was covered in forests. When the first Polynesian tribes came around the year 1250, they caused the deforestation of more than half the archipelago. Centuries later, with the arrival of Europeans, deforestation intensified even more, up to the current situation, with only 23% of the original forest still preserved.

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Photo by Cliff of a Pacific rat (Rattus exulans), one of the main threats for the tuataras.

The introduction of foreign mammals has been one of the main factors of the recent decline of tuataras, especially the introduction of the Pacific rat (Rattus exulans). This rodent has affected the populations of both tuataras and many of New Zealand’s endemic bird species. In studies on coexisting populations of tuataras and rats, it has been observed that rats, apart from preying on eggs and hatchlings, also compete with adult tuataras for resources. With an extremely slow life cycle, tuataras can’t recover from this impact.

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Photo by Br3nda of a reintroduced and tagged tuatara.

Yet, tuataras are currently classified as “least concern” in the IUCN red list. This is thanks to the great efforts of conservation groups that have contributed to the recovery of this species. One of the main tasks has been the eradication of the Pacific rat from the main island where tuataras live. In order to do that, a titanic effort was made in many islets where entire populations of tuataras were captured to participate in captive breeding programs, while the rats were eliminated from these islands. After their main threat was eradicated, all the captured individuals and their captive-born offspring were released in their natural habitat so they could live without such a fierce competitor.

Video by Carla Braun-Elwert, about the breeding success of an old tuatara couple.

Currently, the wild tuatara population is estimated to be between 60.000 and 100.000 individuals. It can be said that this living fossil, which was on the brink of extinction after millions of years of existence, received a second opportunity to keep inhabiting the incredible islands of New Zealand. We hope that in the future, we can keep enjoying the existence of these reptiles, the only survivors of a practically extinct lineage, for many more centuries.

REFERENCES

The following sources have been consulted during the elaboration of this entry:

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The Iberian wolf: laws and conservation in Spain

The wolf is one of the most iconic carnivores, especially in Spain. However, an unwarranted bad reputation kills hundreds of individuals a year. Find out in this post more about this wonderful animal and the conservation efforts that are currently being made with the Iberian wolf.

HOW MANY WOLF SPECIES EXIST?

The classification of species and subspecies of the wolf is still unclear, although most authors consider that there are 7 species of wolf: gray wolf (Canis lupus), red wolf (Canis rufus), ethiopian wolf (Canis simensis), eastern wolf (Canis lycaon), golden jackal (Canis aureus), himalayan wolf (Canis himalayensis) and indian wolf (Canis indica). Although some features are common to all species, we will focus on the gray wolf and specifically in the subspecies iberian wolf (Canis lupus signatus).

canis, lupus, signatus, lobo, ibérico, llop, ibèric, wolf
Canis lupus signatus. Photo: Mireia Querol

THE WOLF

The wolf or gray wolf (Canis lupus) is the largest wild member of the family Canidae. It was the carnivore with the world’s largest area of distribution, but now it has been reduced drastically by human pressure. Canis lupus has about 32 subspecies and it is considered least concern in the IUCN red list globally, but locally it is listed as endangered. As we saw in a past post, the dog (C. lupus familiaris) is subspecies of the gray wolf .

mapa, distribución, lobo, canis lupus, map, dsitribution, distribució, llop
Wolf’s distribution (Canis lupus). Source: IUCN

SOCIAL ORGANIZATION AND HUNTING

Wolves are social animals: their survival and success as a predator depends on their organization in packs (8 to 12 members). The hierarchy within the pack is based on a breeding pair (usually a lifelong couple) and the other members cooperate in hunting and caring for the young.

In a pack, members maintain extensive territories by olfactory and acoustic tags. The howl of the wolf is used to announce their presence and defend territories. It can be heard up to 10 km away and allows rival packs stay away and avoid confrontations. It is also used to communicate and strengthen ties within the members and to express emotions.

Lobo aullando. Foto: UK Wolf Conservation Trust
Wolf howling. Photo: UK Wolf Conservation Trust

They are adapted to walk and run long distances in search of prey in a variety of terrains (forest, meadow, snow…) and are also good jumpers while running. Its great smell, good sight (diurnal and nocturnal thanks to the tapetum lucidum) and impressive teeth makes them effective predators. In addition, the group hunting allows them to kill prey up to 10 times its weight. Once it is tumbled, members wait their turn after the dominant pair has feed on it. In case of shortage of food, wolves can scavenge dead animals and even practice cannibalism.

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Pack lurking a bison. Font

REPRODUCTION

From January to April, the dominant female gives birth to 4-7 cubs. After a month of breastfeeding, the cubs leave the burrow and feed on food regurgitated by their parents and other members of the group. If the food is abundant, after 3-5 months the cubs are ready to travel with the rest of the group. The next breeding season, some youth will abandon the pack searching for mates and territory.

THE IBERIAN WOLF

The Iberian wolf is found exclusively in the Iberian Peninsula. Its scientific name “signatus” refers to the signs in their fur that differentiate it from Eurasian wolf (Canis lupus lupus).

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Eurasian wolf (Canis lupus lupus). Photo: Quartl

 

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Iberian wolf’s fur (Canis lupus signatus). Source

The Iberian wolf packs has fewer individuals (up to 7 and often only a couple with a subadult) due to the smaller size of the prey and food availability (roe deers, sheeps, mountain sheeps, rabbits).

If you want to know more about the iberian wolf you can download the app iFelix (in spanish) listed here .

