Garden Birds - Mike Toms Collins New Naturalist Library

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and soon after that came new forms of sunflower seed and the tiny black seeds of Niger Guizotia abyssinica. While the main markets for wild birdseed are in Europe and North America, the key production areas lie elsewhere, in eastern Europe (particularly important for sunflower seed), China, India and Myanmar.

      The foods provided at garden feeding stations differ in their composition, both in terms of macronutrients like carbohydrate, fat and protein, and micronutrients like calcium, carotenoids and vitamin E. All are important for birds, though in differing amounts and some may be more important at particular times of the year than at others. Protein, for example, plays an important role in female birds as they prepare for the demanding production of a clutch of eggs. When you look at the foods most commonly provided at garden feeding stations here in the UK, you soon discover that they typically have a higher fat content relative to that of protein: black sunflower seeds (fat 44.4 per cent : protein 18.0 per cent), peanuts (44.5 per cent : 28.7 per cent) and peanut cake (70.5 per cent : 17.1 per cent) (Jones, 2018). In addition to their carbohydrate, protein and fat content, foods like peanuts and sunflower seeds may be important sources of micronutrients, such as vitamin E. As will become clear later in this chapter, these micronutrients are not just important for the adult bird; they are also important for eggs and their developing embryos.

      Sunflower seeds and sunflower hearts

      The sunflower seeds used for bird feeding have a relatively high edible oil content, something that results from several decades of work using selective breeding. The plant itself originates in North America and was initially cultivated by Native Americans, the seed probably arriving in Europe through Spain. Russian agronomists took a great deal of interest in sunflower seeds and began a programme of work selecting for those that were high in oil, successfully delivering an increase in edible oil content from 20 per cent to almost 50 per cent. These high edible oil lines from Russia were reintroduced into North America after the Second World War, rekindling interest in the crop. It is from here that sunflower seeds appear to have entered the bird food market, although eastern Europe and Russia – which account for just under half of the worldwide production – are now the most important source for sunflowers entering the UK market. Worldwide production is about 40 million tonnes.

      FIG 19. Sunflower hearts, with their high edible oil content, are very popular with garden birds like Goldfinch. The popularity of these seeds has as much to do with Russian agronomists as it does with American entrepreneurs. (John Harding)

      Sunflower seeds and their oil have a range of market uses, with the black-husked oilseed type a staple for bird food; this was introduced into the UK in the 1970s. Sunflower hearts were first introduced to the UK market during the early 2000s, their use proving popular with both wild birds and with the people putting out food. Unlike black sunflower seeds, hearts are already de-husked so leave less mess under bird feeders that then needs to be cleaned up. The lack of a husk also reduces handling times for feeding birds, which makes the hearts energetically more attractive that the traditional black sunflower seeds. At 6,100 kcal per kg, the calorie content of sunflower hearts is better than that of peanuts (5,700 kcal per kg); because the hearts have been de-husked, by weight they are also significantly higher in kcal than black sunflower seeds (5,000 kcal per kg).

      Peanuts

      Peanuts, also known as monkey nuts or groundnuts, are the edible seeds of Arachis hypogaea, a cultivated leguminous plant originating from a genus that developed in southwest Brazil and northeast Paraguay, where the most ancient species in the genus still grow. Available evidence suggests that Arachis hypogaea itself emerged within the hunter/cultivator communities present in Peru and/or Argentina. Peanut shells dated to 1800–1500 BCE have been excavated from sites near Casma and Bermejo in Peru and in the High Andes of northwest Argentina. There is also evidence of early presence in China, suggesting that mariners from China visited the South American region and returned home with peanuts. Evidence from shipwreck remains off the South American coast adds further support to this hypothesis.

      In recent history, and up until the 1960s, peanut production was dominated by countries within the sub-Saharan region of Africa, but this changed rapidly following low yields, change in domestic policies and a reduction in market pull (Pazderka & Emmott, 2010). Over the same period (see Table 2), China became the dominant producer of peanuts, securing 37 per cent of the producer market share by the mid-2000s and benefitting from internal agricultural reforms and the development of its market economy. Production within some countries (e.g. India and Indonesia) is more targeted towards internal markets than export and there has also been an interesting development in the market for value-added prepared peanuts, which is why the Netherlands features so prominently in the export table.

      Peanuts can vary in their quality, both between regions and in relation to local climatic factors. There is, for example, a general acceptance that those produced in China are of better quality than those originating in India because of the higher oil content that they contain. With more than 100 countries cultivating peanuts, of many different varieties, it is easy to see how the wild bird food peanut market now has global reach. As we will discover in Chapter 4, peanuts are not without their problems; the presence of aflatoxin is a major threat to the market and to peanuts destined for wild bird food. In some years and areas, whole crops can be lost because of the presence of aflatoxin – which is toxic to both humans and birds – and this is why, for example, US producers can spend in excess of $27 million annually in order to ensure that their peanuts meet the agreed standards for aflatoxin control.

      Peanuts were once a staple at UK garden feeding stations, initially presented in mesh bags, and to some extent still are for many of those who feed wild birds. However, the development of new seed mixes and the popularity of sunflower seeds and hearts with both birds and bird feeders have reduced their prominence. It is not unusual for those providing food to comment that the peanuts in their feeders often go largely untouched, except for visiting Great Spotted Woodpeckers and occasional Nuthatches Sitta europaea.

      Seed mixes

      A wide range of seed mixes is now available for use in feeding wild birds and these can vary greatly in their composition. In addition to seed-only mixes, some also include fat- or suet-based material or have invertebrate protein or fruit added to them. Watch a Greenfinch feeding at a feeder containing a seed mix and you’ll soon discover that the bird will typically select certain seeds and drop others. This pattern of selection reflects the fact the different seeds and grains vary in both their nutritional content and in the time required to process them. A feeding bird is seemingly able to balance these two components and make an appropriate selection.

      Recognising the different nutritional content of different types of seed, and wishing to secure an advantage in what is a highly competitive market, a number of wild bird care companies have signed up to the Birdcare Standards Association, an industry body that is governed by a set of guidelines. The guidelines for wild birdseed (see Table 3) effectively identify certain foodstuffs as being largely unsuitable. These, which include buckwheat and whole oats, sometimes feature prominently in cheaper seed mixes, where they effectively provide a bulking agent, which is little used by the birds. When looking for a seed mix, you often find that you get what you pay for, the better-quality mixes commanding a premium. However, you also need to consider the species that will be feeding on the mix; if, for example, the main recipients will be House Sparrows, then a mix with larger seeds and grains is likely to be better used than one which is made mostly of smaller seeds which the sparrows find difficult and time-consuming to process.

      Niger

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