Geographic Range
Groove-billed anis (
Crotophaga sulcirostris
) are found in North, Central, and South America, native to the Nearctic and Neotropical
zones.
- Biogeographic Regions
- nearctic
- neotropical
Habitat
Groove-billed anis are often found in open habitat and flat lands, not often being
sited in higher elevations above 1500 meters. Habitats with dense ground vegetation
and higher humidity, like wetlands or tropical forests, are preferred for foraging
and nesting, but they are also found in drier areas like grasslands and scrub forests.
- Habitat Regions
- temperate
- tropical
- terrestrial
- Terrestrial Biomes
- savanna or grassland
- forest
- rainforest
- scrub forest
- Wetlands
- marsh
- Other Habitat Features
- suburban
- agricultural
Physical Description
Adult groove-billed anis are a medium sized bird. They have black feathers covering
their entire body with gray-bordered, scalloped feathers around their neck, blending
into their breast. They have a lack of feathers around their eyes, giving their face
a 'leathery' appearance.
Groove-billed anis have long, floppy tails and pointed primary flight feathers. Just
like other birds in the
Cuculidae
family, anis have zygodactyl feet with two toes facing forward and two facing backward.
Groove-billed ani beaks are unique in structure; narrow but having a depth that is
taller than their skull. Their upper mandible has a prominent curve downwards. The
beak has grooves along the length.
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
Development
Female groove-billed anis will lay their eggs together in nests in layers of nesting
material. When one layer is filled with eggs, another is added on top with nesting
material and eggs will continue to be laid until there are approximately 15 to 20
eggs in one nest. Eggs in the bottom layer seldom survive.
After 8 to 10 days of incubation, the eggs will hatch. Care and incubation are shared
with all adults in the colony and maybe some offspring from previous breeding seasons.
Young anis will open their eyes around 2 days after hatching and will leave the nest
to hide in foliage as early as 5 days (average of 8 to 10 days).
Reproduction
Groove-billed anis have breeding groups consisting of 2 to 4 unrelated pairs of monogamous
breeding adults.
- Mating System
- monogamous
- cooperative breeder
Adult groove-billed anis will mount and reverse mount each other prior to breeding.
Mounting is when a male ani mounts the female and reverse mounting is when a female
ani mounts the male. This behavior is seen in the early nesting season and is thought
to be a courtship ritual between monogamous breeding pairs which motivates breeding.
Groove-billed anis have breeding groups consisting of 2 to 4 unrelated pairs of monogamous
breeding adults. They breed once a year from early May to late September. One female
will lay an average of 4 eggs in a colony nest with 3 to 4 breeding pairs, caring
for a total of 15 to 20 eggs per season.
Groove-billed ani chicks will hatch around 13 days after being laid. They start fledging
from 8 to 10 days after hatching and will become independent from their colony group
6 weeks after hatching. Just like other aves in the
Cuculidae
family, it is suggested that groove-billed anis reach sexual maturity at around 2
years of age.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- oviparous
Groove-billed anis have shared parental investment where the entire group of 3 to
4 mating pairs partake in taking care of the young. Both males and females invest
in taking care of all the young the groups have produced even if a breeding pair did
not breed for that season.
Groove-billed anis will continue to care for the young after fledging until the young
are able to disperse from their parental group. Young males more often stay with their
parental group for several breeding seasons and help with raising the breeding pairs’
offspring (altruism) until they go off and find a new colony of unrelated anis.
- Parental Investment
- altricial
- male parental care
- female parental care
-
pre-fertilization
- provisioning
-
protecting
- male
- female
-
pre-hatching/birth
-
provisioning
- male
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- male
- female
-
provisioning
-
pre-independence
-
provisioning
- male
- female
-
provisioning
- post-independence association with parents
Lifespan/Longevity
While not much research is done on how long a groove-billed ani lives in the wild,
it is suggested that they live from 15 to 20 years due to having a similar lifestyle
and physiology to the greater ani (
Crotophaga ani
).
Behavior
Groove-billed anis are social birds that live in groups of 3 to 4 breeding pairs.
They will raise young together as a group by laying all of their eggs in one nest
and sharing parental care. They will forage for food with their colony and protect
each other in the presence of predators. Individual anis will change groups every
couple of years although the motive behind this behavior is unknown.
Groove-billed anis are diurnal birds. They have been witnessed basking in the morning,
perching on a branch with their wings outstretched.
Groove-billed anis are observed to have a commensalistic relationships with mammalian
species.
Home Range
Groove-billed anis will stay within a set territory year-round. The breeding pair
colony will work together to defend a territory for breeding and foraging.
