Niche Analysis and Conservation of Bird Species Using Urban Core Areas

Abstract

Knowing the ecological requirements of bird species is essential for their successful conservation. We studied the niche characteristics of birds in managed small-sized green spaces in the urban core areas of southern (Kavala, Greece) and northern Europe (Rovaniemi, Finland), during the breeding season, based on a set of 16 environmental variables and using Outlying Mean Index, a multivariate ordination technique. Overall, 26 bird species in Kavala and 15 in Rovaniemi were recorded in more than 5% of the green spaces and were used in detailed analyses. In both areas, bird species occupied different niches of varying marginality and breadth, indicating varying responses to urban environmental conditions. Birds showed high specialization in niche position, with 12 species in Kavala (46.2%) and six species in Rovaniemi (40.0%) having marginal niches. Niche breadth was narrower in Rovaniemi than in Kavala. Species in both communities were more strongly associated either with large green spaces located further away from the city center and having a high vegetation cover (urban adapters; e.g., Common Chaffinch (Fringilla coelebs), European Greenfinch (Chloris chloris), Eurasian Blue Tit (Cyanistes caeruleus)) or with green spaces located closer to the city center and having high gray area cover and anthropogenic disturbance level (urban exploiters; e.g., Western Jackdaw (Corvus monedula), House Sparrow (Passer domesticus), Eurasian Magpie (Pica pica)). The eleven species that were common to both study areas similarly used the environmental variables and had similar niches, indicating that birds respond similarly to urbanization irrespective of latitude. Sixteen species in Kavala and eleven species in Rovaniemi were identified as conservation priority species, based on their niche specialization level and conservation status. The management actions proposed for the conservation of priority species will also benefit other species with similar ecological requirements and ultimately help maintain diverse bird communities in small-sized green spaces in urban core areas.

New Evidence on the Linkage of Population Trends and Species Traits to Long-Term Niche Changes

“…Detection probability may represent an issue when comparing niche across species [113]. However, intra-species niche comparisons are not supposed to be considerably affected by detection probability when comparing niche metrics of a species across different geographic areas [15] or over time. In fact, in the case of a standardized sampling design, the species habitat-specific detection function is supposed to be constant over time [114], and its effect on niche comparison may be considered negligible.…”

“…The quantification of the realized niche of a species [1] (sensu Grinnell [2][3][4][5], hereafter niche) and how it varies across space and time has received increasing attention in ecological Birds 2022, 3 150 studies, with important implications in evolution, biogeography, and conservation [6][7][8][9][10][11][12][13][14][15]. Many studies have focused on niche evolution in related taxa [16][17][18][19][20][21][22][23], or on niche quantification of alien species to assess their potential as invaders in non-native ranges [24][25][26][27][28][29][30][31][32].…”

Species Traits Drive Long-Term Population Trends of Common Breeding Birds in Northern Italy

“…In Germany, however, this trend has not been confirmed for the entire guild, since differences emerged between trends of farmland insectivorous birds and forest insectivorous birds, with the former decreasing and the latter stable [ 22 ]. Moreover, species with narrow niche breadth (i.e., specialist species) may suffer more from human-driven environmental alterations than species with broad niche breadth (i.e., generalist species), resulting in contrasting trends between the two groups [ 40 , 44 ]. Nesting location can influence the breeding success by affecting the exposure of the nest to predation (e.g., birds or mammals, [ 45 ]).…”

Long-Term Winter Population Trends of Corvids in Relation to Urbanization and Climate at Northern Latitudes

“…Despite that the Eurasian Jay has urbanized in central and southern Europe (e.g., [ 79 , 84 , 85 , 86 , 87 ]), we detected jays only in five surveys. Additionally, Jokimäki and Kaisanlahti-Jokimäki [ 58 ] indicated in their local-level winter study in Rovaniemi, Finland, that Eurasian Jays avoid urban areas.…”