Colony persistence in waterbirds is constrained by pond quality and land use

Abstract

Summary The conservation of wetlands, many threatened by human activities, is paramount to sustaining global biodiversity. Yet the protection of targeted wetlands may not be sufficient to protect the species they host because some species may also be impacted by alterations to the surrounding landscape. Some black‐headed gull (Chroicocephalus ridibundus: Laridae) populations have experienced a sharp decline in population size and number of colonies. Here, we investigated the relative contributions of wetland and its surrounding landscape to two major determinants of population dynamics, i.e. habitat selection and reproductive success, using 37 years of monitoring data. Our analyses revealed that large areas of cultivated land surrounding ponds and high vegetation cover of helophytes promote longer occupation of a pond by gull colonies, probably because they allow better reproductive success. We also found that both agricultural practices in surrounding landscapes and pond vegetation cover have sharply changed over the past 30 years in the study area, with an intensification of the former and a general decrease of the latter. These alterations are likely to have led to the observed decrease in the number of breeding gulls. The decrease in helophyte cover may have reduced their ability to construct nests in vegetation that protects them against flooding, and agricultural intensification may have decreased food availability during the crucial period of reproduction. Our study provides additional evidence, from long‐term changes in habitats and reproductive success, that in order to be effective, waterbird conservation plans should consider the terrestrial landscape surrounding wetlands, in addition to the quality of the wetland.

Assessing Habitat Suitability for the Common Pochard, Aythya Ferina (Anseriformes, Anatidae) at different Spatial Scales in Orel’ River Valley, Ukraine

“…Specialization coefficients correspond to the breadth of the habitat preferences of the species (Francesiaz et al, 2017). MNDW was the most important among EGV for specialization 1 axis at landscape level.…”

Artificial Aquatic Ecosystems

“…A study in the Florida panhandle found that natural streams, altered streams, and ditches within the same forested region had similar macroinvertebrate and fish assemblages [100]. Agricultural intensification around fishponds has contributed to the rapid decline in breeding populations of black-headed gulls (Chroicocephalus ridibundus) in central France [101]. More such comparisons between artificial and natural waterbodies in similar settings are needed to disentangle the effects of watershed setting from other factors that influence the condition of artificial aquatic systems.…”

Multiscale effects of habitat and surrounding matrices on waterbird diversity in the Yangtze River Floodplain

“…For example, Morimoto et al (2006) found that two woodland bird species prefer woodlands surrounded by agricultural areas over those surrounded by urban areas. Francesiaz et al (2017) found that gulls prefer ponds surrounded by meadow and fallow land rather than woodland. Dallimer et al (2010) found that the size of urban area and the amount of grassland patches affect the richness of moorland bird species in northern England.…”