DISTRIBUTION AND ROLE OF THE WOLF IN THE ECOSYSTEM

In the early twentieth century the wolf was distributed throughout all the peninsula. It has now been restricted almost to the peninsular northwest and around 2,800 individuals in total exist. The year 2000 the wolf reappeared in Catalonia, which could give the impression that the Iberian wolf was expanding, although genetic analysis in a 2011 study showed that came from the Italian-French lineage and only 13 different individuals were identified.

Mapa de distribución del lobo ibérico. Fuente
Distribution map of the Iberian wolf. Source

Large predators are essential for the survival of biodiversity of ecosystems. The wolf is a key species in this role, because its influence is greater than other species. This is due to its ability to modify the density and performance of dams and its interactions with other species, as scavengers. An example is this viral video in which the presence of the wolf ultimately led to the modification of the river in Yellowstone:

THREATS OF IBERIAN WOLF

Iberian wolf threats are basically due to humans:

  • Increasing human pressure that invades their original habitats
  • Forest fires
  • Competition with farmers and hunters (economic interests, ignorance and superstitions)
  • Fragmentation of habitat due to highways and railways (which also cause collisions)
  • Disinterest of competent authorities
Corpses of wolves appeared in Asturias. Tensions between farmers and administrations have generated in recent months ghoulish images like these (Tiós, 2015). Various sources

LEGAL STATUS OF THE WOLF IN SPAIN

According to the Red Book of Vertebrates in Spain the wolf is listed as vulnerable. However, populations at north of the Duero River can be controlled hunted and beated in exceptional cases, even during the breeding season. Only the municipality of Muelas de los Caballeros wants to ban hunting considering the wolf as an “emblematic species”. In Portugal conservation is somewhat higher, but when wolves cross the border are hunted indiscriminately in Galicia and Zamora, disabling conservation efforts in the neighboring country.

By contrast, the populations of southern Duero are protected by the Habitats Directive of the EEC and by various laws of the Spanish state. However, in April 2016 the government suggested removing this protection, but it has not succeeded. So a river separates the wolves that can be hunted and prosecuted from those who are protected. But if you look at the distribution map, this protection at south of the Duero may be useless, because probably there are no remaining wolves in that area.

THE VARMINTS’ EXTINCTION JUNTAS

The Juntas de Extinción de Animales Dañinos existed in Spain between 1954 and 1968. Their goal: to offer economical rewards to kill species that were detrimental to hunting and livestock. In that period, 196,147 animals were killed (the numbers are probably higher than reported), including 1,470 wolves. Today there are still people who claim the return of the varmint killers.

Currently it is estimated that each year about 500 wolves die because of legal and illegal hunting, poisoning and vehicle collisions. The greatest enemy of the wolf is the atavistic fear and hatred aroused among people living with they, and the few or inexistence interest of administrations: they do not allocate enough money to offset the economic losses that the wolf may cause farmers.

ECONOMIC LOSSES IN LIVESTOCK

As we have seen, nearly 90% of the wolf population live in Castilla y Leon and Galicia. In Galicia they live in areas with high human density, which forces them to feed mainly on cattle and debris dump. There is a belief that wolves kill for killing, because they attack more sheep than they can feed. It is totally false that wolves kill for pleasure. According to some authors, this corresponds to an ancestral behaviour, not yet lost, to forecast food supplies for periods of scarcity. Others argue that responds to the fact that when the wolf is preparing for the hunting, enters into a state of tension and excitement necessary to bring down wild animals. But as sheep dont’ try to defend themselves or try to scape, the wolf releases this excitement the only way it knowns.

IN CONCLUSION

As the bear and lynx have different conservation plans, the wolf has none. Most regions with the presence of Iberian wolf have to subsidize farmers who suffer economic losses due to wolf. However, some offsets aren’t paid until four years later or they are not implemented at last, and the authorities do not meet the demands of farmers. By contrast, some farmers resort to fraud to take advantage of such compensations. Real conservation policies and the application of subsidies and penalties are necessary to ensure the survival of the Iberian wolf in Spain, an animal that is becoming depleted.

REFERENCES

Reasons to have captive primates (or maybe not!)

These days there is a lot of controversy in Spain because of the TV program Vaya Fauna” in Telecinco, in which captive non-domestic animals show their abilities. Leaving aside the training methods that suffer these animals, like in a previous post by Marc Arenas, Reasons to watch marine mammals in captivity (or maybe not), in this post we will talk about the consequences of keeping primates in captivity, especially great apes, and what is in your hands to preserve your closest relatives, all of them endangered.

MONKEYS SEEM HAPPY INTERACTING WITH US

Surely you’ve ever been to the zoo and have observed human behavior mockery to chimpanzees, gorillas and orangutans. People laughing, pounding his chest, imitating vocalizations. They are responded by chimpanzees, so we believe is an imitation game.

Humans have a tendency to humanize everything, that is, to perceive the reactions of others as human beings, which is not usually related. In the primate communication, the look is very powerful, sometimes intimidating. Who does not look the other way in the elevator when we are with a neighbor? This also happens with gorillas: staring look into their eyes is to them an aggression, so you can suppose the stress of feeling threatened by hundreds of visitors at a zoo watching at you every day. What we interpret as a smile, in which the animal bares his teeth, is actually a gesture of fear or tension. What we interpret as a game or insult, like throwing feces against the glass, it is also a sign of discomfort and stress.

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This chimpanzee is not laughing, he’s scared. Photo: Photos.com

The typical gesture of striking the breast, it is actually a demonstration of strength and health, which can lead to tense situations such as that experienced by this family at the zoo in Omaha when her daughter beat his chest in front of a silverback (male gorilla):

IN ZOOS THE FACILITIES ARE MORE NATURALIZED NOWADAYS

It is true that the trend in zoos is increasingly to mimic the conditions that they could have in nature, with green spaces, logs or ropes to climb, according to species. But primates enjoy these conditions a few hours a day, specifically when zoos are open to the public. At night or in adverse weather conditions, many zoo animals live in cages smaller than the display area without any natural setting.

