Auteur: Henk Tennekes

According to the latest update of “The Atlas of the Breeding Birds of Ontario” the list of songbird species in Ontario that are declining is staggering. “Population trends are generally positive for birds of prey, but biologists are expressing concern about the fate of grassland birds and those that feed on flying insects,” says a statement from the organizers of the survey that led to the first update in 20 years.

According to the latest update of “The Atlas of the Breeding Birds of Ontario” the list of songbird species in Ontario that are declining is staggering. “Population trends are generally positive for birds of prey, but biologists are expressing concern about the fate of grassland birds and those that feed on flying insects,” says a statement from the organizers of the survey that led to the first update in 20 years.

Larger birds of prey have benefitted from a reduction in pesticide usage in the past 20 years but the population of smaller migratory songbirds has been affected dramatically and it may well be the result of urban sprawl which has removed millions of prime natural areas from the ecosystem, and as well as a “mysterious”decline in insect populations which may be related to changing global weather patterns attributed to increases in global warming.

Project co-ordinator Mike Cadman says that “Bald eagles have increased four-fold province-wide – even more so in the south – and peregrine falcons are back from the brink (of extinction),” Those recovering from near extinction include three species of swans, Canada goose and Wild Turkey.

“Unfortunately, the future seems much bleaker … for some other species,” said Gregor Beck, co-editor of the atlas that was updated this year. “For grassland species and birds that eat flying insects, the trend is very worrisome.”
Populations of some species, including the common nighthawk Chordeiles minor, whippoorwill Caprimulgus vociferus, chimney swift Chaetura pelagica and 6 types of swallow have dropped 30 to 50 per cent in the past 20 years. The nighthawk and swift Apus apus were recently designated as “threatened” species in Canada.

The biggest declines in small bird populations occurred in the south western region of Ontario according to many groups involved in the atlas, including Ontario Nature, Bird Studies Canada and the Ontario Field Ornithologists, along with the federal and provincial governments.

Source:
THE WOODSTOCK ONTARIO INDEPENDENT NEWS, 3 February 2008
http://jimbenderoxford.blogspot.com/2008/02/ontario-bird-survey-shows-so…

Sacramento’s remnant population of the Purple Martin Progne subis, a swallow recognized as a state Species of Special Concern, declined again in 2008 according to a recent survey. The number of nesting martins declined to 84 nesting pairs, a 21% decline from last year. The population is at the lowest level recorded since surveys were initiated in the early 1990s. The continued population decline in Sacramento worries biologist Dan Airola, who has been studying and managing the purple martin population for years with a group of dedicated volunteers. “Over the last 4 years, the population has decreased by over 50%, which is pretty dramatic” Airola notes.

Sacramento’s remnant population of the Purple Martin Progne subis, a swallow recognized as a state Species of Special Concern, declined again in 2008 according to a recent survey. The number of nesting martins declined to 84 nesting pairs, a 21% decline from last year. The population is at the lowest level recorded since surveys were initiated in the early 1990s. The continued population decline in Sacramento worries biologist Dan Airola, who has been studying and managing the purple martin population for years with a group of dedicated volunteers. “Over the last 4 years, the population has decreased by over 50%, which is pretty dramatic” Airola notes.

The martin, the largest swallow species in North America, was once common in the Central Valley. It was eliminated from nearly the entire Valley in the 1970s, following the arrival of the non-native European Starling, a nest-site competitor.

In Sacramento, martins survived by learning to nest within longer overpasses and elevated freeways, which they enter through “weep holes” on the undersides of the structures. Use of these bridges apparently minimizes competition for nest sites with starlings. The most likely cause for decline this year is drought, and its effects on the insect food supply for the martins. Martins are “aerial insectivores” capturing larger insects while soaring above the city and adjacent farmland. “When rainfall is low, aerial insect populations decline”, says Airola.

“Although most animals typically recover from drought conditions, the current low population now increases risk of further decline due to other causes” notes Airola. “Also, we don’t know whether this decline is indicating potential long-term effects of climate change, or if it was just a bad year”, he says. “But”, he emphasizes, “it’s pretty clear that any change in climate that creates drier spring conditions would be detrimental to the martins”.

