Bird Communities Research Articles

Three decades of land use and land cover changes in an East African lake and their implications for the conservation of bird communities

AbstractLand use and land cover (LULC) dynamics using GIS and remote sensing techniques measure extent and spatial structure, which are critical for monitoring biomes. A digital LULC detection technique with multi‐temporal satellite imagery analysis was employed at four timepoints from 1987 to 2017 and performed using supervised classifications method in ERDAS imagine 2015. For image classification, the five major LULC types included forests, built‐up land, agricultural land, water bodies and grasslands. LULC of grasslands, forests and water bodies reduced, while LULC of agricultural and built‐up lands increased. Avifaunal surveys were conducted at 11 sites across the LULC classes to compare species richness and abundance. The decrement of forests and water bodies would result in habitat loss, affecting endemic and threatened avifauna, as forests showed highest avifaunal species diversity (H′ = 3.80). Despite the decrement, grasslands demonstrated higher avifaunal species richness (107) and abundance (2767). Species richness decreased significantly from grasslands to water bodies and agricultural land (p < 0.05), and from forests to agricultural and built‐up land (p < 0.05), and water bodies (p < 0.01). Avifaunal abundance decreased significantly from grasslands to all other LULC classes. Regular LULC change assessment is integral to avifaunal habitat and biodiversity conservation efforts, particularly at Lake Tana.

Elevational range size of the breeding bird assemblages and its relationships with richness in the Eastern Himalayas

Species range size reflects the underlying niche of species and directly affects the spatial pattern of species richness. However, the exploration of community mean range size has received relatively limited attention compared to the emphasis on species richness patterns. Additionally, few studies have tested how the rescue effect (the proximity of the distribution limits of potentially interacting species) relates to species richness. In this study, we used a two-year dataset of breeding birds along an elevational gradient in the Lebu Valley, Eastern Himalayas of China, aiming to explore (a) the association between the mean elevational range size of bird community and elevation, using three different ways to calculate the mean elevational range size (Stevens' method, midpoint method and specimen method), (b) examine the influence of drivers (including temperature seasonality, precipitation seasonality, net primary productivity, habitat diversity, geometric constraint, and interspecific competition) on the mean elevational range size pattern, and (c) investigate the effect of rescue effect on species richness pattern. Our results showed that the pattern of mean elevational range size and its underlying drivers vary significantly depending on the assessment method used. Using Stevens' method, which were calculated based on species occurrences, we observed a low-plateau pattern in mean elevational range size. In contrast, the midpoint and specimen methods, which calculate based on the species' distributing midpoint and abundance center, respectively, revealed a mid-peak pattern. Besides, our study supports several ecological hypotheses, including the ambient energy hypothesis, mid-domain hypothesis, and interspecific competition hypothesis. Furthermore, we found that geometric constraints and interspecific competition were the most influential predictors of mean elevational range size patterns, irrespective of the calculation method. Additionally, a significantly positive correlation was observed between the overlap of range margins and species richness, suggesting a contribution of the rescue effect to species richness patterns. The significance of the correlation is associated with the definition of species range size boundaries. Remarkably, this correlation becomes significant only when species range margins reach their 43 % threshold; beyond the 78 % range margin, the increase in correlation strength becomes minimal. Moreover, the rescue effect from low-elevation species was significantly more pronounced than that from high-elevation species, resulting in a species richness hump skewed towards lower elevations. Our findings contribute to validating the applicability and limitations of hypotheses related to species distribution, enhancing both theoretical and empirical aspects of research. This provides deeper insights for a more comprehensive and profound understanding of the local dynamics and interactions within the ecosystem.

Bird community response to one decade of riparian restoration along the Colorado River delta in Mexico

We assessed the response of breeding birds to one decade of riparian restoration in the Colorado River delta including active vegetation management since 2010 and various environmental water deliveries since 2014. Bird surveys were conducted from 2002 to 2021 at 230 bird count stations distributed along five river reaches with different hydrogeomorphic characteristics, across 7 routes in actively revegetated (“restored”) sites, and 20 routes in non-actively revegetated (“control”) sites. Both restored and control sites could be affected by environmental flows/water deliveries. We examined the temporal trajectories of four community-aggregated metrics for 53 breeding species, and the number of detections (counts) for the 30 most frequently detected among the 53 species at the restored and control sites, using generalized linear mixed-effects models. Diversity and richness of the 53 breeding species were highest in the wettest river reach, but higher than in control sites in only one restored site within one of the driest river reaches. The avian community was recovering in control sites, ameliorating a long-term declining trend, perhaps indicating indirect positive effects of active restoration. The response to restoration of the 30 most common species was species-specific. Ten of the 16 riparian forest specialist species had more detections in restored sites of the wettest reach (vs. only two in the driest reach). Species with preference for agricultural fields and generalists had the highest counts along the entire delta. Generalists generally decreased following revegetation, which was another positive restoration effect. Our results will be used to help guide future restoration efforts.