Most great apes are social and have well-established group hierarchies in nature. In captivity, family groups tend to be artificial because the animals are from different origins, in addition to cases where there is overcrowding (too animals in the same facility) or they are kept isolated in cages with tiny dimensions. In case of conflict within a group, animals do not have enough space to keep their distance and avoid future tensions.

Gorilasbuscando alimento en el Parque Natural de los Volcanes, Ruanda. Foto de Philip Kromer.
Foraging gorillas in the Volcanoes National Park, Rwanda. Picture by Philip Kromer.

They are also deprived of natural behaviors such as foraging. In the case of lowland gorillas (Gorilla gorilla gorilla), they can travel several kilometers a day searching for food (mainly shoots, but also fruit and some insects) and never sleep two consecutive nights in the same place. Enrichment plans in zoo are essential to occupy their free time available.

Inappropriate behavior of some visitors does the rest (hitting glass, shouts, pictures with flash, food, excessive influx of public ).

IT HAS EDUCATIONAL AND CONSERVATIONAL VALUE

As in the case of marine mammals, investigations in captive primates do not allow reliable conclusions about the biology and behavior of animals due to the artificial conditions in which they live. In zoos, primates are not animals used in performances or in educational visits to the general public, in other centers, the information given about them is poor and biased in favor of the show or simple display of the animal to the public. The reintroduction of primates in the wild is very complex. The captive breeding programs that are implemented increasingly in zoos for conservation reasons, often produce animals for exhibition and not to release into the natural environment, for lack of means or interest.

THEY ARE ADORABLE AS PETS

The fact that an animal may seem to us nice-looking or share more than 90% of genes with us, does not mean that it will have same needs. These needs usually are not known by people who acquire a primate as a pet, causing them health problems both physical and psychological, including death.

Most come from illegal trade, which means that to capture a baby, hunters have to kill several members of its family, especially in the case of great apes that will protect their offspring to death.

The most famous orphan primate was undoubtedly Snowflake, the only albino gorilla known to date. In this case, his entire family was murdered in 1966 by entering banana and coffee plantations in the jungle of Nko, Equatorial Guinea. Snowflake was sold to Jordi Sabater Pi by 15,000 pesetas in Barcelona and was raised in an apartment in the first 11 months. Then was moved to Barcelona Zoo where he became a symbol of the city and lived there the rest of his life.

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Snowflake on an inside installation. Photo taken from blog Sigur Rós.

Small primates are also victims of illegal trade, which has increased because of the presence of videos on the Internet about how “adorable” are marmosets or loris (Nycticebus) according to a study published in PLoS ONE. Besides many species are endangered, as we saw in a previous post slow lorises are the only poisonous primate in the world, so they are mutilated without anesthesia (they cut them teeth, claws) before sale, which provoke sometimes deadly infections. The study found only in Indonesia 15,000 loris enter the illegal market per year, not counting those who die before. To that evidence must be added the death of the mother and/or entire families. They are sold with a few months of life, when in the wild spend the first 14 months with its mother, so their emotional and nutritional needs will never be covered.

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Loris from Sumatra to sell crammed in a cage without food or water, in daylight (they are nocturnal). Photo by The Little Fireface Project.

It is estimated that the illegal trade in wildlife is worth more than 19 billion dollars annually, equivalent or above the illegal trade in drugs and weapons. In addition to pets, many primates living in zoos come from seizures, like Coco gorilla at Barcelona Zoo.

The Primates order is protected by CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora), so trade is banned or highly regulated. In Spain for example, they can’t be kept in particular installations.

THEY ARE VERY SMART AND CAN DO THINGS LIKE US

Another clear case of humanization is forcing primates to represent situations taking them as natural and easy to learn for them,  like walking upright, cycling and other stunts that are fortunately seen less and less in circuses, movies, commercials or sets of TV.

We have already discussed the origin and living conditions (often unhealthy) of these animals. We won’t go into detail about how they are trained, based on negative reinforcement (deprivation of food, company, beatings, imprisonment…) or stress levels to which they are subjected between spotlights, people and noise. Primatologist Sarah Baeckler conducted a study in 2002 on the status and conditions of these animals. What happens to them when they do not serve to act? They are abandoned, and in lucky cases recovered in sanctuaries or recovery centers, such as Mona Foundation in Catalunya or the Tchimpounga Chimpanzee Rehabilitation Center, the largest sanctuary for chimpanzees in Africa promoted by Dr. Jane Goodall. This video of the emotional release and history of the chimpanzee Wounda by Rebecca Atencio and Jane Goodall went viral:

CONSEQUENCES BEFORE AND AFTER THE FAME”

Chimpanzees are the most commonly apes used for this kind of shows. According to studies, such as the one by the University of Kent (2011), primates end with psychological problems such as:

  • Self harm and mutilation
  • Bone fractures and wounds
  • Psychomotor deficit
  • Malnutrition
  • Development problems
  • Abnormal behaviors such as ingestion of feces and urine
  • Repetitive movements with no function (stereotyping)
  • Decreased gestures to communicate with each other
  • Hyperaggression
  • Social phobia, fear, agoraphobia (phobia of open spaces and agglomerates
  • Apathy
  • Post-traumatic stress disorder
  • Despression
  • Inability to its development in conditions of freedom
Campaña "Los animales no son payasos" de Acção Animal and Liga Portuguesa dos Direitos do Animal (LDPA).
“Animals are not clowns” campaign by Acção Animal y Liga Portuguesa dos Direitos do Animal (LDPA).