Other threats to martins include the wave of recent in-fill development and transportation improvements, which can eliminate key habitat conditions for martins. Currently, projects with possible habitat conflicts are proposed at sites that support over 60% of the remaining nesting population, according to a recent study published by Airola and colleagues.

Redevelopment projects, including the Downtown and Curtis Park Railyards projects, can eliminate critical areas that martins use for perching and collecting nesting material. They also may increase traffic and resulting collision mortalities. The projects also may change the urban habitat in ways that increases starling populations and the resulting nest site competition.

This year, with partial funding from Sacramento Audubon Society, the volunteers have addressed effects of these projects. “It’s been an uphill struggle to get approving agencies to pay attention to the needs of Purple Martins, but I think we got their attention this year”, notes Airola. “Right now, everyone’s being pretty cooperative”.

Martins have a high tolerance for human activity, which explains their persistence to date in highly urbanized areas.
Airola also studied the martins’ response to construction of a parking lot beneath their nesting bridge at one site this year. Despite frequent disturbance, the bird remained at the site and bred successfully. “Honestly, I was surprised that they would tolerate the high level of noise and activity”, says Airola. “It tells us that the martins can be maintained in busy urban areas, as long as their habitat needs are met”.

The biologists, however, are not relying solely on bridges to maintain the remnant martin population. This year Airola and colleagues erected specially-designed martin nest boxes at the California Department of Fish and Game’s Yolo Bypass Wildlife area. There, they play martin songs to attract martins to nest. So far, no martins have adopted the boxes.

“Transitioning Purple Martins to nest boxes requires long-term commitment” notes volunteer Stan Kostka, who manages box colonies in Washington’s Puget Sound, and drives annually to Sacramento to help conduct martin research and management. “We’ve used boxes to recover populations elsewhere, so we are hopeful we can do it here” , Kostka notes.

“The key”, Airola emphasizes, “is to protect the Sacramento bridge-nesting birds, to provide new breeding birds to colonize the boxes and other bridges in the Valley. This colonization would contribute to the ultimate recovery of the species. “We were just lucky that we didn’t lose the species entirely before to the previous starling invasion”, he notes. “If we lose these Sacramento birds now, we pretty much lose the opportunity to recover the species to its former range within the entire Central Valley. But we’re pretty determined to not let that happen.”

Source: Sacramento Audubon Society
http://www.sacramentoaudubon.org/purplemartins.html

Bird List (English-Dutch):
http://members.ziggo.nl/devalk/vogellijst.htm

The Purple Martin (Progne subis) is the largest North American swallow. These aerial acrobats have speed and agility in flight, and when approaching their housing, will dive from the sky at great speeds with their wings tucked. Wintering in South America, purple martins migrate to North America in spring to breed. Their breeding habitat is open areas across eastern North America, and also some locations on the west coast from British Columbia to Mexico. Purple Martins are aerial insectivores, meaning that they catch insects from the air. The birds are agile hunters and eat a variety of winged insects. Rarely, they will come to the ground to eat insects. They usually fly relatively high, so, contrary to popular opinion, mosquitos do not form a large part of their diet.

Source: Wikipedia
http://en.wikipedia.org/wiki/Purple_Martin

Naturschützer schlagen Alarm: Haussperling Passer domesticus, Pirol Oriolus oriolus und Uferschnepfe Limosa limosa werden immer seltener in unserem Land. Nach der gerade vorgestellten “Roten Liste” der bedrohten Arten sind die Bestände der Feldlerche Alauda arvensis im Land seit 1999 um zehn Prozent, regional sogar um bis zu 50 Prozent zurückgegangen, beim Rebhuhn Perdix perdix hat sich der Bestand halbiert. Auch bei Wiesenvögeln wie Kiebitz Vanellus vanellus, Uferschnepfe, Wiesenpieper Anthus pratensis oder dem Braunkehlchen Saxicola rubetra sieht es schlecht aus. Von 212 Vogelarten in NRW stehen 81 Arten als ausgestorben, vom Aussterben bedroht oder gefährdet auf der Roten Liste. Selbst Arten wie Star Sturnus vulgaris und Sperling Passer domesticus sind bedroht, und Pirol Oriolus oriolus, Kuckuck Cuculus canorus und Mehlschwalbe Delichon urbicum wurden in diesem Jahr in dramatischer Weise seltener.

