Houbara Research Articles

Pre-but not post-meiotic senescence affects sperm quality and reproductive success in the North African houbara bustard

Age-dependent reduction in reproductive success can arise due to multiple factors including a deterioration of reproductive physiology. Senescing males have been shown to produce ejaculates with poor sperm quality, which impinges on male reproductive success. In addition to individual age, gamete age can also affect male reproductive success. Accordingly, variance in male reproductive success can be due to pre-meiotic (referring to individual age) and post-meiotic senescence (sperm age). Here, we tested whether male senescence and sperm cell aging have additive or interactive effects on male reproductive success in a bird with a promiscuous mating system, the North African houbara bustard. To assess the effect of pre-meiotic aging, we compared male reproductive success between two age classes (3-6- and 12–16-year-old). To infer the effect of post-meiotic aging, male ejaculates were collected at three-time intervals following a common initial collection (day 1, 5, and 10). Therefore, day 1 ejaculates are supposed to contain younger sperm than day 5 and 10 ejaculates. Following controlled artificial inseminations, reproductive success was assessed using three fitness-linked traits (hatching success, chick growth rate and survival). In addition to reproductive output, we also assessed whether pre- and post-meiotic aging affected a wide range of sperm and ejaculate traits. In agreement with previous reports, we found that males in the older age class produced less sperm with poorer motility compared to young individuals. However, contrary to the prediction, we found that ejaculates collected at day 5 and 10 tended to have better sperm traits such as motility and velocity. The results on sperm traits were generally mirrored in the effect on reproductive success since young males produced offspring that grew faster and had better survival during the first month of life, and eggs fertilized by sperm collected at day 5 had the highest hatching success. In any of the models, there was evidence for interactive effects of male and sperm age. Overall, these results confirm the role of pre-meiotic aging on male reproductive success. The lack of evidence for sperm aging could come from the experimental design but might also reflect the pattern of mating frequency in a species with a lek-based mating system.

Factors modulating home range and resource use: a case study with Canarian houbara bustards

BackgroundThe home range of an animal is determined by its ecological requirements, and these may vary depending on many intrinsic and extrinsic factors, which are ultimately driven by food resources. Investigating the effects of these factors, and specifically how individuals use food resources within their home ranges is essential to understand the ecology and dynamics of animal populations, and to establish conservation measures in the case of endangered species. Here, we investigate these questions in the Canarian houbara bustard, an endangered subspecies of African houbara endemic to the Canary Islands.MethodsWe analysed GPS locations of 43 houbaras in 2018–2021, using solar GSM/GPRS loggers provided with accelerometers. We assessed (1) the variation in their home range and core area with kernel density estimators in relation to several intrinsic and extrinsic factors and (2) their foraging habitat selection.ResultsHome ranges were smallest during the breeding season (November–April), when rains triggered a rapid growth of herbaceous vegetation. Displaying males and nesting females had smaller home ranges than individuals not involved in reproduction. Both sexes used almost exclusively non-cultivated land, selecting low density Launaea arborescens shrublands, pastures and green fallows as foraging habitats. Heavier males used smaller home ranges because they spent more time displaying at a fixed display site, while heavier females moved over larger areas during the mating period, probably visiting more candidate mates. During the non-breeding season (May–October), both sexes showed larger home ranges, shifting to high density shrubland, but also partly to cultivated land. They selected sweet potato fields, green fallows, alfalfas, orchards and irrigated fields, which offered highly valuable food resources during the driest months of the year.ConclusionsOur study shows how Canarian houbara, originally a desert-dwelling species that uses mostly shrublands and pastures, has developed the necessary adaptations to benefit from resources provided by current low intensity farming practices in the study area. Maintaining appropriate habitat conditions in the eastern Canary islands should constitute a key conservation measure to prevent the extinction of this endangered houbara subspecies.

Evaluation of Sodium Alginate Stabilized Nanoparticles and Antibiotics against Drug Resistant Escherichia coli Isolated from Gut of Houbara Bustard Bird.

