Farmland birds

George Orwell (1944): "Those who really have to deal with nature have no cause to be in love with it"

Claiming to be dedicated to wildlife conservation is a constant refrain of farmer groups. In truth, not many farmers are interested in bio-diversity unless the result of it can be put to flight by a dog and shot. In 2010 the 19 species that rely on farmland for their survival were at their lowest populations ever recorded — half what they were in 1970 - while species like the corn bunting Miliaria calandra, grey partridge Perdix perdix, tree sparrow Passer montanus and turtle dove Streptopelia turtur showed a 90 percent decline. To many non-farmers it is a mystery why those who spend their working days amid the wonders of nature aren't more interested in wildlife conservation. But as George Orwell pointed out in 1944 when reviewing Sir William Beach Thomas' The Way of a Countryman: "Real rustics are not conscious of being picturesque, they do not construct bird sanctuaries, they are uninterested in any plant or animal that does not affect them directly... The fact is that those who really have to deal with nature have no cause to be in love with it."

Mark Avery: Little owls - would you miss them?

I haven’t seen a little owl for a while, and on checking my records on Birdtrack I am slightly surprised to find that I didn’t see a little owl Athene noctua in either 2011 or 2010 so it really is some time ago. So the next question has to be – is it just me? The State of the UK’s Birds for 2011 shows that little owls have decined in numbers by 40% in the last 40 years, with most of that decline since 1990. So it’s probably not just me. Given that little owls are farmland species that depend on invertebrates such as large insects and earthworms it may not be surprising that they are declining but I expect someone will blame their decline on the badger if we wait long enough!

Letter: Don’t blame the badgers for the loss of bird species, hedgehogs and bees - overuse of pesticides has had catastrophic effects on wildlife

To blame the badger for the loss of bird species, hedgehogs and bees is ludicrous. Badgers are carriers, not the cause, of disease. Insensitive farming methods and overuse of pesticides has had a catastrophic effect on our wildlife as a whole. I was born and raised on a farm, a farm where hay meadows were full of wild flowers and our wildlife had fantastic habitats. I would like future generations to be able to see the beauty and diversity of all our British wildlife, but it doesn’t look too good at the moment. We still have a little time to try and rectify the damage we have done, but soon it will be too late for some species, and trying to hide behind a creature and blame it for something it hasn’t done doesn’t help the situation.

Letter from A Morris, Oswestry to the Shropshire Star, published 20th January 2012

Irish farmland birds pushed to brink of extinction

Previously common farmland birds such as the corncrake, curlew and yellowhammer are now perilously close to extinction in Ireland, according to a four-year (2007-2011) study of the island’s bird populations. The corncrake Crex crex, whose distinctive cry used to be the bane of sleepless farmers, has seen its breeding population plummet by more than 80 per cent in the past 20 years alone. Breeding populations of curlew Numenius arquata are following a similar trajectory, down 60 per cent. The yellowhammer Emberiza citrinella has seen its numbers drop by more than 40 per cent in the past 20 years. One farmland bird which has already become extinct here is the corn bunting Miliaria calandra. This bird was recorded in modest numbers in the previous 1988-1991 Atlas survey but has since fallen off the radar.

De witte kwikstaart gaat sinds de jaren 1990 achteruit

De witte kwikstaart Motacilla alba is in de Benelux een zeer algemene broedvogel en komt in allerlei biotopen voor, vaak nabij menselijke bewoning, meestal in gebieden met open plekken en lage begroeiing, zoals akkers, buitenwijken van steden, parken, etc. Het zijn insecteneters, die men vaak kan zien rondscharrelen op hoopjes bagger langs slootranden en op hopen mest in het land. De populatie werd in 1998-2000 geschat op rond de 100.000 broedparen. Volgens SOVON is er echter sinds 1990 een significante afname van de broedvogelpopulatie van <5% per jaar. Ook in Zweden, Finland en de Baltische staten nam de broedvogelpopulatie in de jaren 1990 af (gegevens Birdlife International, zie bijlage).

Ooit was Winterswijk een Ortolanenparadijs

In de tweede helft van de jaren zestig van de vorige eeuw schatte ik (op grond van meerdere fietstochten elk voorjaar) het aantal broedparen van de Ortolaan Emberiza hortulana in de verschillende buurtschappen rond Winterswijk op 80-100 broedpaar. De Vogelwerkgroep Winterswijk (later VWG ZO-Achterhoek) houdt -gebaseerd op extrapolaties van latere tellingen- voor die periode nog hogere schattingen aan: 120-150 paar. De VWG schatte het aantal zangterritoria van de Ortolaan rond Winterswijk omstreeks 1980 nog op ca. 20. In 1990 waren er nog twee over. Het laatste broedgeval rond Winterswijk (en daarmee in Nederland) vond plaats in 1994 in de Haart op het biologische bedrijf van de familie Van Iepenburg; daar broedden ook lang nog 2-3 paar Grauwe Klauwieren Lanius collurio. Rond 2000 viel het doek definitief voor de Ortolaan in Nederland. Daarmee verdween naar mijn mening één van de mooiste karaktersoorten van het oude cultuurlandschap op de hoge zandgronden van ons land.