Communication and Perception
Groove-billed anis live together in small groups of breeding adults. They are often
found on the ground or brush foraging for food. Adult anis will stay in their same
colony for several years before switching to another. Young males from broods are
more likely to stay in their family colony for longer than 6 weeks than young females
before moving on to a new colony.
Groove-billed ani calls consist of chirps and rattles. They will communicate the location
of food and the presence of predators. They can call together as a group to find more
or new members.
- Other Communication Modes
- choruses
Food Habits
Groove-billed anis are opportunistic omnivores, eating a varied diet from seeds and
grains, fruits, terrestrial insects, terrestrial arthropods, and small vertebrates.
Anis will forage along the floor or in low hanging branches/fences to ambush and capture
insects. This behavior is observed more during months when food is scarce.
Groove-billed anis have a commensal relationship with other species. This has been
seen with the giant anteater (
Myrmecophaga tridactyla
). As the anteater moves along the forest ground, anis will follow along and consume
the disturbed insects. Anis will also stay near livestock like domesticated cattle
(
Bos taurus
) and eat ticks and other pests on their flanks.
- Primary Diet
-
carnivore
- eats terrestrial vertebrates
- insectivore
- eats non-insect arthropods
- vermivore
- herbivore
- omnivore
- Animal Foods
- amphibians
- reptiles
- insects
- terrestrial non-insect arthropods
- terrestrial worms
- Plant Foods
- seeds, grains, and nuts
- fruit
Predation
Nest predation is common for ani eggs. About 50% of the eggs in the nest do not survive
due to mostly predation. When young anis still in the nest are disturbed by a predator,
they are known to drop to the forest floor and hide in nearby foliage. Adults are
known to group up and attack predators threatening nests by striking at the predator
repeatedly until it retreats.
Some known predators of the groove-billed ani are the spectral bat (
Vampyrum spectrum
) and the roadside hawk (
Rupornis magnirostris
). Many snake species are known to be nest predators for the anis. Parasites are also
a common threat for young and adults.
Ecosystem Roles
Groove-billed anis can disperse the seeds from the fruits they eat.
Groove-billed anis are observed to have a commensalistic (mutual) relationships with
other mammalian species.
- Ecosystem Impact
- disperses seeds
- Giant anteater ( Myrmecophaga tridactyla )
- Domestic cow ( Bos taurus )
Economic Importance for Humans: Positive
Groove-billed anis are good for species richness counts done by the Audubon society.
These counts cause ecotourism with birders in the areas that the anis are found.
- Positive Impacts
- ecotourism
- research and education
Economic Importance for Humans: Negative
Groove-billed anis are seen as crop pests for agricultural areas in Costa Rica. There
was mild damage done to crops like cucumbers, tomatoes, beans, and fruits.
- Negative Impacts
- crop pest
Conservation Status
Groove-billed ani populations are of least concern for conservation efforts. They
are protected under the US Migratory Bird Act.
Additional Links
Contributors
Amber Short (author), Texas State University, Tanya Dewey (editor), University of Michigan-Ann Arbor.
- Nearctic
-
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- Neotropical
-
living in the southern part of the New World. In other words, Central and South America.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- tropical savanna and grassland
-
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
- savanna
-
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
- temperate grassland
-
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- rainforest
-
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
- scrub forest
-
scrub forests develop in areas that experience dry seasons.
- marsh
-
marshes are wetland areas often dominated by grasses and reeds.
- suburban
-
living in residential areas on the outskirts of large cities or towns.
- agricultural
-
living in landscapes dominated by human agriculture.
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- monogamous
-
Having one mate at a time.
- cooperative breeder
-
helpers provide assistance in raising young that are not their own
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- altricial
-
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
- male parental care
-
parental care is carried out by males
- female parental care
-
parental care is carried out by females
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- social
-
associates with others of its species; forms social groups.
- colonial
-
used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.
- visual
-
uses sight to communicate
- acoustic
-
uses sound to communicate
- choruses
-
to jointly display, usually with sounds, at the same time as two or more other individuals of the same or different species
- ecotourism
-
humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.
- carnivore
-
an animal that mainly eats meat
- insectivore
-
An animal that eats mainly insects or spiders.
- herbivore
-
An animal that eats mainly plants or parts of plants.
- frugivore
-
an animal that mainly eats fruit
- granivore
-
an animal that mainly eats seeds
- omnivore
-
an animal that mainly eats all kinds of things, including plants and animals
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
References
Bowen, , R. Koford, Vehrencamp. 1989. Dispersal in the communally breeding groove-billed ani (Crotophaga sulcirostris). The Condor , 91: 52-64. Accessed March 03, 2025 at https://sora.unm.edu/sites/default/files/journals/condor/v091n01/p0052-p0064.pdf .
