8 
Bulletin oftheEANHS 28(1) 
launch a panel of experts, chaired by the former UK 
environment minister John Gummer, discussed the 
report’s findings. 
Evidence includes signs that many bird species in the 
UK. for example, are breeding earlier, including 
Redshank, Wren, Chaffinch and Chiffchaff. Frogs, toads 
and newts are also arriving at ponds earlier to spawn. 
Changes to sea temperatures may affect food supplies 
for seabirds and these effects are already being noticed 
in the Pacific Ocean. Alpine flora has already changed 
in distribution as temperatures have been increasing. 
Migrating birds often rely on traditional stopping off 
places at which they feed and replenish their energy 
supplies. In the UK millions of migrant waders and 
wildfowl use estuaries as feeding grounds to provide 
essential food on their way south to Africa. Sea level 
rise as a result of global warming could lead to many 
vital coastal areas disappearing, resulting in a change 
to migration routes with fewer birds surviving the long 
journeys. 
Among many recommendations, the report 
emphasises the need for: 
• Increased co-ordination between scientific 
disciplines, e.g. climatology and ecology 
• A greater understanding of the mechanisms by 
which climate change affects flora and fauna 
• Long term monitoring of flora and fauna, 
continuing into the future 
• A focus on changes in the timing of life cycles of 
interacting species, e.g. predators and their prey 
• Collecting evidence of the impact of climate more 
widely, especially in the tropics 
• Fully considering competing hypotheses that may 
explain any observed changes 
Bamaby Briggs, BirdLife Intemational/RSPB climate 
change officer, said: “For the first time the very real 
and mounting evidence of climate change affecting 
wildlife has been collated , showing that problems already 
exist for many species. The emerging picture of effects 
on wildlife makes the need for a positive outcome from 
the Climate Change Conference in Kyoto even more 
urgent**. 
EVIDENCE FOR CHANGE 
A study of long-term records from across the UK for 65 
breeding bird species identified the laying dates of the 
first egg in each clutch. Over 25 years, between 1971 
and 1995, 63% of the species showed a tendency to nest 
earlier. This tendency was statistically significant for 
31 % of the species. For these species, nesting dates 
have shifted nine days earlier over the period. Only one 
species showed a significant tendency to lay eggs later 
in the year. The earlier-nesting species were not confined 
to any one ecological or taxonomic grouping, but included 
waterbirds, migrant insect eaters and seed eaters, Some 
of the species affected included Dipper, Wren, Redstart, 
Chiffchaff, Chaffinch and Greenfinch. 
Up to 5 million Sooty Shearwaters used to spend 
their non-breeding period off the west coast of the USA. 
However, between 1987 and 1994, the numbers of 
shearwaters declined by 90%. This observed decline is 
attributed to changes in ocean surface temperature and 
changes in the ocean currents (reduced upwelling) which 
are associated with climate chahge. Some birds may 
have moved to new feeding grounds, but this is unlikely 
because of the huge areas over which declines have 
occurred. 
In the cloud forests of Costa Rica, a variety of 
changes in the wildlife have been linked to global 
warming. Many birds, including the Keel-billed Toucan 
and Blue-crowned Motmot, have extended their ranges 
up the mountain slopes, while Highland Lizard 
populations have declined and disappeared. Studies of 
the changes in relation to patterns of precipitation and 
temperature suggest that warming has raised the height 
at which cloud banks form over the region. The resultant 
drying trend may also have played a key role in a massive 
die-off of the area*s amphibians, including the Golden 
Toad. In total, no fewer than 40% of the frog and toad 
species that previously inhabited a 30 km 2 study area 
have become extinct during the 1990s. 
A 1°C increase in temperature may significantly alter 
the species composition in about half of the statutory 
protected areas in the UK. For example, montane 
habitats supporting Ptarmigans, Snow Buntings and 
Dotterels have a very specific—and very cold—climate. 
Such a cold climate will not, according to one model, 
be found in the UK by the end of the next century. 
Amphibian reproductive cycles can respond 
sensitively to climate change. In a study of UK frogs, 
toads and newts, 17 years of data show that the species 
arrived at ponds and spawned 9-10 days earlier for each 
1°C increase in temperature. The data showed that 
increases in temperature over the 17-year period have 
led to the reproduction cycles beginning earlier. 
A study of the Edith’s Checkerspot Butterfly show 
that populations at the far southern end of its range (in 
Mexico) have four times the extinction rate of populations 
in the far northern end of its range (in Canada). 
Extinctions are also about two-and-a-half times higher 
at low elevations compared with populations above 8,000 
ft (2,400 m). An analysis of Land use change shows that 
human degradation of habitat could not have caused this 
pattern. The pattern of extinctions means that, over this 
century, the average distribution has shifted northward 
by 92 km and upward by 124 m. Climatologists have 
found that the western USA has warmed by 0.7° C, which 
means that the climate bands have shifted 105 km 
northward and 105 m upward—nearly identical to the 
shift shown by the Edith’s Checkerspot Butterfly. 
Changes to alpine flora over 70 to 90 years show that 
even moderate wanning causes plant communities to 
migrate. As the temperature has increased, alpine flora 
has migrated ‘up the hill’ to higher elevations where it 
is relatively cooler. However, migration is occurring at 
a much slower rate than changes in temperature. New 
areas are being colonised more slowly than the rate at 
which the original areas are becoming unsuitable, 
because they are too warm. The area of suitable habitat 
is therefore diminishing. 
