Meet the micromammals

Felines, wolves, elephants, apes… We all know big mammals, but what about the smaller ones? Do you know what is a desman or a solenodon? Read on to find out more about small mammals and their importance.

WHAT IS A MICROMAMMAL?

The word “micromammal” has no taxonomical value: it is not a word that biology uses in the classification of mammals. However, this colloquial term, like the word “dinosaur” sometimes it is used in scientific publications to group together several orders of small mammals, although in the same taxonomic group some species can have a large size.

European hedgehog (Erinaceus europaeus), a micromammal. Source

In general, we consider micromammals animals of the following groups:

• Bats
• Rodents (rats, mice, squirrels, marmots, beavers, prairie dogs, hamsters, lemmings, gerbils, voles, chinchillas…)
• Lagomorphs (rabbits, hares and pikas)
• Insectivores (shrews, hedgehogs, moles, desmans …)

BATS

As we learnt in a previous post, bats are essential animals for ecosystems, they also have unique characteristics that make them worthy of several records: they are the only mammals able to fly actively, they are distributed to nearly every continent, they don’t get sick… to find out more about bats, visit What is a bat for?

Flying fox cubs rescued by the Australian Bat Clinic after the floods of 2010. Source

In the Iberian Peninsula live eight species of bats. Learn more about them in the website Fauna Ibérica.

RODENTS

Rodents are the largest order of mammals, accounting for over 40% of the total and inhabit all continents except Antarctica. Some rodents are not considered micromammals for its large size, such as capybaras or porcupines. Most rodents are quadrupeds with long tail, claws, whiskers and continuously-growing large incisors. This fact forces them to constantly gnaw through its specialized jaws, to wear away the incisors and always keep them sharp. They have a great sense of smell and hearing, and the sense of touch in his whiskers. They communicate by scent and various vocalizations.

Common vole (Microtus duodecimcostatus). Photo: Herminio M. Muñiz

Most species are social and form large communities. Their anatomy is not so specialized than other mammals, allowing them to adapt to different habitats. Added to the high birth rate, they can keep populations stable in adverse conditions. The black rat, for example, can have litters every month of more than 10 babys.

Gray dormouse (Glis glis). Photo: Miguel Ángel Castaño Ortega

Some rodents, especially rats and mice, occupy the same habitats that humans and are considered a plague. In addition to eating human food, they can contaminate it with their urine and feces and they are transmitters of more than 20 diseases, including the typhus and plague.

Common squirrel (Sciurus vulgaris). Photo: Peter Trimming

In the Iberian Peninsula inhabit about 23 species, divided into five categories:

• Cricetidae: voles (8 species), water vole and southern muskrat (non-native).
• Gliridae: Gray dormouse
• Sciuridae: common squirrel
• Muridae: mice and rats
• Myocastoride: Coypu (non-native)

Coypu (Myocastor coypus). Photo: http://www.simbiosisactiva.org

RABBITS, HARES AND PIKAS (LAGOMORPHS)

Ili pika. It is an endangered species, it was seen again after 10 years disappeared. Pic: Li Weidong

Contrary to what a lot of people believe, rabbits and hares are not rodents but they belong to the order of lagomorphs. Unlike rodents, lagomorphs have a small, round tail, paws with thick fur and hair in  their foot sole that helps grip while running.

All species are terrestrial and are distributed almost worldwide. They are among the most hunted animals, so its body has adapted to elude predators:

• Long ears for good hearing
• Eyes on top of the head with a vision of almost 360º
• Elongated hind legs to reach 56 km/h

Like rodents, the incisors are also continuously-growing, but behind them there is another smaller pair. They have high reproductive rates (some species can conceive a second litter before the first is born), sexual maturity within a few months of life and short gestations.

Comparison between the skull of lagomorphs (above) and rodents (below). Source

Lagomorphs are herbivores and practice cecotrophy: substances that can not be diggested, are evacuated through the anus in the shape of soft balls. They eat this balls in order to do a second digestion. If you have a rabbit as a pet ¡this behavior is completely normal!

In the Iberian Peninsula lives a species of rabbit and 4 species of hares (Iberian, European and Cabo del Piornal (non-native).

Rabbit (left) and hare (right). Source

INSECTIVOROUS MICROMAMMALS

Currently the order Insectivora is no longer used and micromammals that feed on insects (and other animals) can be classified into five Orders:

• Hedgehogs, moonrats or gimnurs (Erinaceomorpha)
• Shrews, moles and  solenodons (Soricomorpha).
• Tenrecs and golden moles (Afrosoricida)
• Elephant shrews (Macroscelidea)
• Treeshrews (Scandentia)

Hispaniolan solenodon (Solenodon paradoxus). Photo by M. Eladio Fernandez.