Bowen, B., R. Koford, S. Vehrencamp. 1991. Seasonal Pattern of Reverse Mounting in the Groove-Billed Ani (Crotophaga sulcirostris). The Condor , 93: 159-163. Accessed February 03, 2025 at https://www.jstor.org/stable/1368618?searchText=Crotophaga+sulcirostris&searchUri=%2Faction%2FdoBasicSearch%3FQuery%3DCrotophaga%2Bsulcirostris%26so%3Drel&ab_segments=0%2Fbasic_search_gsv2%2Fcontrol&refreqid=fastly-default%3Af6cee89e6eee3c1ef6241fd4fb9fe6d0&seq=2 .
Chavarria-DurÃaux, L., D. Hille. 2018. Birds of Nicaragua: A Field Guide . Zona Tropical Publications: Cornell University Press, Comstock Publishing Associates. Accessed February 04, 2025 at https://www.jstor.org/stable/10.7591/j.ctvrf89k9.8?searchText=Crotophaga+sulcirostris+wingspan&searchUri=%2Faction%2FdoBasicSearch%3FQuery%3DCrotophaga%2Bsulcirostris%2Bwingspan%26so%3Drel&ab_segments=0%2Fbasic_search_gsv2%2Fcontrol&refreqid=fastly-default%3A30c2e2d09bb77568e39ad2d2f9ba04b6&seq=36 .
Dunn, E., C. Francis, P. Blancher, S. Drennan, M. Howe, D. Lepage, C. Robbins, K. Rosenberg, J. Sauer, K. Smith. 2005. Enhancing the Scientific Value of the Christmas Bird Count. The Auk , 122: 338–346. Accessed March 04, 2025 at https://academic.oup.com/auk/article/122/1/338/5562476 .
Fernández-Ordóñez, J., C. Rivas, C. Morante. 2024. Foraging association of Groove-billed Anis with a Giant Anteater in Cojedes, Central-western Venezuelan Llanos. Food Webs , 40: e00358. Accessed February 03, 2025 at https://www.sciencedirect.com/science/article/abs/pii/S2352249624000247 .
Koford, R., B. Bowen, S. Vehrencamp. 1986. Habitat Saturation in Groove-Billed Anis (Crotophaga sulcirostris). The American Naturalist , 127: 317-337. Accessed January 28, 2025 at https://www.jstor.org/stable/2461403?searchText=Crotophaga+sulcirostris&searchUri=%2Faction%2FdoBasicSearch%3FQuery%3DCrotophaga%2Bsulcirostris%26so%3Drel%26efqs%3DeyJjdHkiOlsiYW05MWNtNWhiQT09Il19&ab_segments=0%2Fbasic_search_gsv2%2Fcontrol&refreqid=fastly-default%3A6386ac8b5f56dd08e18f57e005d09cfb&seq=1 .
Lefebvre, L. 2020. A global database of feeding innovations in birds. The Wilson Journal of Ornithology , 132: 803-809. Accessed January 29, 2025 at https://www.jstor.org/stable/27129748?searchText=Crotophaga+sulcirostris&searchUri=%2Faction%2FdoBasicSearch%3FQuery%3DCrotophaga%2Bsulcirostris%26so%3Dnew%26efqs%3DeyJjdHkiOlsiYW05MWNtNWhiQT09Il19&ab_segments=0%2Fbasic_search_gsv2%2Fcontrol&refreqid=fastly-default%3A1ba7ee1190a1459f415ab4f311d15b38&seq=1 .
Menezes, J., M. Marini. 2017. Predators of bird nests in the Neotropics: a review. Journal of Field Ornithology , 88: 99-114. Accessed January 29, 2025 at https://www.jstor.org/stable/44994041?searchText=Crotophaga+sulcirostris&searchUri=%2Faction%2FdoBasicSearch%3FQuery%3DCrotophaga%2Bsulcirostris%26so%3Dnew%26efqs%3DeyJjdHkiOlsiYW05MWNtNWhiQT09Il19%26pagemark%3DeyJwYWdlIjoyLCJzdGFydCI6MjUsInRvdGFsIjo1MDh9%26groupefq%3DWyJtcF9yZXNlYXJjaF9yZXBvcnRfcGFydCIsInNlYXJjaF9hcnRpY2xlIiwiY29udHJpYnV0ZWRfdGV4dCIsImNvbnRyaWJ1dGVkX2F1ZGlvIiwiY29udHJpYnV0ZWRfdmlkZW8iLCJyZXNlYXJjaF9yZXBvcnQiLCJyZXZpZXciLCJzZWFyY2hfY2hhcHRlciJd&ab_segments=0%2Fbasic_search_gsv2%2Fcontrol&refreqid=fastly-default%3Ae1ede4f65143953a3478c627b33e1732&seq=1 .
