Influencia de la intensidad de pastoreo sobre ensambles de aves en espartillares de la Bahía de Samborombón, Argentina

Mariano  Codesido; David Bilenca

doi:10.56178/eh.v36i1.427

Articles Published 01 August 2021 https://doi.org/10.56178/eh.v36i1.427

Influence of grazing intensity on avian assemblages in espartillares of Samborombón Bay, Argentina

Cistothorus platensis ecorregión Pampeana ganado vacuno pastizales Spartina densiflora Spartonoica maluroides

Mariano Codesido Grupo de Estudios sobre Biodiversidad en Agroecosistemas. Departamento de Biodiversidad y Biología Experimental, Facul-tad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II Ciudad Universitaria, 1428 Ciudad Autónoma de Buenos Aires, Argentina | Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II Ciudad Universitaria, 1428 Ciudad Autónoma de Buenos Aires, Argentina

David Bilenca Grupo de Estudios sobre Biodiversidad en Agroecosistemas. Departamento de Biodiversidad y Biología Experimental, Facul-tad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II Ciudad Universitaria, 1428 Ciudad Autónoma de Buenos Aires, Argentina | Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II Ciudad Universitaria, 1428 Ciudad Autónoma de Buenos Aires, Argentina

Abstract

Changes in the structure of grasslands have been responsible for the decline of several avian species due to the reduction in the quality of available habitat. In the Flooding Pampas (Argentina), espartillares of Spartina densiflora are marginally productive areas for cattle rearing and show great variation in the intensity of their use by ranchers as grazing areas. In this work we compare the responses in abundance and richness of avifauna in espartillares with different stocking rates in the Samborombón Bay area. Our treatments were: 1) plots with low stocking rate (0.4 cows/ha), and 2) plots with high stocking rate (0.8 cows/ha). Our study covered three periods of the birds’ breeding cycle (early, late, post-reproduction) over two years (2011/2012, 2012/2013). The sites with high livestock rate had greater vegetation coverage in the stratum lower than 11cm and lower height with respect to the sites with low livestock loads. Species richness and total abundance of birds were 23% and 29.5% lower, respectively, in grasslands with high livestock rates. Also, species richness and abundance of tall grassland species were 60% and 61% lower, respectively, in grasslands with high livestock rates. High stocking grazing substantially affects the abundances of tall grass specialist species such as the Bay-capped Wren-spinetail (Spartonoica maluroides) and the Sedge Wren (Cistothorus platensis). We encourage to preserve espartillares with high structure (> 70 cm) and dense vegetation, keeping some paddocks or paddock areas in rest/exclusion, instead of a general adjustment of the animal stocking rates for the entire establishment.

