Cardinalidae

Cardinalidae (sometimes referred to as "cardinal-grosbeaks" or simply "cardinals") is a family of New World-endemic passerine birds that consists of cardinals, grosbeaks, and buntings. It also includes several other genera such as the tanager-like ''Piranga'' and the warbler-like '' Granatellus''. Membership of this family is not easily defined by a single or even a set of physical characteristics, but instead by molecular work. Among songbirds, they range from average-sized to relatively large, and have stout features. Some species have large, heavy bills.

Members of this group are beloved for their brilliant red, yellow, or blue plumages seen in many of the breeding males in this family. Most species are monogamous breeders that nest in open-cup nests, with parents taking turns incubating the eggs and taking care of their young. Most are arboreal species, although the dickcissel (''Spiza americana'') is a ground-dwelling prairie bird.

In terms of conservation, most members of this family are considered least concern by the IUCN Red List, though a few birds, such as the Carrizal seedeater (''Amaurospiza carrizalensis''), are considered endangered.

Field characteristics

The grosbeaks, seedeaters, and cardinals have large bills, while ''Granatellus'' and buntings have small bills. The ''cardinalid'' tanagers have stout, near pointed bills, with some species of ''Piranga'' having serrations along the edge of their upper bills. Bill shape is not always an indicator of species' relationships, however, as the various species of blue ''cardinalid'' species, like the blue grosbeak (''Passerina caerulea'') and ''Cyanoloxia'' grosbeaks are related to the buntings. Similarly, the ''cardinalid'' tanagers are closer to the cardinals and masked grosbeaks (see more in the systematics section). The head is medium to large in size, with a medium neck length. ''Cardinalid'' species bodies ranges from small to medium with lengths of 11 to 28 cm (4.5 to 11 in). Legs are also short to medium in length. The wings are medium and pointed. ''Cardinalids'' have nine visible primary feathers with the tenth primary feather short in comparison to the others.

The plumages in ''cardinalids'' are sexually dichromatic, as in many species, the males are bright red, orange, blue, or black. In most temperate species, however, males molt between seasons, such that non-breeding males will somewhat resemble the females of their species. These species, such as the indigo bunting (''Passerina cyanea'') exhibit a complex molt cycle going through four different stages of plumage within their first year of life. From spring to summer, birds start with juvenile plumage to supplemental plumage, then changing to a first basic (non-breeding) plumage from fall to winter, and finally reaching the first alternate (breeding) plumage. Adults will typically have the basic two molt cycle changing to basic or partial in the late summer or fall, and then back to alternate again in the spring. Males of tropical species retain the same coloration year-round. Females of all species are drabber in coloration, and are often a lighter coloration of the males.

The molting pattern in most ''cardinalids'' exhibits delayed plumage maturation, so that first-year male birds are in non-breeding plumage or an intermediate state. The molting pattern in ''cardinalids'' is divided into two types. A preformative molt is a partial molt where only the body feathers get replaced, but not the wing and tail feathers, which is seen in a lot of temperate and neotropical species. The second type is an eccentric preformative molt, in which only the outer primary and inner secondary feathers are replaced. This molt is seen in some species of '' Cyanoloxia'' and ''Passerina''.