So they have the same consequences as any human can suffer in the same situation. We share 96.9% of our DNA with orangutans, 98.4% with gorillas, 98.8% with chimpanzees  and 99.9% with other humans.

Rehabilitation and socialization, it is not impossible in some cases, but it takes years and thousands of euros of effort, which does not justify its use in shows or keeping them as pets.

WHAT CAN YOU DO FOR PRIMATE CONSERVATION?

In June 2015, after years of struggle by Jane Goodall and other institutions, captive chimpanzees enjoy the same protection in the wild USA, they are considered endangered. Two chimpanzees have also been recognized as legal persons in court on his compulsory detention. Primatologists agree that the intelligence of a chimpanzee is equivalent to a 4 years old child and the debate is still alive on the inclusion of the great apes on Human Rights. Something is changing in consideration of our closest relatives, but is still clearly insufficient. What it is in your hands?

  • Learn and share with your children, family and acquaintances capabilities and problems of these wonderful animals.
  • Do not buy or accept a primate as a gift or souvenirs made from them, especially if you are traveling to foreign countries where the sale is cheap and easy. You can go to jail.
Un simple llavero o cenicero hecho con la mano de un gorila lleva muchas muertes detrás. Foto de WWF
A simple key ring leads behind many deaths. Photo by WWF
  • Do not attend circuses or give audience to television programs which use animals and participate in campaigns against it.
  • Do not eat primate meat  (bushmeat)
  • Avoid visiting zoos and other institutions that keep primates in captivity for profit.
  • Do not use products tested on animals, especially cosmetics.
  • Do not buy tropical wood or seek FSC certification of sustainable logging.
  • Extend the life of electronic devices, especially mobile phones and recycle it as coltan and cassiterite it is used for manufacturing it.
  • Report illegal wildlife trading
  • Make donations to recovery centers or adopt a chimpanzee, also here
  • Do not use products with palm oil, responsible for causing the deaths of dozens of orangutans daily.
orangutan quemado, aceite de palma, pal oil, palmitate, pongo, deforestacion, muerto
Orangutan (Pongo spp.) (Literally, “man of the forest”) victim of deforestation for palm oil industry. Photo: unknown credit

REFERENCES

MIREIA QUEROL ALL YOU NEED IS BIOLOGY

The plants and the climate change

Since a few years ago, we have heard about the climate change. Nowadays, it is already evident and also a concern. This not only affects to us, the humans, but to all kind of life. It has been talked enough about the global warming, but perhaps, what happens to the vegetation has not been much diffused. There are many things affected by climate change and vegetation is also one of them. In addition, the changes in this also affect us. But, what are these changes? how can the vegetation regulate them? And how we can help to mitigate them through plants?

CHANGES ON PLANTS

Biomes distribution

In general, due to climate change, an increase of precipitations in some parts of the world are expected, while in others a decrease is awaited. A global temperature increment is also denoted. This leads to an alteration in the location of the biomes, large units of vegetation (e.g.: savannas, tropical forests, tundras, etc.).

biomes
Biome triangle classified by latitude, altitude and humidity (Author: Peter Halasaz).

On the other hand, there is an upward trend in the distribution of species in the high latitudes and a detriment in the lower latitudes. This has serious associated problems; the change in the species distribution affects their conservation and genetic diversity. Consequently, the marginal populations in lower latitudes, which have been considered very important for the long-term conservation of genetic diversity and due their evolutionary potential, are threatened by this diversity loss. And conversely, the populations in high latitudes would be affected by the arrival of other competing species that could displace those already present, being as invasive.

Species distribution

Within the scenario of climate change, species have some ability to adjust their distribution and to adapt to this.

But, what type of species may be responding more quickly to this change? It appears that those with a faster life cycle and a higher dispersion capacity will be showing more adaptability and a better response. This could lead to a loss of some plants with slower rates.

Galactites tomentosa
The Purple milk Thistle (Galactites tomentosa) is a plant with a fast life cycle and high distribution capacity  (Author: Ghislain118).

One factor that facilitates adjustment in the distribution is the presence of wildlife corridors: these are parts of the geographical area that enable connectivity and movement of species from one population to another. They are important because they prevent that some species can remain isolated and because they can also allow the movement to new regions.

Another factor is the altitudinal gradient, which provides shelter for many species, facilitates the presence of wildlife corridors and permits redistribution of species along altitude. Therefore, in those territories where there is greater altitudinal range, the conservation is favored.

In short, the ability of species to cope with climate change depends on the plant characteristics and the territory attributes. And, conversely, the species vulnerability to climate change occurs when the speed to displace their distribution or adapt their lives is less than the climate change velocity.

At internal level

Climate change also affects the plant as an organism, as it causes changes in their metabolism and phenology (periodic or seasonal rhythms of the plant).

One of the effects that pushes the climate change is the carbon dioxide (CO2) concentration increase in the atmosphere. This could produce a fertilization phenomenon of vegetation. Due the COincrease in the atmosphere it also increases the uptake by plants, thus increasing the photosynthesis and allowing greater assimilation. But, this is not all advantages, because for this an important water loss occurs due that the stomata (structures that allow gas exchange and transpiration) remain open long time to incorporate CO2. So, there are opposing effects and fertilization will depend on the plant itself, but the local climate will also determine this process. Many studies have shown that various plants react differently to the COincrease, since the compound affects various physiological processes and therefore there are not unique responses. Then, we find a factor that alters the plant metabolism and we cannot predict what will be the effects. Furthermore, this fertilizer effect is limited by the nutrients amount and without them production slows.

fotosíntesi
Photosynthesis process (Author: At09kg).

