What impact does agriculture have on local bird populations in arid ecosystems?

Agricultural practices have the potential to negatively impact local ecosystems. Further, the clearing of native vegetation to make way for farming land could give rise to the loss of various faunal species. If properly managed, such practices have the potential to adopt a holistic approach combining agricultural produce and local species conservation. To examine such a prospective approach, the community conservation initiatives started by the agricultural village of Kanalsi, Haryana was the focus of attention. To begin with, the land use within the village and nearby areas was considered to examine the forest and agriculture dominated areas. Secondly, a survey was conducted in the month of December, 2012 to record the number of avian species present within this landscape. In total, 79 species of birds were recorded. Despite being an agriculture dominated region, the ecosystem conservation initiatives started by the local village communities had played a positive role for the protection of local avifauna.

Intensive agriculture has had a negative impact on biodiversity and human health across the world. Specifically, bird populations have declined for many years due to soil degradation and agrochemical pollution. This review, which draws on 890 sources, including research articles and literature reviews, examines the interaction between birds and intensive agriculture to better understand its effects and conservation implications. Intensive agricultural activities have resulted in significant population declines among insectivorous and carnivorous birds, while generalist bird populations have increased. The heavy use of pesticides in intensive agriculture affects food availability for birds by reducing invertebrate and vertebrate populations as well as natural vegetation cover, which has a significant impact on bird diversity. Additionally, the accumulation of toxic compounds reduces bird reproductive success. In general, intensive agroecosystems have consistently had lower avian diversity than forest habitats and even lower-impact agricultural systems. However, some agroecosystems, such as rice fields, agricultural drainages, and canal systems, create alternative habitats that can benefit waterfowl. Future work should consider strategies such as restoring and enhancing vegetation edges, preserving natural vegetation, implementing organic farming practices, maintaining water bodies, and providing economic incentives for landowners to conserve biodiversity on their land to promote bird diversity conservation.

Habitat fragmentation can change the community composition of species in remnant habitat patches. We studied the impacts of fragmentation by agriculture on the bird community in heavily fragmented areas of the sagebrush shrubsteppe in western North America. We examined whether bird communities in sagebrush habitat near orchards and vineyards were different from the community in interior sagebrush habitat, and evaluated whether observed differences could be explained by predator abundance, local vegetation, the presence of the habitat edge, or the proportion of land cover in the surrounding landscape. The bird community near agricultural edges differed from interior habitat: edge habitats had higher species diversity and were dominated by generalist bird species, while Vesper Sparrows, which are sagebrush-associated in this region, were strong indicators of interior habitat. The bird community also differed between orchard edge habitat and vineyard edge habitat, although the difference was small. Edge effects on species composition were associated with differences in the local vegetation, rather than the predator community or the proportion of urban, agricultural, and sagebrush cover on the surrounding landscape. We suggest that differences in the bird community within edge and interior habitat are the result of multiple mechanisms: avoidance of exotic grasses and attraction to high shrub cover in edge habitat, attraction to resources in adjacent habitats, and spill-over of generalist birds from the adjacent agriculture. The results of this study suggest that sagebrush bird conservation areas should be placed away from agricultural development.

Oceanic islands are among the most endemically biodiverse ecosystems in the world. They have been adversely impacted by human expansion, which affects regional biodiversity by altering the natural habitats of vulnerable, indigenous species. Birds represent a valuable indicator species of environmental change due to their ability to adapt quickly. Investigating the relationship between environmental change, abundance, and behaviors of birds can help us better anticipate potential impacts to island ecosystems. In addition, we can understand the population trends and restricted ranges of native avifauna, identify the regions needing protection, and assess habitat vulnerability linked to anthropogenic activities. In Mo’orea, French Polynesia, we studied nine passerine bird species using automated acoustic recording devices placed in agricultural, forested, and mixed habitats. Based on call counts per unit time and occupancy modeling, we found evidence that three non-native species preferred agricultural areas and low-canopy cover over dense forested areas. Furthermore, native bird detectability and possibly abundance was significantly lower than non-native birds. Using hierarchical cluster analysis to support inferences regarding behavioral differences, we found that native bird calling activity was negatively associated with non-native bird calling activity. Altogether, these results suggest native bird populations are at risk in all of the habitats studied, but forests serve as a potential refuge.

