ie Dog towns. Likewise the Eurasian Steppes may have been crucial to the breeding success of the Slender-billed Curlew which too may well be extinct and the breeding Sociable Lapwings which are now Critically Endangered. The effects of their conversion to farmland have been devastating as it is breeding success that maintains a population, lack of success is the road to extinction.
Changes in agricultural practices
Where traditional agriculture had already existed, largely in harmony with wildlife, the great advances that technology and science has brought to the industry have caused great and often overwhelming changes.
Northern Lapwings have declined by eighty per cent across the UK in the last fifty years, particularly in southern England and Wales. This is not due to some horrific single piece of environmental vandalism like the Saemangeum project, nor over harvesting of their food supply as in the Delaware Bay Horseshoe Crab situation, no, the blame for the huge reduction in Northern Lapwing numbers in the UK recently can be placed firmly at the door of habitat loss due to changes in agricultural practices.
It is the lack of breeding success due to a paucity of suitable places and despoilment of those that remain, rendering them unsuitable and unsafe, that is undoubtedly driving the numbers down. The species needs a variety of habitats in which to rear its young. Among these are open ground for nesting and incubation and longer vegetation for hiding the young when they have hatched. These habitats were lost at an alarming rate due to cessation of rotation of crops and mixed farming practices.
It’s all about the maths, and logic will tell you that a stable population relies on each adult being able to replace itself in its lifetime. If a pair can bring off two fledglings a year and survive for the average four and a half years, and if just two of those nine chicks can outlive their parents, which doesn’t seem like too much of an ask even in the harsh natural world then, as a species, they have cracked it. Sadly of late, it seems that this is not possible, especially in arable land, in the modern world of mega farming.
A trip to warmer places for birders is never complete without a visit to rice fields, they provide both food and shelter for many bird species and in particular waders. However once again the changes in the patterns of flooding are compromising their suitability for waders. Some rice strains can now be grown in relatively dry fields much reducing their suitability for waders and those that are still wet are advancing harvesting times. Conversely higher temperatures due to climate change are also affecting the flooding of rice fields. An example of this can be seen in Japan where the higher summer temperatures are bad for the rice harvest. In this case the farmers are delaying the flooding so that the harvest can be done in more suitable temperatures. The main use of the fields by waders is in the spring as they migrate north, and increasingly they find the rice fields dry and of little value for feeding.
In some places the rice fields are being abandoned altogether when they quickly become covered with tall vegetation making them of little use to waders. However, all is not lost for waders who frequent rice fields, particularly in the USA where the rice fields in South Carolina are managed wetlands and many areas are managed with waders in mind. Water levels are controlled to benefit them making areas always available to them, an idea that can be exported around the world and indeed has been with students at Gifu University in Japan involved in a project to persuade rice farmers to do just that.
Over grazing and under grazing by livestock
Grazing has been a friend to waders in the past, keeping vegetation relatively short can be an advantage along with the promotion of plant rich environments in which many invertebrates can dwell. However, over grazing turns the tables very quickly due to the increased threat to the eggs and young from trampling and also the reduction of any sort of cover for the birds.