They are considered to be the most primitive mammals. Many species are characterized by:

• Elongated, thin and mobile snout. They have a good sense of smell
• Ears and small eyes in some species, like moles
• Five clawed toes on each paw
• They are plantigrades
• Some species, such as hedhehogs and tenrecs have spikes
• The solenodonts, water shrews and shrews are among the few poisonous mammals in the world. Read this post to learn more.

Mediterranean water shrew (Neomys anomalus). Photo by Rollin Verlinde

Most of them are nocturnal and their diet is based on insects, spiders and worms, but they also eat plants and other animals. Besides, they are not the only mammals that eat insects.

Lowland streaked tenrec (Hemicentetes semispinosus). Photo by Robert Siegel

In the Iberian Peninsula lives the Pyrenean desman, two species of hedgehog, about five species of shrews, two species of water shrews, and the Spanish mole. To learn more about the Pyrenean desman, in the website El Bichólogo you can find more information.

Pyrenean desman (Galemys pyrenaicus). Photo: David Perez

IMPORTANCE OF MICROMAMMALS

• In Paleozoology, the fossils of micromammal provide a lot of information as they tend to be found more often in deposits than other mammals. In addition, many times their bones are accumulated due to the eating habits of their predators. They provide valuable information on the climate of the past (paleoclimatology) and the classification of rocks in layers (biostratigraphy).
• Despite its bad reputation, some rodent species are beneficial, controlling insect populations and destroying weeds, contributing to the health of forests spreading fungus… and  are still used in scientific research.
• Many species are responsible for the spread of pollen or seeds.
• They are vital for the conservation and maintenance of their predatory species in decline, as the Pyrenean owl or Iberian Lynx.
• Since some of them live in burrows (rabbits) or they are burrowers (moles), they contribute to the ventilation of the soil and its fertility.

REFERENCES

• Clutton-Brock, Juliet et al. 2002. Animal. Pearson Education
• Diversidad con los micromamíferos de la Sima del Elefante (Atapuerca, Burgos)
• fauna ibérica
• Botanical-online
• Por qué es tan importante el conejo?
• Source of cover image (star-nosed mole)

5 experiences in a wildlife rescue center

If you’re a former, present or future biology student this interests you. One of the most rewarding work experiences I ever had was working in a wildlife rescue center. Actually, I worked as a technical assistant veterinary, but allowed me to know how a center like this (led by a biologist) works and have direct contact with wildlife. These are just 5 experiences and lessons learned from that adventure.

WHAT IS A WILDLIFE RECOVERY CENTER?

It is a center where sick or injured wild animals are welcome where they have veterinary care and food until they are able to fend for themselves. Then they are released into the wild. This centers are of great importance for the conservation of the species, especially those that are endangered or vulnerable. The contact with animals should be the minimum to avoid humanizing them and not change their behavior so they can survive once reintroduced in nature.

Some centers also breed in captivity threatened species, such as the Hermann’s tortoise (Testudo hermanni) to try to recover wild populations introducing the offspring in nature.

Eagle flying in the Wildlife recovery center “El Valle”, Murcia. Photo taken from Murcia enclave environmental

Unfortunately, some animals are unrecoverable due to his injuries or behavior, so in the center they lived some birds of prey such as the goshawk (Accipiter gentilis) to be an example in environmental education and awareness.

If you find an injured animal, NEVER try to keep, treat or feed it: probably you’ll cause more injuries. Always call one of these centers or local authorities. They have the facilities and appropriate knowledge to treat these animals.

1. CLEAN, CLEAN AND…  MORE CLEANING

The first information I got when I entered the center was: “80% of the time of this work is to clean the animal facilities. But the remaining 20% ​​is  worth rewarding. “

The director was right. It is a job where you’ll get dirty, and if you’re a little apprehensive, it is not for you or you’ll need to get used (and believe me, you get used to almost everything , cleaning was not the hardest thing I faced). But see how it goes ahead an animal that you have taken care, is priceless.

2. THE WONDER OF WORKING IN THE MIDDLE OF NATURE

The dream of many biologists is working in direct contact with nature. These centers are usually in it, which gives the opportunity to work outdoors, away from the stress and pollution of the city. Sometimes it rains, makes a blazing sun or cold temperatures will freeze your hands and cut your skin. But the good times are terribly comforting. Many of us prefer put up with occasionally adverse weather conditions  rather than being locked in a windowless office for 8 or more hours

In my case we also had a pair of attached facilities outside the center and had to go every day strolling through the woods, with the added appeal and adrenaline (especially if you met a wild boar) to see animals and plants in their habitat.

Natural park of Montseny. Photo by Mireia Querol

The field work was completed by the laboratory and treatment room: analysis of feces, blood, muscle… to detect the presence of parasites in new animals, future reintroduced ones and dead ones: autopsies allow to have a record of possible diseases and epidemics of local fauna.

