Manuel B. Morales

Universidad Autónoma de Madrid | UAM · Department of Ecology and Research Centre in Biodiversity and Global Change (CIBC-UAM))

Farmland biodiversity is in alarming decline worldwide due to agriculture intensification. In this context, the umbrella species concept may help in better targeting conservation efforts, focusing on species whose requirements may best cover those of other components of biological communities. We test this idea using the little bustard (Tetrax tetr...

Agricultural intensification is a persistent and growing threat to biodiversity worldwide. Olive groves cover extensive areas in the Mediterranean basin and play a fundamental role as refuge and wintering quarters for many bird species, but the effects of their current intensification on bird communities remain unclear. This study aims to evaluate...

Trophic niche partitioning is a mechanism that facilitates the coexistence of ecologically similar species by sharing their resource use. However, detailed information of the trophic niche in insectivorous birds is usually limited by the lack of accurate identification of consumed food resources. The use of DNA‐metabarcoding has proved useful for m...

Monitoring temporal dynamics in genetic diversity is of great importance for conservation, especially for threatened species that are suffering a rapid population decline and increased fragmentation. Here, we investigate temporal variation in genetic diversity, structure, and gene flow in the Dupont’s lark (Chersophilus duponti) across most of its...

Adult sex ratios (ASRs) have proved to correlate with population trends, which make them potential useful indicators of a species' population trajectory and conservation status. We analysed ASRs and proportion of juveniles in flocks of an endangered steppe bird, the Little Bustard Tetrax tetrax, using surveys made during the non-breeding period in...

European green agricultural policies have been relaxed to allow cultivation of fallow land to produce animal feed and meet shortfalls in exports from Ukraine and Russia. However, conversion of semi-natural habitats will disproportionately impact long term biodiversity and food security. In their Comment in @CommsEarth, Manuel Morales and colleagues...

Red-legged partridge is a very adaptable species that can be found in a wide variety of habitats and climates. Nevertheless, it is in agrarian pseudo- steppes of the Mediterranean basin where partridges reach their highest densities. In this chapter we reviewed habitat preferences for red-legged partridges during their life cycle along their range....

The agriculture intensification required to provide enough food commodities for humans has negative impacts on the environment. To reduce these drawbacks Agri-Environmental Schemes (AES) have been implemented in Europe since the last decade of the twentieth century. One of the measures included in these schemes was the introduction of alfalfas in c...

The European Union's Common Agricultural Policy (CAP) has not halted farmland biodiversity loss. The CAP post‐2023 has a new ‘‘Green Architecture,’’ including the new ‘‘Eco‐scheme’’ instrument. How can this new Green Architecture help tackle the biodiversity crisis? Through 13 workshops and an online survey, over 300 experts from 23 European Member...

Despite conservation efforts made over three decades and the improvements in protection status at different levels (global, European, national and regional), the current situation of the little bustard has not improved. Increased knowledge on the species’ biology, and projects aimed at improving its conservation status, such as the designation of p...

Over the last two decades, monitoring of and research into the little bustard was carried out mainly in western Europe, and has enabled the identification of important threats to the species. Detailed information on the eastern populations’ breeding and wintering grounds is, however, still scarce. Within the western range of the species, the Europe...

In this chapter, we focus mainly on the behavioural ecology of the little bustard (i.e. how behaviour relates to ecology and evolution), with particular emphasis on breeding behaviour, sexual selection and mating systems, as well as their relevance for little bustard conservation. We discuss the evolutionary forces that drive the species’ lekking b...

In this chapter, we revise the role of interspecific relationships between the little bustard and other species and the potential implications for its conservation. Despite the effort made during the last years, the role of biotic interactions on the little bustard population dynamics remains mostly unexplored. Studies on competition between little...

The little bustard is distributed over an extensive Palearctic range from north-western Africa and Iberia to central Asia, encompassing France, Italy, southern Russia and the Middle East. Over such a vast region, it occupies natural grass steppes, pastured grasslands and cereal farmland, avoiding extreme climatic conditions. Nowadays, two main dist...

The little bustard Tetrax tetrax is one of the smallest members of the family Otididae, and has many remarkable life history traits, in its anatomy, biology and ecology. Some of them are shared with other bustard species, but others are unique to the little bustard. In this chapter we first describe plumage and biometry. Moreover, we present and ex...

We summarize what is known about the variation in little bustard (Tetrax tetrax) vital parameters across its distribution range, regarding densities, breeding phenology, nesting and brooding, breeding success and sex ratio, as well as chick and adult survival. Breeding densities are highly variable, but generally higher in non-intensified farmland...

Little bustard seasonal movements are complex. Besides the long known fully long-distance migratory populations (i.e. those of western France, Russia, and Central Asia), there are also others fully migratory that perform shorter migrations, such as many from northern Spain, or partially migratory, such as those from central Spain. Moreover, there a...