Naturschützer schlagen Alarm: Haussperling Passer domesticus, Pirol Oriolus oriolus und Uferschnepfe Limosa limosa werden immer seltener in unserem Land. Nach der gerade vorgestellten “Roten Liste” der bedrohten Arten sind die Bestände der Feldlerche Alauda arvensis im Land seit 1999 um zehn Prozent, regional sogar um bis zu 50 Prozent zurückgegangen, beim Rebhuhn Perdix perdix hat sich der Bestand halbiert. Auch bei Wiesenvögeln wie Kiebitz Vanellus vanellus, Uferschnepfe, Wiesenpieper Anthus pratensis oder dem Braunkehlchen Saxicola rubetra sieht es schlecht aus. Von 212 Vogelarten in NRW stehen 81 Arten als ausgestorben, vom Aussterben bedroht oder gefährdet auf der Roten Liste. Selbst Arten wie Star Sturnus vulgaris und Sperling Passer domesticus sind bedroht, und Pirol Oriolus oriolus, Kuckuck Cuculus canorus und Mehlschwalbe Delichon urbicum wurden in diesem Jahr in dramatischer Weise seltener.

Tschilp, tschilp” tönt es aus dem Busch am Wegesrand. Hoch oben in der Pappel darüber flötet ein sehr melodisches “düd-liu”, während auf der Wiese nebenan ein vehementes Piepen zu vernehmen ist – ein Stück Natur am Niederrhein im Frühjahr 2009. Und eine echte Rarität, denn Haussperling, Pirol und Uferschnepfe werden immer seltener in unserem Land. Nach der gerade vorgestellten “Roten Liste” der bedrohten Arten sind die Bestände der Feldlerche im Land seit 1999 um zehn Prozent, regional sogar um bis zu 50 Prozent zurückgegangen, beim Rebhuhn hat sich der Bestand halbiert.

Auch bei Wiesenvögeln wie Kiebitz, Uferschnepfe, Wiesenpieper oder dem Braunkehlchen sieht es schlecht aus. “Der Rückgang zeigt, dass Artenschutz in den Agrar- und Umweltprogrammen bisher nicht angekommen ist”, sagt Bernd Jellinghaus vom Naturschutzbund Deutschland (Nabu). Schuld sei vor allem die intensive landwirtschaftliche Nutzung von immer mehr Flächen. Von 212 Vogelarten in NRW stehen 81 Arten als ausgestorben, vom Aussterben bedroht oder gefährdet auf der Roten Liste. Selbst Arten wie Star und Sperling sind bedroht, und Pirol, Kuckuck und Mehlschwalbe wurden in diesem Jahr in dramatischer Weise seltener. Nach aktuellen Zählungen schlägt der Nabu Alarm: Droht uns 2010 ein stummer Frühling?

Ganz so schlimm wird es wohl nicht werden, aber: Wenn jetzt nicht rasch gehandelt wird, dürfte es für manche Vogelart in den nächsten Jahren ziemlich eng werden. Denn die Landwirtschaft hat sich industrialisiert: Bauer sein lohnt sich nur, wenn große Flächen intensiv bewirtschaftet werden, und so wird der letzte Winkel der Flächen gepflügt, bespritzt und bepflanzt – Rückzugsflächen für viele Vogelarten gibt es dann nicht mehr.

Wo früher viele kleinere Bauern teils in extensiver Bewirtschaftung, teils über ein oder zwei Jahre gar nicht säten und ernteten, ist jetzt eine Kultursteppe entstanden, mit Raps- und Maisfeldern, so weit das Auge reicht. Gab es einst zehn Ackerrandstreifen, Feldwege oder Hecken, ist jetzt nur noch einer. Vögel finden weniger Schutz, Nistmöglichkeiten und Nahrung. Es gibt immer weniger Brachflächen, auf denen Insekten und Schnecken leben, von denen die Vögel sich und ihre Jungen ernähren – und wenn, werden sie oft von Erholungssuchenden Menschen genutzt. “Statt vieler kleiner alter Feldwege mit einem Erdstreifen in der Mitte, gibt es nur noch einen asphaltierten”, sagt Jellinghaus. Der Haussperling kann keine Staubbäder mehr nehmen, um Milben aus den Federn zu schütteln. “Oft sind es nur Kleinigkeiten in der Struktur der Landschaft, die man korrigieren müsste”, sagt Jellinghaus. Ein Randstreifen am Feld voller Kräuter biete Insekten und Vögeln Nahrung, ein Stück freie Fläche könne helfen.