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References

Agra M, Bilenca DN y Codesido M (2015) Responses of birds to planting of Lotus tenuis pasture in the Flooding Pampas, Argentina. Emu 115:270-276.
Aizen MA, Garibaldi LA y Dondo M (2009) Expansión de la soja y diversidad de la agricultura argentina. Ecología Austral 19:45-54.
Askins RA, Chávez-Ramírez F, Dale BC, Haas CA, Herkert JR, Knopf FL y Vickery PD (2007) Conservation of grassland birds in North America: understanding ecological processes in different regions. Ornithological Monographs 64:1-46.
Azpiroz AB, Isacch JP, Dias RA, Di Giacomo AS, Fontana CS y Palarea CM (2012) Ecology and conservation of grassland birds in southeastern South America: a review. Journal of Field Ornithology 83:217-246.
Bibby CJ, Burgess N, Hill D y Mustoe S (2000) Bird Census Techniques. Academic Press, San Diego.
Bilenca D, Codesido M, Abba A, Corriale M, González-Fischer C, Pérez Carusi L y Zufiaurre E (2018) Conservación de la biodiversidad en sistemas pastoriles. Buenas prácticas para una ganadería sustentable de pastizal. Kit de extensión para las Pampas y Campos. Fundación Vida Silvestre Argentina, Buenos Aires.
Bilenca D y Miñarro FO (2004) Identificación de áreas valiosas de pastizal (IVPs) en las pampas y campos de Argentina, Uruguay y sur de Brasil. Fundación Vida Silvestre Argentina, Buenos Aires.
Biondini ME, Patton BD y Nyren PE (1998) Grazing intensity and ecosystem processes in a northern mixed-grass prairie, USA. Ecological Applications 8:469-479.
BirdLife International (2020a) Species factsheet: Porzana spiloptera. URL: http://datazone.birdlife.org/species/factsheet/dot-winged-crake-laterallus-spilopterus.
BirdLife International (2020b) Species factsheet: Spartonoica maluroides. URL: http://datazone.birdlife.org/species/factsheet/bay-capped-wren-spinetail-spartonoica-maluroides.
Brandolin PG, Blendinger PG y Cantero JJ (2016) From relict saline wetlands to new ecosystems: changes in bird assemblages. Ardeola 63:329-348.
Brooks ME, Kristensen K, van Benthem KJ, Magnusson A, Berg CW, Nielsen A, Skaug HJ, Maechler M y Bolker BM (2017) glmmTMB balances speed and flexibility among packages for zero-inflated generalized linear mixed modeling. The R Journal 9:378-400.
Cardoni DA, Greenberg R, Maldonado JE y Isacch JP (2013) Morphological adaptation to coastal marshes in spite of limited genetic structure in the Neotropical passerine Spartonoica maluroides (Aves: Furnariidae). Biological Journal of the Linnean Society 109:78-91.
Cardoni DA, Isacch JP y Iribarne O (2012) Effects of cattle grazing and fire on the abundance, habitat selection, and nesting of the Bay-capped Wren-spinetail (Spartonoica maluroides) in coastal saltmarshes of the Pampa region. Condor 114:1-9.
Cardoni DA, Isacch JP y Iribarne O (2015) Avian responses to varying intensity of cattle production in Spartina densiflora saltmarshes of South-Eastern South America. Emu 115:12-19.
Coconier E (2007) Bahía de Samborombón y Punta Rasa. Áreas importantes para la conservación de las aves en Argentina. Aves Argentinas/Asociación Ornitológica del Plata, Buenos Aires.
Codesido M y Fraga RM (2009) Distributions of threatened grassland passerines of Paraguay, Argentina and Uruguay, with new locality records and notes on their natural history and habitat. Ornitologia Neotropical 20:585-595.
Codesido M, González-Fischer CM y Bilenca DN (2011) Distributional changes of landbird species in agroecosystems of central Argentina. Condor 113:266-273.
Comparatore VM, Martínez MM, Vasallo AI, Barg M y Isacch JP (1996) Abundancia y relaciones con el hábitat de aves y mamíferos en pastizales de Paspalum quadrifarium manejados con fuego (Prov. de Buenos Aires, Argentina). Interciencia 21:228-237.
Di Bella CE, Rodríguez AM, Jacobo E, Golluscio RA y Taboada MA (2015) Impact of cattle grazing on temperate coastal salt marsh soils. Soil Use and Management 31:299-307.
Fernández GJ, Beade MS, Pujol EM y Mermoz ME (2004) Plan de manejo de la Reserva de Vida Silvestre “Campos del Tuyú”. Fundación Vida Silvestre Argentina, Buenos Aires.
Fisher R y Davis SK (2010) From Wiens to Robel: A review of grassland-bird habitat selection. Journal of Wildlife Management 74:265-273.
Fraga RM (2003) Distribution, natural history and conservation of the Black-and-white Monjita (Heteroxolmis dominicana) in Argentina, a species vulnerable to extinction. Ornitología Neotropical 14:145-156.
Gillen RL, Eckroat JA y McCollum FT (2000) Vegetation response to stocking rate in southern mixed-grass prairie. Journal of Range Management 53:471-478.
Goriup PD (1988) Ecology and conservation of grassland birds. International Council for Bird Preservation, Cambridge.
Isacch JP, Costa CSB, Rodríguez-Gallego L, Conde D, Escapa M, Gagliardini DA y Iribarne O (2006) Distribution of saltmarsh plant communities associated with environmental factors along a latitudinal gradient on the south-west Atlantic coast. Journal of Biogeography 33:888-900.
