First confirmed breeding of an invasive alien species in the lagoon of Venice (Italy): the Sacred Ibis Threskiornis aethiopicus

After more than a decade of regular occurrence, the first confirmed breeding of the Sacred Ibis Threskiornis aethiopicus in the lagoon of Venice (Italy) was observed in 2020, in three sites. The ibises nested in colonies with of one or more species of Ardeidae and Phalacrocoracidae. The colonies were on islets < 2 ha in size, covered with thick vegetation. Nests were placed on the top of bushes or trees, at a height of 1.5-5 m. The colony sites seemed not occupied by adults until the end of February - half of March; laying took place from early May, with hatchings occurring from the end of that month until July. Overall, 22-24 pairs nested in 2020. Birds were observed feeding at saltmarshes, freshwater wetlands and arable fields; a public garbage collection site was also used regularly. Given the high number of suitable nesting and feeding sites, a rapid growth of the Sacred Ibis population is expected in the next years.

A rapid assessment of waterbirds and the mangrove status in the Menabe Antimena Protected Area, Madagascar

Mangroves are of great ecological importance that provide multiple ecosystem services, shelter, and habitat for many threatened waterbird species. The mangroves of the Menabe Antimena Protected Area (MANAP) in western Madagascar are among the most extensive remaining on the island. The remaining dryland forests of the MANAP have been subjected to immense deforestation in recent years. Although remote sensing studies indicate that the mangrove forest loss is considerably lower than the dryland forest loss, little is known about the mangroves’ degradation status. Furthermore, detailed information on bird diversity and numbers is scattered, and previous surveys focused on northern parts of the MANAP, recently designated as the Wetlands of the Tsiribihina RAMSAR site. This study aims to assess bird diversity and abundance, as well as the status of mangroves in the MANAP. We conducted a rapid survey using direct observations at three sites along the coastal regions of the MANAP from 24 Sep–2 Oct 2019. We recorded 71 species of birds in the mangroves and coastal wetlands. High numbers of individuals were counted for several species. Numbers of the Madagascar Plover Charadrius thoracicus and the Madagascar Teal Anas bernieri fulfill criteria for important bird areas at single survey sites and the site is likely to be of importance for Madagascar Sacred Ibis Threskiornis bernieri; these three species are all globally threatened. Mangrove degradation is still limited, but numerous threats to mangroves are present. Our results highlight the importance of the mangroves of the MANAP for several endemic bird species in Madagascar. We provide recommendations for conservation management and future research.

The spreading of the invasive sacred ibis in Italy

The spreading of invasive species in new continents can vary from slow and limited diffusion to fast colonisations over vast new areas. We studied the sacred ibis Threskiornis aethiopicus along a 31-year period, from 1989 to 2019, with particular attention to the first area of release in NW Italy. We collected data on species distribution through observations by citizen science projects, population density by transects with distance method, breeding censuses at colonies, and post breeding censuses at roosts. The birds counted at winter roosts in NW Italy increased from a few tens up to 10,880 individuals in 2019. Sacred ibises started breeding in 1989, with a single nest in north-western Italy. The number of breeders remained very low until 2006, when both overwintering and breeding sacred ibises started to increase exponentially and expand their range throughout northern Italy with isolated breeding cases in central Italy. In 2019, the number of nests had increased to 1249 nests in 31 colonies. In NW Italy, the density of foraging birds averaged 3.9 ind./km2 in winter and 1.5 ind./km2 in the breeding period, with a mean size of the foraging groups of 8.9 and 2.1 birds respectively. Direct field observations and species distribution models (SDM) showed that foraging habitats were mainly rice fields and wetlands. A SDM applied to the whole Italian peninsula plus Sardinia and Sicily showed that the variables best related to the SDM were land class (rice fields and wetlands), altitude, and the temperature seasonality. The areas favourable for species expansion encompass all the plains of Northern Italy, and several areas of Tuscany, Latium, Sardinia, and Apulia.

African Sacred Ibis (Threskiornis aethiopicus Latham, 1790).

This chapter describes the terminology, nomenclature, morphology, geographical distribution, diet, physiology, reproduction, behaviour, ecology, habitats, invasion patterns, environmental impact, control and human use of the African sacred ibis (Threskiornis aethiopicus).