Systematics

Traditionally, members of this group were classified as a tribe of the finch family Fringillidae (Cardinalini), characterized by heavy, conical, seed-crushing bills. The group consisted of the genera '' Pheucticus'', '' Parkerthraustes'', '' Saltator'', '' Spiza'', '' Cyanocompsa'', ''Cyanoloxia'', '' Porphyrospiza'', ''Passerina'', '' Caryothraustes'', '' Periporphyrus'', and ''Cardinalis''. The issue that taxonomists had faced was that there were no unifying morphological traits that were in agreement for various studies. In 2007, a mitochondrial DNA study by Klicka, Burns and Spellman sampling all of the aforementioned genera and 34 of the total 42 species, found that the genera ''Parkerthraustes'', ''Saltator'', and ''Porphyrospiza'' were not members of the cardinal-lineage, but instead are found throughout in the tanager-lineage (Thraupidae). The genera classified as thraupids at the time, ''Piranga'', '' Habia'', '' Chlorothraupis'', and '' Amaurospiza'', are found to be part of cardinalid radiation. In addition the genus '' Granatellus'', originally classified as a parulid warbler, are also found to be part of Cardinalidae. The study found that with this new relationship ''Cardinalidae'' can be classified into six subgroups, which have been supported by subsequent studies. The six subclades consists of the ''Pheucticus'' lineage, the ''Granatellus'' lineage, the “blue” lineage (''Spiza'', ''Cyanoloxia'', ''Amaurospiza'', ''Cyanocompsa'', and ''Passerina''), the ''Habia'' lineage (''Habia'' and ''Chlorothraupis''), the “masked” lineage (''Caryothraustes'', ''Periporphyrus'', and ''Cardinalis''), and the ''Piranga'' lineage (''Piranga'' and ''Driophlox''). These subclades and membership of these genera have been widely supported in subsequent studies. A 2021 paper by Guallar et al. based on the preformative molting pattern of cardinalids suggested the ancestor of this group was a forest-dwelling bird that dispersed into open habitats on numerous occasions.

The ''cardinalids'' are part of a larger grouping of American endemic songbirds, Emberizoidea, which also includes the aforementioned ''thraupids'' and ''parulids'', as well as ''icterids'' (New World blackbirds), ''passerellids'' (New World sparrows), and several smaller families that contain one or a couple of genera. Several studies have placed ''cardinalids'' as either the sister group to ''Thraupidae'', ''Mitrospingidae'' (a small family whose genera were formerly classified as ''thraupids''), or as a sister to a clade containing ''thraupids'' and ''mitrospingids''. At least one study suggested that ''cardinalids'' could be treated as a subfamily of ''Thraupidae''.

Phylogeny

The genus level cladogram of the Cardinalidae shown below is based on molecular phylogenetic study published in 2024 which analyzed DNA sequences flanking ultraconserved elements (UCEs). The number of species in each genus is taken from the list maintained by Frank Gill, Pamela C. Rasmussen and David Donsker on behalf of the International Ornithological Committee (IOC).

Species list

The following 53 species and 14 genera are recognized by the IOC as of July 2024:

Natural history

Habitat, distribution and migration

The ''cardinalids'' can be found from Canada to northern Argentina and Uruguay, with Central America having the largest concentration of species. Species are found year-around in the Central United States and the Eastern United States down to the neotropics. Cardinalids found in the West Indies are non-breeding migrants and those in the Western United States and Canada are breeding migrants. The western tanager (''Piranga ludoviciana'') is the northernmost species in the family; their breeding ranges occur in southern portions of the Northwest Territories. The northern cardinal (''Cardinalis cardinalis'') has been introduced in Hawaii and Bermuda. They occupy a variety of habitats from forests to grassland and arid scrubland. Most North American ''cardinalid'' species migrate south for the winter, whether further south in the continent or extending into the neotropics, except the northern cardinal and pyrrhuloxia which stay year-round. The neotropical species are residential year-round in their range.

Feeding ecology

Cardinals, the dickcissel, seedeaters, buntings, and grosbeaks have the thicker, seed-crushing bills that enabled them to feed heavily on fruits and seeds outside of the breeding season (especially in the winter for northern species like the aforementioned dickcissel and northern cardinal). Once their breeding season begins, members of this group will supplement themselves with invertebrate prey, vital when raising their young and refueling the energetic costs of reproduction and other daily activities. The genera ''Chlorothraupis'', ''Habia'', ''Piranga'', and ''Granatellus'' have slightly longer and less deep bills, which their diet mostly consists of insects, fruit, nectar and sap, less so on seeds. ''Cardinalids'' typically forage alone low level or on the ground, though some like ''Piranga'' and grosbeaks will forage high in the tree canopy. Many will come to bird feeders, especially during the winter.