Stress in birds has been widely studied through the measurement of heterophil-to-lymphocyte ratio (H/L ratio). In this study we aimed to assess for the first time the potential variation of stress, measured as H/L ratio, associated to geography (between-country variation) and seasonality (between seasons and within the breeding season), as well as...

The little bustard is an iconic species, indicator of healthy grassland and farmland ecosystems. It formerly ranged almost continuously from north-western Africa and Iberia to central Asia, encompassing France, Italy, southern Russia and the Middle East, occupying natural grass steppes, pastured grasslands and extensive cereal farmland. Today, two...

The next reform of the EU Common Agricultural Policy (CAP) for the period 2021- 2027 (currently extended to 2023-2030) requires the approval by the European Commission of a Strategic Plan with environmental objectives for each Member State. Here we use the best available scientific evidence on the relationships between agricultural practices and bi...

Abstract Agriculture intensification threatens farmland bird populations because, among other reasons, it reduces the availability of food resources required to rear their offspring. In our study, we sampled and analyzed total arthropod abundance, biomass and richness, and orthopteran and coleopteran abundance and biomass in different agricultural...

Landscape modification and habitat fragmentation are one of the major current threats to biodiversity. The main source of habitat fragmentation is the loss of focal habitat area, but changes in the composition of the surrounding landscape also have a direct effect on biodiversity. These changes may lead to the loss of some species but also may favo...

Reducing greenhouse gas emissions is a global priority. To meet this goal, the Spanish government is planning 89 GW of wind and solar photovoltaic energy in the draft of the National Integrated Energy and Climate Plan (PNIEC) for 2021–2030 (1). Despite the Spanish government's efforts to prevent a speculative bubble in the secondary market, there a...

The European Union’s (EU) Common Agricultural Policy (CAP) still fails to address the environmental and socioeconomic challenges of EU’s agriculture. Agricultural ecosystems are further degrading, biodiversity is declining and agricultural Greenhouse Gas (GHG) emissions remain high. At the same time, farms are facing unresolved socio-economic chall...

Agri-environment schemes directly focused on bird conservation have been implemented in agropastoral Mediterranean drylands aiming to guide the design of agricultural landscapes to enhance biodiversity and associated ecosystem services. In this study, by linking agricultural intensification indicators with the richness of grassland specialist birds...

Anthropogenic noise is spreading worldwide and can interfere with the acoustic communication of multiple animal groups. Species communicating in low-frequency ranges (having large sound production structures) and with limited vocal learning are expected to be especially vulnerable to human noise-induced masking interference. yet how such species ma...

Agricultural intensification is one of the main drivers of species loss worldwide, but there is still a lack of information about its effect on functional diversity of arable weed communities. Using a large‐scale pan European study including 786 fields within 261 farms from eight countries, we analysed differences in the taxonomic and functional di...

In the last decades, western Iberian Mediterranean drylands have experienced a shift from extensive sheep to beef-cattle farming. In this 5-year study in Évora region (Southern Portugal), we investigated the role of livestock species in favouring grassland bird habitat suitability, starting from the hypothesis that livestock species complement bird...

The release of farm-reared game birds for hunting is an increasingly common game management practice. However, releasing could have negative effects on sympatric wild species, for example, through parasite transmission. Here, we document the spatial-temporal patterns and intensity of red-legged partridge releases in the province of Ciudad Real, Spa...

Multidimensional approaches must be employed when addressing habitat use patterns. In this study, we aim to elucidate the hierarchical nature of space use by species inhabiting fragmented landscapes, using the threatened Dupont’s lark (Chersophilus duponti). The intensity of space use by Dupont’s lark was estimated using the Kernel Density Function...

Agricultural intensification has profoundly affected European farmlands in the last decades, and their associated biodiversity has undergone a widespread decline. Although largely considered by farmers to be a threat to crop productivity, weeds and arthropods are key factors in farmland ecosystems and provide multiple ecosystem services. We analyze...

Farmland bird populations have strongly declined across Europe over the last decades due to agriculture intensification, despite successive reforms of EU’s Common Agricultural Policy (CAP). In parallel, CAP has led to a reduction of fallow land, a critical habitat for biodiversity in agroecosystems. Fallow land in Spain, a country harboring the lar...

In conservation biology, population monitoring is a critical step, particularly for endangered groups, such as steppe birds in European agrosystems. Long-term population monitoring allows for determination of species population trends and also provides insights into the relative roles that environmental variability and human activities have on prio...

Conservation agriculture (CA) gained recently some visibility in the Mediterranean region. By affecting soil and plant ecology, CA is expected to influence other biological groups, notably farmland birds. This study aims to assess (1) the importance of tillage regime (conventional vs. no-tillage) and frequency of cultivation under these two regimes...

Little bustard populations are showing alarming trends throughout the species’ large geographic distribution range, particularly in its western sector. For this reason, the little bustard has been globally classified as Near Threatened, although its decline in Western Europe has led to its classification as Vulnerable, according to IUCN criteria, b...

