Population 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.

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Growing urbanization increasingly influences ecosystems worldwide. While the effects of urban conditions within species (through either plastic or evolutionary responses) have been widely studied, their potential influences among species (through environmental filter), especially concerning their colouration, remain poorly known. Here, we investigated whether avian communities breeding inside and outside a major European city (Paris) differ with regards to melanin‐based plumage colouration. Melanins are heritable pigments present in many taxa and have a series of unique properties that may allow coping with urban conditions. Using melanic‐based colouration as an integrative phenotypic marker, we predicted 1) that the probability of breeding inside the city should increase with the intensity of species melanin‐based colouration, 2) that for species breeding both inside and outside the city, density should increase with the intensity of dark colouration inside the city, but not outside the city and 3) that species not breeding inside the city should not exhibit this positive relation between density and colouration. Our results confirmed these predictions. In addition, the density of species not breeding inside the city decreased with the darkness of their plumage. Altogether, these results suggest that bird species experience a balance between costs and benefits of melanin‐based colouration shaped by environmental conditions. Both the environmental filtering and the urbanisation‐shaped relation between density and colouration evidenced here are likely a general trend, however possibly modulated by additional local environmental conditions. Their importance may even be underestimated given the restricted geographical scale and the overall urbanization rate of the region studied. Further studies involving regions with contrasted environmental conditions should gain insight into the consequences of urbanization worldwide on traits associated with melanin‐based colouration.