Farmland biodiversity continues to decline because changes in modern agriculture have led to the degradation and loss of key habitats. One farmland habitat that has received little attention during development of conservation measures is farmsteads. We use bird count data from a survey conducted at over 600 sites in 3725km2 agricultural landscapes in southern Sweden to investigate the importance of farmsteads as potential sources of biodiversity in simplified landscapes. We found that farmsteads, on average, had more bird species and individuals than semi-natural pastures and infield infield non-crop islands, probably due to a larger area of non-field habitats at farmstead sites. Presence of farm animals was an important predictor of bird diversity and numbers at farmsteads while variables associated with arable land-use intensification had limited effect. Old farmsteads with no current active farming, on average, had low bird numbers. We found no effect of agricultural intensification at the landscape level on alpha diversity at farmstead sites. Rather, species richness and abundance of birds tended to increase as landscapes became characterized by more intensive agriculture with larger fields. Farmsteads are widespread in simplified agricultural landscapes and may provide habitat to a range of farmland species. Applying conservation measures to farmsteads and local surroundings that increase the availability of safe nest-sites and good foraging grounds for birds could be implemented through publicity driven schemes. This combined with other agri-environment schemes in the surrounding landscape could enhance the amount of critical resources for farmland birds.

Farmland birds have suffered notable declines in Europe in recent decades, mainly due to agricultural intensification and climate change. Organic farming, which has been shown to enhance biodiversity, is increasingly being put into practice in European vineyards. Nevertheless, no previous studies have reported significant positive responses in avian communities to organic practices. On the other hand, cover cropping is a common practice in both organic and conventional vineyards and is thought to have positive effects on bird communities and, particularly, on insectivorous species that may help control pests in agroecosystems. In this work, we studied bird communities in Mediterranean vineyards in Catalonia (NE Iberian Peninsula) in both the breeding and wintering seasons, and tested the effects of two common management options – organic vs. conventional farming and herbaceous cover vs. bare soil – on bird communities. In particular, we focused on (a) insectivorous birds that may help control pests and (b) avian species negatively affected by climatic warming whose population fluctuations may reflect the resilience of these bird communities to future climate change. Organic farming had a positive effect on vineyard bird communities and, specifically, increased species richness and overall bird abundance. This farming technique also positively affected the abundance of both insectivorous species and species whose populations are declining due to climate change. The presence of inter-row herbaceous cover between vines also had positive effects on bird community parameters, specifically in spring and in organic vineyards, when herbaceous cover favours species richness and the abundance of insectivorous species. However, further investigations are still needed to better understand the effects of different types of vegetation cover - i.e. plant origin and composition (e.g. sown vs. spontaneous vegetation) and proportion of vegetation cover (full vs. partial vegetation cover) - when employed as tools in wildlife conservation. This work provides useful information regarding bird conservation, which will help mitigate the effects of climate change on bird populations.

In the last decades, profound modifications of agricultural practices occurred in Europe, including the introduction of modern livestock farming. These modifications negatively affected the fauna of rural areas, as indicated by the large demographic declines suffered by several populations of birds typical of these habitats. The impact of agricultural practices on bird populations has been widely investigated, while the effect of livestock farming has seldom been assessed. To fill this gap, we carried out a quantitative meta-analysis of the existing scientific literature and evaluated the size of the effects of livestock farming on birds of rural areas in Europe. We only found 26 papers on this topic, from which 72 effect sizes could be estimated. The barn swallow (Hirundo rustica) was the species on which most studies focused. Livestock farming positively influenced presence and distribution of barn swallows in breeding habitats, while it did not significantly affect reproduction of this species. Effects on other bird species typical of rural habitats were non-significant. The positive effect on the insectivorous barn swallow might be mediated by the enhanced insect abundance where livestock is reared. In addition, habitat features typical of rural settings where livestock is reared (e.g. cattle-sheds or large hayfields) positively affected barn swallows independently of actual presence of livestock at a setting. Presence of livestock at rural setting therefore seems beneficial to barn swallows, but not significantly to other bird species typical of rural habitats. The effect of livestock farming on birds of rural habitats has been under-investigated to date.