Zwar hat die Landesregierung 2007 “Richtlinien zur Förderung einer markt- und Standortangepassten Landbewirtschaftung” erlassen und gibt Bauern Geld, die eine vielfältige Fruchtfolge einhalten, Unkräuter am Feld-, Wald- und Wegesrand stehen lassen und ökologischer bewirtschaften.

Doch der Preisdruck in der Landwirtschaft scheint so groß zu sein, dass von diesen Förderprogrammen nur zögerlich Gebrauch gemacht wird. 320 Millionen Euro sind bis 2013 für diese “Agrarumweltmaßnahmen” vorgesehen, aber wie viel davon tatsächlich bedrohten Vogelarten nützt, weiß niemand. Immerhin wurden allein 2007 etwa 14 Millionen Euro für Extensivierung und über 10 Millionen für Vertragsnaturschutzmaßnahmen ausgezahlt, aber nur 800 000 Euro für Flächenstilllegungen. Und genau diese Brachflächen wären für viele Tiere ideal.

Allerdings bringt es auch nichts, bisheriges Acker- und Weideland einfach sich selbst zu überlassen. “Das verbuscht in kurzer Zeit, und Wiesenvögel haben darin keine Chance. Denn sie sind nur dank menschlicher Bewirtschaftung in den letzten 200 Jahren häufiger geworden”, sagt Jellinghaus. Also könne auch nur der Mensch dafür sorgen, dass sie weiter eine Zukunft in der modernen Landwirtschaft hätten. Immerhin lobt der Nabu Umweltminister Eckard Uhlenberg (CDU) dafür, dass er durch die geschickte Nutzung von EU-Mitteln 50 Millionen Euro für den Artenschutz mobilisiert habe. “Aber der Minister muss größere Schritte machen und zudem auf den Rückhalt seiner Kollegen aus den übrigen Ressorts zählen können”, fordert Nabu-Chef Josef Tumbrinck. Die Landesregierung müsse den Umwelt- und Naturschutz endlich als Querschnittsaufgabe begreifen, bei dem jedes Ressort gefordert sei. Und: Außerhalb von Schutzgebieten geht es vielen Vögeln schlecht. Jäger und Fischer fordern den Abschuss von Kormoranen, und die Jagd auf Wildgänse wird immer wieder hitzig diskutiert.

Auf Bauernhöfen werden Hohlräume und Löcher unter Dächern geflickt, die Tiere finden keine Nisthöhlen mehr, und mancher wundert sich im Sommer über die vielen Fliegen und Spinnen – kein Wunder, wenn er zuvor die Insekten fressenden Vögel vergrault hat. Die Wärmedämmung an Gebäuden stopft alle Fugen und Ritzen zu. “Dabei gibt es heute sogar Dämmungen, in die ohne Aufwand Nisthilfen für Mauersegler eingearbeitet werden können”, sagt Jellinghaus. Der Nabu sei mit Architekten im Gespräch, um Bauherren darauf hinzuweisen.

Überhaupt reichen oft kleine Maßnahmen, um Tieren zu helfen. So versucht der Nabu zusammen mit dem Deutschen Bauernverband Landwirte für sogenannte “Lerchenfenster” zu gewinnen. Feldlerchen Alauda arvensis brüten am Boden; in dicht zugewachsenen Wintergerstefeldern geht das nicht. “Deswegen bitte wir die Landwirte, beim Säen ein paar Meter freizuhalten, und im Frühjahr baut die Lerche dort ihr Nest”, sagt Jellinghaus, der weiß, “dass viele Landwirte im Moment ganz andere Sorgen haben als Vögel”. Aber wenn die Maßnahmen doch teilweise so einfach umzusetzen seien, warum nicht? So könnten Bauern ihre Stallfenster offen halten, damit Schwalben im Stall Nester bauen können, und eine Hofecke ungepflastert lassen, damit die Tiere an Pfützen trinken oder Nistmaterial besorgen könnten.

