Populations of migratory bird species that did not show a phenological response to climate change are declining ? PNAS

[Giuseppe]

Populations of migratory bird species that did not show a phenological response to climate change are declining ? PNAS

Populations of migratory bird species that did not show a phenological response to climate change are declining

1. Anders Pape M?ller*,?, 2. Diego Rubolini?,?, and 3. Esa Lehikoinen?

Author Affiliations
1. *Laboratoire de Parasitologie Evolutive, Centre National de la Recherche Scientifique Unit? Mixte de Recherche 7103, Universit? Pierre et Marie Curie, F-75252 Paris Cedex 05, France;
2. ?Dipartimento di Biologia, Universit? degli Studi di Milano, I-20133 Milano, Italy; and
3. ?Department of Biology, University of Turku, FI-20014, Turku, Finland
1. Edited by May R. Berenbaum, University of Illinois, Urbana, IL, and approved August 27, 2008 (received for review April 21, 2008)

Abstract

Recent rapid climatic changes are associated with dramatic changes in phenology of plants and animals, with optimal timing of reproduction advancing considerably in the northern hemisphere.

However, some species may not have advanced their timing of breeding sufficiently to continue reproducing optimally relative to the occurrence of peak food availability, thus becoming mismatched compared with their food sources.

The degree of mismatch may differ among species, and species with greater mismatch may be characterized by declining populations.

Here we relate changes in spring migration timing by 100 European bird species since 1960, considered as an index of the phenological response of bird species to recent climate change, to their population trends.

Species that declined in the period 1990?2000 did not advance their spring migration, whereas those with stable or increasing populations advanced their migration considerably.

On the other hand, population trends during 1970?1990 were predicted by breeding habitat type, northernmost breeding latitude, and winter range (with species of agricultural habitat, breeding at northern latitudes, and wintering in Africa showing an unfavorable conservation status), but not by change in migration timing.

The association between population trend in 1990?2000 and change in migration phenology was not confounded by any of the previously identified predictors of population trends in birds, or by similarity in phenotype among taxa due to common descent.

Our findings imply that ecological factors affecting population trends can change over time and suggest that ongoing climatic changes will increasingly threaten vulnerable migratory bird species, augmenting their extinction risk.

* conservation
* extinction risk
* migration phenology
* population trends

Footnotes
* ?To whom correspondence may be addressed. E-mail: amoller@snv.jussieu.fr or diego.rubolini@unimi.it
* Author contributions: A.P.M. designed research; A.P.M. and D.R. performed research; A.P.M., D.R., and E.L. analyzed data; and A.P.M., D.R., and E.L. wrote the paper.
* The authors declare no conflict of interest.
* This article is a PNAS Direct Submission.
* This article contains supporting information online at www.pnas.org/cgi/content/full/0803825105/DCSupplemental.
* ? 2008 by The National Academy of Sciences of the USA
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<cite cite="http://www.pnas.org/content/105/42/16195.short?rss=1">Populations of migratory bird species that did not show a phenological response to climate change are declining ? PNAS</cite>

 

[AlaskaDenise]

Re: Populations of migratory bird species that did not show a phenological response to climate change are declining ? PNAS

It would be interesting to know which species are in the slow-responding category. However, reading the article requires a subscription.

There might be a good reason why certain species don't advance on a similar schedule and instead decline. There might be insufficient food for all species to move into a new area at the same time. Perhaps their digestive system cannot acclimate to new food as quickly as other species. Their adaptation scheme might be to reduce their population, rather than relocate.

I'm not convinced that all population declines are undesirable. It could be an appropriate response to changing conditions.

Remember the Sandhill cranes. They've been around for at least 10 million years (through many climate changes).

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[Sally Furniss]

Bird migration times, climate change, and changing population sizes

Bird migration times, climate change, and changing population sizes

Bird migration times, climate change, and changing population sizes


ABRAHAM J. MILLER-RUSHING ^{<nobr>*</nobr>}??, TREVOR L. LLOYD-EVANS?, RICHARD B. PRIMACK ^{<nobr>*</nobr>} and PAUL SATZINGER ^{<nobr>*</nobr>} ^{<nobr>*</nobr>} Department of Biology, Boston University, 5 Cummington Street, Boston, MA 02215, USA, ?Rocky Mountain Biological Laboratory, PO Box 519, Crested Butte, CO 81224, USA, ?Department of Biology, University of Maryland, College Park, MD 20742, USA, ?Manomet Center for Conservation Sciences, 81 Stage Road, PO Box 1770, Manomet, MA 02345, USA
Correspondence: Abraham J. Miller-Rushing, Rocky Mountain Biological Laboratory, PO Box 519, Crested Butte, CO 81224, USA, and Department of Biology, University of Maryland, College Park, MD 20742, USA, e-mail: abe@rmbl.org

ABSTRACT

Past studies of bird migration times have shown great variation in migratory responses to climate change. We used 33 years of bird capture data (1970?2002) from Manomet, Massachusetts to examine variation in spring migration times for 32 species of North American passerines. We found that changes in first arrival dates ? the unit of observation used in most studies of bird migration times ? often differ dramatically from changes in the mean arrival date of the migration cohort as a whole. In our study, the earliest recorded springtime arrival date for each species occurred 0.20 days later each decade. In contrast, the mean arrival dates for birds of each species occurred 0.78 days earlier each decade. The difference in the two trends was largely explained by declining migration cohort sizes, a factor not examined in many previous studies. We found that changes in migration cohort or population sizes may account for a substantial amount of the variation in previously documented changes in migration times. After controlling for changes in migration cohort size, we found that climate variables, migration distance, and date of migration explained portions of the variation in migratory changes over time. In particular, short-distance migrants appeared to respond to changes in temperature, while mid-distance migrants responded particularly strongly to changes in the Southern Oscillation Index. The migration times of long-distance migrants tended not to change over time. Our findings suggest that previously reported changes in migration times may need to be reinterpreted to incorporate changes in migration cohort sizes.


