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La cabra, espècie invasora de les Balears
... Their generalist feeding behavior and high reproductive rates have contributed to their success as invaders. Indeed, numerous endemic plant species have become extinct or are currently endangered due to introduced goats (Mayol et al., 2017;Abe, 2021;Menezes de Sequeira et al., 2021). For example, on Great Island (New Zealand), over 70 plant species vanished as a result of goat overbrowsing (Turbott, 1948). ...
... Feral goats, in particular, have emerged as a serious concern for the Balearic endemic flora in recent decades (Mayol et al., 2017;Capó et al., 2022). Although their introduction dates back thousands of years , the abandonment of rural life in the 1960s has contributed to the feralization and widespread expansion of goat populations throughout the mountains (Vives and Baraza, 2010;Roque, 2017). ...
... Although their introduction dates back thousands of years , the abandonment of rural life in the 1960s has contributed to the feralization and widespread expansion of goat populations throughout the mountains (Vives and Baraza, 2010;Roque, 2017). With their high reproductive rate and the lack of predators, goat populations have experienced exponential growth, currently exceeding 20,000 individuals in Mallorca (Vives and Baraza, 2010;Mayol et al., 2017). Nonetheless, as mentioned earlier, non-native species like feral goats can sometimes assume the functional role of extinct native species, thereby making positive contributions to specific ecosystem services (e.g. ...
Invasive non-native species are major drivers of biodiversity loss, particularly on island ecosystems where endemicity rates are high and food webs simplified compared to the mainland. Herbivores, specifically, are among the most destructive invaders worldwide, as they dramatically damage native flora and alter ecosystem functioning. Plant reproductive performance can be directly impacted by herbivore consumption of flowers and indirectly by resource allocation and disruption of plant-animal interactions. However, the understanding of these indirect effects remains limited. Moreover, plant-herbivore interactions can switch from positive to negative outcomes depending on the identity and density of the interacting species, making the situation more complex when multiple herbivore species affect the same plant. It is crucial thus to comprehensively understand the full range of ecological impacts exerted by non-native herbivores in order to effectively preserve native biodiversity and associated ecosystem services. This thesis aims to enhance our knowledge of how contrasting invasive non-native herbivores influence plant reproduction and plant-animal interactions from a multi-specific and density-dependent perspective. To this end, I used the model system composed by the Mediterranean dwarf palm Chamaerops humilis L. and its two main invasive herbivores in Mallorca (Balearic Islands, Spain), the stem-boring moth Paysandisia archon Burmeister and the feral goat Capra hircus L. Direct and indirect effects were evaluated throughout several stages of the palm’s life cycle by combining intensive observational field work and spatially explicit modelling. Spatial point pattern analyses revealed that the probability and intensity of moth herbivory and goat herbivory were determined by the density of dwarf palms. The sign and strength of the spatial patterns were highly variable as they changed across distance (distance- and density-dependent effects), types of herbivory (moth herbivory, goat florivory, goat folivory), study sites, and even between palm sexes. At the flower stage, moth herbivory positively affected pollinator abundance and fruit initiation, while goat herbivory had negative effects, mainly though intense florivory. Interestingly, only the nitidulid pollinator Meligethinus pallidulus Erichson was impacted by herbivory, positively by moth herbivory while negatively by goat herbivory. Furthermore, both herbivore species exerted nonadditive effects on palm reproduction as, for instance, the palms that experienced simultaneous attacks showed remarkably lower rates of fruit initiation. At the fruit stage, moth-attacked palms showed higher rates of pre-dispersal insect-seed predation, likely due to the observed decreased pulp content in fruits. Surprisingly, legitimate seed dispersers consumed fruits more often from attacked palms, suggesting that herbivore-mediated changes might boost frugivore attraction or, alternatively, that both mutualistic and antagonistic animals select the same palm traits. Lastly, a comparative spatially explicit analysis among three study plots with varying levels of goat activity revealed that the net outcome of the palm-goat interaction shifted from mutualism to antagonism depending on goat density. Low goat activity led to an aggregated seed rain and, in turn, higher rates of insect-seed predation and lower rates of germination. High goat activity almost completely canceled palm recruitment, leading to the population reproductive collapse. By contrast, an intermediate goat activity maintained a balance between mutualistic and antagonistic effects. Overall, this thesis provides valuable insights into the diverse and multiple pathways through which contrasting non-native herbivores can impact plant reproductive performance, highlighting the importance of considering intraspecific variability and the context-dependence nature of plant-animal interactions. Given the ongoing increase in non-native species worldwide, it becomes essential to implement adaptive and cooperative management strategies among the different social stakeholders to efficiently safeguard native biodiversity.
