A Look at the Portuguese World

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The real batman

Written by  yvette vieira fts luca cistrone e Christian Dietz

 

Sérgio Teixeira is the only accredited researcher on the bats of Madeira and his thesis confirmed the vital importance of the various species to the ecosystem of the island.

How many species of bats exist in Madeira?
Sérgio Teixeira: In this phase from the data that we have we can say that there are five species, except one we do not know very well what it is. We obtained the genre, but we're not sure how the species specifically, was never captured, only heard it twice so the few attempts we have made to record the sound in order to be able to confirm were unsuccessful because it is a specimen that enters in mode silent when hunting their prey and in these circumstances never managed to get anything, but we felt it is the greater-mouse-eared bat, whose scientific name is Myotis myotis. Then we have the bat of Madeira or Madeira pipistrelle (Pipistrellus maderensis) is one of the smallest in Europe, it is an endemic species of Macaronesia, exists in Madeira, the Canaries and the Azores, although it was not described in the Azorean islands two years ago to date had not been able to confirm. The Madeiran Leisler’s bat (Nyctalus leisleri verrucosus) is an endemic subspecies of the island, there is only here, never saw them elsewhere in the past may have existed in Porto Santo and the uninhabited islands, but not anymore, only exists in Madeira. The Pipistrelles Kuhl bat (Pipistrellus kuhlii) has a genetic affinity with pipistrelle of Madeira, both it and the other came from the West African coast to Madeira, about one million two hundred thousand years, so it differed and it became a different species. Also, we have a very cute Grey long-eared bat (Plecotus austriacus). So those are the species identified so far, except myotis we do not know what the species is, but the match will be the greater-mouse-eared bat due to the skulls found of this specimen in the Azores in 1979, however, no longer exists and here in Madeira they were found in the mountainous areas of Funchal in 2004 and in 2010 in the Santana coastal zone. It is a great bat, is one of the biggest there is in Europe. In Madeira, these species can coexist because they exploit different habitats and prey. If not for such in this small island would be impossible to have so many species, it appears that five are few.

The endemic species how it distanced from the others, what are those features that make these unique bats?
ST: At the outset when colonized the island were already differentiated millions of years however, it is necessary to clarify that there are two kinds of bats, the microchiropteran that are small in size and the megaquchiropteran, which are the large animals as seen in TV. These animals are mammals, not birds, because they use their hands, fingers grew, the skin stretched a lot and they use this physical characteristic to be able to fly, so are chiropteran, ie, hand-wing. Contrary to what people think are not flying mices, they are much more like the man and the apes than you think, because when they were first described by Linnaeus, were placed in the same category of primates and only later that they have been reclassified. The specimens we have in Madeira belong to the group of microchiropteran and have been around for 50 million years, long before man and when the island of Madeira has emerged in the ocean 5 million years ago these species have had almost 45 million years of evolution in planet, so when the Portuguese arrived here and colonized the island bats were already differentiated in terms of gender, so we have the pipistrelles, gender, madeirensis, kuhlii, Nyctalus, myotis and plecotus, there were a number of minor adjustments in the Madeiran bat in particular, has become smaller.

But what do they measure as a whole?
ST: An adult weights 3 grams, their wing span is up to 24 cm and the body of the bat when it measures 8 cm with the wings closed. Really small. In flight they look great because it has huge wings, but they are mammals and as such had to adapt to the characteristics of their environment, it's body mass had to download to be able to fly efficiently. Teething adapted to the types of insects found on the island and which could feed, to emphasize that all species that exist in Madeira are insectivorous thus feed exclusively on insects. This also happened to the Madeiran Leisler’s bat is smaller than its continental counterpart, which is funny and even their teeth changed. The plecotus is different, the bat is very similar to what exists on the continent in terms of teeth and the skull is slight differences, but overall this within the morphological range of the species that exist in Europe. Moreover we can never capture a myotis and we captured some kohlii , but were few, but this specimen is within the expected for this species.