Alternative approaches and/or modified approaches to tackle resistance in gut microbes are need of the hour. The current study was planned to find the resistance modulation and toxicity potential of sodium alginate stabilized MgO nanoparticles and antibiotics against Escherichia coli (E. coli) isolated from the gut of Houbara bustard bird (n = 105 fecal samples). The preparations consisted of gel stabilized ampicillin (G+A), gel stabilized MgO and ampicillin (G+M+A), gel stabilized MgO and cefoxitin (G+M+C), gel stabilized tylosin (G+T), gel stabilized MgO and tylosin (G+M+T), and gel stabilized MgO (M+G). The fecal samples showed 53% (56/105) prevalence of E. coli which was found to be significantly (p < 0.05) associated with most of the assumed factors and resistant to multiple drugs. G+M+T showed the lowest (4.883 ± 0.00μg/mL) minimum inhibitory concentration (MIC) followed G+M+C, G+M+A, G+A, M+G, and G+T. Significant reduction (p < 0.05) in MIC with respect to incubation interval found at the 16th hr for G+M+A, G+A, and G+M+C that further remained nonsignificant (p > 0.05) onwards until the 24th hr of incubation. In the case of G+T and M+G, significant reduction in MIC was found at the 20th hr and 24th hr of incubation. Ecotoxicology and histopathology trials on snails showed mild changes in MICs of the preparations. The study thus concluded increasing drug resistance in E. coli of houbara bird while sodium alginate stabilized MgO nanoparticles and antibiotics were effective alternative antibacterial composites with mild toxicity.

Maximizing sexual signal transmission: use of multiple display sites by male houbara bustards

A good location of song or call posts and visual display sites of males is crucial for territory defence and mate attraction. These sites are typically located at prominent positions to ensure an efficient, long-distance sexual advertisement. If the purpose of display sites is to maximize visibility, a suitable strategy would be to use multiple display sites rather than just one site. We investigated this in the ground-displaying houbara bustard by using two recent technological advances that enabled us collecting high precision data, GSM/GPRS loggers provided with accelerometer and very high-resolution digital elevation models of the terrain. We found that 12 out of 20 marked males used two or three display sites instead of just one as previously assumed in this species. The most used display site had the largest viewshed and use of both alternative sites decreased in proportion to their decreasing viewsheds. The number of display sites was apparently determined by two factors. First, it was correlated with display intensity, suggesting that using multiple display sites may be a mechanism to increase sexual signal transmission in males that are dominant or in better condition. Second, supplementary display sites were not used when the principal display site already provided an excellent view of the surroundings, e.g. when it was located on a hilltop. These results confirmed that the function of secondary display sites is to supplement the viewshed provided by the principal display site, and so maximize sexual signal transmission.Significance statementPerforming sexual display from just a single place is often not enough to reach all possible mates or competitors, so using multiple posts may be crucial for an effective sexual signal transmission. This is particularly important when the display is visual, and topographical barriers or vegetation may block the male’s line of view. Using last generation GSM/GPRS loggers equipped with accelerometers and very high-resolution digital elevation models of the terrain, we show how houbara bustard males, who perform a costly running display on the ground, have developed a complex display pattern that involves the use of various nearby display sites. These display sites are used in proportion to their visibilities, which shows that this multiple display site system has evolved to maximize the aggregated visual field of males and so increase their visibility to females and neighbour males.

Pathologic findings of acantholytic squamous cell carcinoma coexisting with cutaneous cryptococcosis in a Houbara bustard (Chlamydotis undulata)

A 2-year-old Asian Houbara bustard was presented with a solitary well-defined, firm cutaneous mass on the hock region. Grossly, the mass protruded from the surface was located on the hairless and unpigmented areas of the right hock joint with ulceration and dried hemorrhagic foci. On microscopic examination, ulceration, hemorrhage, as well as hyperkeratosis were observed. Large round, oval to polygonal neoplastic cells extended into the dermis were arranged to form cords, trabeculae, islands or glandular-like structures without keratin pearls. These pseudoglandular structures were composed of pseudolumina containing acantholytic and detached tumor cells. Necrosis of the neoplastic cells was accompanied by infiltration of inflammatory cells particularly heterophils. Unlike pleomorphic tumor cells, mitosis count was almost frequent. No evidence of other abnormalities and tumor metastasis was found. These gross and microscopic features appeared to be suggestive of a rare histologic variant of squamous cell carcinoma (SCC), acantholytic SCC.