On the other hand, we must not forget that climate change also alters the weather and that this affects the vegetation growth and its phenology. This can have even an impact on a global scale; for example, could produce an imbalance in the production of cultivated plants for food.

PLANTS AS CLIMATE REGULATORS

Although one cannot speak of plants as regulators of global climate, it is clear that there is a relationship between climate and vegetation. However, this relationship is somewhat complicated because the vegetation has both effects of cooling and heating the weather.

The vegetation decreases the albedo; dark colours absorb more solar radiation and, in consequence, less sunlight is reflected outward. And besides, as the plants surface is usually rough, the absorption is increased. Consequently, if there is more vegetation, local temperature (transmitted heat) intensifies.

But, on the other hand, by increasing vegetation there is more evapotranspiration (set of water evaporation from a surface and transpiration through the plant). So, the heat is spent on passing the liquid water to gas, leading to a cooling effect. In addition, evapotranspiration also helps increase local rainfall.

Biophysical effects of landcover
Biophysical effects of different land uses and its consequences on the local climate. (From Jackson et al. 2008. Environmental Research Letters.3: article 0440066).

Therefore, it is an ambiguous process and in certain environments the cooling effect outweighs, while in others the heating effect has more relevance.

MITIGATION

Nowadays, there are several proposals to reduce climate change, but, in which way can the plants cooperate?

Plant communities can act as a sinks, carbon reservoirs, because through CO2 assimilation, they help to offset carbon emissions. Proper management of agricultural and forest ecosystems can stimulate capture and storage of carbon. On the other hand, if deforestation were reduced and protection of natural habitats and forests increased, emissions would be diminished and this would stimulate the sink effect. Still, there is a risk that these carbon sinks may become emission sources; for example, due to fire.

Finally, we must introduce biofuels: these, unlike fossil fuels (e.g. petroleum), are renewable resources, since they are cultivated plants for use as fuels. Although they fail to remove CO2 from the atmosphere or reduce carbon emissions, they get to avoid this increase in the atmosphere. For this reason, they may not become a strict mitigation measure, but they can keep neutral balance of uptake and release. The problem is that they can lead to side effects on social and environmental level, such as increased prices for other crops or stimulate deforestation to establish these biofuel crops, what should not happen.

800px-Canaviais_Sao_Paulo_01_2008_06
Sugarcane crop (Saccharum officinarum) in Brazil to produce biofuel (Author: Mariordo).

Difusió-anglès

REFERENCES

 

Bearded vulture: conservation of a unique bird

Last month a bearded vulture was born for the first time in Spain of parents bred in captivity and reintroduced into the wild. The bearded vulture is the only bird in the world that feeds almost exclusively on bones. Like the Iberian lynx, it is one of the emblematic animals of the Iberian Peninsula and it is endangered, so it is subject to various conservation and reintroduction programs. In this article, we encourage you to find out more about the bearded vulture and the spanish conservation projects.

DESCRIPTION

The bearded vulture (Gypaetus barbatus) is a diurnal bird of prey popularly included in what is called vultures, scavenger and ghoul birds (they feed on dead animals). However, the bearded vulture is quite different from other vultures:

Quebrantahuesos (Gypaetus barbatus) adulto. )Foto de Jose Luis Ojeda)
Adult bearded vulture (Gypaetus barbatus). (Photo by Jose Luis Ojeda)

 

  • It is so highly specialized that 85% of their diet are bones (osteophague) of dead mammals such as wild ungulates (chamois) and domestic cattle (goats, sheep). It can swallow bones up to 25 cm, and if they are too large catches them, rises them to 20-40 m and crashes bones against the rocks into smaller pieces that can swallowIt also uses the same technique to break tortoise shells.
  • It is very large, with a wingspan up to 2.8 meters and a weitgh up to 7 kg.
  • In general it isn’t noisy: it just whistles if it is excited or during the mating season.
  • It hasn’t the typical plucked vulture head. Vultures have a few or no feathers on their heads to maintain an optimum hygiene after putting their head in dead animals. Due to its peculiar diet, the bearded vulture has more feathers on head and neck, with its characteristic beard” below the peak.
  • The plumage is the same for both sexes but changes with age. The typical reddish and yellowish adults plumage is due to their habit of bathing in mud rich in iron oxides, otherwise they will had a white breast.
Fases del plomatge del trencalòs, segons Adam i Llopis (2003). (Imatge de © X. Parellada.)
Plumage phases of the bearded vulture, Adam and Llopis (2003). (Image by © X. Parellada.)

In this video (5 minutes, catalan) you can see bearded vultures in flight, breaking bones, engulfing them, raising a chick in the nest and bathing in mud.

REPRODUCTION

Bearded vultures nests on ledges and natural rock caves in the mountainous and rugged areas where they live. They have stable partner for life from age 7 and the reproductive cycle has different stages:

  • Pre-laying (September to November): nest building (covering it with branches, wool, feathers, bones ), defense of territory and sexual activity.
  • Incubation (December-February): they lay one or two eggs with a time difference of 6 days. Both sexes participate in the incubation for 53 days.
  • Nurturing (March-August): the largest chick kills his brother (fraticidal violence) to ensure survival. Parents provide food and when the chick leaves the nest (June-July), learn from them to find and prepare food until their emancipation.
  • Emancipation (January): displacement (thousands of kilometers) and dating back to the land where it was born to breed (philopatric instinct).
Seguimiento de nidos naturales mediante cámaras. (Foto: FCQ)
Tracking of natural nests with cameras. (Photo: Foundation for the Conservation of the Bearded Vulture)

DISTRIBUTION

Subspecies Gypaetus barbatus meridonalis is distributed by the South and East Africa, while Gypaetus barbatus barbatus by North Africa and parts of Eurasia (see map).

