Despite its size and symbology, the Andean condor’s nesting habits are poorly known. Andean condors are secretive nesters and place their nests in inaccessible cliffs. Most aspects of its breeding biology come from birds kept in zoos. In this article, I compile the available information mostly from wild birds.
- The Andean condor has one most prolonged breeding cycles
- Condors in northern latitudes appear to breed earlier than those in southern latitudes
- The Andean condor is monogamous and mates for life
- They breed every other year or 18 to 20 months
- The female lays a single
- Both parents incubate and take care of the young
Juvenile Andean condor. Photo: Walter Baliero.
What months of the year do Andean condors breed?
The breeding seasonality of the Andean condor was thought to be variable and poorly understood. Recent studies have shed some light on what appears to be a recognizable pattern of nesting within the species’ range.
Wild Andean condors in the northern part of the Andes breed earlier than those in the southern part of the species range. This latitudinal variation appears more diffuse in the central region, which has no well-defined seasons. Nesting records are very few, so this interpretation should only be considered preliminary.
Table showing the month when each pair of wild Andean condors was incubating eggs (from Saenz et al., 2016).
|Region||Records of incubating pairs|
|Northern Andes (Colombia & Ecuador)||Jan. Feb, Apr, and Oct|
|Central Andes (N. Peru, Bolivia)||Feb, Jun, and Aug|
|Southern Andes (Chile & Argentina)||Aug, Sep, Oct, Oct, Oct, and Oct.|
How long does the Andean condor breeding cycle last?
The condor’s reproductive cycle lasts approximately 18 to 19 months, from the day an egg is laid to the day the chick becomes nutritionally independent from its parents.
- The incubation period lasts between 57 to 60 days or 2 months.
- The period between the egg’s hatching and the young condor’s fledging lasts approximately 6 months.
- After fledging, the parents continue feeding and assisting the young condor for up to 10 months.
- The Andean condor’s breeding cycle is among the longest in the bird world.
Based on the observations of a wild Andean condor pair (Lambertucci and Mastrantuoni, 2008), the breeding cycle is detailed as follows:
- On 4 August 2005, the pair roosted inside the nest cave for the first time in what may constitute the initiation of a breeding cycle.
- The pair started incubating the egg in the first week of October 2005.
- One parent was always in the nest between October and the first week of December 2005.
- On December 5, 2005, the parents were seen together outside the nest for the first time since the first week of October. After two months of incubation, the chick is about one month old.
- February 1, the parents no longer roosted in the nest. The chick is about three months old.
- June 12, 2006, the chick fledged the nest. This period of time is approximately 6 months and 12 days after hatching. June 12, 2006, is also nine months after the female laid the egg.
- From December 2006 through February 2007, the adults fed the fledgling, usually responding to the chick begging for food.
- On 19 March 2006, 16 September, and 7 October 2006, the adults were observed performing courtship displays. However, the pair was still feeding the chick in 2006 and did not nest.
- In October 2007, a pair of condors, presumably the same pair, began incubation at the same nest site.
Andean Condor Pair Formation
Adult male Andean condor performing the typical courtship display. Notice the low, guttural clucking sound produced by the bird.
- Pair formation can take place any time of the year
- Courtship displays and copulation may occur any time of the year.
- Mated pairs stay in close proximity year-round.
Because the Andean condor has a wide distribution, low numbers, and remoteness of sites where males and females interact, it is rare to observe behavior indicative of pair formation.
The timing and behavior associated with pair formation can be determined using scattered field observations and observations of birds in zoos.
Pair formation begins months before the nesting period. In Argentina, a wild nesting pair initiated courtship displays in April and continued until October, when incubation started (Lambertucci y Mastruantoni 2008).
A separate wild pair showed a courtship display followed by copulation in August. However, this pair laid eggs in October (Cailly-Arnulphi, et al 2014).
As with other large birds of prey, the Andean condor forms pairs, engage in courtship displays, and copulates throughout the year. When far from the nesting period, the courtship displays are less elaborate but peak in frequency and intensity before egg fertilization and laying.
Likely trigger of breeding activity
The initiation of breeding activity of Andean condors in zoos appears to be triggered by changes in temperature and day length. Zoos in the northern hemisphere report condors breeding from midwinter to midsummer, which corresponds to January through July.
A breeding pair at the San Diego Zoo, California, showed signs of interacting with one another only when the weather conditions warmed up. Before that, both males and females were motionless for hours in their cages.