3. GIVE LIFE… BUT ALSO QUIT LIFE

In addition to maintain proper hygienic conditions, the main occupation that I had was to feed the animals. At that time there were mammals like hedgehogs, badgers or foxes which we fed with fodder and supplements such as worms.

For raptors, one of the most frequent tenants, the diet was based mainly in chicks and mice. The chicks were bought frozen, you just had to plan the thawing and leave them on their premises. In one case I had to hand feed one tawny owl (Otus scops) with a broken wing, so the contact with the animal was inevitable. And feeding a nocturnal bird of prey, althought it was a small one, is complicated task the first time!

Tawny Owl (Otus scops). Photo by Mario Cea

The mice instead were kept alive. By ethics and risk the animal was injured, we had to kill them with the least possible suffering before serving them as food. To learn the technique and do it properly, creates a sense of contradiction, so it’s better to focus on the animal you’re trying to save as a peregrine falcon (Falco peregrinus), a viper (Vipera Aspis), a tawny owl (Strix aluco), kestrels (Falco tinnunculus), a hawk (Accipiter gentilis)… For herbivores, such Hermann’s tortoises (Testudo hermanni), was much easier to prepare their food. And the nicest thing, to feed a baby squirrel (Sciurus vulgaris).

Nurse feeding a baby squirrel. Photo by Ezequiel Becerra

The hardest moment is where you have to euthanize an animal. Unfortunately, some animals are seriously injured and you can not do anything to save them. In other cases, if it is not priority species (such as gulls, pigeons, invasive species…) lack of resources and/or legislation euthanasia is the only solution left. First the animal anesthetized to avoid unnecessary suffering, and then euthanized with a syringe directly into the heart to make it as fast as possible. Find the heart with a stethoscope and have to check it has stopped is one of the most harrowing experiences that I had to live there.

So death is also present in these centers. Causes frustration and sadness see dying an animal you are trying to get ahead, or having to euthanize it to avoid suffering, but it is one of the difficulties it has to be faced.

4. HUMANS, THE MAIN REASON OF INCOME OF WOUNDED ANIMALS

The animals arrived to the center through forest rangers, with which you have constant communication, associations or other institutions or individuals. On occasions we moved because it was impossible to move the animal: a huge wild boar (Sus scrofa) hit by a train. The collisions are a leading cause of death of wild animals. The situation could not be more daunting: rain, the animal on the roadside in a pool of his own blood and mud. Were difficult times as we had to apply higher euthanasia doses than normal because he clung to life, besides having to ensure our own security. Finally, for all of us the suffering ended. Dirty and sad, we get on the jeep back to the center.

Fox hit by a car. Photo taken from 20 minutos

The possession of wild animals as pets causes accidents by negligence or ignorance of their owners: was the case of an eagle which it had cut its primary feathers so he could not fly when it wasn’t a harmless chick anymore. He had to undergo surgery and expect to grow new feathers and learn to fly again.

Pets themselves also causes serious injuries: for example tortoises, iguanas bitten by dogs…

The traps, poisoning and direct shots of hunters , even on protected species like raptors, is another cause of having animals in these centers. Birds also face hazards such as power lines, pylons, wind turbines, wired fences … death traps for many of them.

Dead eagle because shot pellets. Photo taken from Quo

There were few cases where the causes of admission to the center were natural or impossible to determine. In fact, I do not remember any.

5. THAT FEELING WATCHING A RECOVERED ANIMAL FLYING TO FREEDOM

The most wonderful moment is that one in which the animal is ready to return to nature. Planning how and where, taking the journey to the place, checking the surroundings (and if lucky, with the sighting of other species) the moment you open the cage. .. and you see these two kestrels that you have been feeding for months, eager to rise into the sky, you with binoculars in your hand observing them away into the vastness to become tiny black dots… and disappear. I’ve never seen more clearly a metaphor of what freedom is. That feeling, like love, can not be explained.

Maybe it is love, after all

Cover photo: Mireia Querol. Griffon vulture (Gyps fulvus) in flight over the Foz of Lumbier (Navarra, 2007).

* The photos of this post do not belong to the animal rescue center, they are used as an example of the species listed in the post

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 alba, and 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.

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 (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.

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.

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.

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.

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.

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

• Pestana Salido, Antonio J. 2009. Ed. Tundra. Las aves ibéricas en la cultura popular.
• Nicolai, Jürgen. Ed. Everest. 1995. Aves rapaces diurnas y nocturnas.
• Búhos, lechuzas y leyendas
• Brinzal. Centro de recuperación de rapaces nocturnas
• Seo Birdlife
• The Owl pages
• Cim d’Àligues
• Cover image by Luc Viatour

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?

This publication is licensed under a Creative Commons:

Licencia Creative Commons Atribución-NoComercial-CompartirIgual 4.0 Internacional.