Green kingfisher

Chloroceryle americana is a kingfisher of the family Alcedinidae, described by Gmelin in 1788 ^[1]. It is a bird of rivers, streams and lagoons ranging from the southern United States to central Argentina ^[2], and on the coast of Peru it has been recorded in wetlands such as those of Eten, in Lambayeque, and Pantanos de Villa, in Lima ^[3],[4]. The IUCN Red List classifies it as Least Concern ^[5].

The sexes differ on the breast: the male has a white throat and collar and, below them, a rufous chestnut breast, whereas the female shows a double green collar on the breast ^[2]. The bill is stout and black, with the base of its lower half dark grey ^[2].

It is the smallest of the 3 most common kingfishers of the Brazilian Pantanal, which share its temporary ponds: it measures about 21.8 cm in length, against about 29.5 cm for Chloroceryle amazona and about 39.6 cm for Megaceryle torquata ^[6]. In the functional-trait database used to characterise the birds of Peru's coastal wetlands, its body mass is 33.7 g, while that of Megaceryle torquata is 317 g ^[7].

Similar species

• Megaceryle torquata: It is much larger: about 39.6 cm long against about 21.8 cm ^[6].
• Chloroceryle amazona: It is larger, about 29.5 cm long against about 21.8 cm ^[6].

Its range runs from the southern United States to central Argentina, where it reaches the provinces of Buenos Aires, Córdoba, San Luis and Mendoza ^[2]. It frequents humid forests and the banks of rivers, streams, pools, ditches and lagoons, as well as marshes ^[2].

On the coast of Peru it lives in wetlands. At Eten, in Lambayeque, it appears in the bird list compiled from observations made from 1978 to 2009, associated with the wetland habitat ^[3]. At Pantanos de Villa, in Lima, it is classed as a resident that does not breed at Villa but in other areas of the Peruvian coast ^[4]. Further north, it is on the bird list of the Santuario Nacional Los Manglares de Tumbes ^[8].

A literature review of 12 coastal wetlands of Peru recorded it at 3 of them: the San Pedro de Vice mangroves, the Eten wetland and Pantanos de Villa ^[7]. In the trait database that study used, its main habitat is riverine ^[7].

Its karyotype was described in 2018 from 3 birds, 2 males and 1 female, from Santa Maria, in southern Brazil: it has 94 chromosomes (2n = 94), and only 4 of its pairs have 2 arms, while all the others are telocentric ^[9]. The Z sex chromosome is the largest of the whole set ^[9]. In the same work Megaceryle torquata had 2n = 84, and the authors suggest that the higher number in this species arose because some large chromosomes split in 2 at the centromere ^[9].

In Pre-Delta National Park, in Entre Ríos, Argentina, an adult male with a deformed bill was observed and photographed on 24 December 2015: the upper half curved to the left from about the middle of its length and the tips of the two halves stood about 70° apart ^[2]. Even so, its plumage was in good condition and it was alert and active; the authors link the rarity of such deformities in kingfishers to their catching fish with the bill, which probably exerts strong selection against them ^[2].

It is a carnivorous bird that hunts in water: in the trait database used by the study of Peru's coastal wetlands it is classed as an aquatic predator ^[7]. In the Pantanal it feeds mainly on fish in shallow water, and at times on terrestrial and aquatic arthropods and even lizards ^[6].

At those ponds, perches let kingfishers spot their prey and prepare the attack from some height ^[6]. In September 2018, during the dry season, kingfisher perches were studied at 13 temporary ponds in the Pantanal of Miranda, Brazil: the 5 birds of this species always sat on natural perches, on average 1.38 m high and always below 5 m, lower than Megaceryle torquata, whose perches averaged 4.08 m ^[6].

At Pantanos de Villa it uses the cattail beds as perches from which it fishes ^[4].

Its global category on the IUCN Red List is Least Concern ^[5]. The bird list of the Santuario Nacional Los Manglares de Tumbes assigns it no threat category under Supreme Decree N.° 004-2014-MINAGRI ^[8].

At Pantanos de Villa its population is small and is affected because the cattail beds it uses for fishing are shrinking ^[4]. At the Eten wetlands, the problems noted for the area are uncontrolled hunting, rubbish, livestock and the spread of farming, and the authors proposed that those wetlands be given formal protection by the regional government of Lambayeque ^[3].

At Pantanos de Villa, in Lima, it is rated scarce, meaning seen with some regularity or a few times a year, is usually seen alone or occasionally in small groups, and is recorded by sources dated from 1994 to 2017 ^[4]. It also appears on the bird list of the Eten wetlands, in Lambayeque, compiled from observations made from 1978 to 2009 ^[3], and on that of the Santuario Nacional Los Manglares de Tumbes ^[8].