Contents lists available at ScienceDirect Acta Oecologica journal homepage: www.elsevier.com/locate/actoec Qualitative aspects of the effectiveness of Culpeo foxes (Lycalopex culpaeus) as dispersers of Prosopis alba (Fabaceae) in a Bolivian dry valley D.E. Maldonado a,*,1 , A.P. Loayza b , E. Garcia c , L.F. Pacheco a a Colección Boliviana de Fauna, Instituto de Ecología, Universidad Mayor de San Andrés, La Paz, Bolivia b Instituto de Investigación Multidisciplinario en Ciencia y Tecnología, Universidad de La Serena, La Serena, Chile c Herbario Nacional de Bolivia, La Paz, Bolivia ARTICLE INFO Keywords: Arid Legume Gut-passage Germination Legitimate ABSTRACT Foxes disperse several plant species in arid and semi-arid environments, but their effectiveness as dispersal agents still remains unclear. In this study, we examined qualitative components of the effectiveness of L. culpaeus as a disperser of P. alba seeds in an inter-Andean dry valley of La Paz, Bolivia. Specifically, we determined seed deposition microhabitats, and the probabilities of germination, seed removal and seedling recruitment in these microhabitats. Additionally, we assessed the effect of gut-passage on P. alba germination. We collected 159 scats, which contained a total of 3402 endocarps fragments. Foxes dispersed seeds into two microhabitats: open areas and under woody vegetation, but more frequently in the former. The probability of germination did not differ between gut-passed and control seeds, but control seeds germinated faster than gut-passed ones. The likelihood of removal was greater for endocarps fragments in open microhabitats than under woody vegetation. Only a small percentage of the seeds in each microhabitat germinated, but none survived more than a week. We conclude that although the Culpeo fox can defecate intact P. alba seeds, it does not provide effective dispersal services. 1. Introduction It is widely acknowledged that seed dispersal by vertebrates is a key ecological process that influences the structure and dynamics of plant communities (Howe and Miriti, 2004). By consuming fruits, frugivores can move seeds away from parent plants (Wang and Smith, 2002). This process typically increases seed survival and seedling establishment by reducing the effects of negative density-dependence (Comita et al., 2014) and by allowing seeds to reach suitable habitats for recruitment (Howe and Smallwood, 1982). Hence, seed deposition patterns de- termine the initial template for plant regeneration (Nathan and Muller- Landau, 2000; Wang and Smith, 2002; Howe and Miriti, 2004). How- ever, depending on the effectiveness of the disperser (sensu Schupp, 1993), this template may or may not translate into the same spatial pattern of seedling recruitment, A frugivores' seed dispersal effective- ness (SDE) is determined by two components; a quantitative and a qualitative component. The quantitative component of the SDE refers to the number of seeds dispersed by the frugivore, while the qualitative one refers to the probability that a dispersed seed will become a new recruit (Schupp et al., 2017). For a frugivore to provide high quality dispersal services, gut passage should not have a negative effect on seed viability or germination (Traveset et al., 2007), and most seeds should be dispersed to.habitats with high probabilities of establishment (i.e., directed dispersal, Wenny, 2001). Consequently, a disperser is con- sidered effective when the dispersal services it provides have positive demographic consequences on plant populations (Schupp, 1993; Schupp et al., 2010). Carnivores, and particularly foxes, are known seed dispersers of many plant species in semi-arid ecosystems (Castro et al., 1994; Campos and Ojeda., 1997; Varela et al., 2008; Rosalino et al., 2010; Cares et al., 2013). Compared to passerine bids, they are considered long-distance dispersers (Jordano et al., 2007; González-Varo et al., 2013), however, there is still no consensus on how effective they are. For example, in Mediterranean Spain, Farris et al. (2017) showed that Sardinian foxes provide directed dispersal (i.e., they are effective dispersers) to Juni- perus phoenicea. In contrast, red foxes are not effective dispersers of Celtis australis, as they destroy most of its seeds during gut passage (Rost et al., 2012). Contrasting results have also been obtained for New World plant species, with some authors suggesting that seeds consumed by foxes may be scarified during digestion (Bustamante et al., 1992; Castro et al., 1994; Silva et al., 2005), whereas others indicate that seed pas- sage does not have an effect on germination (León-Lobos and Kalin- https://doi.org/10.1016/j.actao.2018.02.005 Received 8 July 2017; Received in revised form 5 December 2017; Accepted 6 February 2018 * Corresponding author. 1 Current address: Doctorado en Ecología de Zonas Áridas, Departamento de Biología, Universidad de La Serena, La Serena, Chile. E-mail address: diegoeduardo_mv@hotmail.com (D.E. Maldonado). Acta Oecologica 87 (2018) 29–33 1146-609X/ © 2018 Elsevier Masson SAS. All rights reserved. T