Isacch JP y Cardoni DA (2011) Different grazing strategies are necessary to conserve endangered grassland birds in short and tall salty grasslands of the flooding Pampas. Condor 113:724-734.
Isacch JP y Martínez MM (2001) Estacionalidad y relaciones con la estructura del hábitat de la comunidad de aves de pastizales de paja colorada (Paspalum quadrifarium) manejados con fuego en la provincia de Buenos Aires, Argentina. Ornitología Neotropical 12:345-354.
Jacobo E y Rodríguez A (2012) Manejo de pastizales naturales para una ganadería sustentable en la Pampa Deprimida: buenas prácticas para una ganadería sustentable de pastizal. Fundación Vida Silvestre Argentina/Aves Argentinas, Buenos Aires.
Lanctot RB, Blanco DE, Dias RA, Isacch JP, Gill VA, Almeida JB, Delhey K, Petracci PF, Bencke GA y Balbueno R (2002) Conservation status of the Buff-breasted Sandpiper: Historic and contemporary distribution and abundance in South America. Wilson Bulletin 114:44-72.
Marino GD (2008) Buenas prácticas ganaderas para conservar la vida silvestre de las pampas. Una guía para optimizar la producción y conservar la biodiversidad de los pastizales de la Bahía Samborombón y la cuenca del Río Salado. Aves Argentinas AOP, Buenos Aires.
Matteucci SD y Colma A (1982) Metodología para el estudio de la vegetación. OEA, Washington DC.
R Core Team (2020) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Viena. (URL: http://www.R-project.org/)
Reed MS (2008) Stakeholder participation for environmental management: a literature review. Biological Conservation 141:2417-2431.
Remsen Jr. J, Areta JI, Bonaccorso E, Claramunt S, Jaramillo A, Pacheco J, Ribas C, Robbins M, Stiles F, Stotz D y Zimmer K (2020) A classification of the bird species of South America. American Ornithologists’ Union, Washington DC. (URL: [http://www.museum.lsu.edu/∼530 Remsen/SACCBaseline.htm](http://www.museum.lsu.edu/∼530 Remsen/SACCBaseline.htm))
Rodríguez A y Jacobo E (2010) Glyphosate effects on floristic composition and species diversity in the Flooding Pampa grassland (Argentina). Agriculture, Ecosystem and Environment 138:222-231.
Roitman G y Preliasco P (2012) Guía de reconocimiento de herbáceas de la Pampa deprimida: características para su manejo: buenas prácticas para una ganadería sustentable de pastizal: kit de extensión para las pampas y campos. Fundación Vida Silvestre Argentina/Aves Argentinas, Buenos Aires.
Rotenberry JT y Wiens JA (1980) Habitat structure, patchiness, and avian communities in North American steppe vegetation: A multivariate analysis. Ecology 61:1228-1250.
Sala OE, Osterheld M, León RJC y Soriano A (1986) Grazing effects upon plant community structure in subhumid grasslands of Argentina. Vegetatio 67:27-32.
Sliwinski MS y Koper N (2015) Managing mixed-grass prairies for songbirds using variable cattle stocking rates. Rangeland Ecology and Management 68:470-475.
Soriano A, León RJC, Sala OE, Lavado RS, Deregibus VA, Cauhepé MA, Scaglia OA, Velázquez CA y Lemcoff JH (1991) Río de la Plata grasslands. Ecosystems of the world, Volume 8A. Natural grasslands: introduction and Western Hemisphere. Elsevier, Amsterdam, pp. 367-407.
Vaccaro AS, Dodyk L, Lapido R, De Miguel A y Grilli P (2020) ¿Cómo contribuye la alianza del pastizal a la conservación de las aves en la pampa deprimida? Hornero 35:95-109.
Vervoorst FB (1967) Las comunidades vegetales de la Depresión del Salado (provincia de Buenos Aires). Instituto Nacional de Tecnología Agropecuaria, Buenos Aires.
Vickery JA, Tallowin JR, Feber RE, Asteraki EJ, Atkinson PW, Fuller RJ y Brown VK (2001) The management of lowland neutral grasslands in Britain: effects of agricultural practices on birds and their food resources. Journal of Applied Ecology 38:647-664.
Viglizzo EF, Frank F, Carreño LV, Jobbágy EG, Pereyra H, Clattz J, Pincén D y Ricardz MF (2011) Ecological and environmental footprint of 50 years of agricultural expansion in Argentina. Global Change Biology 17:959-973.
Zar JH (1996) Biostatistical analysis. Tercera edición. Prentice Hall, Upper Saddle River.
Zufiaurre E, Codesido M, Abba A y Bilenca D (2016) Uso diferencial de lotes agrícolas y ganaderos por aves terrestres en la región pampeana, Argentina. Hornero 31:41-52.
Zufiaurre E, Codesido M, Abba A y Bilenca D (2017) The seasonal role of field characteristics on seed-eating bird abundances in agricultural landscapes. Current Zoology 63:279-286.
Zufiaurre E, Codesido M, González Fischer C, Abba A y Bilenca D (2019) Landbird assemblages in temperate agroecosystems: analyses at plot and landscape scales. Ornithological Science 18:69-79.
Zuur AF, Ieno EN, Walker N, Saveliev AA y Smith GM (2009) Mixed Effects Models and Extensions in Ecology With R, Statistics for Biology and Health. Springer, New York.