Patterns and processes underlying understory songbird communities in southern China

AbstractUnderstory bird communities, especially those comprising insectivores, are highly sensitive to forest loss and fragmentation. Currently, there is little knowledge regarding the large‐scale diversity patterns of understory bird communities, particularly in Eastern Asia. Consequently, we aimed to identify the distribution patterns of understory birds in southern China and the factors underlying these patterns. We analysed the diversity distribution patterns of taxonomic and functional α and β diversity for understory Passeriformes birds in southern China utilising cluster and ordination analyses. Subsequently, we analysed the effects of geographic distance, annual mean temperature, annual temperature range, annual mean precipitation, and annual precipitation range on diversity distribution patterns. In total, 9282 individuals belonging to 11 orders, 48 families, and 297 species were captured over 98,544 net hours, with Alcippeidae being the most abundant family in southern China. The understory bird communities of the 25 sites were categorised into six sub‐regions of the Oriental Realm (Indo‐Malayan Realm). The pattern in the distribution of taxonomic and functional β‐diversity of understory birds in southern China was consistent with zoogeographical regionalisation. Three distinct geographical groups were identified: Group 1 was located in the Min‐Guang Coast and Hainan sub‐regions; Group 2 was located in the East Hilly Plain, Southwest Mountains, and Western Mountains and Plateaus sub‐regions; and Group 3 was located in the Southern Yunnan Mountain subregion. The most critical factors related to the distribution patterns of β‐diversity were geographical distance, annual mean temperature, and annual temperature range. Our results showed that the understory bird communities of the Southwest Mountain, East Hilly Plain, and Western Mountains, and Plateaus sub‐regions were similar, as were those of the Min‐Guang Coast and Hainan sub‐regions. Our results underscore the joint roles of distance, temperature, and historical evolution in understory bird communities.

Environmental and ecological factors affecting tick infestation in wild birds of the Americas

The Americas hold the greatest bird diversity worldwide. Likewise, ectoparasite diversity is remarkable, including ticks of the Argasidae and Ixodidae families – commonly associated with birds. Considering that ticks have potential health implications for humans, animals, and ecosystems, we conducted a systematic review to evaluate the effects of bioclimatic, geographic variables, and bird species richness on tick infestation on wild birds across the Americas. We identified 72 articles that met our inclusion criteria and provided data on tick prevalence in wild birds. Using Generalized Additive Models, we assessed the effect of environmental factors, such as habitat type, climatic conditions, bird species richness, and geographic location, on tick infestation. Our findings show that most bird infestation case studies involved immature ticks, such as larvae or nymphs, while adult ticks represented only 13% of case studies. We found birds infested by ticks of the genera Amblyomma (68%), Ixodes (22%), Haemaphysalis (5%), Dermacentor (1%), and Rhipicephalus (0.8%) in twelve countries across the Americas. Our findings revealed that temperature variation and bird species richness were negatively associated with tick infestation, which also varied with geographic location, increasing in mid-latitudes but declining in extreme latitudes. Our results highlight the importance of understanding how environmental and bird community factors influence tick infestation in wild birds across the Americas and the dynamics of tick-borne diseases and their impact on biodiversity.