Agricultural activities are a major cause of change in avifauna, frequently resulting in diminished diversity and biotic homogenization, and ultimately compromising ecosystem functioning and resilience. Arid ecosystems, which provide habitat for numerous native and endemic bird species, are vulnerable to global change and valuable in predicting future ecosystem shifts in regions undergoing aridification as a result of climate change. However, the impacts of agriculture on bird communities in arid ecosystems are understudied. Here, we evaluate these impacts in the arid Limarí watershed in north-central Chile, a region that has experienced extensive land use conversion to agriculture over the past 50 years. Specifically, we investigated current spatial patterns of avian beta diversity and the impact of landscape context on this diversity facet. Moreover, we evaluated how bird species respond to land cover and habitat conditions and the role of specific bird traits in this regard. To achieve this, we evaluated taxonomic and functional beta diversity across 26 sites distributed along a gradient of agricultural development, applied a beta diversity decomposition procedure, and carried out hierarchical joint species distribution modeling. Our study revealed high taxonomic but low functional beta diversity of the avifauna in the Limarí watershed, potentially indicative of past functional homogenization. Contrary to our initial expectations, present agricultural practices did not decrease beta diversity. While human-related landscape elements and agricultural features mostly had neutral or positive effects on bird occurrence, they negatively affected endemic species and certain bird traits related to diet and habitat. Riparian vegetation cover and quality, unrelated to agricultural and urban development, emerged as key factors structuring the regional bird community, and influenced beta diversity. Our results underscore the profound influence of land use change on the avian community in this arid region and the vital role of riparian ecosystems in this regard. Balancing conservation objectives with agricultural development is key to ensuring both the persistence of several functional groups in the region as well as the ecosystem services they provide.

Abstract Organic farming is considered beneficial for biodiversity conservation in agricultural landscapes but the role of agricultural land use intensity (‘agricultural intensity’), particularly at regional scales, has often been neglected. We used breeding season bird abundance estimates from paired organic‐conventional fields in Saskatchewan (31 pairs), Ontario (36) and Québec (15), Canada to test two alternative predictions: that the positive effect of organic farming on bird abundance was (a) smaller when controlling for overall effects of local‐ and landscape‐scale agricultural intensity (accounting for main effects on abundance); or (b) increases with local‐ or landscape‐scale agricultural intensity (an interaction effect of intensity × organic farming). We also evaluated whether positive effects of organic farming were stronger in regions with greater agricultural intensity. The effect of organic farming on the cross‐species abundance of birds was only statistically supported in Ontario when not accounting for agricultural intensity. However, the estimated effect of organic farming was the same whether or not we controlled for agricultural intensity in Saskatchewan (supported positive effect) and Québec (unsupported effect). Little support existed for more positive effects of organic farming on abundance in areas with greater local‐ or landscape‐scale agricultural intensity. In Ontario, there was a trend for more positive effects of organic farming in more intensively farmed landscapes. Our results showed, for the first time in North America, an effect of regional‐scale agricultural intensity on the potential benefit of organic farms. The influence of organic farming on abundance was most positive in the region with the most intensive agriculture (Saskatchewan) and least positive in the region with the least intensive agriculture (Québec). Additionally, we showed that benefits of organic farming can be overestimated if the effects of local‐ and landscape‐scale agricultural intensity are not considered. However, positive effects of organic farming on cross‐species abundance and the abundance of individual species were still detectable when we controlled for agricultural intensity at local‐ and landscape‐scales. Synthesis and applications. When evaluating impacts of organic farming on biodiversity, it is important to consider the intensity of surrounding agricultural practices at local to regional scales. Our cross‐regional comparison showed that organic farming had the most positive effect on abundance of birds in the region with the most intensive agriculture (Saskatchewan) and least positive effect in the region with the least intensive agriculture (Québec). This demonstrates that birds can benefit from organic farming and this effect can be most pronounced in regions with more intensive agriculture, implying that birds may benefit most from expansion of the area of organic farming in regions where farming is most intensive.

Agricultural practices constitute both the greatest cause of biodiversity loss and the greatest opportunity for conservation1,2, given the shrinking scope of protected areas in many regions. Recent studies have documented the high levels of biodiversity-across many taxa and biomes-that agricultural landscapes can support over the short term1,3,4. However, little is known about the long-term effects of alternative agricultural practices on ecological communities4,5 Here we document changes in bird communities in intensive-agriculture, diversified-agriculture and natural-forest habitats in 4 regions of Costa Rica over a period of 18 years. Long-term directional shifts in bird communities were evident in intensive- and diversified-agricultural habitats, but were strongest in intensive-agricultural habitats, where the number of endemic and International Union for Conservation of Nature (IUCN) Red List species fell over time. All major guilds, including those involved in pest control, pollination and seed dispersal, were affected. Bird communities in intensive-agricultural habitats proved more susceptible to changes in climate, with hotter and drier periods associated with greater changes in community composition in these settings. These findings demonstrate that diversified agriculture can help to alleviate the long-term loss of biodiversity outside natural protected areas1.