May 27, 2007

First spring observation dates in Khovd 2006 / 2007,
and some thoughts about climate change and spring arrivals

by Axel Braunlich

Igor Fefelov from Irkutsk, Russia has left a question at the comment section of my blog:

Amar sain Axel,
What are the data on bird arrival this spring? We have had some extremely early records, i.e. Porzana pusilla on 20 April (!! - common arrival falls on middle May, not earlier) and
Phylloscopus inornatus on 9 May (common date is later than 15 May in the last decades of years).

Dear Igor,
I have limited experience since I spent only two spring seasons (2006 & 2007) here in Khovd. However, here is a selection of my first observations for some species.

First observations in Khovd 2006/07 (sorted by date for 2006). Note:
underlined: first observation dates 2006 and 2007 rather similar (+/–5 days difference)
bold: first observation date in 2007 much earlier (>10 days) than in 2006

Fieldfare - 11 Feb / 28 Mar
Pine Bunting - 14 Mar / 23 Mar
male Evermann's Redstart - 18 Mar / 18 Mar
Black-throated Accentor - 18 Mar / 23 Mar
Steppe Buzzard - 21 Mar / 01 Apr
Common Starling - 23 Mar / 23 Mar
Black-throated Thrush - 23 Mar / 28 Mar
Common Reed Bunting - 24 Mar / 17 Mar
Mongolian Gull - 25 Mar / 23 Mar
Black-eared Kite - 25 Mar / 23 Mar
Lapland Bunting - 25 Mar / 17 Mar
Eurasian Skylark - 26 Mar / 24 Mar
female Evermann's Redstart - 28 Mar / 02 Apr
Desert Wheatear - 28 Mar / 13 Apr
Common Jackdaw - 28 Mar / 13 Apr
Ruddy Shelduck - 29 Mar / 11 Mar
Hoopoe - 29 Mar / 13 Apr
Masked Wagtail 29 Mar / 01 Apr
Whooper Swan - 30 Mar / 13 Apr
Yellowhammer - 30 Mar / 14 April
Chaffinch - 30 Mar / 03 Mar
Brambling - 30 Mar / 02 Apr
Eurasian Sparrowhawk - 31 Mar / 06 Apr
Long-eared Owl - 03 Apr / 02 Apr
Stock Pigeon - 04 Apr / 13 Apr
Black Redstart - 04 Apr / 07 Apr
Pallas's Gull - 04 Apr / 06 Apr
Great Egret - 06 Apr / 01 Apr
Lapwing - 06 Apr / 01 Apr
Citrine Wagtail - 06 Apr / 06 Apr
Red-throated Thrush - 06 Apr / 10 Mar
Siberian Chiffchaff - 07 Apr / 07 Apr
Water Pipit - 07 Apr / 06 Apr
Bluethroat - 07 Apr / 13 Apr
Booted Eagle - 11 Apr / 13 Apr
Demoiselle Crane - 12 Apr / 01 May
Black-headed Gull - 14 Apr / 07 Apr
Black Stork - 16 Apr / 07 Apr
Pied Wheatear - 16 Apr / 07 Apr
Northern Wheatear - 17 Apr / 08 Apr
House Martin - 19 Apr / 01 May
Barn Swallow - 22 Apr / 25 Apr
Isabelline Wheatear - 24 Apr / 07 Apr
Scaly Thrush - 24 Apr / 06 May
Crag Martin - 24 Apr / 14 Apr
Common Redstart - 27 Apr / 25 Apr
Little Ringed Plover - 29 Apr / 29 Apr
Common Sand Martin - 29 Apr / 26 Apr
Green Sandpiper - 29 Apr / 02 May
Song Thrush - 03 May / 03 May
Lesser Whitethroat - 07 May / 11 May
Hume's Leaf Warbler - 10 May / 02 May
Eastern Stonechat - 10 May / 01 May
Tree Pipit - 10 May / 02 May
Eurasian Hobby - 10 May / 01 May
Isabelline Shrike - 10 May (isabellinus) / 11 Apr (phoenicuroides)
Paddyfield Warber - 10 May / 02 May
Ortolan Bunting - 10 May / 01 May
Oriental Turtle Dove - 15 May / 07 May
Spotted Flycatcher - 15 May / 16 May
Booted Warbler - 16 May / 16 May
Common Rosefinch - 16 May / 11 May
Common Cuckoo - 16 May / 26 Apr
Richard's Pipit - 19 May / 07 May
Rose-coloured Starling - 19 May / 18 May
Great Reed Warbler - 19 May / 12 May
Taiga Flycatcher - 19 May / 20 May
Blyth's Reed Warbler - 23 May / 11 May
Dusky Warbler - 24 May / 11 May
Common Swift - 26 May / 20 May
Barred Warbler - 30 May / 26 May

So there is no obvious pattern of very early arrivals in Khovd this spring. But note, my observations here are not part of a scientific study. I rather try to go birding as often as possible in my spare time. My first observations are no necessarily “arrival dates”, quite a few factors must be considered when looking at my data:

  • I don’t necessarily visit exactly the same sites (=same habitats!) on the same day in both springs.

  • Conditions at the sites I visit may differ from day to day (the area is irrigated and irregularly flooded).

  • I am not birding every day.

  • I have been away this spring from 19-22 March and 16-23 April.

  • Some days in spring are so windy / stormy that observations are hindered very much – thus new arrivals can easily be missed.