Background Identifying the factors that affect ranging behavior of animals is a central issue to ecology and an essential tool for designing effective conservation policies. This knowledge provides the information needed to predict the consequences of land-use change on species habitat use, especially in areas subject to major habitat transformatio...

Traffic noise is an associated effect of roads, potentially impacting wildlife. In the case of birds, it may alter spatial distribution, behavioural responses and physiological status, frequently masking acoustic signals of conspecifics and predators. We analyse how road traffic noise affects habitat selection of Little Bustard males during the bre...

Sex allocation models still fail to predict the complex sex ratio patterns in broods of vertebrates. A major problem when studying motherebrood interactions is the difficulty in disentangling hypotheses involving maternal preferences from processes that do not imply maternal manipulation. We studied maternal resource allocation in mixed-sex, same-s...

The Little Bustard Tetrax tetrax (Linnaeus, 1758) is a medium-sized, ‘Near Threatened’ steppe bird, whose Iberian population has been alarmingly declining over recent decades. Although this population loss has been mainly attributed to agricultural intensification, there is no information on Little Bustard adult mortality levels and their drivers....

Interspecific competition is a dominant force in animal communities that induces niche shifts in ecological and evolutionary time. If competition occurs, niche expansion can be expected when the competitor disappears because resources previously inaccessible due to competitive constraints can then be exploited (i.e., ecological release). Here, we a...

The effect of management of Mediterranean dry grasslands on farmland bird populations has been scarcely studied. We investigated population productivity and habitat selection of the little bustard Tetrax tetrax in the late breeding period, in grassland dominated landscapes of Southwest Iberia. Specifically our goals were to investigate how these pa...

Foraging strategies and diet selection play an essential role in individual survival and reproductive success. The study of feeding ecology becomes crucial when it concerns endangered species such as the Little Bustard (Tetrax tetrax), whose populations are suffering strong declines as a consequence of agricultural intensification. Despite the fact...

The inherent defencelessness against natural predators of bustards, which have relatively small bills and can neither perch in trees nor take refuge in water at night, renders them warier than other large-bodied birds. They are therefore dependent on large areas of little-disturbed, little-developed open country within which they can see and keep d...

In recent years, haying has extended to Iberian Mediterranean dry grasslands potentially impacting on grassland bird ecology. We evaluated the impact of haying on a grassland bird community of South Portugal. Our main goals were: (1) to investigate the exposure of different species to haying, (2) to investigate potential removal of nests and dead b...

Human recreational activities are becoming increasingly widespread and frequent, a fact that may potentially exacerbate their effects on wildlife. These human-related disturbances on animals may induce behavioural and physiological changes that can ultimately affect their fitness. Here we combine the use of behavioural and physiological approaches...

As the world's population continues to grow, the demand for food, fodder, fibre and bioenergy will increase. In Europe, the Common Agricultural Policy (CAP) has driven the intensification of agriculture, promoting the simplification and specialization of agroecosystems through the decline in landscape heterogeneity, the increased use of chemicals p...

1. Increasing land use intensification is leading to biodiversity losses worldwide, which can reduce the functioning of ecosystems. However, it is increasingly clear that not all species are equally important for ecosystem processes: whereas the loss of a functionally unique species may reduce the capacity of the community to perform some functions...

With the aim to identify priorities in conservation-oriented research, this paper reviews the level of scientific attention given to steppe birds in Spain during the last 50 years. We surveyed scientific literature using Thomson Reuters Web of Science and the journal Ardeola, using the English names of 28 species of steppe birds and the word “Spain...

Introducción Las aves esteparias están sufriendo un declive generalizado que las si-túan como uno de los grupos de aves más amenazados de Europa (Donald et al. 2001). La disminución de sus po-blaciones es debido a la intensificación agraria, la fragmentación del hábitat y a la alteración del paisaje (Devictor et al. 2008; Devictor y Robert 2009; Mo...

In order for competing species to coexist, segregation on some ecological niche component is required and is often mediated by differential habitat use. When unequal competitors are involved, the dominant species tends to displace the subordinate one to its less preferred habitat. Here, we use habitat isodars, an approach which reflects evolutionar...

We modelled the distribution of two vulnerable steppe birds, Otis tarda and Tetrax tetrax, in the Western Palearctic and projected their suitability up to the year 2080. We performed two types of models for each species: one that included environmental and geographic variables (space-included model) and a second one that only included environmental...

Methods, results and projections for three additional SDMs. (PDF)

Additional figures. (PDF)

In recent years, haying has extended to Iberian Mediterranean dry grasslands potentially threatening grassland birds. We evaluate the between and within-year effects of haying on grassland birds in Alentejo region, Portugal. Our main goals were: (1) to investigate variations on bird abundance and species richness in the fields hayed, with respect t...