Andean Ibis Theristicus branickii Scientific name definitions

Fernando Medrano and Peter Pyle
Version: 2.0 — Published May 12, 2023

Demography and Populations

Measures of Breeding Activity

Age at First Breeding

Information needed.

Intervals Between Breeding

Information needed.

Clutch Size and Number of Clutches per Season

Little known. It appears to lay a single clutch per season, with two eggs (28).

Annual and Lifetime Reproductive Success

Little is known about annual reproductive success and nothing about lifetime reproductive success. In one study in Ecuador, hatching success was 88%, while the fledging success (percent of successfully hatched eggs that resulted in fledged young) was 57% (n = 4 nests; 28). It appeared that the nestlings of one nest were predated, while one nestling from another nest appeared to have fallen from the nest and died (28).

Number of Broods Normally Reared per Season

Likely only a single brood is reared per season, but information needed to confirm this.

Proportion of Total Females that Rear ≥ One Brood to Nest-Leaving

Information needed.

Life Span and Survivorship

Information needed.

Disease and Body Parasites

Information needed.

Causes of Mortality


Information needed. One nestling appeared to have died after it fell from its nest during as study in Ecuador (28).


Information needed. Its relationship with Carunculated Caracara in Ecuador is not clear; caracaras have been observed chasing and pursuing Andean Ibis (27), but whether this is related to predation is not known.


Information needed.

Direct Human Impacts

The only known cause is hunting in Ecuador (31). Nothing else is known.

Population Spatial Metrics

Individual Distance

Very little information. Four nests at Antisana Ecological Reserve, Ecuador were between 3–10 km from each other (28).

Territory Size

Information needed.

Home Range Size

Information needed.

Population Status


Mostly unknown.


In the Napo province there were estimates of 85, 94, and 134 individuals in 2016, 2017, and 2018 respectively (32).


Unknown, but based on the densities from Ecuador, and the large area occupied by the species in this country, the population seems to exceed several thousand individuals.


The population in Chile might not exceed 200 individuals (FM, personal observation).


Apparently declining, with the rate of decline thought to be approaching 30% over three generations (29 years).

Population Regulation

Information needed.

Recommended Citation

Medrano, F. and P. Pyle (2023). Andean Ibis (Theristicus branickii), version 2.0. In Birds of the World (S. M. Billerman, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.bkfibi2.02