It is the capybara (Hydrochoerus hydrochaeris), also known as chigüire, chigüiro or carpincho. It can measure 50-60 cm high and 1.3 m long and can weigh… more than 50 kg! This species lives exclusively in South America. It lives in more or less numerous groups in the vicinity of watercourses. A curious feature is that … Read moreThe largest rodent
Bradypus tridactylus, the pale-throated sloth, belongs to the supraorder Edentata, just like the armadillo and the anteater. Ground speed: 2.44m/min (0.105km/h), although it increases slightly when climbing trees using its 3 long claws, reaching 4.57m/min (0.272km/h). Its neck has a great mobility, it can turn it almost 360º. It almost never descends to the ground, … Read moreThe slowest terrestrial mammal
Hummingbirds are a family of birds (Trochilidae) composed by many species. The size of the hummingbirds varies depending on the species: the smallest weighs about 2.2 grams and the largest about 20 g. They feed on flowers’ nectar (they are important pollinators) and small insects. They have a very large heart beating at more than … Read moreThe peculiarities of hummingbirds
This type of displacement basically consists of “floating” in the air through silk threads. That is, the air pushes the silk thread and the spider will hang from it in the air. The spider is usually placed in an elevated area, aims the opisthosoma (“abdomen”) upward and expels the thread… A timely blast of air … Read moreBallooning or the flight of spiders
Females can be fertilized by several males because the sperm share space once inside the female. As a result, different types of adaptations have appeared to ensure the reproductive success of males. Two types of adaptations can be distinguished: 1. TO ACHIEVE A PREFERENTIAL USE OF SPERM. The best known case is that of some … Read moreThe tricks of some insects to ensure offspring
Courtship is defined as specific behavioural patterns that induce sexual receptivity, i.e. it facilitates recognition between species and also serves as a mechanism to prevent mating between different species. It can be done by visual, tactile and/or chemical stimulation. A curious mechanism is that of some species of butterflies, called “puddling“, which consists of the … Read moreSodium and the courtship of butterflies
Asian hornet, raccoon, water hyacinth, red swamp crayfish, red-eared slider, monk parakeet, fountain grass, red palm weevil, wels catfish, Xyllela fastidiosa… They are all names of organisms that increasingly dominate the headlines of the major media in various countries. They are a real problem in many ways. The environment, the economy and the health system … Read moreInvasive alien species. They have come… to stay
They do not present sexual dirmorphism (differences between males and females) in size neither in dentition, only in coloration in the first two genera of the 4 existing ones: Nomascus, Hoolock, Hylobates and Symphalangus. The intermembral index (length of upper extremities/lower ext*100) is the highest of all primates: 127-147. They are the only apes with … Read moreThe peculiarities of gibbons
Daubentonia madagascariensis, also known as Aye-aye is a strepsirrhine endemic to Madagascar. Acording to the UICN Red List, it is endangered. They usually weigh between 2.5-2.7 kg and their life spectancy is about 24 years in captivity. SOME CURIOUS AND UNIQUE MORPHOLOGICAL FEATURES They are the largest nocturnal primates. They have orange eyes surrounded by … Read moreMeet the Aye-aye
The spider Agroeca brunnea makes a simple-looking egg sac and usually attaches it to an elevated site. But the curious thing is that it is bicameral, composed by the chamber of the eggs (1) and the chamber of molt (2). Eggs hatch in chamber 1 and newborn spiders pierce the cover plate, falling into chamber … Read moreAn egg sack to take care of the offspring
Orangutan females reach sexual maturity at 11-15 years. Males reach puberty at 7-9 years and thereafter they have 2 possibilities : 1.Reach adult size with all its features (such as lateral facial pads -green arrow-). 2.Stay in an adolescent state (development interrupted) in terms of morphology, but still are fertile and reproductively active. Possible meaning? … Read moreThe orangutans’ “trick” to ensure their reproductive success
These spiders of the genus Deinopis are weavers, but the web they manufacture consists of a few threads attached to the front legs. When prey (e.g. a moth) approaches, the spider separates the legs, extends the spiral and rushes over it to catch it. They’re called “ogre-faced” because of the “face” of the prosoma. They … Read moreHow does the ogre-faced spider hunt?
The intergenesic interval (the time from one birth to a potential next pregnancy.) of orangutans is the largest of all primates and mammals: 6-8 years. During all this time the offspring are very dependent on the mother because they need a long learning period in order to survive on their own. For instance, they learn … Read moreOrangutans, the mammals that take the longest to have a calf
Snakes don’t have eardrums… HOW DO THEY HEAR THEN? What happens is that the lower jaw is connected to the columella (homologus organ to the mammalian stapes), a bone that connects to the oval membrane, which in turn connects to the inner ear. In this way, being in contact with the ground or water, the … Read moreThe hearing of snakes
It is Argyroneta aquatica. This spider not only dive, but completes its entire life cycle underwater. How does it breathe? It produces an air bubble that envelops the opisthosoma (the “body” without the “head”). As the bubble consumes, the spider comes to the surface to add other bubbles and increase its supply of air. How … Read moreAn aquatic spider?
Amphibians have two ways to capture the vibrations of the medium and transform them into sound: In one hand, through their legs… What actually happens is that when the ground vibrates, vibrations are transmitted by the legs to the scapula of these animals, and through the opercular muscle and opercular bone, reaching the oval membrane … Read moreHow do amphibians hear?
Scorpions emit fluorescence…when they are illuminated with ultraviolet light. It is supposed to be a kind of warning. The same happens with centipedes. In biology this phenomenon is called aposematism, that is, warning mechanisms to indicate that they are dangerous. There are several types of aposematism, especially in relation to color (intense colors such as … Read moreScorpions also shine
Surely, many of you have seen these animals flutter in the field… And surely many of you have turned away when you saw them nearby and shouted: “Watch out, a wasp!” Well, they’re actually flies… yes, harmless FLIES known as syrphid flies, flower flies or hoverflies. They imitate the coloration of wasps, which warns of … Read moreSyrphids. Camouflaged as wasps
There are up to 7 types of silk-producing glands (and each silk is different). But not all spiders have all those glands. Not all the spiders build cobwebs, but all of them have the ability to produce silk. The construction of cobwebs is genetically codified, it is not by learning. In addition, it is done … Read moreCobwebs: Architecture in miniature
Behavioral control has always aroused deep fears. For instance, the mere idea of the existence of institutions and projects that have tried to manipulate the most private and apparently untouchable aspects of an individual arouses evident uneasiness. However, human being is not pioneer in behavioral control techniques. In nature, several species have been practicing these … Read moreBehavior manipulators. The organisms capable of breaking the will