Anthropogenic influences on habitat use by African houbaras Chlamydotis undulata on Lanzarote, Canary Islands

African Houbara Chlamydotis undulata is threatened in North Africa by unsustainable hunting and massive overuse of captive-bred birds to replace wild losses. A small population on the Canary Islands is protected from these threats, but the archipelago is economically dependent on tourism which has led to extensive land-use change, particularly close to the coasts. We investigated the drivers of houbara distribution and abundance in and around the large semi-desert El Jable region of northern Lanzarote in order to identify potential measures to conserve this important population. All houbaras seen during point counts in the centre of 30 tetrads (2 km × 2 km) were recorded, along with their location. We used negative binomial regression to evaluate the effects of land use and human activity on the abundance of birds at tetrad scale. At finer scale we used logistic regression to assess the effect of land use on the distribution of displaying males. We recorded 196 houbara sightings on our surveys, although only 10 males were observed displaying. Houbara abundance had a quadratic relationship with the proportion of huerta (agricultural gardens) in a tetrad. The distribution of male displays was positively related to the proportion of long-abandoned farmland within a 100 m radius of their display site. African Houbaras favour the vicinity of small-scale agriculture and abandoned farmland, but avoid areas with higher levels of human land-use. Reduction of extensive land-use change and disturbance in El Jable are key conservation measures.

Density-dependence of reproductive success in a Houbara bustard population

Although density-dependent processes and their impacts on population dynamics are key issues in ecology and conservation biology, empirical evidence of density-dependence remains scarce for species or populations with low densities, scattered distributions, and especially for managed populations where densities may vary as a result of extrinsic factors (such as harvesting or releases). Here, we explore the presence of density-dependent processes in a reinforced population of North African Houbara bustard ( Chlamydotis undulata undulata ). We investigated the relationship between reproductive success and local density, and the possible variation of this relationship according to habitat suitability using three independent datasets. Based on eight years of nests monitoring (more than 7000 nests), we modeled the Daily Nest Survival Rate (DNSR) as a proxy of reproductive success. Our results indicate that DNSR was negatively impacted by local densities and that this relationship was approximately constant in space and time: (1) although DNSR strongly decreased over the breeding season, the negative relationship between DNSR and density remained constant over the breeding season; (2) this density-dependent relationship did not vary with the quality of the habitat associated with the nest location. Previous studies have shown that the demographic parameters and population dynamics of the reinforced North African Houbara bustard are strongly influenced by extrinsic environmental and management parameters. Our study further indicates the existence of density-dependent regulation in a low-density, managed population. • Density-dependency mechanisms also occur in low-density populations. • Reproductive performance is impacted by the density of birds around the nests. • Density-dependent effects do not vary in space and time.

Short‐distance nocturnal migration in an island endemic bustard

Migratory birds typically fly long distances in response to large‐scale seasonal climate variation. However, most migratory species are partial migrants, and some fly only short distances, for example to take advantage of suitable feeding conditions during the non‐breeding season. In spite of their short distance, such migrations may also be fixed in populations as a result of evolutionarily adaptive responses to local habitat conditions, but the causes and details of these partial, short‐distance migrations have been scarcely investigated. Here we analyse the migratory patterns of the insular endemic subspecies of Houbara BustardChlamydotis undulata fuertaventuraein a small island of the Canary archipelago. We tagged 41 individuals with GSM/GPRS loggers and tracked them over two annual cycles (2017–2019). We found that Canarian Houbara Bustards are short‐distance, partial migrants. Once the mating season was over, more than one‐third of all males and females moved from their breeding territories to non‐breeding areas where they spent the hottest months of the year. No bird changed its migratory status between years, and most individuals showed interannual fidelity to their breeding and non‐breeding areas. There were differences in the productivity of green vegetation between breeding and non‐breeding areas, as estimated from remote‐sensing‐based indicators of vegetation productivity (Normalized Difference Vegetation Index and Soil‐Adjusted Vegetation Index). During the non‐breeding period, values of both indices were higher at the non‐breeding than at the breeding areas in migratory birds, providing a plausible explanation of why these individuals moved to non‐breeding areas rather than remaining in their territories. Moreover, during the non‐breeding period, Soil‐Adjusted Vegetation Index values were lower at breeding areas abandoned by migratory birds than at breeding areas occupied year‐round, although values at the latter did not differ from those at non‐breeding areas, suggesting that partial migration arises from variability in food availability during summer across different areas. One of the four non‐breeding areas was selected by over half of migrant individuals. This area had a mosaic of cultivated and non‐cultivated patches, with more fallow fields and irrigated farmland than the other areas. Finally, most migratory flights were performed at night. The Houbara Bustard is globally threatened, and given its vulnerability to collision with electric and telephone lines during migration, we recommend burying electric and telephone lines in high‐traffic areas underground. Finally, we urge protection of the known non‐breeding areas, and recommend that current farming condition practices and natural shrubland at these areas continue to provide suitable habitat for Houbara Bustards.