How to cite

Mariano Codesido, David Bilenca (2021). Influence of grazing intensity on avian assemblages in espartillares of Samborombón Bay, Argentina. El Hornero, Vol. 36 No. 1 (2021), 27-38. https://doi.org/10.56178/eh.v36i1.427

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[1] Agra M, Bilenca DN y Codesido M (2015) Responses of birds to planting of Lotus tenuis pasture in the Flooding Pampas, Argentina. Emu 115:270-276.

[2] Aizen MA, Garibaldi LA y Dondo M (2009) Expansión de la soja y diversidad de la agricultura argentina. Ecología Austral 19:45-54.

[3] Askins RA, Chávez-Ramírez F, Dale BC, Haas CA, Herkert JR, Knopf FL y Vickery PD (2007) Conservation of grassland birds in North America: understanding ecological processes in different regions. Ornithological Monographs 64:1-46.

[4] Azpiroz AB, Isacch JP, Dias RA, Di Giacomo AS, Fontana CS y Palarea CM (2012) Ecology and conservation of grassland birds in southeastern South America: a review. Journal of Field Ornithology 83:217-246.

[5] Bibby CJ, Burgess N, Hill D y Mustoe S (2000) Bird Census Techniques. Academic Press, San Diego.

[6] Bilenca D, Codesido M, Abba A, Corriale M, González-Fischer C, Pérez Carusi L y Zufiaurre E (2018) Conservación de la biodiversidad en sistemas pastoriles. Buenas prácticas para una ganadería sustentable de pastizal. Kit de extensión para las Pampas y Campos. Fundación Vida Silvestre Argentina, Buenos Aires.

[7] Bilenca D y Miñarro FO (2004) Identificación de áreas valiosas de pastizal (IVPs) en las pampas y campos de Argentina, Uruguay y sur de Brasil. Fundación Vida Silvestre Argentina, Buenos Aires.

[8] Biondini ME, Patton BD y Nyren PE (1998) Grazing intensity and ecosystem processes in a northern mixed-grass prairie, USA. Ecological Applications 8:469-479.

[9] BirdLife International (2020a) Species factsheet: Porzana spiloptera. URL: http://datazone.birdlife.org/species/factsheet/dot-winged-crake-laterallus-spilopterus.

[10] BirdLife International (2020b) Species factsheet: Spartonoica maluroides. URL: http://datazone.birdlife.org/species/factsheet/bay-capped-wren-spinetail-spartonoica-maluroides.

[11] Brandolin PG, Blendinger PG y Cantero JJ (2016) From relict saline wetlands to new ecosystems: changes in bird assemblages. Ardeola 63:329-348.

[12] Brooks ME, Kristensen K, van Benthem KJ, Magnusson A, Berg CW, Nielsen A, Skaug HJ, Maechler M y Bolker BM (2017) glmmTMB balances speed and flexibility among packages for zero-inflated generalized linear mixed modeling. The R Journal 9:378-400.

[13] Cardoni DA, Greenberg R, Maldonado JE y Isacch JP (2013) Morphological adaptation to coastal marshes in spite of limited genetic structure in the Neotropical passerine Spartonoica maluroides (Aves: Furnariidae). Biological Journal of the Linnean Society 109:78-91.