<hr xmlns="http://www.w3.org/1999/xhtml" align="left" size="1" width="25%"> http://www3.interscience.wiley.com/journal/119881756/abstract?CRETRY=1&SRETRY=0

 

[Sally Furniss]

Re: Bird migration times, climate change, and changing population sizes

Re: Bird migration times, climate change, and changing population sizes

INTERPRETING VARIATION IN BIRD MIGRATION TIMES AS OBSERVED BY VOLUNTEERS

<trans-title xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" language="SP">Interpretación de la Variación en los Tiempos de Migración de las Aves a partir de las Observaciones de Voluntarios</trans-title>
ABRAHAM J. MILLER-RUSHING,^1,³ RICHARD B. PRIMACK,¹ AND ROBERT STYMEIST

*² ¹Department of Biology, Boston University, 5 Cummington Street, Boston, Massachusetts 02215, USA; and
²Nuttall Ornithological Club, Department of Ornithology, Harvard University, 26 Oxford Street, Cambridge, Massachusetts 02138, USA

³Present addresses: Rocky Mountain Biological Laboratory, P.O. Box 519, Crested Butte, Colorado 81224, USA, and Department of Biology, University of Maryland, College Park, Maryland 20742, USA. E-mail: abe@rmbl.org

ABSTRACT
As a result of changes in climate over the past 100 years, many birds are arriving at points along their migration routes earlier in the spring now than they did in the past. Increasingly, researchers are relying on a variety of data sources, such as naturalist journals and bird-club records, to document migration times. However, it is not clear whether researchers can successfully use different sources of data to compare changes in migration times. We examined 25 years of changes in migration times for 30 species of birds at Mt. Auburn Cemetery in Cambridge, Massachusetts, as documented by bird-club members and published in a regional bird journal. We found that, overall, birds arrived earlier in warmer springs in eastern Massachusetts. We compared our findings with those of previous studies in Massachusetts, which included data from a standardized bird-banding station and observations from a naturalist's journal and bird-club records. On a species-by-species basis, changes in migration times were not correlated among the studies. We believe that local changes in population sizes and sampling effort at some of the sites may have contributed to the lack of correlation. For the purpose of comparing changes in migration times across species and locations, standardized bird-banding data are preferable to data collected by volunteer naturalists. However, naturalist data sources are useful and reflect the widely observed trend toward earlier migrations in warm springs.


http://caliber.ucpress.net/doi/abs/10.1525/auk.2008.07005

 

[Sally Furniss]

Re: Populations of migratory bird species that did not show a phenological response to climate change are declining ? PNAS

Early birds catch the worm

Migratory birds that don't adjust their annual cycles to climate change show declining populations.

As climate warms and temperatures rise, many plants and insects have advanced their annual cycles. But consumers of these species and higher-level predators have tended not to breed so much earlier in the year, which brings them in danger of mis-matching the birth of their young and the peak availability of food.

Now a team from Pierre and Marie Curie University in France, the University of Milan, Italy, and the University of Turku, Finland, has carried out the first study of how trends in bird populations depend on their phenological [annual cycle] response to climate change.

The team looked at the timing of spring migration for 100 European bird species since 1960. Species whose populations declined from 1990 to 2000 did not advance their spring migration, whereas in species that did bring their migration dates forward, populations were stable or increased.

"It provides a first scary insight into a major problem," Anders Møller of Pierre and Marie Curie University told <cite>environmentalresearchweb</cite>. "Threatened species are not changing their phenology when the world is changing."

Long-distance migrants tended to advance their spring migration the least, while species that lay a larger number of clutches generally brought their migration forward much earlier. The mechanisms that underlie long-term changes in migration timing are not currently known for definite.

Population trends from 1970 to 1990, in contrast, were predicted not by change in migration timing but by factors such as breeding habitat type, northernmost breeding latitude and winter range. Species that live in agricultural habitats, breed at northern latitudes and winter in Africa fared particulary poorly over this period.

"Our findings imply that ecological factors affecting population trends can change over time and suggest that ongoing climatic changes will increasingly threaten vulnerable migratory bird species, augmenting their extinction risk," wrote the researchers in their paper in <cite>PNAS</cite>.

"This should focus our efforts to understand why threatened species do not respond to climate change," added Møller.

About the author

Liz Kalaugher is editor of <cite>environmentalresearchweb</cite>.
http://environmentalresearchweb.org/cws/article/research/36234

 

[AlaskaDenise]

Re: Populations of migratory bird species that did not show a phenological response to climate change are declining ? PNAS

see similar articles at:
http://www.flutrackers.com/forum/newreply.php?do=newreply&noquote=1&p=186753

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