The necessity of considering founder kinships in conservation breeding programs

AbstractConservation breeding programs pursue the double objective of preserving genetic diversity and producing individuals to support in situ conservation measures. Genetic management and monitoring are commonly based on pedigree analyses and are therefore dependent on the pedigree quality and the underlying assumption that founders of the captive population are neither inbred nor related to each other or to the captive population. Should founders be related, this assumption may lead to an overestimation of genetic diversity and an underestimation of inbreeding in captivity. In this study, we examined the effects of the founder assumption on estimates of genetic diversity by combining three approaches: (1) computer simulations of pedigrees of theoretical captive populations and their associated in situ source populations, (2) analysis of pedigrees of real conservation breeding programs and (3) microsatellite‐based computation of kinship among founders from a captive population of houbara bustard. The theoretical approach revealed that the captive population's average mean kinship Mk increases linearly with founder average Mk. The bias in Mk due to the founder assumption was strongly related to the effective size of the source population and to pedigree quality while remaining critical after 25 generations of captivity. Results based on real populations were consistent with theoretical ones and confirmed the overestimation of genetic diversity in captive populations. Overall, our results indicate that under situations classically encountered in conservation breeding programs (e.g. small and isolated source population, incomplete pedigrees), estimates of genetic diversity are potentially highly overestimated, challenging the genetic management of captive populations of species of conservation concern.

Transnational Seasonal Land Grabbing in Pakistan: Power Positions and Resistance

Each year, the Ministry of Foreign Affairs (MoFA), Pakistan issues a special 10-day hunting permit to royal family members of Gulf countries for seasonal hunting of Asian Houbara bustard ( Chlamydotis macqueen). This paper attempts to systematically present the understandings on seasonal land grabbing and its political economy in Pakistan. The role of local elites and government institutions and the response of local people, as well as their resistance, is discussed in detail.

Enforced monoandry over generations induces a reduction of female investment into reproduction in a promiscuous bird.

While uncovering the costs and benefits of polyandry has attracted considerable attention, assessing the net effect of sexual selection on population fitness requires the experimental manipulation of female mating over generations, which is usually only achievable in laboratory populations of arthropods. However, knowing if sexual selection improves or impairs the expression of life‐history traits is key for the management of captive populations of endangered species, which are mostly long‐lived birds and mammals. It might therefore be questionable to extrapolate the results gathered on laboratory populations of insects to infer the net effect of sexual selection on populations of endangered species. Here, we used a longitudinal dataset that has been collected on a long‐lived bird, the houbara bustard, kept in a conservation breeding program, to investigate the effect of enforced monoandry on female investment into reproduction. In captivity, female houbara bustards are artificially inseminated with sperm collected from a single male (enforced monoandry), or sequentially inseminated with semen of different males (polyandry), allowing postcopulatory sexual selection to operate. We identified female lines that were produced either by monoandrous or polyandrous inseminations over three generations, and we compared reproductive investment of females from the two mating system groups. We found that females in the polyandrous lines had higher investment into reproduction as they laid more eggs per season and produced heavier hatchlings. Higher reproductive investment into reproduction in the polyandrous lines did not result from inherited differences from females initially included in the two mating system groups. These results show that removal of sexual selection can alter reproductive investment after only few generations, potentially hindering population fitness and the success of conservation breeding programs.