[14] Cardoni DA, Isacch JP y Iribarne O (2012) Effects of cattle grazing and fire on the abundance, habitat selection, and nesting of the Bay-capped Wren-spinetail (Spartonoica maluroides) in coastal saltmarshes of the Pampa region. Condor 114:1-9.

[15] Cardoni DA, Isacch JP y Iribarne O (2015) Avian responses to varying intensity of cattle production in Spartina densiflora saltmarshes of South-Eastern South America. Emu 115:12-19.

[16] Coconier E (2007) Bahía de Samborombón y Punta Rasa. Áreas importantes para la conservación de las aves en Argentina. Aves Argentinas/Asociación Ornitológica del Plata, Buenos Aires.

[17] Codesido M y Fraga RM (2009) Distributions of threatened grassland passerines of Paraguay, Argentina and Uruguay, with new locality records and notes on their natural history and habitat. Ornitologia Neotropical 20:585-595.

[18] Codesido M, González-Fischer CM y Bilenca DN (2011) Distributional changes of landbird species in agroecosystems of central Argentina. Condor 113:266-273.

[19] Comparatore VM, Martínez MM, Vasallo AI, Barg M y Isacch JP (1996) Abundancia y relaciones con el hábitat de aves y mamíferos en pastizales de Paspalum quadrifarium manejados con fuego (Prov. de Buenos Aires, Argentina). Interciencia 21:228-237.

[20] Di Bella CE, Rodríguez AM, Jacobo E, Golluscio RA y Taboada MA (2015) Impact of cattle grazing on temperate coastal salt marsh soils. Soil Use and Management 31:299-307.

[21] Fernández GJ, Beade MS, Pujol EM y Mermoz ME (2004) Plan de manejo de la Reserva de Vida Silvestre “Campos del Tuyú”. Fundación Vida Silvestre Argentina, Buenos Aires.

[22] Fisher R y Davis SK (2010) From Wiens to Robel: A review of grassland-bird habitat selection. Journal of Wildlife Management 74:265-273.

[23] Fraga RM (2003) Distribution, natural history and conservation of the Black-and-white Monjita (Heteroxolmis dominicana) in Argentina, a species vulnerable to extinction. Ornitología Neotropical 14:145-156.

[24] Gillen RL, Eckroat JA y McCollum FT (2000) Vegetation response to stocking rate in southern mixed-grass prairie. Journal of Range Management 53:471-478.

[25] Goriup PD (1988) Ecology and conservation of grassland birds. International Council for Bird Preservation, Cambridge.

[26] Isacch JP, Costa CSB, Rodríguez-Gallego L, Conde D, Escapa M, Gagliardini DA y Iribarne O (2006) Distribution of saltmarsh plant communities associated with environmental factors along a latitudinal gradient on the south-west Atlantic coast. Journal of Biogeography 33:888-900.

[27] Isacch JP y Cardoni DA (2011) Different grazing strategies are necessary to conserve endangered grassland birds in short and tall salty grasslands of the flooding Pampas. Condor 113:724-734.

[28] Isacch JP y Martínez MM (2001) Estacionalidad y relaciones con la estructura del hábitat de la comunidad de aves de pastizales de paja colorada (Paspalum quadrifarium) manejados con fuego en la provincia de Buenos Aires, Argentina. Ornitología Neotropical 12:345-354.

[29] Jacobo E y Rodríguez A (2012) Manejo de pastizales naturales para una ganadería sustentable en la Pampa Deprimida: buenas prácticas para una ganadería sustentable de pastizal. Fundación Vida Silvestre Argentina/Aves Argentinas, Buenos Aires.

[30] Lanctot RB, Blanco DE, Dias RA, Isacch JP, Gill VA, Almeida JB, Delhey K, Petracci PF, Bencke GA y Balbueno R (2002) Conservation status of the Buff-breasted Sandpiper: Historic and contemporary distribution and abundance in South America. Wilson Bulletin 114:44-72.

[31] Marino GD (2008) Buenas prácticas ganaderas para conservar la vida silvestre de las pampas. Una guía para optimizar la producción y conservar la biodiversidad de los pastizales de la Bahía Samborombón y la cuenca del Río Salado. Aves Argentinas AOP, Buenos Aires.