Ein weiteres großes Problem: Jeden Tag würden 15 Hektar Fläche für Industrie, Hausbau oder Straßen zubetoniert. Minister Uhlenberg habe zwar 2007 versprochen, diese Entwicklung zu stoppen, doch passiert sei seither nicht viel. “Gemeinden sollten Industriebrachen umwidmen, anstatt die Landschaft zuzubauen”, sagt Jellinghaus.

Von Robert Lücke, 4. Oktober 2009
Quelle: Welt Online
http://www.welt.de/die-welt/vermischtes/article4727813/Sag-mir-wo-die-Vo…

Research into the declines of some species of farmland birds have shown that there is no single reason, but that different species have reacted to different factors, and that often, declines are associated with more than one factor impacting on a species simultaneously. Loss of insect food could be a major factor.

Research into the declines of some species of farmland birds have shown that there is no single reason, but that different species have reacted to different factors, and that often, declines are associated with more than one factor impacting on a species simultaneously. Loss of insect food could be a major factor.

Research has shown that the main factors driving declines since 1970 are:
The loss of mixed farming causing a loss of habitat diversity, leading to less diversity of plants and animals, and fewer opportunities for birds to forage in different habitats throughout the year. The increased use and efficacy of pesticides leading to the loss of insect food and weed seeds. Changes in crops grown, such as the loss of spring crops which provide nesting habitat for lapwings Vanellus vanellus and better habitat for other ground-nesting birds such as skylark Alauda arvensis, yellow wagtail Motacilla flava and corn bunting Miliaria calandra. Also loss of winter fallow habitats, such as winter stubbles, which are important for winter foraging.

Large areas of single crops can have dramatic impacts on the abundance of less mobile invertebrates, particularly when insecticides are used. Many changes in grassland management have led to a reduction in the abundance of seeds and insects, and the quality of grassland as a nesting habitat. These include increased stocking rates, more efficient grazing systems, increased nutrient inputs, reseeding and the switch from hay to silage. Increased field sizes have caused the loss of nesting habitat for some species, but more importantly, the loss of insect-rich foraging habitat and weedy field margins. Field drainage has not only removed wetland habitats, but also damp areas with more soil invertebrates that provided food for birds such as tree sparrows, reed buntings and yellow wagtails. Predation has had an additive effect to the impacts of pesticide use on grey partridges and the loss of nesting habitat on some local populations of lapwings when populations are already at low levels. Many predators, such as foxes and crows, have increased since 1970.

Population trends of common birds of prey have been largely stable since the mid-1990s, apart from the buzzard, which has increased substantially. Sparrowhawk numbers climbed in arable England in the 1980s and the increase in buzzard numbers started in the 1990s, both after the sharpest decline of the farmland birds occurred. Weather has an impact on all bird species: the harsh winters experienced in the late 1970s and early 1980s hit resident species hard, but these were interspersed with milder winters when most species recovered. This could have had an additive impact on birds that were also struggling for other reasons. Much of the annual variation in population trends is related to weather, with stable species declining in years with poor weather (such as cold winters or dry summers) but bounce back in better years.

To date, weather-related factors have not been found to cause any long-term declines. There are a number of declining bird species which make an annual migration across the Sahara, including two declining farmland birds: the turtle dove and the yellow wagtail. The decline of turtle doves has been linked to the shortage of summer seed sources on farmland, but it is also likely that factors affecting them on their migration routes or wintering grounds are exacerbating this decline.

Source: Royal Society for the Protection of Birds (RSPB), 04 September 2009
http://www.rspb.org.uk/ourwork/farming/advice/conservation/explanation/index.asp

Also:
http://www.oursouthwest.com/farming/decline.htm

There is growing concern about increased population, regional, and global extinctions of species. A key question is whether extinction rates for one group of organisms are representative of other taxa. We present a comparison at the national scale of population and regional extinctions of birds, butterflies, and vascular plants from Britain in recent decades. Butterflies experienced the greatest net losses, disappearing on average from 13% of their previously occupied 10-kilometer squares. If insects elsewhere in the world are similarly sensitive, the known global extinction rates of vertebrate and plant species have an unrecorded parallel among the invertebrates, strengthening the hypothesis that the natural world is experiencing the sixth major extinction event in its history.