... Some authors consider these breeds to be of no taxonomic interest, as they come from artificial selection, and that their contribution to biodiversity should be restricted to the livestock world (Mayol et al. 2017). However, reality shows that most goat populations, domestic or feral, are present in ecosystems, playing the role of large wild herbivores and therefore do have ecological value both on the mainland (Herrero et al. 2013) and on the islands (Seguin et al. 2001). ...
... In recent decades, there has been an increase in forest land and at the same time in large forest fires (IFN4 2012). In Mallorca, pine seedlings have a survival rate after a fire of 23% without goats, while the rate is just 5% with them (Mayol et al. 2017), highlighting how useful grazing can be for control. Among ruminants, goats can reduce bush cover more efficiently than sheep or cattle (Sineiro 1982;Benavides et al. 2009). ...
... Hunting enclosures could be used to remove specimens that do not conform to the trophy pattern and thus maintain the genetic heritage. The decrease in domestic livestock on some Mediterranean islands has led to the proliferation of feral goat populations and this, in turn, has made it easier for some owners to obtain additional income from hunting activities (Mayol et al. 2017). ...
Mediterranean islands had long been the home of several mammalian herbivores in pre-human times, which differentiates them from other islands where such fauna was absent until its introduction as domestic species. Man colonized the Mediterranean islands thanks to goats, which was well-adapted to their climate. After several millennia of coexistence its role is generating controversy. Many studies have argued that some Mediterranean islands are suffering from overpopulation, which are seriously threatening landscapes, endemic plants, and reforestation. However, little is known about the ecosystem services they provide, whereby they not only provide food, but also maintain plant heterogeneity and diversity, prevent forest fires, conserve animal genetic heritage, benefit other animal species, and contribute to the maintenance of endemic plant resistance and tolerance to herbivory. The clues that these herbivores offer regarding the structure of pre-human ecosystems, as well as their equivalents after faunistic turnover in human times, is sometimes neglected. The conclusion is not only a call for caution when applying certain actions, such as eradication, but also for recognition of certain ecosystem functions as well as genetic, taxonomic, and social aspects.
... In particular, the introduction of exotic herbivores has provided evidence of profound changes in island ecosystems (Courchamp et al. 2003) and the degradation impact can remain for hundreds or thousands of years until the herbivores are eradicated (Chapuis et al. 2004;Garzón-Machado et al. 2010;Velamazán et al. 2017). Goats, sheep and rabbits are considered huge threats to the conservation of insular biodiversity when they become feral in natural areas Mayol et al. 2017). The negative effects of these feral livestock on insular plant communities and endemic flora, such as predation of endangered species, impact on demographical structure or propagation of alien species, among others, have been intensively studied by several authors since the middle of the last decade (Sventenius 1946;Ceballos and Ortuño 1951;Nogales et al. 1992;Salgado-Luarte et al. 2019), but information on how ecosystems respond to their impact remains largely unresolved in many systems. ...
... The first colonizing human populations are thought to have arrived on the islands about 4000 years before the present, which almost coincides with the last fossil records of M. balearicus (Bover et al. 2016). The most plausible scenario is based on a continuum between the last natural populations of native M. balearicus and the human introduction of new mammalian herbivores, mainly goats, rats, rabbits and sheep (Mayol et al. 2017). ...
... These species were managed and used by humans for centuries, and some populations were evolutionarily driven to form varieties of domestic animals such as the goat variety known as 'Cabra mallorquina' from Mallorca or 'Cabra eivissenca' from Eivissa. The first of these species is now used for hunting purposes, while the other is still used for cattle (Mayol et al. 2017). ...