In conditions where warm temperatures are recorded throughout the year, Andean condors do not appear to breed seasonally. Over the 10 years between 1992 and 2002, a pair of Andean condors in Cali, Colombia, laid eggs almost every month.
What does the Andean condor courtship display look like?
- The male begins the courtship display by opening his wings up and back, curving his head down in a hook shape. A bird in display mode may inflate its neck and change the color of its neck and head from pinkish-gray to a distinctive pale rose and sulfur yellow.
- With its wing extended, the male may move its head up and down or rub its head and neck against the ground or a nearby rock. It may also wrap its neck around a nearby rock. A low, guttural clucking sound can accompany all of these.
- In addition, the male condor may push and drag objects under its lifted wings with its beak.
- Males often spin around in place and shake their wings.
- In response to this display directed at her, the female may remain motionless or perform a simpler version of what the male is doing. In response to a male’s display, she can spread her wings and stretch her neck. She may pick up straws and any other object and put them aside without a particular order or attempt to form something.
After intermittent displays, both birds may copulate or simply lose interest and continue their daily activities.
Andean condor mating
Following the courtship display, the male approaches the female and may raise his leg in an attempt to mount her. He mounts her and positions himself for cloacal contact if the female shows interest.
The female leans forward, lowering her chest to the ground and elevating her rear half to facilitate cloacal contact. A male can take up to three minutes to complete a copulation and sperm transfer.
Are Andean condors monogamous and mate for life?
The Andean condor is monogamous and mates for life for as long as both pair members survive. If one of the individuals dies or disappears, the survivor will find a mate with which to breed.
Birds that share key aspects of the Andean condor’s natural history are monogamous and mate for life.
Typically, birds that mate for life have long lives, care for their young long after leaving the nest, have low reproductive productivity, are large, and take multiple years to reach sexual maturity. Andean condors meet these criteria exceedingly well, making them prime examples of birds that are monogamous and mate for life.
Further evidence that Andean condors are monogamous can be found in the fact that they roost close to their mates throughout the year.
Additionally, male and female condors seem to engage in courtship displays and copulate throughout the year, which is generally regarded as a way to strengthen the pair’s bond.
The nest of the Andean Condor
- The Andean condor does not construct a nest.
- It nests in caves o cliff ledges.
- The Andean condor uses the same nest over multiple years
The Andean condor does not build a nest or collect any building material. Condors choose a flat surface that has loose soil, sand, or gravel where they can dig a small depression to lay their eggs.
During nest building, both parents spend considerable time lying down on the nest site, arranging the substrate with their beaks to shape the dirt or gravel around them in a process called “edge building”.
Where do Andean condors build their nests?
Typically, Andean condors nest in caves and on ledges of vertical cliffs. The size of the cave or ledge they choose to nest in depends on what is available in the region.
Nests are usually found in places that are inaccessible to land predators.
Usually, the nest site has adjacent perches marked with whitewash (droppings) where the birds perch and roost when not in the nest. It is noteworthy that the outside of the cave or cliff ledge used for nesting is not used as a perch or roost and does not have whitewash.
Andean condors choose nest sites protected from strong winds and direct sunlight for long periods.
Andean condors nest at elevations ranging from 1,000 to 5,000 meters above sea level. Nevertheless, most nests are located near 3500 m of altitude.
Does the Andean Condor use the same nest every year?
During its reproductive cycle, it is likely that the Andean condor uses the same or a limited number of nest sites. A bird pair that successfully raises young in a nest is likely to return to the same nest when they breed again.
When birds don’t build nests, they need to find nesting sites that offer the best conditions. Changing the nesting site is not an option. There is no information on whether nesting sites for the Andean condor are easily accessible or constitute a limiting factor.
It is well known that Andean condors use and rotate their roosting sites over extensive areas all year round. As food availability changes, the Andean condor is likely to choose nesting sites centrally located in relation to food sources.
Nesting Andean condors return to the same nest every other year in the limited number of nests studied in the wild.
What are the predators of Andean condor nests?
Nest predators are few in the Andean condor, mainly because their nests are in vertical cliff faces that are inaccessible from the ground.
The Andean condor nests on vegetated cliffs accessible to small mammals in its range’s northern and more humid parts. The only study video-monitoring an Andean condor nest in Colombia’s Paramo region lost the egg to an unknown predator during the night.
