The black-headed duck is a small waterfowl that lives only in South America. It is distinguished by never building its own nest, instead laying eggs in the nests of other birds.
The black-headed duck is the only duck in the world that always uses foster parents. It helps nature by spreading eggs across different water bodies and participating in the food chains of South America's freshwater ecosystems.
Immature form that undergoes metamorphosis before adulthood.
Worker
birth time
Submerges underwater to reach prey or food at depth.
bottom
Dogs, dolphins, lynx hang out for 9-25 years and party on their birthday three times a year
m
Map
will celebrate their {n} birthday
g
t
When your next jubilee falls in {name} life years
Human
days
South and Central America, hot and humid, huge forests
Warm summer
How old you would be if you lived as {name}
Theoretical maximum lifespan estimated from the Dynamic Energy Budget (DEB) mathematical model. This value reflects a biological potential derived from metabolic parameters, not from direct observation — real recorded lifespans are often significantly shorter.
mollusks
adult
Maturity
South and Central America, hot and humid, huge forests
insects
About health
When your next birthday would fall if you lived as {name}
Repro interval
results
summer warm, winter not very cold
Colors
Sex
Upcoming jubilees
Gremllins
diving
mo
conifer cones
all seas and oceans
Trophic type
Filters
Upcoming birthdays
standing fresh waters — lakes, ponds, oxbow lakes
Truly long lives: 40-100 years. Bowhead whales, albatrosses, giant tortoises recall their birthday at most once a year
Lifespan
Desert and dry shrubs
rains almost always, very humid
Age (juvenile)
Parasite
Age (from birth to death)
cones of coniferous trees with seeds
Foraging occurs on the floor of aquatic or terrestrial habitats.
Age (embryo)
Wanderers
Food items are collected from exposed outer surfaces of substrates.
Age (larva)
algae
Jubilee = every 10th birthday
Warm summer and frequent rains
Earliest developmental stage inside an egg or womb.
Business sausages
Lifespan average
young after fast growth
Juvenile stage following larval metamorphosis but not yet adult.
summer warm, rains frequent
What do they look like?
Maturity
emergence (insects)
end of lifespan
Wings color
How do they live?
fertilization / egg laying
How do they behave?
birth / hatching
metamorphosis / end of larval stage
end of acceleration
Share
swampy freshwater biotopes — peat bogs, marshes, river mangroves
live snails, mussels, oysters
Find a pet...
Mature, fully developed individual capable of reproduction.
hot, uneven rains, lots of grass and trees
Actively hunting and capturing live prey.
where the river flows into the sea, slightly salty water, lots of fish and birds
Pets
{name} jubilee
cm
Old-timers
Find an animal or breed...
turns
Rascals
Flooded grasslands
Litter size
Tropical savanna
Map data sources: Ecosystem classification — IUCN Global Ecosystem Typology (Keith et al., 2022), indicative distribution maps Keith et al. (2020), https://doi.org/10.5281/zenodo.3546513; Large Marine Ecosystems — NOAA LME Program; Bathymetry — GEBCO Bathymetric Compilation Group (2026), GEBCO_2026 Grid, https://doi.org/10.5285/4f68d5c7-45eb-f999-e063-7086abc036fa; Climate data — Generated using Copernicus Climate Change Service information; Species occurrence data — GBIF.org, Derived dataset "all animals", https://zveriki.com/dataset/dataset.tsv; Terrestrial ecoregions — RESOLVE Ecoregions 2017 (Dinerstein et al., 2017), CC BY 4.0
How to care for them?
Living from 25 to 40 years. Orangutans, bald eagles, African elephants celebrate their birthday twice a year
Body plumage color
°C
Not specified
Actively searching habitats to locate food items.
Where are they found?
Species lacks any fixed or lasting shelter structure.
38 to 65 grams, 15 – 40 centimeters
all rivers and lakes
Down color
Locomotion through water employed while searching for or capturing prey.
Legendary longevity: over 100 years. Galapagos tortoises, Greenland sharks, ocean quahogs celebrate with family once every 4 years
Offspring
Elders
Bro
lakes and ponds
freshwater marsh and wetlands
Taxons
if born as {name}
omnivore
age
birth date
swimming
no permanent shelter
Close
was
Career from 7 to 15 months. Dwarf hamsters, voles, field crickets celebrate their birthday twice a month
The basics
Neotropical realm
My weight?
Non-stop carnival: they only live a few days. Mayflies, rotifers, midges celebrate their birthday more than twice a day
surface
primary food sources
Neotropical realm
Beak size
Potential Habitat
Very hot summer
d
In husbandry
On the go from 1.3 to 3.5 years. Forest mice, anoles, rainbow fish party on their birthday once a month
Feeding occurs in water bodies such as rivers, lakes, or oceans.
Mass
mother dumps offspring on other parents, like cuckoos in a nest high on branches
Mosquitoes, fruit flies, small crustaceans hustle for up to 7 months and throw a birthday party every week
aquatic
summer very hot, above +25…+30 °C
{name} birthday
No results found
diving and collecting from the surface or bottom
On the map
small crustaceans
Pleasant summer
all life stages
Female ♀
Map data sources: Ecosystem classification — IUCN Global Ecosystem Typology (Keith et al., 2022), indicative distribution maps Keith et al. (2020), https://doi.org/10.5281/zenodo.3546513; Large Marine Ecosystems — NOAA LME Program; Bathymetry — GEBCO Bathymetric Compilation Group (2026), GEBCO_2026 Grid, https://doi.org/10.5285/4f68d5c7-45eb-f999-e063-7086abc036fa; Climate data — Generated using Copernicus Climate Change Service information; Species occurrence data — GBIF.org, Derived dataset "all animals", https://zveriki.com/dataset/dataset.tsv; Terrestrial ecoregions — RESOLVE Ecoregions 2017 (Dinerstein et al., 2017), CC BY 4.0
Potential habitat modelled from GBIF occurrence data. Map © Zveriki.com, licensed under CC BY 4.0.
Beak count
birth year
lots of grass, few trees, rains occur
Maturity
terrestrial habitat, land surface outside water
sq mm
yr
Beak color
comfortable summer, +20…+25 °C
How similar?
Male ♂
until the celebration
baby / chick
age as {name}
How do they breed?
On the go from 3.5 to 6 years. Hedgehogs, crows, lizards treat themselves to birthday snacks 6 times a year
Legs color
What if eaten?
Neither
from birth to adulthood
Young offspring still dependent on parental care.
What do they eat?
Where do they live?
Immature individual that has not yet reached reproductive maturity.
Marine world
from birth to death
early young
water often floods the land, lots of grass
River estuary into the sea
Freshwater
Temperate mixed forest
Duration
live insects
This is me
freshwater
Always very wet
Gamers
aquatic plants and algae
How are they built?
shallow near the shore, water rises and falls, crabs live here
Temperate steppe
mm
Theoretical lifespan
ml
Stars
Link copied
foster parents
My age?
wk
My size?
terrestrial
Asexual
swap
freshwater environment — rivers, lakes, ponds, swamps
active predation
Rabbits, falcons, red-eared turtles hang out for 6-9 years and party on their birthday four times a year
Where do they take shelter?
Warm summer and lots of rain
Head color
celebrated their {n} birthday
When you would have been born if you lived as {name}
Littoral Zone
Daddies
small crabs, amphipods and other crustaceans
Lifespan maximum
foraging
Hermaphrodite ⚥
embryo
Orange
summer warm, many oaks, birches, maples
Length
kg
very hot and dry, rare rains, cacti live
lots of rain, warm and pleasant summer
Observations
◉{N} more on tap