There is growing concern about increased population, regional, and global extinctions of species. A key question is whether extinction rates for one group of organisms are representative of other taxa. We present a comparison at the national scale of population and regional extinctions of birds, butterflies, and vascular plants from Britain in recent decades. Butterflies experienced the greatest net losses, disappearing on average from 13% of their previously occupied 10-kilometer squares. If insects elsewhere in the world are similarly sensitive, the known global extinction rates of vertebrate and plant species have an unrecorded parallel among the invertebrates, strengthening the hypothesis that the natural world is experiencing the sixth major extinction event in its history.

Source: J. A. Thomas et al.
Science 19 March 2004:
Vol. 303. no. 5665, pp. 1879 – 1881
http://cmbi.bjmu.edu.cn/news/report/2004/2004sc/files/1879.pdf

Population declines in many farmland bird species have been documented during the last quarter of the 20th century in parts of Europe and North America where agricultural intensification has been most marked. ‘Intensification’ is multivariate, difficult to define precisely, but taken to subsume all those advances that have allowed farmers to increase primary productivity. Increased pesticide use on arable land has been a key cause of Grey Partridge Perdix perdix decline through its impact on the availability of insect foods to chicks, and hence on reproductive success.

Population declines in many farmland bird species have been documented during the last quarter of the 20th century in parts of Europe and North America where agricultural intensification has been most marked. ‘Intensification’ is multivariate, difficult to define precisely, but taken to subsume all those advances that have allowed farmers to increase primary productivity. Increased pesticide use on arable land has been a key cause of Grey Partridge Perdix perdix decline through its impact on the availability of insect foods to chicks, and hence on reproductive success.

Source: J.D. Wilson et al. (2005). British Ornithologists’Union, Ibis, 147, 453-463
http://www.ncl.ac.uk/biology/assets/MWhitt_pdf/05wilson_ibis.pdf

There is continuing debate about the impact of agricultural practices on farmland wildlife. In particular, it has been postulated that a general decline in insect abundance linked with intensification of agriculture may have contributed to farmland bird decline. While some autecological studies have supported this hypothesis, larger-scale and long-term studies are needed.

• Suction traps mounted on 12·2-m towers (Rothamsted-type) have been sampling aerial insects for nearly 40 years throughout the UK. Their catches are correlated over large spatial scales. We analysed insect catch data from a single suction trap run for 27 years in a rural location in Scotland, and showed that insect numbers have changed significantly over time, although non-linearly. The multivariate data set (numbers from the 12 common arthropod groups) was summarized using principal components analysis (PCA) to extract three components explaining 62% of the variation.

• We also used PCA to describe agricultural change, using published agricultural data for eight measures of farming in Scotland. Arthropod abundance and principal component (PC) scores were significantly related to the agricultural PC scores as well to summary climatic measures.

• Using Scottish data from the British Trust for Ornithology Common Birds Census, we extracted three PC to describe the time-dependent average densities of 15 common farmland birds in Scotland. Measures of bird density were significantly related to insect abundance and PC scores and, independently, to measures of agriculture and climate.

• These data from a broad suite of species provide support for linked temporal change between farmland birds, invertebrate numbers and agricultural practice in Scotland. Although entirely correlative, the results are consistent with the view that agricultural change has influenced birds through changes in food quality or quantity. The work also shows how large-scale invertebrate sampling, in this case using suction traps, is useful for monitoring farmland biodiversity.

There is continuing debate about the impact of agricultural practices on farmland wildlife. In particular, it has been postulated that a general decline in insect abundance linked with intensification of agriculture may have contributed to farmland bird decline. While some autecological studies have supported this hypothesis, larger-scale and long-term studies are needed.

• Suction traps mounted on 12·2-m towers (Rothamsted-type) have been sampling aerial insects for nearly 40 years throughout the UK. Their catches are correlated over large spatial scales. We analysed insect catch data from a single suction trap run for 27 years in a rural location in Scotland, and showed that insect numbers have changed significantly over time, although non-linearly. The multivariate data set (numbers from the 12 common arthropod groups) was summarized using principal components analysis (PCA) to extract three components explaining 62% of the variation.

• We also used PCA to describe agricultural change, using published agricultural data for eight measures of farming in Scotland. Arthropod abundance and principal component (PC) scores were significantly related to the agricultural PC scores as well to summary climatic measures.