Hatchlings are at risk from aerial predators such as hawks, caracaras, and falcons. During the first month after hatching, one of the parents always broods and protects the nestling while the other searches for food. After two months or so, the chick is big enough not to be vulnerable to avian predators, and both parents search for food, leaving the chick alone.
Egg laying and incubation
- The Andean condor lay only one egg
- Both parents incubate the eggs.
- The Andean condor incubation period ranges from 58 to 62 days
- The egg is white and unmarked
The two members of the pair begin to roost in the nest site when they are about to lay eggs. The female lays one egg at night or early in the morning in captive birds.
How many eggs does a female Andean Condor lay?
Each nesting season, the Andean condor lays one egg. A breeding pair of condors lay an egg every other year due to their long parental care of the young after they leave their nests.
Pairs may delay laying eggs and even skip breeding in one year when feeding conditions are not conducive to a successful breeding attempt.
It is unknown if Andean condors lay another egg after losing one, although it can be assumed that they do.
Andean condors readily lay another egg within approximately 30 days after losing an egg in captivity. An Andean condor pair laid up to four eggs in a single breeding season after the egg was removed to increase production in a zoo.
The Andean condor incubation period
The incubation period of wild Andean condors is about 60 days. Condors breeding in captive conditions ranged between approximately 58 to 62 days.
Interestingly, the range variation in incubation period was observed at the same zoo, where an egg took 58 days to hatch, and another female’s egg took 62 days.
The incubation period of the Andean condor is one of the longest among birds.
Male and female Andean condors incubate the egg
Both male and female Andean condors incubate the eggs nearly equally, which is unusual among most birds of prey where the female does most of the incubation.
Both in the field and in the zoo, the male was most anxious to incubate the eggs, and he did not want to leave the nest when it was time for the female to incubate them. On the other hand, the female left the nest as soon as the male arrived to take over incubation duties.
Andean condor egg appearance and measurements
Due mainly to the difficulty of accessing a nest, descriptions, and measures of the Andean condor egg come from Zoos and other breeding facilities. The egg of the Andean condor is oval and white with a faint bluish tinge when laid. The egg is unmarked. After some time of incubation, the egg becomes stained with dirt and the parents’ body fluids.
Approximate measures of the Andean condor egg include:
- Length: 3.7 inch
- Weight: 9.4 oz
- Width: 3.1 inch
Egg Hatching and Brood Care
- Chicks hatch with a thin coat of white down
- The chick is cared for by both parents.
- The chick leaves the nest after 6 months after hatching
- The chick stays with the parents for up 10 months after leaving the nest
Chicks of Andean condors hatch with a thin layer of white down covering their bodies, except for the head and neck. They have partially opened eyes. Their heads are dark with reddish-brown tones. Their beaks are black. Their legs and feet are gray.
From the time of hatching, male condors show a rudimentary comb while females have a flat forehead.
By the fourth week after hatching, the chick begins to grow a thick layer of down, which is gray in color.
Care and feeding of the baby Andean condor
Field observations of a wild breeding pair indicate that the two parents continue to brood the chick after hatching. Brooding continues for about two months, and one parent is always in the nest.
After two months, the parents begin to leave the nest but stay close. A two-month-old baby condor has a thick coat of down and is able to thermoregulate its own temperature. While the parents leave the chick alone for part of the day, they continue brooding the nestling during the freezing cold nights of the high Andes.
Do both parents feed the young?
Both parents feed the chick nearly equally, with the male making a slightly larger number of feeding trips.
Most daily feeding occurs during the hours of 11 through 4 PM. This time period coincides with the time of the day when thermal updrafts are most active, and flying takes the least amount of effort.
Andean condors bring food in their expandable crops, where they can store a substantial amount of food. Unlike other birds of prey, they are unable to grab and carry objects with their feet.
Visit this article to continue reading about the Andean condor’s growth stages and plumage development (forthcoming link).
- Lambertucci, S.A. and Mastrantuoni, A. (2008). Breeding behavior of a pair of free-living Andean Condors. J. Field Ornithol. 79(2):147–151.
- Plan de acción para la conservación del cóndor andino en Ecuador. October 2018.
- Saenz, F., Ciri, F. Sheppard, J. Parrado-Vargas, M. (2016). Andean condor (vultur gryphus) nesting in northeastern Colombia and differences in laying dates along the Andes. Ornithologia Neotropical, 27(1):67-71.