In the Iberian Peninsula is found naturally only in the Pyrenees (Catalonia, Aragon and Navarra). Spain is the European country with more breeding couples registered (about 130, 2014 data).

gypaetus barbatus, quebrantahuesos, trencalòs, berded vulture distribution, distribución
Bearded vulture distribution. In red, areas in which has been reintroduced . (Image by Mario, Wikimedia).

THREATS

Bearded vulture populations are declining. It is ranked globally asnear threatened” in the IUCN Red List and “endangered” in the Spanish Catalogue of Endangered Species. Current threats they face are:

  • Death by poisoning (illegal baits, poisoned animal consumption, consumption of remains of lead hunting ammunition plumbism).
  • Death by electrocution or collisions with power lines and wind turbines of wind farms.
  • Poaching
  • Habitat loss and decreasing of reproductive efficiency because of the humanization of the medium (urbanisation, adventure sports )
  • Reduction of food (cattle in stables, obligation to bury the corpses )
Quebrantahuesos muerto por envenenamiento. (Foto: DARPAMN)
Bearded vulture dead by poisoning. (Photo: DARPAMN)

CONSERVATION IN SPAIN

Due to the limited distribution of populations, their low number and difficulty to colonize new territories, in 2014 thirteen autonomous communities signed a protocol for the recovery of vultures in Spain. The most prominent action of this protocol is to strengthen the National Strategy for the Conservation of the Bearded Vulture in Spain (started in 2000) and the Programme Captive Breeding (2001), with actions such as the revaluation of rural areas, supplementary feeding and support for traditional farming practices. This strategy also involves the reintroduction in historic areas where the bearded vulture has been extinguished:

WHAT IS HACKING?

Hacking or rural upbringing is a technique that involves the release of captive-bred animals in an area that the bird assimilates as its birthplace. If successful, the bearded vulture returns to settle and breed. This technique did not has a conservationist origin, since it was developed by falconers in the Medieval Age. Falconry (hunting with birds of prey) are also currently used for wildlife control at airports or cities.

In falconry hacking consists in lefting in an elevated cage chicks that can feed by themselves. Falconer feeds them without being seen. After a few days they open the cage, using it as a basis for learning to fly. They are still feeding them until they learn to hunt by themselves and leave the cage. The young ones connect the cage as its birthplace so it will always return.

Alimentación de un pollo con un señuelo para evitar el contacto humano. Foto: Fundación para la Conservación del Quebrantahuesos
Feeding a chick with a decoy to avoid human contact and make its life possible in the wild. (Photo: Foundation for the Conservation of the Bearded Vulture)

The center managed by the Gypaetus Foundation is based on the natural breeding, with minimal human intervention. Parents raise and feed their young from the second week of hatching. To monitor the nests a video surveillance system is used.

Since 2006, 31 bearded vultures have been released from captive breeding and each one is tracked by GPS transmitters. Currently 15 individuals are still sending signals (9 were killed and 7 stopped working). As said in the introduction, the good news is that last month was born the first chick result of released individuals (Tono and Blimunda) by hacking technique.

For more information, check out this documentary (in spanish) about the bearded vulture and its conservation (El bosque protector. Fauna amenazada, El Quebrantahuesos, 29 minutes).

REFERENCES

MIREIA QUEROL ALL YOU NEED IS BIOLOGY

Pangolin: poaching is condemning it to extinction

Neither the tiger or elephant or rhino: the most hunted mammals by humans are pangolins, to the point of critically threaten their survival as a species. Discover the only mammal with scales, its current condition and what can we do to prevent the extinction of all species of pangolin in the world.

WHAT IS A PANGOLIN?

manis tricuspis, pangolin, árbol, tree, trepando
Tree pangolin (Phataginus tricuspis). (Photo by Bart Wursten).

The name pangolin (also known as scaly anteater or trenggiling) includes 8 different species distributed by a variety of habitats (tropical rainforests, dry forests, savanna areas, cultivated fields…) in Africa and Asia. They measure between 90 cm and 1.65 m. They are the only family in the order Pholidota: although physically similar, armadillos, sloths and anteaters are not its relatives (order Xenarthra). Most are nocturnal, solitary and shy, so there are still many questions about their biology and behavior in the wild (they don’t usually survive captivity).

MORPHOLOGY

Pangolins are the only mammals with scales: they are made of keratin (like our nails) and give them a look like a pineapple or artichoke. Scales are very sharp and they can move them voluntarily. If pangolins feel threatened hiss and puff, curl into a ball leaving the scales exposed and secrete pestilential acids to ward off predators (tigers, lions, panthers and humans).

leon, leona, pangolin, bola, lion, defensa
An impenetrable defense even to a lioness. (Photo by Holly Cheese)

The claws allow them both climb as digging: terrestrial pangolins hide and breed in underground galleries and arboreal pangolins do the same in hollows on trees. The tail of the tree pangolin is prehensile to attach to the branches. In addition, pangolins are excellent swimmers.
They are mainly bipedal animals: forepaws are so large that force them to walk on its hind legs, with a maximum speed of 5 km/h. Watch a pangolin walking and feeding:

NUTRITION

Pangolin has no teeth and is unable to chew. It feeds on ants and termites, which locates with its powerful sense of smell (the view is underdeveloped) and catch them with its sticky and long tongue (may be longer than the body itself, up to 40 cm). The stones swallowed involuntarily and corneal structures of their stomach help them to crush the exoskeletons of insects. With its powerful claws destroy their nests to access them and avoid their attack plugging his ears and nostrils, besides having an armored eyelid. It is estimated that a pangolin can consume about 70 million insects per year, which makes them important regulators of the population of ants and termites.

lengua, pangolin, tongue
The tongue of the pangolin. (Photo by Wim Vorster).