Impact of habitat management of small game species on bird communities in French Mediterranean scrublands

Impact of habitat management of small game species on bird communities in French Mediterranean scrublands

Breeding bird communities of the pine forests in the forest-steppe zone

Breeding bird communities of the pine forests in the forest-steppe zone

Resilience of Bird Communities After Wildfires in Algerian Cork Oak Forests

Resilience of Bird Communities After Wildfires in Algerian Cork Oak Forests

A country‐wide examination of effects of urbanization on common birds

AbstractUrbanization forms one of the most drastic alterations of the environment and poses a major threat to wildlife. The human–induced modifications of the landscape may affect individual's fitness resulting in population declines. Research on how urbanization affects fitness traits has shown mixed results. However, studies typically contrasted data from a single species from few urban and non‐urban sites collected over short timeframes. Examining multiple species across a broad urbanization gradient enables a more robust comparison and understanding of how different species are impacted by urbanization‐knowledge crucial for generating population predictions, which are essential for conservation management. Here, we use data from a nation‐wide citizen science project to examine variation in survival and relative body mass and size (wing length) of common passerine birds, collected along an urbanization gradient in the Netherlands over an 8‐year period. Urbanization was measured as the distance from the city's border and the proportion of impervious surface area. Although the overall association between urbanization and survival was slightly negative, there was support for lower survival closer to the city in three species (chiffchaff Phylloscopus collybita, European robin Erithacus rubecula, European greenfinch Chloris chloris) and higher survival closer to the city in two (great tit Parus major and house sparrow Passer domesticus) of the 11 species examined. The contrasting survival successes among species suggest that ongoing urbanization may lead to shifts in community structure and loss of biodiversity. Impacts of urbanization on relative mass and size also exhibited varying effects, albeit less pronounced, and these effects were not correlated with the effects on survival. This implies that body mass and size cannot be used as indicators for urban‐associated patterns of survival. Our results further imply that effective conservation management targeting bird communities should involve a range of diverse actions, as focusing on single measures is unlikely to simultaneously impact multiple species due to the variation in responses to urbanization.

Plant Invasion-Induced Habitat Changes Impact a Bird Community through the Taxonomic Filtering of Habitat Assemblages.

Describing the spatial distribution of communities is crucial to understanding how environmental disturbance can affect biodiversity. Agricultural lands are susceptible to disturbances of anthropogenic origin and have been identified as ecosystems of conservation concern. Such lands are vulnerable to invasions by anthropogenically introduced non-native plants disturbing habitats. This research focused on the invasion-induced taxonomic filtering of birds with shared habitat requirements. The birds were surveyed along a gradient of invasion-altered areas (far from the invasion, uninvaded although susceptible to invaders, and invaded) to identify changes in bird assemblages (ground/herb dwellers, bush foragers, ecotone birds, and tree foragers) caused by this disturbance. Data were collected from 112 sites sampled in southeastern Poland. There were significantly fewer bird species from each assemblage on invaded sites than on uninvaded sites, although exposed to invasion, despite the decrease in the abundance of only ground/herb dwellers. Beta diversity analysis showed that sites with invasion contained bird communities significantly different from those at other sites. Invasion-induced changes resulted in a significant reduction in the diversity of ground/herb dwellers in comparison with uninvaded sites and created a distinctive bush bird assemblage. This was most likely due to the transformation of the grassland layer and the thickening of the shrub layer by plant invaders, which resemble shrubs in morphology. The results indicated the filtering effect of invasion on bird species composition at the level of two habitat assemblages despite the decreases in bird abundance and species diversity of the whole community.

Urbanization reduces diversity, simplifies community and filter bird species based on their functional traits in a tropical city

Understanding how organisms are coping with major changes imposed by urban intensification is a complex task. In fact, our understanding of the impacts of urbanization on biodiversity is scarce in the global south compared to the north. In this study, we evaluated how bird communities are affected by impact of urban intensification in a tropical city. Thus, we assessed whether increased urban intensification 1) jeopardizes bird diversity (taking into account taxonomic-TD, phylogenetic-PD, and functional-FD dimensions), 2) drives changes in bird community composition and enables the detection of indicator species of such impact, and 3) leads to changes in bird functional traits linked to reproduction, resource acquisition, and survival. We found that urban intensification has a direct impact on the bird community, reducing all three types of diversity. Communities in areas of greater urban intensity are represented by fewer species, and these species are PD and FD less distinct. In addition, we detected at least ten species of areas of lower urban intensity that proved to be more sensitive to urban intensification. With regard to bird traits, we found no significant responses from reproductive, habitat use and feeding variables. Body weight and tail length were the only variables with significant results, with higher urbanization intensity areas selecting for species with lower weights and longer tails. Given the global biodiversity loss we are observing, this information can guide urban managers and planners in designing urban landscapes to maintain biodiversity in cities.