Biological invasions are a major cause of loss of biodiversity worldwide, particularly on islands. Introduced mammalian herbivores are among the most threatening of all invasive species, especially goats [Capra hircus (Linnaeus, 1758)], sheep [Ovis orientalis aries (Linnaeus, 1758)], mouflon (Ovis orientalis musimon [Pallas, 1762)], Barbary sheep [Ammotragus lervia (Pallas, 1777)], and rabbits [Oryctolagus cuniculus (Linnaeus, 1758)]. The vulnerability of insular plant communities, especially the endemic flora, is strongly influenced by their historic (and present) herbivory context, within which these introduced herbivores have played a key role. The effects of the introduction of mammals such as goats and rabbits are difficult to elucidate, as their introductions occurred thousands (or hundreds) of years ago and data on the previous status of the plant communities are not available. However, the present-day impacts of both of these herbivores on insular plant communities have been intensively studied. Herbivory can reduce the distribution area and constrain insular endemic species to inaccessible areas such as cliffs or islets, which impoverishes the original insular ecosystems and changes their species composition. Moreover, the negative effects of these species on the insular native flora have led to the development of eradication and control programmes on many islands, with the aim to recover and protect native plants. Coordination between policymakers, managers, researchers, hunters and society is crucial in order to identify efficient solutions to protect and restore insular plant communities, effectively manage hunting activities and optimally limit the effects of introduced mammals.
... Domestic goat herds have been widely introduced to islets that surround other larger islands or mainlands to use the islets as breeding areas (Mayol, Alcover, & Domenech, 2017). In fact, many islets have been severely affected by goat herbivory (Daly, 1989), and their small dimensions do not allow plant species to escape from herbivory; thus, plant communities on islets are more impacted by herbivory than on larger islands (Campbell, Donlan, Cruz, & Carrion, 2004). ...
... The management of introduced goats is currently a key issue on the Balearic Islands (Western Mediterranean Basin) and its impact on vegetation has recently been evaluated (Rivera et al. 2015;Bartolomé et al. (2019); Limpens, Serrano, Rivera-Sánchez, Bartolomé, & Baraza, 2020). Herds of goats are mainly located in the mountains of the northwest of Mallorca, with other groups located on the east of Mallorca and also on Menorca (Mayol et al. 2017). A very fluctuant herd was also present on Es Vedrà, an islet located on the Western coast of Eivissa. ...
The introduction of mammalian herbivores negatively affects insular vegetation, especially plant species with narrow distributions that are vulnerable to herbivory or that evolved in the absence of native mammal herbivores. Eradication programs have been performed on many islands worldwide, though assessment of the responses of vegetation is crucial to guarantee the success of these programs. In this study, we aimed to evaluate vegetation recovery after a reduction in the feral goat population on Es Vedrà, an islet in the Balearic Islands (Western Mediterranean Basin). We monitored nine permanent plots in three different habitats (rocky areas, grasslands, shrublands) to evaluate the variation in plant coverage, functional traits and diversity indexes over time. We obtained data for each plot by annual field sampling in mid-May of 2016 to 2019. We observed a significant recovery of the predominant species in each plant community and an increase in many functional traits. We found significant variation in taxonomic diversity in rocky areas and grasslands, but not in shrublands, and functional diversity only varied in rocky areas. Therefore, plant diversity benefited from the reduction in the goat population and functional redundancy increased in rocky areas, improving the capacity to respond against disturbances. However, the reduction in the goat population was not sufficient to preserve plant communities and negative effects reappeared in 2019, coinciding with the increase in the goat population. Therefore, absolute eradication of introduced herbivores represents a unique, efficient strategy to guarantee the ecological restoration of affected habitats in microinsular ecosystems.
... Currently, this circumstance does not seem to pose an important risk of predation for the adult individuals of F. balearica because plants have thorns that provide them with some protection against herbivory due to an exaptation phenomenon (Capó et al., 2023). Although herbivory could be a threat to seedlings that have not yet developed spines (Mayol et al., 2017), the main problem posed by herbivores in the area could be habitat alteration by soil erosion and nitrification of the environment. Besides, after the winter time -when the population is covered by snow for several days-the water runoff also causes soil erosion, which can pose a problem for ecosystems (Calsamiglia et al., 2020). ...
Demographic data on threatened species is crucial to understand their conservation status and make management decisions when necessary, which is especially relevant for narrow endemic species with isolated populations. This is the case of Femeniasia balearica (J.J. Rodr.) Susanna, a narrow endemic cushion-like shrub that grows in coastal areas of northern Menorca (Balearic Islands, western Mediterranean Basin) and catalogued as Vulnerable according to the IUCN categories. Recently, a new population has been located in the center of the Serra de Tramuntana of Mallorca (Balearic Islands). In this study, the demographic status of the population from Mallorca has been studied, geolocating all of the individuals with a differential GPS to obtain a detailed map. Data on stage of development (seedling, vegetative or reproductive), morphometry and the overall status of all the individuals have been compiled. A total of 116 individuals and 96 seedlings have been counted. The fact that most of the individuals are reproductive (86.70%) and the confirmation of the presence of seedlings suggest that the population may be maintained in the future. This study provides valuable data on the demographic status of the new population of the species, but long-term monitoring is necessary for analyzing demographic trends.