[32] Matteucci SD y Colma A (1982) Metodología para el estudio de la vegetación. OEA, Washington DC.

[33] R Core Team (2020) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Viena. (URL: http://www.R-project.org/)

[34] Reed MS (2008) Stakeholder participation for environmental management: a literature review. Biological Conservation 141:2417-2431.

[35] Remsen Jr. J, Areta JI, Bonaccorso E, Claramunt S, Jaramillo A, Pacheco J, Ribas C, Robbins M, Stiles F, Stotz D y Zimmer K (2020) A classification of the bird species of South America. American Ornithologists’ Union, Washington DC. (URL: [http://www.museum.lsu.edu/∼530 Remsen/SACCBaseline.htm](http://www.museum.lsu.edu/∼530 Remsen/SACCBaseline.htm))

[36] Rodríguez A y Jacobo E (2010) Glyphosate effects on floristic composition and species diversity in the Flooding Pampa grassland (Argentina). Agriculture, Ecosystem and Environment 138:222-231.

[37] Roitman G y Preliasco P (2012) Guía de reconocimiento de herbáceas de la Pampa deprimida: características para su manejo: buenas prácticas para una ganadería sustentable de pastizal: kit de extensión para las pampas y campos. Fundación Vida Silvestre Argentina/Aves Argentinas, Buenos Aires.

[38] Rotenberry JT y Wiens JA (1980) Habitat structure, patchiness, and avian communities in North American steppe vegetation: A multivariate analysis. Ecology 61:1228-1250.

[39] Sala OE, Osterheld M, León RJC y Soriano A (1986) Grazing effects upon plant community structure in subhumid grasslands of Argentina. Vegetatio 67:27-32.

[40] Sliwinski MS y Koper N (2015) Managing mixed-grass prairies for songbirds using variable cattle stocking rates. Rangeland Ecology and Management 68:470-475.

[41] Soriano A, León RJC, Sala OE, Lavado RS, Deregibus VA, Cauhepé MA, Scaglia OA, Velázquez CA y Lemcoff JH (1991) Río de la Plata grasslands. Ecosystems of the world, Volume 8A. Natural grasslands: introduction and Western Hemisphere. Elsevier, Amsterdam, pp. 367-407.

[42] Vaccaro AS, Dodyk L, Lapido R, De Miguel A y Grilli P (2020) ¿Cómo contribuye la alianza del pastizal a la conservación de las aves en la pampa deprimida? Hornero 35:95-109.

[43] Vervoorst FB (1967) Las comunidades vegetales de la Depresión del Salado (provincia de Buenos Aires). Instituto Nacional de Tecnología Agropecuaria, Buenos Aires.

[44] Vickery JA, Tallowin JR, Feber RE, Asteraki EJ, Atkinson PW, Fuller RJ y Brown VK (2001) The management of lowland neutral grasslands in Britain: effects of agricultural practices on birds and their food resources. Journal of Applied Ecology 38:647-664.

[45] Viglizzo EF, Frank F, Carreño LV, Jobbágy EG, Pereyra H, Clattz J, Pincén D y Ricardz MF (2011) Ecological and environmental footprint of 50 years of agricultural expansion in Argentina. Global Change Biology 17:959-973.

[46] Zar JH (1996) Biostatistical analysis. Tercera edición. Prentice Hall, Upper Saddle River.

[47] Zufiaurre E, Codesido M, Abba A y Bilenca D (2016) Uso diferencial de lotes agrícolas y ganaderos por aves terrestres en la región pampeana, Argentina. Hornero 31:41-52.

[48] Zufiaurre E, Codesido M, Abba A y Bilenca D (2017) The seasonal role of field characteristics on seed-eating bird abundances in agricultural landscapes. Current Zoology 63:279-286.

[49] Zufiaurre E, Codesido M, González Fischer C, Abba A y Bilenca D (2019) Landbird assemblages in temperate agroecosystems: analyses at plot and landscape scales. Ornithological Science 18:69-79.

[50] Zuur AF, Ieno EN, Walker N, Saveliev AA y Smith GM (2009) Mixed Effects Models and Extensions in Ecology With R, Statistics for Biology and Health. Springer, New York.