Assessing the potential of BirdNET to infer European bird communities from large-scale ecoacoustic data

1.Passive acoustic monitoring has become increasingly popular as a practical and cost-effective way of obtaining highly reliable acoustic data in ecological research projects. Increased ease of collecting these data means that, currently, the main bottleneck in ecoacoustic monitoring projects is often the time required for the manual analysis of passively collected recordings. In this study we evaluate the potential and current limitations of BirdNET-Analyzer v2.4, the most advanced and generic deep learning algorithm for bird recognition to date, as a tool to assess bird community composition through the automated analysis of large-scale ecoacoustic data.2.To this end, we study 3 acoustic datasets comprising a total of 629 environmental soundscapes collected in 194 different sites spread across a 19° latitude span in Europe. We analyze these soundscapes using both BirdNET and manual listening by local expert birders, and we then compare the results obtained through the two methods to evaluate the performance of the algorithm both at the level of each single vocalization and for entire recording sequences (1, 5 or 10 min).3.Since BirdNET provides a confidence score for each identification, minimum confidence thresholds can be used to filter out identifications with low scores, thus retaining only the most reliable ones. The volume of ecoacoustic data used in this study did not allow us to estimate species-specific minimum confidence thresholds for most taxa, so we instead used and evaluated global confidence thresholds selected for optimized results when consistently applied across all species.4.Our analyses reveal that BirdNET identifications can be highly reliable if a sufficiently high minimum confidence threshold is used. However, the inevitable trade-off between precision and recall does not allow to obtain satisfactory results for both metrics at the same time. We found that F1-scores remain moderate (<0.5) for all datasets and confidence thresholds studied, and that acoustic datasets of extended duration seem to be currently necessary for BirdNET to provide a reliable and minimally comprehensive picture of the target bird community. We estimate, however, that the usage of species- and context-specific minimum confidence thresholds would allow to substantially improve the global performance benchmarks obtained in this study.5.We conclude that a judicious use of AI-based identifications provided by BirdNET can represent a powerful method to assist in the assessment of bird community composition through the automated analysis of ecoacoustic data, especially when applied to acoustic datasets of extended duration.

Responses of bird functional communities to anthropogenic disturbances in the naturally fragmented Southern Mistbelt Forests in the Midlands of KwaZulu-Natal, South Africa

Forest disturbance poses major threats to biodiversity and forest ecosystem processes. Understanding bird species’ responses to disturbed forests is important for species conservation and forest management. Here, we assessed the impact of selective logging history (∼150 years), livestock grazing, alien plant invasion and adjacent matrix-type surrounding forest patches on bird species richness and functional diversity in 14 Southern Mistbelt Forest patches in the Midlands of KwaZulu-Natal, South Africa. The bird communities were surveyed using fixed-radius point-counts. We quantified functional diversity using three functional indices functional richness, functional divergence, and functional evenness. None of the disturbance types assessed affected the richness of bird species. The size of the forest patch affected bird species. For functional diversity, FRic was significantly higher in disturbed forest patches for forest specialists, insectivores and cup or ball-nesting birds. Functional evenness for the forest-sensitive groups, like forest specialists and insectivores, was significantly lower in disturbed sites. The results of this study showed that responses of functional communities and forest specialist bird species varied depending on disturbance type and intensity. We recommend that future studies assessing forest disturbance impacts on bird species use taxonomic proxies with different functional diversity indices for forest bird species conservation and management.

Springtime spatio-temporal distribution of bird diversity in urban parks based on acoustic indices