The long-term declines of invertebrates and birds on farmland

Invertebrates are an essential food source for most farmland birds. Dvac suction sampling was used to determine the abundance, biomass and community composition of those invertebrate groups considered important in the diet of farmland birds for the commonest arable crops. Approximately 40 fields were sampled at the edge and mid-field over 2 years in three different locations in England. In cereals, the fauna was primarily comprised of Araneae (10%), Coleoptera (30%) and Hemiptera (58%), whereas the oilseed rape fauna was dominated by Coleoptera (65%) and peas and potatoes by Hemiptera (89%). Beans contained a high proportion of Coleoptera (39%) and Hemiptera (49%). Aphididae were the most abundant family (20–86% of total), although in oilseed rape and beans, Chrysomelidae, Curculionidae and Nitidulidae formed ca 20% of the fauna. Aphids only formed a small proportion (7%) of the total biomass, except in peas (32%). Instead, Araneae, Carabidae, Heteroptera, Homoptera and Tipulidae formed much larger and more equal proportions. The highest abundance and biomass of invertebrates were recorded in cereals and least in potatoes. The Grey Partridge chick-food index in all crops was only a half or less of the level required to ensure that chick survival is sufficient to maintain numbers of this red-listed species.

Pesticides have major indirect effects on birds

Pesticides have major indirect effects on birds via the killing of both invertebrates important for food and also agricultural weeds which provide seed resources and also cover for invertebrates. Several pieces of evidence support the negative relationship between insecticide spraying and vital rates of farmland bird populations. Probably the best example comes from a fully replicated study of the grey partridge (Perdix perdix L.). This study showed that pesticide spraying affected the invertebrate food of partridge chicks, which was correlated with chick survival, and was the main cause of population decline. More recent examples come from another farmland bird specialist, the yellowhammer (Emberiza citrinella). A study showed that arable fields sprayed during the summer were used less frequently than fields not sprayed during the summer by adult yellowhammers foraging for food for their young. The availability of arthropods was depressed up to 20 days after an insecticide spraying event and this negatively affected yellowhammer chick survival. Both herbicide spraying and fungicide spraying have also been shown to be negatively correlated with invertebrate populations and weed populations and so these are also likely to negatively affect farmland bird populations.

Die Anwendung von Pestiziden in Landwirtschaftsflächen reduzierte Rebhuhn-Lebensraum und -Nahrung

Die Arten der Agrarlandschaft erleiden in den letzten Jahrzehnten erhebliche Bestandseinbrüche. Für die Hälfte der Pflanzenarten, ein Drittel der Insektenarten und vier Fünftel der Vogelarten sind Rückgänge der Populationsgrößen belegt. Das Rebhuhn ist besonders dramatisch zurückgegangen. Für ganz Europa wird geschätzt, dass der Bestand in den letzten Jahrzehnten um über 83 % zurückgegangen ist. In der Schweiz ist das Rebhuhn bereits fast ausgestorben. Die Vergangenheit als Steppenvogel erleichterte es dem Rebhuhn seit dem Mittelalter sich in den landwirtschaftlich genutzten Bereichen, in denen Felder und Wiesen die ursprüngliche Bewaldung ersetzten, neue Lebensräume zu erobern. Die Landwirtschaft damals war eine Mischung aus Tier- und Pflanzenzucht, und auf den zahlreichen, meist kleinen Feldern wuchsen zwischen den Feldfrüchten zahlreiche Wildkräuter („Unkräuter“). Auch Insekten fanden hier in großer Zahl und vielen Arten einen idealen Lebensraum. In der ersten Hälfte des zwanzigsten Jahrhunderts war das Rebhuhn eine zahlreiche und flächendeckend vorkommende Wildtierart in Deutschland. Der folgende Rückgang der Rebhühner ist vor allem mit der Intensivierung der Landwirtschaft nach 1950 verbunden. Die damals einsetzende Anwendung von Pestiziden und Herbiziden zur notwendigen Ertragssteigerung in Landwirtschaftsflächen verhinderte das Wachsen und Überleben von Wildkräutern und Insekten in den Feldern und reduzierte somit Rebhuhn-Lebensraum und -Nahrung. Die wichtigste Ursache für den Rückgang der Rebhühner ist die erhöhte Kükensterblichkeit, die sich seit den 1930er Jahren von ca. 50 % auf ca. 70 % erhöht hat. Großräumige Untersuchungen zeigen den Zusammenhang zwischen dem Rückgang der Rebhühner auf Grund der Abnahme der Insekten (Kükennahrung) durch den Gebrauch von Pestiziden, insbesondere von Herbiziden, da die Insektendichte von der Artenzahl und Häufigkeit der in der Kultur vorhandenen Wildpflanzen abhängt. Auf den meisten Feldern sind die Küken nicht in der Lage, den Tagesbedarf an Insekten in der zur Verfügung stehenden Zeit zu finden.

The breeding population of Northern Lapwing in Switzerland declined by 78% from 1993–1996 to 2005–2008

Numbers and distribution of Northern Lapwings breeding in Switzerland have undergone strong fluctuations over the last 150 years. In the 19th and at the beginning of the 20th century a decline to about 180 breeding pairs was noted. In the 1940s numbers started to increase again, when Lapwings began to nest on arable land. In the 1970s the population reached a peak with 1000 breeding pairs. In the 1980s a decline was observed again, which accelerated since the 1990s. In the most recent survey 2005–2008 only about 100 pairs (83–116) were found. This amounts to a decline of 78 % since the last national survey 1993–1996, carried out for the national distribution atlas. The number of 100 km2 squares occupied by Lapwings declined from 20.1 % to 6.6 % in the same period. In several regions Lapwings have completely disappeared. The decline was strongest in agricultural areas.