The objective of the present study was to find the presence of coccidia in passerine birds in the La

Loma de Santa María Protected Natural Area, Michoacán, Mexico. Non-sporulated coccidial oocysts

were found in passerine birds in that locality. A total of 61 birds were captured during three field

(Melozone kieneri)1; Black and white warbler (Mniotilta varia)3; Brown-backed Solitaire (Myadestes

occidentalis)1; Slate-colored Solitaire (Myadestes unicolor)2; Yellow-tailed grackle (Quiscalus

mexicanus)7; Yellow-rumped Warbler (Setophaga coronata)1; Plumbeous Vireo (Vireo plumbeus);1.

This is the first study to examine passerine birds from Michoacán.

coccidios no esporulados en aves paseriformes, en esa localidad. Se capturaron un total de 61 aves

durante tres muestreos de campo desde diciembre de 2022 hasta abril de 2023, obteniendo muestras

de heces que fueron examinadas. Un total de muestras examinadas fueron 39 positivas a ooquistes de

coccidios no esporulados. Las especies de aves muestreadas fueron: Reinita Roja (Cardellina rubra)1

Zorzal Ruisset Russet (Catharus occidentalis)1; Papamoscas Cordillerano (Empidonax occidentalis)2;

Eufonía de garganta amarilla (Euphonia hirundinacea)1; Pinzón común (Haemorhous mexicanus)1;

Reinita de Nashville (Leiothlypis ruficapilla)1; Sinsonte azul (Melanotis caerulescens)6; Gorrión de

Lincoln (Melospiza lincolnii)4; Gorrión de tierra corona oxidada (Melozone kieneri)1; Reinita blanca y

negra (Mniotilta varia )3; Solitario de lomo marrón (Myadestes occidentalis)1; Solitario de color

pizarra (Myadestes unicolor)2; Zanate de cola amarilla (Quiscalus mexicanus)7; Reinita rabadilla

Artículo recibido 27 junio 2024

Protozoa parasites of the genera Eimeria or Isospora infect avian species. In diseased birds, signs may

include diarrhea, fever, inappetence, weight loss and emaciation (SEMARNAT 2016; Villaseñor

2005). Nevertheless, many infections are subclinical (Constable 2014). Other vertebrates can be

parasitized with coccidia, being Isospora Schneider 1881, considered the genus most important,

before the genus Eimeria Schneider 1875 (Pereira et al. 2011).

Michoacan State are unknown. Hence the aim this present study was the identification of the presence

of coccidia oocysts in passerines birds from the La Loma de Santa Maria Protected Natural Area,

Michoacan, Mexico.

Sixty-two passerines were caught with six mist nets (19°40´41´´ N; 101°10´23´´ W), on and

longitudinal gradient ranging from 1,920 to 2,390 (m a.l.s.) (Chávez, 1993) from October 2022 to

April 2023, the mist nets were placed in the first 7 hours after dawn for three days followed for visit,

with sufficient distance between them so as not to interfere with the capture and in its manipulation.

The birds were withdrawing from the nets and placed in cotton bags designed for this activity, after

defecation were released, the stool samples, were processed by the technique of direct observation,

The 62 stool samples, were processed periodically according to corresponding field sampling within

12 hours after the collection (Ralph and Sauer 1995). Positive results to unsporulated coccidia oocysts

were found in 39 samples, however they were all kept refrigerated at 7°C, and processed again (all at

the same time) to confirm their absolute positivity (Rodríguez and Cob 2005). The second processing

of the samples was carried out in Centro de Investigación y Estudios Avanzados en Salud Animal

(CIESA). A total of 39 of them positive to unsporulated coccidia oocysts; Red Warbler (Cardellina

mexicanus) (7); Yellow-rumped Warbler (Setophaga coronata) (1); Curve-billed Trasher (Toxostoma

curvirostre) (3); Warbling Vireo (Vireo gilvus) (1) and Plumbeous Vireo (V. plumbeus) (1),that

represent the 62% of positivity of the total simples obtained in that period.

63% of the birds studied were positive to unsporulated coccidia oocysts, significant results because of

61 birds captured, 39 were positive, representing more than 50% of parasitized passerine birds of the

presence of these unicellular parasites in four endemic birds; Red Warbler (Cardellina rubra); Russet

Nightingale-Thrush (Catharus occidentalis); Blue Mockingbird (Melanotis caerulescens); Rusty-

crowned Ground-Sparrow (Melozone kieneri) (Berlanga et al. 2020). The difficult to detect and study

keywords (in Spanish, English, and Latin): coccidia, coccidiosis, oocyst, oocysts, oocisto, oocistos,

Eimeria, Isospora, ave, aves, pájaro, pájaros, bird, birds, passerine, Passeriformes, Mexico, in the

most popular databases (e.g. Web of Knowledge, PubMed, Searchable Ornithological Research

Archive, Scopus, SciELO, Redalyc). Some studies were found on the presence of coccidia in

passerines in the State of Mexico, which was useful to strengthen the present study. A publication on

coccidia in wild passerines from the Americas was also found but did not show records for Mexico

(Pereira and Lopes 2013). Therefore, our study appears to provide the first evidence of the presence of

We acknowledge the Comite of Protected Areas in Michoacan for the facilities provided to carry out

this study, to the parasitology area of the FMVZ-UMSNH for immediate sample processing, to the

Benito Juárez de Michoacan zoological park for their support in the field work, to CIESA-FMVZ-

UAEM project 5000/2020CIB and Consejo Nacional de Ciencia y Tecnología (CONACYT), we also

acknowledge the iBird International.

1. Berlanga, H., Gómez de Silva, H., Vargas-Canales, V.M., Rodríguez-Contreras, V., Chávez

3. Fair J.M., Paul E, Jones J., Barrett C.A., Davi C., Kaiser G. (2010) Guía para la utilización de

4. Gobierno Constitucional del Estado de Michoacán de Ocampo. (2009) Decreto por el que se

7. Ohlson L.I., Irestedt M., Ericson P.G.P., Fjeldså J. (2013). Phylogeny and classification of the

8. Pereira Berto, B. and Gomes Lopes, C.W. (2013). Distribution and dispersion of coccidia in

9. Pereira Berto, B., Gomes Lopes, W., McIntosh, D., Teixeira-Filho, W.L. and Lopes Carlos,

11. Rodríguez V.R.I and Cob G.L.A. (2005) Técnicas diagnósticas en parasitología veterinaria

12. Sánchez-González, L.A. Ortega-Álvarez, R y Calderón-Parra, R. (2021). Aves de México

13. SEMARNAT (Secretaria de Medio Ambiente y Recursos Naturales). (2016). Licencia de