Human-dominated urban ecosystems have encroached on native habitats, positioning urban parks as crucial sanctuaries that support bird diversity conservation. Bird communities tend to act as significant indicators of habitat quality. Birds play a key role in generating soundscapes in urban environments, where a healthy acoustic environment is essential not only for human well-being but also serves as a core focus for environmental monitoring and landscape enhancement. Previous studies have pointed out that acoustic indices have great advantages and strong feasibility for long-term environmental monitoring. However, few studies on the comparative analysis of bird diversity across urban parks subject to varying degrees of urbanization have been published in this field. In this study we recorded the springtime soundscape across 8 urban parks in Nanjing (China) from March to April 2023 for 10 hours each day. Six acoustic indices of Acoustic Complexity Index, Acoustic Diversity Index, Normalized Difference Soundscape Index, Bioacoustic Index, Acoustic Entropy Index and Power Spectral Density were used to quantify the monitoring results. To investigate the influence of vegetation habitats on bird activity, we utilized K-means clustering analysis to categorize the parks based on their developmental gradient, while Principal Component Analysis (PCA) was employed to simplify the dimensions of 12 vegetation factors. The results revealed that the distribution of birds in urban parks is a complex interplay of variables including the gradient of urban development, the functions of park plots, and the characteristics of vegetation habitats, among others. Day-to-day, human and bird activities show similarities, yet birds' responses to urban environments vary by location. The daily movement of visitors exerts a discernible influence on park birds, even those adapted to urban life. In instances of heightened human activity, birds demonstrate a proclivity for seeking refuge in less disturbed areas, and their activity space tends to be concentrated on higher plants. Vegetation communities in areas of high human disturbance are found to provide substantial support to bird habitats. Specifically, vegetation communities featuring tall trees or ground cover that form buffer zones have a significant positive effect on weakening the impact of human activities on bird communities. In terms of monitoring bird diversity with acoustic indices, Bioacoustic Index and Acoustic Diversity Index show more consistent performance, rendering them more reliable than other acoustic indices.

Regional differences of functional and taxonomic bird diversity in tropical agroforests of Peru

AbstractDiversity and functionality of bird communities in tropical agroforests are shaped by their surrounding landscape, particularly the extent and type of natural forest. However, most evidence comes from tropical rainforest landscapes, whereas the bearing of such trends in other forest types remains understudied. We compared functional and beta diversity of bird communities in 23 cacao agroforests embedded in landscapes of two contrasting Peruvian regions: seasonally‐dry tropical forests and subtropical rainforests from the Andean foothills. Strong climatic seasonality affects both landscapes, but forest vegetation structure and complexity differ. We found higher bird species richness (n = 179 spp) and higher species turnover in the subtropical forest than in the dry forest landscape (n = 64 spp). Only in the dry forest landscape, distance from forest increased dissimilarity driven by species loss, that is, the nestedness component of beta diversity. This points to the importance of conserving dry tropical forests within the broader landscape matrix, with known benefits for pest control and cacao yield. Functional diversity indices were not influenced by forest distance in either landscape, but the proportion of insects in birds' diet decreased by 27% along a 1 km distance gradient from forest in the subtropical forest landscape. In the dry forest landscape, however, it decreased by only 3% across the same distance gradient. Far from forest (≥1 km), forest specialization decreased by ~33% and 20% in the subtropical and dry forest landscapes, respectively. These differences indicate that regionally‐adapted agroforest management is paramount for conserving bird diversity and ecosystem services as pest control. Procuring high‐canopy shade trees and adequate microhabitats for insectivorous species is essential to maintain biocontrol services in the subtropical forest. Conversely, in the dry forest enhancing low‐canopy vegetation with a focus on frugivores and ensuring forest closeness to agroforests may maximize bird diversity and their ecosystem services. A complete version of this article is translated to Spanish in the supplements.

Home-range positions in a bird community from south-eastern Australia - questions and answers

ABSTRACT Territoriality in birds has been studied for almost 100 years, but a quantitative, simple and common unit which describes the position of a home range or territory on a study site, is lacking. Consequently it is difficult to assess, or to compare, any data that include for example, the putative movement of home-ranges between breeding seasons. The aim of this study of 11 species (18 species breed regularly on the study site) was to determine, using home-range centroids as the position of the home-range (a) the distance between the home-ranges of the male and female of a breeding pair, (b) the scatter of the home-range positions of a repeat (in different seasons) breeding male, and (c) the distance between the nest of a pair and the home-range centroid of the male. Over eight breeding seasons, all nests were found, and sightings of multiple individuals from each species were recorded and used to determine the centroid of the home-range of each individual. Nest positions and homerange centroids were used to investigate the three aims stated above. There are no differences between species for any of the three measurements. The male and female of a pair occupy homeranges with similar positions. Repeat nesters return to similarly positioned home-ranges each season, and nests are not positioned in any particular relation to the centroid of a home-range. Other studies using centroids are rare, but we found some similarities between our data and those from one other study that used the centroid concept.