Rand, A. 1953. Factors Affecting Feeding Rates of Anis. The Auk , 70: 26-30. Accessed February 03, 2025 at https://www.jstor.org/stable/4081055?seq=2 .
Riehl, C., M. Strong. 2019. Social parasitism as an alternative reproductive tactic in a cooperatively breeding cuckoo. Nature , 567: 96-99. Accessed April 09, 2025 at http://nature.com/articles/s41586-019-0981-1 .
Skutch, A. 1959. Life History of the of the Groove-billed Ani. The Auk , 76: 281-317. Accessed February 01, 2025 at https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=17786&context=auk .
Smith, M., C. Riehl. 2020. Intermittent breeding is associated with breeding group turnover in a cooperatively breeding bird. Oecologia , 192: 953-963. Accessed January 29, 2025 at https://www.jstor.org/stable/48695915?searchText=Crotophaga+sulcirostris&searchUri=%2Faction%2FdoBasicSearch%3FQuery%3DCrotophaga%2Bsulcirostris%26so%3Dnew%26efqs%3DeyJjdHkiOlsiYW05MWNtNWhiQT09Il19&ab_segments=0%2Fbasic_search_gsv2%2Fcontrol&refreqid=fastly-default%3A1ba7ee1190a1459f415ab4f311d15b38&seq=1 .
Sánchez-Núñez, C., J. Monge-Meza. 2021. Birds' community and the damage they generate in agricultural production in Alajuela, Costa Rica. Costarricense , 46: 135-146. Accessed February 03, 2025 at https://www.scielo.sa.cr/scielo.php?pid=S0377-94242022000200135&script=sci_arttext&tlng=en .
Turner, R. 2021. Avian biodiversity of the Indian River Lagoon System, Florida. Florida Scientist , 84: 252-274. Accessed January 29, 2025 at https://www.jstor.org/stable/27091252?searchText=Crotophaga+sulcirostris&searchUri=%2Faction%2FdoBasicSearch%3FQuery%3DCrotophaga%2Bsulcirostris%26so%3Dnew%26efqs%3DeyJjdHkiOlsiYW05MWNtNWhiQT09Il19&ab_segments=0%2Fbasic_search_gsv2%2Fcontrol&refreqid=fastly-default%3A17e83d506da8c66c81d3b3d901856677&seq=1 .
Vaurie, C. 1957. Field Notes on Some Cuban Birds. The Wilson Bulletin , 69: 301-313. Accessed February 01, 2025 at https://www.jstor.org/stable/4158615?casa_token=2yGaeyrvfB0AAAAA%3AzOYTFWw9gjn7sJBwkhYKWpTkkD9fupswKfsFJmGBNABWyrj0qjYkTpBJyJPU87B8PnekgGGQdLYN5DOl3Cbo2RFKNoGZqcHjXNV6J1IYmGT2eKzLotu6&seq=1 .
Vehrencamp, S., Stiles, J. Bradbury. 1977. Observations on the Foraging Behavior and Avian Prey of the Neotropical Carnivorous Bat, Vampyrum spectrum. Journal of Mammology , 58: 469-478. Accessed March 04, 2025 at https://www.researchgate.net/publication/271802746_Observations_on_the_Foraging_Behavior_and_Avian_Prey_of_the_Neotropical_Carnivorous_Bat_Vampyrum_spectrum .
U.S. Fish & Wildlife Services. 2024. "Eastern North Carolina Red Wolf Population: Release Plan " (On-line pdf). Accessed April 10, 2025 at https://www.fws.gov/media/eastern-north-carolina-red-wolf-population-release-plan-2024-2025 .
U.S. Geological Survey (USGS). 2018. "Groove-billed Ani (Crotophaga sulcirostris) bGBANx_CONUS_2001v1 Habitat Map" (On-line). Gap Analysis Project (GAP). Accessed February 03, 2025 at https://www.sciencebase.gov/catalog/item/58fa4b26e4b0b7ea54524fb5 .
2021. "Groove-billed Ani" (On-line). IUCN Red List. Accessed April 10, 2025 at https://www.iucnredlist.org/species/22684438/188619408 .
2020. "Migratory Bird Treaty Act of 1918" (On-line). U.S. Fish & Wildlife Service Utility (Top) navigation About Us Laws & Regulations Library. Accessed April 10, 2025 at http://www.fws.gov/birds/policies-and-regulations/laws-legislations/migratory-bird-treaty-act.php .