Patterns of abundance reveal evidence of translocation and climate effects on Houbara bustard population recovery

AbstractPopulation reinforcement, through translocations of individuals, aims to restore populations of threatened species. The increase in population size or geographic distribution is often used as positive facts when assessing the recovery of a species, making abundance monitoring a major criterion. Based on 8‐year monitoring of a reinforced population of North African Houbara bustard (Chlamydotis undulata undulata), over an area of 50 170 km² in the eastern region of Morocco, we assessed the success of management actions by assessing spatial and temporal variation in abundance as well as the factors driving this variation. We used count data to estimate and spatialize population abundance. We then assessed environmental (climate) and management covariates (release effort and hunting management) associated with temporal and spatial variation in abundance. The overall estimate of abundance in the study area was 16 918 individuals (95% CI = 13 629–21 027) over our study period, with strong variation between years (range = 10 409–32 401). Our results highlighted strong spatial heterogeneity over the study area, linked to spatial variation in local climate and management conditions. Local abundances were negatively associated with local temperature, were higher in hunting than in non‐hunting areas, and were positively influenced by the number of birds released around the focal point. In addition to describing the spatio‐temporal variation in the abundance of the species on a large scale, we estimated two major proxies of its conservation status: population size and population trend. The determination of these proxies and the comparison with the counterfactual state of the species confirms the beneficial impact of the restoration and protection program on the dynamics of the North African Houbara bustard, while underlining the dependence of these dynamics on ongoing management.

Exposure assessment for avian influenza and Newcastle disease viruses from peridomestic wild birds in a conservation breeding site in the United Arab Emirates.

Worldwide, wild birds are frequently suspected to be involved in the occurrence of outbreaks of different diseases in captive-bred birds although proofs are lacking and most of the dedicated studies are insufficiently conclusive to confirm or characterize the roles of wild birds in such outbreaks. The aim of this study was to assess and compare, for the most abundant peridomestic wild birds, the different exposure routes for avian influenza and Newcastle disease viruses in conservation breeding sites of Houbara bustards in the United Arab Emirates. To do so, we considered all of the potential pathways by which captive bustards could be exposed to avian influenza and Newcastle disease viruses by wild birds, and ran a comparative study of the likelihood of exposure via each of the pathways considered. We merged data from an ecological study dedicated to local wild bird communities with an analysis of the contacts between wild birds and captive bustards and with a prevalence survey of avian influenza and Newcastle disease viruses in wild bird populations. We also extracted data from an extensive review of the scientific literature and by the elicitation of expert opinion. Overall, this analysis highlighted those captive bustards had a high risk of being exposed to pathogens by wild birds. This risk was higher for Newcastle disease virus than avian influenza virus, and House sparrows represented the riskiest species for the transmission of both viruses through direct exposure from direct contact with an infectious bird that got inside the aviary and indirect exposure from consumption of water contaminated from the faeces of an infected bird that got inside the aviary for Newcastle disease virus and avian influenza virus, respectively. These results also reaffirm the need to implement biosecurity measures to limit contacts between wild and captive birds and highlight priority targets for a thoughtful and efficient sanitary management strategy.

Reproductive performance in houbara bustard is affected by the combined effects of age, inbreeding and number of generations in captivity

Although captive breeding programs are valuable for conservation, they have been shown to be associated with genetic changes, such as adaptation to captivity or inbreeding. In addition, reproductive performance is strongly age-dependent in most animal species. These mechanisms that potentially impact reproduction have often been studied separately, while their interactions have rarely been addressed. In this study, using a large dataset of nine male and female reproductive parameters measured for 12,295 captive houbara bustards (Chlamydotis undulata undulata) over 24 years, we investigated the relative and interactive effects of age, inbreeding and number of generations in captivity on reproduction. We clearly identified (1) senescence patterns in all parameters studied; (2) negative effects of inbreeding on sperm characteristics, display behavior, egg weight, egg volume and hatching probability; and (3) changes in phenotypic values for seven parameters according to number of generations in captivity. However, the effect sizes associated with age were substantially greater than those associated with inbreeding and number of generations in captivity. Beyond the independent effects of these three factors on reproductive parameters, the results highlighted their interactive effects and thus the importance of integrating them in the design of genetic management plans for conservation breeding programs.

