Birds and mammals of Manu

The extraordinary capacity to adapt that mammals have demonstrated by populating the most varied places on Earth is primarily due to two notable characteristics: their ability to maintain their body temperature relatively stable (warm-blooded) and the relatively long gestation period of the embryo in the placenta, with the exception of echidnas, duckbill platypus and marsupials.

For mammals, food provides heat for the body. This heat triggers a complex mechanism that allows the body to adapt to external conditions, giving mammals greater independence. Thermoregulation requires the participation of several parts of the body, the hair being one of the principal components in this function.

According to the density and disposition of the fur, the animal can generate air pockets that retain heat. In some cases, like the Water Opossum (Chironectes minimus), the fur is also waterproof, which prevents contact with water and the consequent loss of heat. Moreover, the fur protects the animal against scrapping and bumps and in some obvious cases, like porcupines, the fur is modified to dissuade attackers. The sweat glands and the sebaceous glands also contribute to thermoregulation. The former are rapid tracts to eliminate excessive heat and the latter lubricate the skin to keep it flexible and in good condition.

The development of the embryo in the placenta is a tremendous advantage. There, the young spend the time necessary to prepare themselves to face the world in which they will live. Although the rast majority of mammals employ this successful strategy, marsupials complete their development in a pouch outside of the womb. Marsupials are a primitive group and, according to researchers, have their origins in Australia. Throughout their long history, however, they have developed more in the tropics of South America than in any other place on Earth and consequently the greatest diversity of species of marsupials is found on this continent.

The tremendous diversity of the tropical rainforests is due to their great number of different habitats. In South America, the Andes mountains, the environments created by the numerous kinds of forests and the different strata of these forests are primarily responsible for giving rise to so many species of mammals.

According to researchers, the forests in the lower part of Manu National Park close to the Cocha Cashu Biological Station have the highest diversity of mammals in the Amazonian plain and probably in the world. To date, there have been 190 species of mammals recorded in the Manu Biosphere Reserve between 365 and 3450 metres aboye sea level in the Amazonian basin.

To the exceptional biodiversity of Manu can also be added an astounding number of endemic mammal species: Anderson’s mouse opossum (Marmosa Andersoni), Incan shrew opossum (Lestoros inca), Sanborn’s squirrel (Sciurus sanborm), Keays’s rice mouse (Oryzomys keaysl), Cloud forest grass mouse (Akodon torques), Distinguished old field mouse (Thomasomys notatus), (Neustícomis peruviensis) and in neighbouring regions: Long-nosed bats (Anoura sp.), Dusky arboreal rice rat (Oecomys phaeotis), Spiny mice (Neacomys sp.), Silent grass mouse (Akodon surdus) and Koford’s grass mouse (Akodon kofordi).

In contrast to birds with flashy plumage and distinct songs, mammals are normally dull in colour and are very quiet, as well as being mostly nocturnal and quite timid.

In general, mammals have poor vision and some species are unable to distinguish colours. However, they have an excellent sense of smell and good hearing, which is why they often sense the presence of humans before an actual encounter. The tracks that they leave on the ground are an invaluable tool for identifying different species. In this guide, in addition to illustrations we have included drawings :f those footprints that you may encounter during your travels in Manu. Remember that tracks tend to be clearer and fresher in moist soil after a rainfall. Also, it is helpful to consider other indicators, such as feces, the shape and size of burrows or marks on tree trunks.

_ ke parrots and macaws, many species of mammals visit special aces where they ingest soil that is rich in minerals. These «colpas» are good places to photograph some of the less frequently seen species Also, the beaches along the Manu river offer an unobstructed view where it may be possible to see capybaras (Hydrochaeris hydrochaeris), small weasels called tayras (Eira barbara) or, with a little Iuck, a tapir (Tapírus terrestris). Large groups of squirrel monkeys (Saimírí sciureus) and capuchin monkeys (Cebus apella) move through the middle strata of the trees. Black spider monkeys (Atetes paniscus) prefer the higher levels and the large red howler monkey (Alouatta seniculus) climbs out onto exposed limbs so that its potent voice can travel even further.

Bats are by far the most numerous group of mammals in Manu. More than eighty species have already been reported and it is .pected that final count will exceed 100. These flying mammals -e an excellent example of specialization. Some, like Macconnell’s : t (Mesophylla macconnelli) have developed astounding habits. On a palm leaf, the bat cuts small aligned holes from the edge towards the centre, forming a «V». In this way, it constructs a tent

roost with two sloping ceilings. It rests and awaits nightfall in thish tent at approximately 1.5 metres aboye the ground. Even thoug

this species lives quite close to the tourists, it often goes unseen.

The giant river otter (Pteronura brasiliensis), extirpated in most Amazonian forests, lives in very stable populations inside Manu National Park. This species can be seen quite frequently playing in small family groups, capturing fish or resting on trunks that protrude from the waters of the oxbow lakes in the lower regions of Manu.

Many visitors hope to see large mammals like jaguars, puma and spectacled bears. However, these are solitary animals that range over extensive territories and are very difficult to find. But, Manu always holds surprises!