... En Baleares, la población de cabras asilvestradas, estimada en muchos miles de ejemplares, se concentra, aunque no sólo, en las montañas (Mayol, Alcover et al. 2018), donde coinciden con algunas especies de fl ora críticamente amenazadas por la herbivoría (tal es el caso de algunas poblaciones de Agrostis barceloi, Chaenorhinum rodriguezii (Chaenorhinum origanifolium subsp. rodriguezii), Colchicum longifolium o Coristospermum huteri (Ligusticum lucidum subsp. ...
... No obstant això, sí que en ocasions la caça ha pogut contribuir, en cert grau, a la transformació de paisatges com ara en casos d'incendis (Doctor, 1991) o de presència d'espècies com la cabra (Vives i Baraza, 2010;Mayol et al., 2017) o el tord (Conesa i Flexas, 2013), si bé, la gestió cinegètica és una de les millors alternatives per contribuir a la recuperació paisatgística (Bota et al., 2001;Seguí et al., 2005). ...
Landscape and heritage implications of huntingy in Mallorca are analyzed
based on the island's social and territorial context and from the geographical
point of view. Hunting activity contributes to the definition of the landscape
mosaic and presents a heritage value, especially according to traditional
hunting modalities based on dry stone constructions. Hunting has contributed
to create this heritage and game management can preserve it. In addition, it is
also necessary to keep in mind that hunting helps to maintain the landscape
from the moment it constitutes an activiry with an economic volume than can
contributs to the safeguarding of the rural environament.
... Recently the corpses of goats left in the bush after culls have aroused the sensibility of animal welfare groups who oppose these operations (Mayol et al. 2017). Their vocal complaints have rendered the culling of goats a much less socially acceptable form of feral goat management, which itself has become the object of conflicts on social media. ...
... So far, there are no known works that analyze the role that feral goats can play in the maintenance of firebreaks. The island of Mallorca, in the western Mediterranean, enables us to address this issue, since it has a network of firebreak areas and a population of feral goats, with serious management problems [22,23]. ...
The threat of large forest fires is increasing, and the main causes are the depopulation of rural areas, along with the effects of climate change. To counter this threat in recent decades, there have been numerous proposals and actions aimed at promoting grazing in the forest as a tool for controlling biomass fuel. However, the continued disappearance of traditional herds makes this activity difficult. Rural depopulation has also meant that domestic species become feral, being habitual in the case of goats. Currently, little is known about the role that feral goats can play in the fight against forest fires. In this work, an analysis is made on the effect of feral goats on the control of the vegetation in firebreak areas. Furthermore, the effect of attractants, such as water, salt, or food, on goat behavior is also studied. The study was carried out on the island of Mallorca, where a population of feral goats occupies the mountain areas, and where it is common for them to graze on the network of firebreaks. The results showed that these areas in themselves exert an attractive effect with respect to the neighboring forest, and that the herbaceous biomass is reduced. This effect was enhanced with the implementation of water and salt points, although only in certain periods of the year. In general, it was possible to reduce the phytovolume of many species without affecting biodiversity in the short or medium term. Therefore, strategic management of feral animals, aimed at firebreak areas, could contribute not only to reducing the risk of fires and, consequently, to the mitigation of climate change, but also to attracting these animals to the forests, thus avoiding their dispersion to conflictive places such as roads, residences, agricultural fields, and gardens.
L’estudi, realitzat per la doctora en Antropologia ambiental Maria Cifre, fa una anàlisi acurada de les característiques del foodscape, o paisatge gastronòmic, propi d’aquesta regió de Mallorca, com a construcció social que ens permet analitzar com els aliments, els llocs i les persones estan interconnectades i interactuen. A la presentació de l’estudi, l’autora afirma que “cal tenir en compte que la gastronomia és un element que actua tant a l’espai natural com al social, que influeix tant en la producció d’aliments com en la transformació territorial d’una regió”.
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