Supplementary feeding can affect populations of birds. It reduces energy spent on foraging and reduces the risk of starvation, but it also increases the risk of disease transmission and predation. Supplementary feeding may reduce species richness if some species are better able to exploit supplementary food resources than others. Feeding may also artificially inflate the carrying capacity of the ecosystem, leading to bird nuisance in the form of droppings and noise. The aim of this study was to characterise and quantify the risk factors and consequences of feeding free‐living birds in public areas in the western part of the city of Amsterdam. In seven study areas, the following data were collected: bird population size and species composition, feeding events, and the type and amount of supplementary food offered. Estimations were made of the nutritional energy provided and the number of birds that could be supported by the food offered. Members of the public who fed the birds were invited to complete a questionnaire on various aspects of feeding. Results showed that supplementary feeding attracts juvenile gulls and feral pigeons, which could in the long‐term affect biodiversity. Bread was the main category of supplementary food being offered (estimated to be 67% of the total amount of food). The majority of respondents fed birds so as not to waste bread and meal leftovers. In six of the seven areas studied, an overabundance of nutritional energy was calculated. We conclude that the current type and extent of supplementary feeding in the city of Amsterdam is nutritionally unbalanced and affects species diversity at a local level. The overabundance is undesirable for reasons of both animal health, because it can lead to malnutrition, and public health, because surplus food attracts rats and may also have a negative effect on water quality.

中文翻译：

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在公共城市地区喂养自由生活鸟类的营养意义

补充喂养会影响鸟类的数量。它减少了用于觅食的能量并降低了饥饿的风险，但它也增加了疾病传播和捕食的风险。如果某些物种比其他物种能够更好地利用补充食物资源，则补充喂养可能会降低物种丰富度。喂食也可能人为地增加生态系统的承载能力，导致鸟类以粪便和噪音的形式滋扰。本研究的目的是表征和量化在阿姆斯特丹市西部公共区域喂养自由生活鸟类的风险因素和后果。在七个研究区域中，收集了以下数据：鸟类种群大小和物种组成、喂养事件以及提供的补充食物的类型和数量。估计了所提供的营养能量和所提供的食物可以支持的鸟类数量。喂养鸟类的公众成员被邀请完成关于喂养各个方面的调查问卷。结果表明，补充喂养会吸引幼海鸥和野鸽，从长远来看，这可能会影响生物多样性。面包是提供的辅食的主要类别（估计占食物总量的 67%）。大多数受访者喂鸟是为了不浪费面包和剩饭。在研究的七个区域中的六个区域中，计算出营养能量过剩。我们得出的结论是，阿姆斯特丹市目前的补充喂养类型和范围在营养上是不平衡的，并影响了当地的物种多样性。