You said that bats had to adapt the island's conditions, it is because of the topography, or crosswinds?
ST: No, usually when mammals colonize islands or new territory, depending on the size and available resources, the various species may increase or decrease in size. There is even the famous case of an island where they found bones of dwarf elephants, the same happened in Madeira with cows in just hundreds of years, they decreased in size because the energy effort to climb the mountain in order to be fed is greater even happened with the locals in general are of short stature compared with other areas of Europe, this also happens in the Alps. Everything depends on the energy balance, thus the energy is necessary on energy spent, bats in this respect are not different, that feed on insects do not exist in large quantities in terms of species. Obviously, in the nineteenth century there was no large studies, naturalists had limited resources and could not cover all areas to be able to perform exhaustive work and we still have to consider the island's accessibility, ie, we did not have the facilities that exist today. As there were few publications and because of large imports of species in our gardens and vegetables that happened during the twentieth and twenty-first century. Thus, there were many insects were introduced into the territory, are likely natives and so we have not even sure existed in Madeira, or were brought thru the XVI, XVII and XIX centuries through the studies they did at the time we are sure of the species that have existed on the island, but even so, these data mostly comes from the nineteenth century. For a bat that has lived on the island and has few insects which can feed obviously had to adapt to survive and decrease in size, it is necessary to see that although there are 30 different species of insects the Madeira Pipistrelles only feeds on a few and myotis others.

So what are the species feeding on?
ST: There are no studies of diets, were never made because it is impossible to start some things, research in this field never advanced much, what was done was more trying to figure out which species exist on the island, which is the work basis and where It existed because there was conflicting information of the list that existed which were based on dubious sightings and then I came to check with my thesis that there were discrepancies between existing lists and visible that species in the territory.

You underline that the island that there was an increase in the number of plants and flowers do not increase the ability of bats consume more insects by chance?
ST: Yes, of course, recently, from most of the nineteenth century, have more insect species and some are preyed upon by bats, but we are talking about an evolutionary process of hundreds of thousands of years with the plants that existed here, we can not forget that it is an ecosystem in which species are all interconnected, plants, insects, bats and birds, so evolution is a continuous process and the different species will be adapting to their environment and the bats have adapted to the island, with the colonization his life has undergone tremendous change and no one knows if there were no other species that were extinguished however, it is a possible scenario.

Regarding the myotis you clamed they found skeletons in the Azores, in Madeira you saw this living species? And in what areas of the island?
ST: Yes, we observed live specimens. In mountainous areas of Funchal as I mentioned, it is not an exact location and I captured some individuals with scientific purposes, the animal got through a very small hole in the net because it is a species that has an excellent ability to navigate in very tight spaces. In 2010 I visualized one in flight and used a device, the ultrasonic detector, which are used to listen to bats and I caught some very short pulses, because it used the same frequency as the myotis use and then the rest of suspicion was based in behavior, the animal began to hunt in the very near bush in silent mode which is a characteristic of this species. This bat for example uses only the hearing to hear the insects, because contrary to what one might think there are some species of insects have an earing membrane, like a rudimentary ear, this tuned to the frequencies that bats use, so to prevent the prey to escape the myotis makes no noise so it can hear where the insect is and capture it on the plant surface, but for scientific purposes is not sufficient to use this information to confirm the existence of this bat species on the island.

Where we found the endemic species of Madeira?
ST: The bat Madeira is relatively common throughout the island, the pipistrelles adapt well to urban areas, now is not abundant, the estimates made for the Red Book of vertebrates of Portugal, point to a lower population of 1000 individuals adults.

So do not live in caves?
ST: The pipistrelles not by nature are not cave species, each genre has specific adaptations to a kind of flight, prey and habitat, in this case, are very adaptable animals, in general take shelter in cracks in rocks, by example, in urban areas it is possible to find them under tiles and in the construction of cement blocks. The Madeiran Leisler’s bat I' ve seen in the expansion joints, but as a rule, as the name implies, are animals that prefer dead trees, plantains, adopt the laurel and chestnut trees as well. The plecotus prefer large spaces for shelter, especially in ceilings, on rafters, the barns, because they require space to fly against the pipistrelles and Nyctalus which choose confined areas and only when they are out they loose the wings. The myotis also chooses abandoned buildings and we can catch sight of them under bridges, the kohlii bat is like Madeiran Pipistrelles.

