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Learn about ducks and geese

Most of us have heard about the French delicacy called foie gras. However, do we really know what goes on behind the production of this world renowned dish? The truth is that to create this, most foie gras comes from ducks and geese which are confined in extremely tight places for several weeks and have their throats pumped forcefully into them many times during the day. This practice of force feeding (or "gavage" as people call it in France) is the cause of the fat livers in ducks and geese, which are deformed due to the grotesque swelling. 


 Whereas foie gras is considered the most luxurious dish by many, its production has shrunk significantly in recent years due to the policies adopted by many countries as more experts and consumers become aware of the brutal effects this production has on ducks and geese.

Let's get scientific about ducks and geese!

a) General characteristics

Both ducks and geese are waterfowl, with their feathers waterproof by nature and insulating, which helps raise their tolerance to colder temperatures. These two species get along well together and both are social creatures who do not like isolation. On average, a typical domestic duck can live from 10-15 years while a goose can live a few years longer, from 15-20 years. 

Geese have a tendency to be territorial. They can fence off intruders and tend to be extra aggressive during breeding seasons. One of the difference between geese and ducks is that geeese molt once a year and mate for life while ducks molt twice a year. Molting can last from 6 to 8 weeks. Ducks and geese spend a large portion of their days foraging and a lot of time bath and preen to keep their plumage in good conditions. 

Domestic ducks has origins from the mallard, which is the most well-known duck species in the Northern Hemisphere that has been domesticated for over 2000 years. Mallards can fly fast, swim well, walk and run with ease.  Like the domestic ducks, muscovies can also fly. swim and walk well. But they tend to be active at dawn or dusk, around the time they forage for food. The other time during the day they roost in trees near water. They originate in Central and South America. Muscovies' natural habitat is streams, ponds and marshes. 

Mulard is the term used to call ducks used for foie gras. Mulards are hybrids created by crossing a female domestic duck of a breed like the Pekin duck with a male Muscovy duck. Only males are used to produce foie gras. Mulards inherit a combination of traits from both species in terms of anatomy and behaviors. 

Most geese kept for force feeding are the Oie du Gers and the Oie Grise du Sud Ouest. The greylag goose is the ancestor of most farmed geese. The greylag geese spend the bulk of their time in water but otherwise they move and forage extensively on land. They are also very social creatures, except when they are nesting. 

b) Senses



c) Migration

Greylags are capable of migrating long distances, from their breeding bases in the north all the way to their southern winter areas. Some mallard populations migrate as their summer grounds become frozen during the winter months, while some are sedentary. As regards the muscovy ducks, they are a tropical species that does not engage in migratory behaviors. 

Advocates of foie gras production may reason that the act of force feeding is similar to what wildfowl do before migrating naturally, which is increasing their food intake to accumulate fat to fuel their long journeys. However, experts pointed out that even in cases where migrating birds store fat in the liver, their organs never grow by more than twice its initial volume. However, force feeding can cause the liver to enlarge to 6-10 times the regular size.

d) Behaviors 

e) Territoriality

A “home range” as a well-defined region of space to which fish or other animals restrict their activities (Lucas and Baras, 2001).  While some experts use “home range” and “territory” interchangeably, others characterize territories as specific areas, much smaller than home ranges, that can be defended against intruders (Gibson, 1993).

It has been theorized that in the case of fish, if parental care is more pervasive, territoriality would also be more common.  Fish who live in coral reef habitats tend to display more defensive and territorial behaviors. Grant proposed that the high productivity of these reef environments allows individuals to occupy small home ranges, which are more easily protected than larger areas. Godin elaborated that intruder pressure, and resource density and dispersion, dictate whether fish defend territories. Due to their less prolific environment, freshwater fish do not show such defensive strategies as it relates to food, although they will defend a food resource in the laboratory when it is arranged in such a way that it can be protected. Researchers have found that mates, spawning sites, nests, and offspring elicit defensive and territorial behavior more often than food in many fish (Grant, 1997).

f) Foraging

Fish employ a variety of techniques to forage for food; some species use a “sit and wait” strategy while others join schools of fish. Researchers have established that many fish rely on sight to obtain food and navigate within their environment.

For fish that have established a feeding position or territory, they will likely employ a “sit and wait” strategy whereby they swiftly grab any prey items that pass by with the current (Metcalfe, Taylor & Thorpe, 1995). For others, foraging takes place while swimming and artfully dodging other fish’s territories (Puckett & Dill, 1985). 

g) Social and parental behaviors

Fishes exhibit a range of social tendencies; some live largely solitary lives while others prefer the protection and company of schools. Familial relationships vary in importance from species that recognize and reduce aggression toward those with whom they are related to those that do not. Communication also plays an important role in communicating social and reproductive status.


Schools provide fish with protection from predators, as each individual’s chance of being taken is decreased when part of a group (Pitcher & Parrish, 1993). These schools of fish, or shoals, may be more or less tightly grouped, with loosely knit groups common in low light conditions and tightly grouped schools likely when predators are nearby (Brännäs, Alanärä & Magnhagen). The environment often dictates what type of social arrangement the fish adopt. Large bodies of water, like lakes and oceans, more often require fish to accept the added protection of a school, while streams and shallow lakes allow individuals to remain solitary. Schools of fish not only decrease a fish’s predation risk but they also increase the likelihood of finding food as many individuals are foraging at once. However, this common desire to forage can result in considerable competition for food.

A connection between body size and dominance has been observed in many fish species. However, scientists increasingly question whether large body size is not so much the cause of a fish’s dominance as the result of superior access to prime feeding areas enjoyed by dominant individuals. Communication appears to be common in fish, particularly via sound, in the contexts of competition, territoriality, aggression, and mating Hawkins, 1993). Olfaction is another widespread form of communication that assists fish with predator avoidance through alarm signals and in attracting mates (Reebs, 2001).


Other species use a unique form of communication involving electric charges in which each species has distinct discharge patterns. In such species, both sexes are assisted in mate choice by deciphering the unique electric charge characteristic of his, or her, own species (Reebs, 2001).

Parental care is not as widespread in fish as it is in other animal species: 78% of today’s fish families are made up of species that do not practice parental care. Of the remaining 22%, species engaging in bi-parental care make up 32%. In fish families that dedicate only one parent to care of the young, males guard the nest in 50% while females are the sole protector in 18% (Sargent, 1997).

h) Intelligence

A variety of fish species have shown the ability to learn through classical conditioning. Imprinting, an important mechanism that facilitates survival in other young animals, is seen in fish as it relates to their natal stream.  

Instrumental conditioning, when the frequency of a behavior increases or decreases depending on whether it is rewarded, has also been observed in fish. A number of species have been trained to push levers to receive a food reward, but researchers realize that there are limitations to what behaviors fish will perform for rewards due to their innate behavioral repertoire.

Individual recognition is often associated with intelligence in animals, and a number of fish species appear capable of the task.

Let's get scientific about fish
Fun facts about fish

Fun facts about fish

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