Avifauna Diversity in the Gate between Humid Atlas and Saharan Desert: Midelt Province, Morocco

The analysis of biological diversity at a regional scale is the first step to understand and classify the biological importance of a specific region and therefore the adoption of implementing conservation strategies. We conducted weekly bird counts by using the point count method from January 2015 to December 2017 in Midelt province, Morocco. A total of 130 bird species were observed, among breeding, migrant, and wintering species belonging to 42 families. Accipitridae (15 species), Muscicapidae (9 species), and Alaudidae (9 species) were the most observed families. Order of Passeriformes was the dominant order represented with 16 families and 68 species. Moreover, five species of conservation concern were recorded such as the vulnerable European turtle dove, houbara bustard, and Dupont’s lark; the near threatened ferruginous duck and bearded vulture; and the endangered Egyptian vulture. On the other hand, the results of the diversity analysis (Margalef index, Shannon–Wiener index, and Simpson index) showed the highest diversity in wetlands, forests, steppes, and farmlands, while cliff, landfills, and urban areas were the least diversified habitats. Finally, with its geographic situation between humid Atlas and Sahara desert, as well as the diversity of habitats and avifauna, Midelt region needs advanced analysis in terms of biodiversity and environmental characteristics, in order to provide effective conservation management.

Comparative Mapping of the Macrochromosomes of Eight Avian Species Provides Further Insight into Their Phylogenetic Relationships and Avian Karyotype Evolution

Avian genomes typically consist of ~10 pairs of macro- and ~30 pairs of microchromosomes. While inter-chromosomally, a pattern emerges of very little change (with notable exceptions) throughout evolution, intrachromosomal changes remain relatively poorly studied. To rectify this, here we use a pan-avian universally hybridising set of 74 chicken bacterial artificial chromosome (BAC) probes on the macrochromosomes of eight bird species: common blackbird, Atlantic canary, Eurasian woodcock, helmeted guinea fowl, houbara bustard, mallard duck, and rock dove. A combination of molecular cytogenetic, bioinformatics, and mathematical analyses allowed the building of comparative cytogenetic maps, reconstruction of a putative Neognathae ancestor, and assessment of chromosome rearrangement patterns and phylogenetic relationships in the studied neognath lineages. We observe that, as with our previous studies, chicken appears to have the karyotype most similar to the ancestor; however, previous reports of an increased rate of intrachromosomal change in Passeriformes (songbirds) appear not to be the case in our dataset. The use of this universally hybridizing probe set is applicable not only for the re-tracing of avian karyotype evolution but, potentially, for reconstructing genome assemblies.

Individuality in houbara chick calls and its dynamics throughout ontogeny

In many taxa, breeding success depends heavily on reliable vocal recognition between parents and offspring. Although the acoustic basis of this recognition has been explored in several species, few studies have examined the evolution of acoustic cues to identity across development. Here, in a captive breeding program, we investigated for the first time the acoustic signals produced by North African houbara bustard Chlamydotis undulata undulata chicks. Two call types (contact and distress) were recorded from 15 chicks in 4 age classes. Acoustic analyses showed that the acoustic parameters of the calls varied systematically with age in both contact and distress calls. However, both call types remained highly stereotyped and individualized between chicks at every tested age, indicating that calls encode reliable information about individual identity throughout development, thus potentially enabling the mother to distinguish her own chicks through their development up to fledging. Playback experiments are now needed to verify such parent-chick recognition in houbara bustards and its efficiency across chick ontogeny.