  • With the trees and herbaceous plants getting green it is much more difficult to spot new arrivals now than a month ago.

So, some of my first observation dates may not be particularly meaningful – but they may be of value to anyone who wants to compare with elsewhere in north-easten Asia.

Publishing lists of first observations/first arrivals in defined areas can be very helpful understanding the effects of climate change on bird migration. Such lists are for example published for Iceland for 1998-2007 on The Icelandic Bird Pages, and for Christchurch Harbour by the Christchurch Harbour Ornithological Group (south coast of England)

The past winter was rather “mild” (for local standards) here, and spring arrived earlier. Khovd experienced a rather dramatic temperature increase recently: In general the mean annual air temperature has risen by around 3.5° C between 1983 and 2005 according to Meteorological Survey Station Khovd.

April 2007 was the third warmest April for the globe on record, and the first four months of 2007 were the warmest ever, according to statistics released by the National Climatic Data Center. The global average temperature for April was 1.19°F/0.66°C above the 20th century mean. Over land, April global temperatures were the warmest ever measured. Ocean temperatures were a bit cooler (seventh warmest on record), thanks to the cooling associated with the disappearance of the winter El Niño event. Source: Dr. Jeff Masters' WunderBlog.

Temperature departure from average for April 2007.
Image credit: National Climatic Data Center.

The map above shows that especially Mongolia, Central Siberia to the Russian Far East, and the area to the south-west of Mongolia (where many spring migrants to Mongolia and Central Siberia presumably originate) had above the average temperatures in April 2007. This might explain the very early arrivals of some bird species in the Irkutsk region.

There have been a lot of debates about climate change and birds (and about climate change and global warming in general of course! See links at the end of this post). There are overwhelming proofs that humans, through increased emissions of atmospheric greenhouse gases and aerosols, are causing climate change, which in turn is linked to changes seen in the springtime activity of numerous animals and plants.

I have selected two abstracts of scientific publications dealing with spring arrival dates of birds, one from Manitoba, Canada, and one from south-western Germany to give examples of how much global warming already changed the behaviour of migratory birds.

Murphy-Klassen, H. M, Underwood, T. J., Sealy, S. G. & Czyrnyj, A. A.2 005. Long-term trends in spring arrival dates of migrant birds at Delta Marsh, Manitoba, in relation to climate change. The Auk 122: 1130-1148.
We examined a 63-year data set of dates of first spring sightings for 96 species of migrant birds at Delta Marsh, Manitoba, and considered the influence of local climate change on those arrival dates. Mean monthly spring temperatures increased (0.6-3.8°C) for all four months considered; however, trends for February and March were stronger than those for April and May. Over the 63-year period, 27 species significantly altered their arrival dates. Most of those species arrived significantly earlier; whereas only two species, Greater Yellowlegs (Tringa melanoleuca) and Lesser Yellowlegs (T. flavipes), arrived significantly later over time. About half of the migrants showed significant relationships between arrival dates and mean temperature for their month of arrival. Fifteen species showed significantly earlier arrivals over time and a significant relationship between arrival date and temperature. We also characterized migrants by taxon, breeding status, and wintering location to determine whether there were any trends for altered arrivals within certain groups. Waterfowl, species that breed at Delta Marsh, and short-distance migrants showed slightly higher incidences of advancing arrival dates compared with other groups. Our results provide evidence that climate warming has influenced spring migration arrival dates of several species in Manitoba. source.

Peintinger, M. & S. Schuster 2005: Changes in first arrival dates of common migratory bird species in southwestern Germany. Vogelwarte 43: 161-169.
Global change affects the timing of bird migration. It presumed (and has been shown) that, (1) species arrived earlier in spring and that (2) this response to climate change is stronger in short-distance than in long-distance migratory species. To confirm this pattern we analysed long-term observational data from field ornithologists under the condition that (1) at least eight arrival dates for the periods 1970-1986 and 1987-2003 were available, (2) observers had not changed their study area during these years, and (3) at least three time series were available for a species. In total, we examined the first arrival dates of 17 migratory species at 13 sites in south-western Germany. To analyse changes in arrival times we used two statistical procedures: linear regression for the period 1970-2003 and Mann-Whitney U-test to compare median arrival dates of the periods 1970-1986 and 1987-2003. Out of 103 time series 96 showed a trend towards earlier spring arrival, whereas series only for seven time series the reverse was true. Using linear regression for 58 species time series we found a significantly earlier arrival date. On average, arrival date changed 0.3 (max. 2.9) days per year. Only one species showed a significant later arrival date. The U-test revealed similar results. An analyses of variance (ANOVA) showed that this effect was stronger in short-distance than in long-distance migrants. We suggest that earlier spring arrival could be due to a shift of wintering areas towards the North – even in some long-distance migratory species.

The whole volume 43 (2005) of the journal Vogelwarte (6.8 MB) can be downloaded

© Tom Toles at the Washington Post

More information on climate change, global warming and birds

American Bird Conservancy: Some general information on climate change and birds.

A blog on Birds and Climate Change.

BirdLife International: Birds to become latest indicators of climate change.

What is Global Warming? - Learn about Global Warming at National Geographic.

Smog obscuring the view of Ulaanbaatar,
17 Dec 2006. Photo © A. Braunlich

1 comment:

Anonymous said...

Thank you Axel!