REPRODUCTION

Pangolins can reproduce at any time of the year. After pregnancy (two to five months, depending on species) only one young is born (African species) or up to three (Asian species).

pangolin, hembra, female, mamas, breast, pecho, tetas
Female pangolin. (Photo by Scott Hurd)

The pangolin is born with soft scales, which begin to harden after two days. When after a month come out of the burrow, they travel on the tail of her mother and become independent at 3-4 months. Their lifespan is unknown, although in captivity an individual lived until 20 years old.

pangolin, baby, cría, zoo bali
Female with her baby in the tail. Bali zoo. (Photo by Firdia Lisnawati)

THREATS AND CONSERVATION

In addition to habitat destruction, the main threat that pangolins face is direct hunting for human consumption. Although there are international laws to protect them, it is estimated that about 100 000 pangolins are hunted annuallyGiven the defense strategy of this animal, poachers only have to catch them of the ground. Like other species, like sharks, the food market and traditional medicine are the main causes of directing the pangolin towards extinction.

pangolin, jaulas, tráfico ilega, illegal trade, bushmeat
Illegal trade in pangolin. (Photo by Soggydan Benenovitch).

WHY PANGOLINS ARE POACHED?

  • Bushmeat is considered a delicacy and an indicator of high social status in Vietnam and China. The pangolin fetus soup is sold as an elixir to increase virility and improve breast milk production. The price of bushmeat on the black market can reach $ 300 per kilo. The price of an individual can reach $ 1,000.
sopa, feto, soup, pangolin, feto, fetus
Pangolin fetus soup. (Photo by TRAFFIC).
  • Blood is sold as a tonic to improve health and as an aphrodisiac.
  • Scales can reach $ 3000 per kilo and are used for almost anything: to cure from acne to cancer. This belief is curious, considering that the scales have the same structure as our fingernails.
pangolín, china, medicina, medicine, tradicional, cura para el cáncer
Products of traditional Chinese medicine made of pangolin. (Photo by TRAFFIC).

All these purported medicinal and magical effects have no scientific basis, making yet more nonsense pangolin smuggling.

CONSERVATION

The population trend of all species of pangolin is declining in some cases to an alarming extent. The IUCN (International Union for the Conservation of Nature) Red List of Threatened Species classifies them as it follows:

RED LIS CATEGORIES IUCN
IUCN Red List categories. (Image from iucn.org)

Because of their status, IUCN restored in 2012 a group of specialists within the Species Survival Commission (SSC) dedicated to pangolins (Pangolin Specialist Group -PangolinSG-). Its main objective are do research to increase knowledge of pangolins, the threats they face and how they can be mitigated to facilitate preservation.

The conservation projects that are being carried out include campaigns to reduce the demand of bushmeat and pangolin scales and the tightening of laws. Still, the total ignorance of populations’ state and low survival in captivity for breeding makes it difficult to design strategies for their conservation.

WHAT CAN YOU DO FOR PANGOLIN?

  • Reject any product derived from this animal, either bushmeat, scales or “miracle” products for the cure of diseases. Read the labels of any traditional remedies, especially if they are from the Asian market, and recall that its hypothetical benefits have no scientific basis, so that you can rethink their use.
  • Share information. If you own new data on pangolins, photos or videos contact with PangolinSG to cooperate with the investigation. Talk about them in your immediate environment to raise awareness and publicize this fantastic single animal.
  • Do a PhD about pangolins. Lot of research on these species is still needed, so if you are a student and you are planning to do a PhD, you can collaborate with PangolinSG with your future research.
  • Become a PangolinSG volunteer. Get involved in the development and implementation of projects and conservation programs.
  • Make a financial donation so PangolinSG can continue its work.

In conclusion, more scientific research, a change of mind and protection policies are needed to prevent the pangolin become an example of extinct species at the hands of ours, as it is about to happen to white rhino.

REFERENCES

MIREIA QUEROL ALL YOU NEED IS BIOLOGY

Nocturnal birds of prey: the barn owl, legends and myths

Nocturnal birds of prey have suffered since a long time ago an unfair bad reputation that has led them in some cases to be persecuted and hated. What are these superstitions? Which is their conservation state? What can you do for them? In this article you will discover owls and the barn owl, Tyto albaand the legends associated with them.

GENERAL CHARACTERISTICS OF NOCTURNAL BIRDS OF PREY

As its name suggests, most nocturnal birds of prey (owls, owls, tawny owls) have nocturnal or crepuscular habits. They are carnivorous, with beaks and claws (two toes forward and two backward) adapted to tear flesh from their prey (small mammals, birds, reptiles, large insects ).

HEARING

Owls usually have a rounded shape and apparent large head, with the face feathers forming the so-called facial disk. The facial disc serves as a dish heading sounds towards the ears. The opening of the ear is large, with a fold of skin (preaural halda), which functions as a pinna and is movable as in some mammals.

Oído de lechuza norteña (Aegolius acadicus). (Foto tomada de Jim McCormac).
Norther saw whet owl ear (Aegolius acadicus). (Photo by Jim McCormac).