Breeding and reproduction

Nearly all ''cardinalids'' are monogamous breeders, and are highly territorial. Most species are monogamous during the breeding season, and each year birds may find different partners. The only exception is the dickcissel which is a polygynous species which nest in dense grasses and sedges. Other non-monogamous species include the lazuli and painted buntings which perform extra-copulation with multiple partners. The family is known for their intense brilliant songs. In some species like the lazuli bunting and indigo bunting the bird learn singing by match-based, meaning that first year breeding males will learn by copying the songs of nearby males, as opposed of learning it while they are in the nest. Even more unusual is the females of a few species, such as the scarlet tanager, northern cardinal, pyrrhuloxia, and black-headed grosbeak, which sing as well. In temperate species the breeding season occurs annually, while in tropical species it is year-around. The breeding seasons are in sync with the abundance of insects. Most species build open-cup nests made of grasses and twigs depending on the species. These nests would be in the trees, often high up in the crown. The nest building is done by both partners or by the female alone. The male and female take turns incubating the nest, often the male would feed the female. A clutch averages one to six eggs, with tropical species laying the fewest. ''Cardinalids'' produce one to three broods per season. As with other passerines, the young are born altricial and fledged between one and two weeks.

Conservation

As of 2021, the IUCN Red List has nearly 82 percent of cardinalids to be least concern. However, there are a handful of species that are of conservation concern. The rose-bellied bunting is an endemic near-threatened species as they are found in a small area of Oaxaca and Chiapas, Mexico; the black-cheeked ant-tanager is another endemic species found in Osa Peninsula in Costa Rica and the carrizal seedeater a critically endangered species found in the spiny bamboo thickets in the understory of deciduous forest in a remote southeastern corner of Venezuela. All of these species are threatened with habitat loss and the confinement within their much smaller range. The IUCN has not yet reevaluate the other species of seedeaters in the genus ''Amaurospiza''.

Despite the vast majority of species being classified as least concern, there is growing recognition that the climate crisis may impact the distribution and migration of many ''cardinalid'' species. One study led by Dr. Brooke L. Bateman, published in July 2020, focused on the risk North American birds will face from climate change, as well as the measures required to protect them. The first study assessed 604 species from the United States, and found that if the planet warmed by 3.0 degrees Celsius many species, especially arctic birds, waterbirds, and boreal and western forest birds, will be highly vulnerable to climate change and future conservation efforts will need to be in place. Among the species sampled, the North American species of ''Piranga'' and ''Pheucticus'' are found to be most climate vulnerable of the ''cardinalids''. These species will either lose an substantial amount of their range or they will migrate north to escape the sudden change in their habitat.

A possible extinct species is the controversial Townsend's bunting (''Spiza townsendi''), a supposed enigmatic species related to the dickcissel. The Townsend's bunting is only known from a single type specimen collected from Chester County, Pennsylvania by John Kirk Townsend and described by John James Audubon in 1834. The specimen is housed in the National Museum of Natural History. Genetic analysis has not been done on this specimen, but study of the plumage has been conducted. Researchers are unsure about the specimen's status as an extinct species, a rare color-variant of the dickcissel, or a hybrid (of a female dickcissel and male blue grossbeak). If the bird is indeed a dickcissel, however, it lacks any of the known field characteristics seen in the species in all its life stages and sexes.

References

External links

Cardinalidae videos, photos and sounds
on the Internet Bird Collection
Cardinalidae sounds
on xeno-canto.org
Northern cardinal (bird information)
on petinfospot.com
Northern cardinal
including sound and video clips, on Cornell Lab of Ornithology

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Bird families

Birds of the Americas
Taxa named by Robert Ridgway