Application of citizen science with the nationwide bird census

Citizen science (CS) is the most effective tool for overcoming the limitations of government and/or professional data collection. To compensate for quantitative limitations of the 'Winter Waterbird Census of Korea', we conducted a total of four bird monitoring via CS from 2021 to 2022. To use CS data alongside national data, we studied CS data quality and improvement utilizing (1) digit-based analysis using Benford’s law and (2) comparative analysis with national data. In addition, we performed bird community analysis using CS-specific data, demonstrating the necessity of CS. Neither CS nor the national data adhered to Benford's law. Alpha diversity (number of species and Shannon index) was lower, and total beta diversity was higher for the CS data than national data. Regarding the observed bird community, the number of species per family was similar; however, the number of individuals per family/species differed. We also identified the necessity of CS by confirming the possibility of predicting bird communities using CS-specific data. CS was influenced by various factors, including the perceptions of the survey participants and their level of experience. Therefore, conducting CS after systematic training can facilitate the collection of higher-quality data

Avian functional diversity retained in a tropical rainforest fragment after more than 120 years of turnover

Deforestation is linked to the increasing prevalence of small forest fragments worldwide and an associated loss in functional diversity. However, our long-term understanding on how biodiversity and functional roles respond in such isolated fragments is limited, especially in Southeast Asia. We compared the bird community in a small primary rainforest fragment in the Singapore Botanic Gardens, a UNESCO World Heritage Site, using historical records in 1898 and contemporary surveys conducted in 1998 and 2018–2021. Species composition was expectedly dissimilar between the 1898 and contemporary bird communities (50%), driven mostly by turnover (45.5%) rather than nestedness (4.5%). Despite the changes in community composition and species extirpations, both species richness and functional diversity were retained. Our results suggest that small forest fragments can form novel bird communities that are functionally similar to previous communities that inhabited the fragment, leading to the retention of functional diversity. Such functional redundancy may be encouraged through habitat restoration initiatives adjacent to fragmented forests.

Reorganization of bird communities along a rainforest elevation gradient during a strong El Niño event in Papua New Guinea.

The El Niño 2015 event, most extreme since 1997, led to severe droughts in tropical wet Papua New Guinea (PNG), reducing May to October dry season rainfall by 75% in the lowlands and 25% in the highlands. Such droughts are likely to have significant effects on terrestrial ecosystems, but they have been poorly explored in Papua New Guinea. Here, we report changes in bird community composition prior to, during, and after the 2015 El Niño event along the elevational gradient ranging from 200 m to 2700 m a.s.l. at the Mt. Wilhelm rainforest in PNG. The abundance of birds in the lowlands dropped by 60% but increased by 40% at elevations above 1700 m during El Niño year. In the following year, the individual bird species reached mean population sizes similar to pre-El Niño years but did not fully recover. Species richness roughly followed the pattern of observed abundance and quickly and fully re-established after the event to the pre- El Niño values. Thus, at least some terrestrial birds seem to react quickly to the extreme droughts in lowlands and shift to less affected mountain habitats. We recorded upper elevational range limits to shifts by more than 500 m a.s.l. in 22 bird species (out of 237 recorded in total) during El Niño year, in contrast to their typical ranges. Our study suggests that a strong El Niño event can have strong but reversible effects on bird communities as long as they have an opportunity to move to more favorable sites through undisturbed habitats.

Birds of Berlin: Changes in communities and guilds in the urban park "Tiergarten" since 1850.

Urbanization has far-reaching consequences on birds, and knowledge of the impacts on taxonomic and functional diversity is necessary to make cities as compatible as possible for species. Avian diversity in parks in urban centers has been investigated multiple times, but rarely so in long-term studies due to lacking data. The Tiergarten in Berlin is a large-scale park in the city center of great value for people and many species including birds. We compiled bird species lists since 1850 and from monitoring in 2022 in one dataset to investigate how bird communities and guilds have changed over time and how these alterations were influenced by the eventful history of the park's vegetation conditions. Long-term changes in species assemblages were analyzed with an ordination analysis, and changes in guild presence and functional richness were discussed with regard to landscape transitions. A gradual development of species assemblages yet only small changes in guild composition since 1850 was detected, whereas the 1950 community stands out with a drop in species richness and replacement of forest species with an open land community, which reflects the deforestation of the park during World War II. Consideration of habitat, lifestyle, trophic, and migration guilds revealed no sign of functional homogenization over the last 172 years (1850-2022). Despite the high frequentation of the park by humans it still allows for a high bird diversity due to the Tiergarten's sheer size and heterogeneity of vegetation and habitats. We recommend that the park is maintained and managed accordingly to preserve this condition and advise other urban parks to strive for these beneficial features.