• Using Scottish data from the British Trust for Ornithology Common Birds Census, we extracted three PC to describe the time-dependent average densities of 15 common farmland birds in Scotland. Measures of bird density were significantly related to insect abundance and PC scores and, independently, to measures of agriculture and climate.

• These data from a broad suite of species provide support for linked temporal change between farmland birds, invertebrate numbers and agricultural practice in Scotland. Although entirely correlative, the results are consistent with the view that agricultural change has influenced birds through changes in food quality or quantity. The work also shows how large-scale invertebrate sampling, in this case using suction traps, is useful for monitoring farmland biodiversity.

Authors: Benton, Tim G.; Bryant, David M.; Cole, Lorna; Crick, Humphrey Q. P.
Source: Journal of Applied Ecology, Volume 39, Number 4, August 2002 , pp. 673-687(15)
Publisher: Blackwell Publishing
http://www.ingentaconnect.com/content/bsc/jappl/2002/00000039/00000004/a…

Britain’s House Sparrow Passer domesticus population has declined by 68 percent since 1977. Though still relatively plentiful in small towns in the countryside and by the sea, the bird has disappeared in many major conurbations, including central London, where the species has virtually vanished. House Sparrows are also disappearing from Bristol, Edinburgh, and Dublin, as well as Hamburg, Prague, and Moscow. Now, according to a scientific paper to be published in a forthcoming issue of the journal Animal Conservation, there’s a compelling theory for why: insect decline.

Britain’s House Sparrow Passer domesticus population has declined by 68 percent since 1977. Though still relatively plentiful in small towns in the countryside and by the sea, the bird has disappeared in many major conurbations, including central London, where the species has virtually vanished. House Sparrows are also disappearing from Bristol, Edinburgh, and Dublin, as well as Hamburg, Prague, and Moscow. Now, according to a scientific paper to be published in a forthcoming issue of the journal Animal Conservation, there’s a compelling theory for why: insect decline.

Based on research conducted in Leicester, scientists from the Royal Society for the Protection of Birds, De Montfort University in Leicester, and Natural England have shown that sparrow chicks are starving in their nests because their parents can’t find enough insects to feed them. So many chicks are dying that the birds’ population level as a whole is declining.

“Where there were few insects, young House Sparrows were likely to die,” the lead author told the Independent newspaper. “Young House Sparrows need insects rather than seeds, peanuts or bread to survive.”

Population declines among invertebrates in general and insects in particular were the subject of a very sobering article in the newspaper earlier this week. “There are more extinctions among invertebrates than in any other groups, and a greater proportion of the species are in decline, and the decline is steeper, than in plants, birds, and mammals wherever there is data,” says Matt Shardlow, director of Buglife, the Invertebrate Conservation Trust.

Examples from the Independent:

Two-thirds of Britain’s moth species have declined in the past 40 years, some by enormous amounts.
Seven in 10 of Britain’s 58 butterfly species have declined in the past 30 years.

Of the 25 species of bumblebee traditionally native to Britain, three have gone extinct, and four more are designated “UK Biodiversity Action Plan species” in recognition of their precarious situation.

Among insects, mayflies appear to have dropped in abundance by about two-thirds in the past 50 years.
At least 250 of Britain’s 4,000+ species of beetle have not been seen since 1970.

“A very severe problem is that many invertebrates are highly specialised in what they require,” Shardlow says. “They can’t just live anywhere, they need a specific habitat feature, and often these habitat features are now highly fragmented and isolated, such as fenlands, or ancient woodland.”

Source: Birder’s Magazine, 20 November 2008
http://bwfov.typepad.com/birders_world_field_of_vi/2008/11/insect-crash-at-root-of-house-sparrow-decline.html

A fundamental problem in estimating biodiversity loss is that very little quantitative data are available for insects, which comprise more than two-thirds of terrestrial species. We present national population trends for a species-rich and ecologically diverse insect group: widespread and common macro-moths in Britain. Two-thirds of the 337 species studied have declined over the 35 yr study and 21% (71) of the species declined >30% 10 yr−1.

A fundamental problem in estimating biodiversity loss is that very little quantitative data are available for insects, which comprise more than two-thirds of terrestrial species. We present national population trends for a species-rich and ecologically diverse insect group: widespread and common macro-moths in Britain. Two-thirds of the 337 species studied have declined over the 35 yr study and 21% (71) of the species declined >30% 10 yr−1.

