A neglected opportunity for bird conservation: The value of a perennial, semiarid agroecosystem in the Llanos de Ojuelos, central Mexico Eric Mellink a, * ,M  onica E. Riojas-L  opez b , Patrick Giraudoux c a Departamento de Biología de la Conservaci on, Centro de Investigaci on Científica y de Educaci on Superior de Ensenada, Carretera Ensenada-Tijuana No. 3918, Zona Playitas, 22860 Ensenada, Baja California, Mexico b Departamento de Ecología, CUCBA, Universidad de Guadalajara, Km.15.5 carr. Nogales, 45000 Zapopan, Mexico c D epartement de Chronoenvironnement, Universit e de Franche-Comt e/CNRS and Institut Universitaire de France, La Bouloie 25030, Besançon Cedex, France article info Article history: Received 26 November 2014 Received in revised form 24 June 2015 Accepted 13 July 2015 Available online xxx Keywords: Nopal orchards Opuntia spp. Agroecology Agrohabitat Conservation Biodiversity abstract Perennial, low-input, dry-farmed agroecosystems, especially those focused on fruit production, offer important opportunities to conserve biodiversity in semi-arid lands where fragmented natural habitats are unlikely to be restored. We studied the use of nopal orchards by birds and the effect of neighboring vegetation (shrubland, grassland, and annual rain-fed cropland) in the Llanos de Ojuelos, in the south- center of the Mexican Altiplano. Orchards were as rich as shrublands in terms of bird species, and richer than grasslands and croplands, and this did not depend on the adjacent habitat. Some bird species were more frequent in orchards and shrublands, but there was no typical orchard-shrubland bird assemblage, nor a grassland or cropland assemblage. Nopal orchards provided habitat for shrub-loving birds, and for birds typically found in grasslands of good condition, which are now uncommon in the area. Variation among orchards is not a function of the habitat to which they are adjacent, and it does not follow a geographical pattern; rather, it reflects the physical conditions (soil, rainfall of a particular year) and the idiosyncrasies of the owners regarding orchard and edge constitution and management. This work reaffirms that nopal orchards could be a valuable habitat for biodiversity conservation in this area. © 2015 Elsevier Ltd. All rights reserved. 1. Introduction During the last 100 years, land use by humans has led to the fragmentation of natural landscapes on a considerable scale and at a considerable speed. The Food and Agriculture Organization of the United Nations (FAO, 2006) estimated that 13 million hectares of forests are converted into agricultural land every year, in addition to other modifications of native vegetation. These changes repre- sent major threats to the conservation of our biological heritage and the environmental services that depend upon it, and are re- flected in population reductions and wildlife extinctions (Millennium Ecosystem Assessment, 2005). Species loss has been addressed through the use of different measures, such as establishing protected areas. These were once thought to be sufficient to offset biodiversity loss, but are now recognized as lacking the capacity to conserve healthy and viable populations of all life forms, at least in many regions. It has become clear that if we intend to successfully conserve biodiversity we must incorporate habitats subject to natural resource use into conservation objectives, including agricultural systems (Millennium Ecosystem Assessment, 2005; Riojas-L opez and Mellink, 2005; Perfecto and Vandermeer, 2008; Scherr and McNeely, 2008). The potential for agrohabitats to aid in biological conservation goes beyond providing habitat for wildlife, as they can also serve as stepping stones to facilitate the movement of animals between patches of suitable habitat (Uezu et al., 2008). The value of an agrohabitat to wild animals depends on several features: habitat heterogeneity (Mellink, 1991a, b; Benton et al., 2003; Riojas-L opez, 2006, 2012), the presence of arboreal elements (Harvey et al., 2006; Clough et al., 2009) and other “keystone structures” (Tews et al., 2004), including life fencerows, rock fences, and open herb * Corresponding author. E-mail addresses: emellink@cicese.mx (E. Mellink), meriojas@cucba.udg.mx (M.E. Riojas-L opez), patrick.giraudoux@univ-fcomte.fr (P. Giraudoux). Contents lists available at ScienceDirect Journal of Arid Environments journal homepage: www.elsevier.com/locate/jaridenv http://dx.doi.org/10.1016/j.jaridenv.2015.07.005 0140-1963/© 2015 Elsevier Ltd. All rights reserved. Journal of Arid Environments 124 (2016) 1e9