These species are endangered or not really?
ST: They are status of threatened species, other vulnerable, but is an issue that I would rather not go into, because it was never done a population study in the true sense of the word, it relies on a rough estimate of the contacts we had a bit throughout island. A true study involves marking bats, find shelter, do counts, make recaptures and this would give us a more precise estimate. They are generally very endangered species, as I said, the myotis only saw him twice within 14 years and that alone indicates that it is a very rare specimen, the eared bats are very complicated, because even with use of ultra sound, it emit very low sounds, the English even call them whispering bats, because to catch them on the device only with good condition, must be a perfect day with no wind and we have to be within walking distance, 2.5 meters in max. As for sighting a bat when seen at a certain distance 15 to 20 meters it is known that is myotis, the Pipistrelles, on the other hand, will be able to hear it. Another advantage is that we can return to the same area, they are philopatrics species, as it remains faithful to the place, that is, always they return home and they use the same way of feeding areas to their usual shelter. Along the way they use temporary spaces for shelter, hence it is important to preserve them, especially if they are nurseries, because in this phase are concentrated in these areas tens of juvenile bats. Once was found in a haystack fifty plecotus bats and were referred as the largest colony in whole Portugal and despite the owner having kept this space closely, because the owner liked bast and knew a lot, but something happened, problably fed on insects with pesticide, or found other obstacles along its path back and unfortunately in a space of four years all disappeared.

So what are the causes of death of bats?
ST: The causes of death can be forestry fires, or destruction of shelters, because of urban growth and accumulation of pesticides in vegetables, chemical treatment of wood shelters, or by transfer of the insects on which they feed. There has been in recent years a very serious disease that has killed millions of bats in the US, but has not yet arrived in Europe and there is no cure, is the white-nose syndrome is a fungus that grows inside your nose and when the animal dies with a white nose. There are species that migrate in the Arctic Circle, northern Canada to Norway, but then return, but it's enough to bring the disease in the future. In the case of Madeira, it was important to preserve our species, because, for example, the bat Madeiran Leisler’s bat is the largest predator of the pest of the chestnut and also attacks apple and pear. To get an idea a single bat can eat 3,000 insects in a night, they eat 50% of their body weight, but why this happens? Because in temperate or cold zones bats must accumulate energy to hibernate, because the flight itself is already a huge energy outlay when are flying bats have a thousand beats per minute.

But the island does not have a harsh winter and they need also to hibernate?
ST: No, not in Madeira, but come into turpor, lower the metabolism enough to not hibernate, especially when there is bad weather, in hail falls, in the colder days that are not many insects flying, so not worth performing unnecessary energy expenditure. Thus, in these times for a few days they lower metabolism and then resume hunting when temperatures go up, because then it's worth the outlay of energy. One of the doubts that there is in the number of juveniles that have a year as a rule in Europe is only once and each female has only one baby, although there are cases of twins. Here in Madeira the weather is milder have evidence that can be have more than once a year, however, there are no certainties was necessary to make a study in this regard. However it is known that in tropical areas of the world other species of bats are reproduced more than once.

Which means that this particular species disappearing will be very damaging for farmers?
ST: Quite undoubtedly farmers know that the insect life cycle, in particular, pest, females lay hundreds of eggs and of these over 50% are females who hold more eggs by the thousands and each insect that is eaten by bats reduces the possibilities of reproduction.

And farmers face positivley the bats?
ST: No. Nor people because bats have a bad image. Normally, all the nocturnal animals are associated with evil and in the case of Madeira, there are those who say that when you see a bat your soul is lost for a day. But it is only animals that have nightlife activity for survival strategy of the species to avoid predators and because there are huge moths. Farmers should be trained, there was even an informative initiative created by me to lay out a poster for the fair of agriculture in Porto Moniz, a few years ago, unfortunately it was not possible to carry out, but the idea is to show that all species of bats the island are beneficial because they eat different types of insects, in the end by eliminating, or at least control various types of horticultural pests, i.e., are outstanding in an all a cleaning assembly. Bats maintains the ecological balance and when this mammals disappear natural control disappears and there may be economic damage for farmers. We should focus on these awareness campaigns and the creation of special shelters to see if these species are fixed more in agricultural areas where they are most needed.

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