Captive breeding and the conservation of the threatened houbara bustards

Translocation of captive-bred individuals to reinforce wild populations may be an important conservation approach for some species, but can be detrimental when employed to boost exploited wild populations, particularly where repeated long-term reinforcement aims to compensate for repeated unregulated offtake. We review evidence that captive breeding alters multiple physiological, life-history and temperamental traits through founder effects, genetic drift and unintended adaption to captivity; degrades learnt behaviours; and compromises biogeography, population structure and viability through introgression. We highlight these risks for the globally threatened African houbara Chlamydotis undulata and Asian houbara C. macqueenii, 2 bustard species hunted throughout much of their ranges and now subject to multiple large-scale captive-breeding programmes and translocations. In eastern Morocco, annual releases of captive-bred African houbara are 2‒3 times higher than original wild numbers, but no investigation of their potentially deleterious effects has, to our knowledge, been published, although most wild populations may now have been replaced by captive-bred domestic stock, which are reportedly not self-sustaining. Despite multiple decades of reinforcement, we are not aware of any analysis of the contribution of captive breeding to African houbara population dynamics, or of the genomic consequences. Asian houbara release programmes may also be promoting rather than preventing declines, and need to contextualise themselves through rigorous analyses of wild population numbers, demographic rates and threats, maintenance of phylogeographic concordance of released with supplemented populations, profiling of traits crucial to survival and the measurement and modelling of the impacts of reinforcement on physiological and behavioural fitness of wild populations.

Moonlight triggers nocturnal display in a diurnal bird

The importance of nocturnal display in diurnal birds has been neglected for a long time, owing to the difficulties in recording behaviour by night. Using loggers with an accelerometer (ACC) we studied nocturnal display in male African houbara bustards, Chlamydotis undulata, ssp. fuertaventurae. Diurnal display of male houbaras consists of a visual component, the display run, and an acoustic component, the boom. Nocturnal display runs were only recorded twice, both on full moon nights. Nocturnal booming intensity was highest on full moon nights when it reached similar levels to those during peak diurnal display at dawn. The more favourable physical conditions for sound transmission and the reduced acoustic competition with wind and other birds at night have been proposed to explain nocturnal vocalizing. Minimizing copulation disruptions, a frequent intramale competition mechanism in bustards, could be an additional advantage of nocturnal display. However, these factors do not explain why vocal activity is highest on full moon nights. We suggest that moonlight may help displaying males to detect predators, as well as to communicate visually with approaching females. Moonlight also allows males to combine booms with visual signals produced by the white neck feathers exposed during booming into more efficient multimodal signals. Moonlight would thus ultimately lead to males achieving nocturnal copulations, which indeed might be more frequent than previously thought, according to rates of nocturnal ACC-recorded precopulatory movements. Finally, nocturnal booming sequences had almost twice as many booms as diurnal ones, which suggests that nocturnal vocalizations transmit higher-quality information about signalling males than diurnal vocalizations. Nocturnal booming significantly increased the total display time of male houbara bustards; thus, future studies should investigate whether nocturnal vocal activity represents an important contribution to individual fitness in this and other nocturnally vocalizing diurnal species.

Genetic assessment of a conservation breeding program of the houbara bustard (Chlamydotis undulata undulata) in Morocco, based on pedigree and molecular analyses.

Protection and restoration of species in the wild may require conservation breeding programs under genetic management to minimize deleterious effects of genetic changes that occur in captivity, while preserving populations' genetic diversity and evolutionary resilience. Here, through interannual pedigree analyses, we first assessed the efficiency of a 21-year genetic management, including minimization of mean kinship, inbreeding avoidance, and regular addition of founders, of a conservation breeding program targeting on Houbara bustard (Chlamydotis undulata undulata) in Morocco. Secondly, we compared pedigree analyses, the classical way of assessing and managing genetic diversity in captivity, to molecular analyses based on seven microsatellites. Pedigree-based results indicated an efficient maintenance of the genetic diversity (99% of the initial genetic diversity retained) while molecular-based results indicated an increase in allelic richness and an increase in unbiased expected heterozygosity across time. The pedigree-based average inbreeding coefficient F remained low (between 0.0004 and 0.003 in 2017) while the proportion of highly inbred individuals (F > .1) decreased over time and reached 0.2% in 2017. Furthermore, pedigree-based F and molecular-based individual multilocus heterozygosity were weakly negatively correlated, (Pearson's r = -.061 when considering all genotyped individuals), suggesting that they cannot be considered as alternatives, but rather as complementary sources of information. These findings suggest that a strict genetic monitoring and management, based on both pedigree and molecular tools can help mitigate genetic changes and allow to preserve genetic diversity and evolutionary resilience in conservation breeding programs.