The position of each ear is asymmetric in some species (one is higher than the other), so some of them -like the barn owl- can locate prey in complete darkness: an ear perceives sound before the other, so their  brain can calculate the exact place where prey is (directional hearing).

Boreal owl skull, cráneo de mochuelo boreal
Boreal owl skull (Aegolius funereus) where can be seen the asymmetric hearing openings and sclerotic eye rings. (Photo taken of Jim Williams)

EYESIGHT

Owl’s vision is highly developed. Eyes, unlike most birds, are in front position, which allows a perfect estimation of depth and three-dimensional vision. On the other hand, eyes are tubular (not spherical like ours) due to the large size of the cornea and lens, which prevents owls from moving them within their sockets. Also they have a protective bone plate around the eyes (sclerotic rings) that also impede movement. To solve this problem, they are able to turn his head 270 degrees. It can be considered that they see in black and white (they best perceive changes in light rather than colors), the pupil dilates a lot in bad light conditions (iris is hidden by dilated pupil) and they are the only birds in which the eyelid closes up to below. They also have a transparent lid” that moistens and protects the eye, called the nictitating membrane.

Visión lechuza, binocular, vista, búho, razces nocturnas
Binocular vison of a nocturnal bird of prey. Humans have a field vision of 180 degrees, 140 of them binocular). (Image by The Owl Pages)

PLUMAGE

Owls, unlike diurnal birds of prey, have a special flight feathers structure, fringed at the top surface and contours. The friction between them and the air is damped, achieving a spectacular silent flight undetectable by preys.

Pluma de lechuza común y autillo, donde se observan las barbicelas. (Foto tomada de Pedro Montoya).
Barn owl feather (Tyto alba) and european scops owl (Otus scops), (Image taken of Pedro Montoya).

THE BARN OWL

The barn owl (Tyto alba), is unmistakable: it has a very well defined and heart-shaped facial disk. The back is gray with golden spots and fine black and white dots.

DISTRIBUTION AND BEHAVIOUR

The barn owl lives all over the world (except Antarctica, north Europe and most Asia) and don’t build a nest, but lays eggs in tree holes, holes in the rock or human buildings (barns, attics, farmhouses, castles, churches ).

Why the barn owl has this negative reputation that caused their persecution in many parts of the world and in Spain? Causes are diverse, all fed by human fear:

  • They can nest in abandoned or sacred locations as churches (some with their own cemetery).
  • Nocturnal habits
  • They are sendentary, they can stay in the same hunting ground for years until food is scarce.
  • Ghostly appearance due to their colors and smooth and silent flight.
  • By their vocalizations (they have 17 different ones) like human screams and peculiar snorts. Listen to some owls making a defense vocalization in the following video:

THE BARN OWL IN THE POPULAR CULTURE. BELIEFS, SUPERSTITIONS, MYTHS AND LEGENDS

In the Iberian Peninsula was believed that owls drank the oil of the lamps in churches, leaving the Saints in the dark (when the real thieves were sacristans). By landing on lamps or touching them and pouring the oil, it was believed that owls hated light, like evil spirits. In spanish and catalan there are sayings that refer to this myth. They were hunted, killed and hanged above the doors of churches and barns to ward off fire and lightning.

The vocalizations of barn owls are also interpreted as announcements of death, and there is a belief (without basis) that if someone hear an owl for several nights (something not difficult given their sedentary habits) a person suddenly will lose life.

Tyto alba, lechuza común, lechuza de campanario
Barn owl (Tyto Alba). (Photo by Kerkuil André).

In other cultures there are also negative legends about owls: in Africa that are sent by sorcerers to kill people or evil demons announcing disasters, in the Argentine pampas that they are sisters of the devil; in Sicily, death or illness for all these reasons they have been killed and tortured.

However, they can also be a good sign (such as guardians of women who die in Australia), but the best known case is the representation of Athena, Greek goddess of wisdom. Currently still appears as a symbol of many institutions and in Greek euro coins.

Euro grecia, euro griego
Greek euro. (Resource: RTVE)

CURRENT STATUS AND THREATS

Nowadays the barn owl is in a state of decline and with an uncertain future due to changes introduced by humans in rural areas, such as changes in cultivation or use of pesticides and rodenticides, which kill their prey (mice) or indirectly birds themselves. The works and renovations of buildings where they used to nest also interfere with reproduction. They also suffer accidents due to the towers and power lines and are often hit by cars. Canary subspecies (Tyto alba gracilirostris) is disappearing due its habitat fragmentation and the low number of individuals in their populations.

Lechuza muerta
Barn owl in a barbed wire. (Photo by PacoT).

It is listed as Endangered in the Red Book of Birds of Spain and included in the National Catalogue of Endangered Species in the category “Special interest“.

WHAT CAN YOU DO FOR OWLS?

Try to find out about these magnificent birds and make them known to your immediate surrounding, banishing misconceptions, especially if you live near their nesting and feeding areas. If you own crops, try to minimize the use of pesticides: a pair of barn owls hunt in average about 2,000 mice a year, being therefore even beneficial to humans.

If you find an owl or wounded bird, you have to pick it carefully (using a towel or a jacket) to avoid hurt it or being hurt, and leave it in a dark, quiet place inside a box pierced so it can breathe. Do not feed it. Then contact a wildlife recovery centre.

REFERENCES

If you enjoyed this article, please share it on social networks to spread it. The aim of the blog, after all, is to spread science and reach as many people as possible. Feel free to share your experience with birds of prey in the comments below. ¿Do you know someone who still believe in this owl legends?

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