If IUCN (World Conservation Union) criteria are applied at the national scale, these 71 species would be regarded as threatened. The declines are at least as great as those recently reported for British butterflies and exceed those of British birds and vascular plants. These results have important and worrying implications for species such as insectivorous birds and bats, and suggests as-yet undetected declines may be widespread among temperate-zone insects.

Source: Kelvin F. Conrad et al. (2006) Biological Conservation 132, 279-291
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V5X-4K9C5J1-1…

Nearly 40,000 conservation-minded drivers counted the bugs splattered on their vehicle number plates this summer, the Royal Society for the Protection of Birds (RSPB) announced yesterday. The motorists were helping the world’s first mass survey into possible insect decline, a UK-wide Big Bug Count held throughout June, and the initial results appear to confirm suspicions that insect numbers have fallen, the RSPB said.

Nearly 40,000 conservation-minded drivers counted the bugs splattered on their vehicle number plates this summer, the Royal Society for the Protection of Birds (RSPB) announced yesterday. The motorists were helping the world’s first mass survey into possible insect decline, a UK-wide Big Bug Count held throughout June, and the initial results appear to confirm suspicions that insect numbers have fallen, the RSPB said.

Using a cardboard counting-grid dubbed the “splatometer”, they recorded 324,814 “splats”, an average of only one squashed insect every five miles. In the summers of 30-odd years ago, car bonnets and windscreens would quickly become encrusted with tiny bodies.

“Many people were astonished by how few insects they splatted,” the survey’s co-ordinator Richard Bashford, said.

People were asked to wash their number plates, drive for between 20 and 80 miles, and count the insects on the plate, using the grid to make counting easier. The study was prompted by fears that a decrease in insect populations could cause problems for birds which rely on them for food.

Swallows and house martins are specialist insect feeders, and seed-eating birds, such as skylarks and house sparrows, both in decline, need insects to feed to their young. Numbers of many bird species have been dropping alarmingly, and the house sparrow population has crashed by 65 per cent in the past 31 years. Theories abound about why insect populations seem to be declining, and include habitat loss and pesticides.

Mr Bashford said. “variation in insect numbers across the UK was small, but there appears to be a gradual increase in numbers from the South-east of England to Scotland. The reasons for this, and the potential consequences for birds, will be the focus of future research.”

The RSPB plans more “splatometer” tests to gather more data.

Source: The Independent, 2 September 2004
http://www.independent.co.uk/environment/40000-splatometers-cant-be-wron…

Car ‘splatometers’ may help scientists solve riddle of insect decline

Introducing the splato-meter! You might think it’s wacky. You might think it’s the midsummer version of an April fool. But it’s a perfectly serious invention, and may yet unlock the secrets of an ominous yet little-publicised environmental phenomenon: the widespread disappearance of insects.

It’s so simple you wonder why no one has thought of it before. A postcard-sized piece of plastic film, the splatometer fits to the front of your car and measures the number of airborne bugs that splat against it during a road journey. It is intended to give a statistical basis to a growing public perception – that a lot fewer of them are about than there used to be.

It has been devised by conservation scientists at the Royal Society for the Protection of Birds who intend it to be used by tens of thousands of people in a mass “citizen science” exercise, like its Big Garden Birdwatch, which more than 300,000 people responded to this year.

Concerned over declines in many bird species, the RSPB thinks – like a growing number of conservationists – that a general decline in insect numbers may well be responsible. Bumblebees, mayflies, butterflies, moths, beetles and many other insect species appear to be tumbling in numbers and vanishing from many places, the common species as much as the rare ones.

It is a critical development, because insects are the most numerous of all organisms and underpin all ecosystems, providing food for countless other species and playing a crucial role in plant pollination. But it is only just being noticed by scientists, and hard data is lacking.

The splatometer aims to remedy the data deficiency. At the end of a journey, it peels off from the front of your car and can be scanned by a computer to show how many bugs you have splattered.

“We think the splatometer will give us better information on insect abundance than has been collected before,” said Dr Mark Avery, the RSPB director of conservation. “We do think insects are declining, but there aren’t lots of long-term data sets that show it, like there are for birds and plants. Insects have been a neglected group.”

Source: The Independent, 30 June 2003
http://www.independent.co.uk/environment/car-splatometers-may-help-scien…