The Influence of Climate Change on Animals, Especially Butterflies

Compiled by Steven Schafersman
2013 September 24

Phenology -- the science dealing with the influence of climate on the recurrence of such annual phenomena of animal and plant life as budding and bird migrations; the study of recurring phenomena, such as animal migration, especially as influenced by climatic conditions.

Phenology is the study of periodic plant and animal life cycle events and how these are influenced by seasonal and interannual variations in climate, as well as habitat factors (such as elevation). Examples include the date of emergence of leaves and flowers, the first flight of butterflies and the first appearance of migratory birds, the date of leaf colouring and fall in deciduous trees, the dates of egg-laying of birds and amphibia, or the timing of the developmental cycles of temperate-zone honey bee colonies.

[A review of the literature suggests that butterflies are one of the most important group of organisms used to document northward range expansion and earlier appearance due to climate change. It is a model organism for phenology. -- Compiler]


Butterflies and Climate Change

Roger L. H. Dennis

Butterflies are particularly sensitive to climate and are important "bio-indicators" of climatic change. This book not only explores how butterflies adapt to climatic gradients and weather patterns, but also shows how their biogeography and evolution have responded to climate change in the past, and how they are likely to respond in the future as the enhanced greenhouse effect increasingly alters the world's climate. Roger Dennis begins by explaining the atmospheric systems in which butterflies live and which impose constraints upon their activity, development and function. He examines how butterflies thermoregulate, despite having very little capacity for generating their own heat. He then covers butterflies' life history strategies, their adaptations to seasonality and their tolerance of extreme conditions. The discussion takes him into the controversial areas of population dynamics and species diversity. He presents a new model to explain how gradients in adult butterfly morphology and colour patterns relate to gradients in climate. Finally, Dennis explores further adaptive responses to climatic change, using models to explain past events and to predict the impact on butterfly populations of global warming. "Butterflies and Climate Change" aims to contribute not only to insect ecology, but also to our understanding of how anthropogenic climate change affects natural populations and ecosystems. The book is designed to be readable and accessible to the non-specialist, but fully referenced and with a detailed bibliography.

Product Details
Paperback: 200 pages
Publisher: Manchester University Press (February 1994)
[out of print; very expensive]


Biological consequences of global warming: is the signal already apparent?

Trends in Ecology & Evolution, Volume 15, Issue 2, 56-61, 1 February 2000

Lesley Hughes
Dept of Biological Sciences and Key Centre for Biodiversity and Bioresources, Macquarie University, NSW 2109, Australia


Increasing greenhouse gas concentrations are expected to have significant impacts on the world’s climate on a timescale of decades to centuries. Evidence from long-term monitoring studies is now accumulating and suggests that the climate of the past few decades is anomalous compared with past climate variation, and that recent climatic and atmospheric trends are already affecting species physiology, distribution and phenology.

Flying insects

A recent survey of 35 non-migratory European butterfly species found that the ranges of 22 (63%) have shifted northwards by 35–240 km this century, with only two species (3%) having shifted south. Two-thirds of the species showing extensions at their northern boundary had southern boundaries that remained stable, thus, effectively expanding their range. In North America, a survey of 151 previously recorded populations of Edith’s Checkerspot butterfly (Euphydryas editha) found significant latitudinal and elevational clines in extinction rates. Sites where populations had persisted were, on average, further north than sites where populations had become extinct. Populations in Mexico were four times more likely to be extinct than those in Canada, and populations above 2400 m were significantly more likely to persist than those at lower altitudes.


Ecological responses to recent climate change

NATURE|VOL 416| 28 MARCH 2002. p. 389-395

Walther Glan-Reto et al.


There is now ample evidence of the ecological impacts of recent climate change, from polar terrestrial to tropical marine environments. The responses of both flora and fauna span an array of ecosystems and organizational hierarchies, from the species to the community levels. Despite continued uncertainty as to community and ecosystem trajectories under global change, our review exposes a coherent pattern of ecological change across systems. Although we are only at an early stage in the projected trends of global warming, ecological responses to recent climate change are already clearly visible.

Range shifts to keep up with climate change

It is generally agreed that climatic regimes influence species' distributions, often through species-specific physiological thresholds of temperature and precipitation tolerance. With general warming trends, these `climate envelopes' become shifted towards the poles or higher altitudes. . . . It is now clear that poleward and upward shifts of species ranges have occurred across a wide range of taxonomic groups and geographical locations during the twentieth century.

18 butterfly species, UK, Earlier appearance by 2.8±3.2 days per decade, Past 23 years
Roy, D. B. & Sparks, T. H. Phenology of British butterflies and climate change. Glob. Change Biol. 6, 407-416 (2000) [see next]


[PDF through university access to scientific database only]

Roy, D. B. & Sparks, T. H., Phenology of British butterflies and climate change, Glob. Change Biol. 6(4), 407-416 (April 2000).


Data from a national butterfly monitoring scheme were analysed to test for relationships between temperature and three phenological measures, duration of flight period and timing of both first and peak appearance. First appearances of most British butterflies has advanced in the last two decades and is strongly related to earlier peak appearance and, for multibrooded species, longer flight period. Mean dates of first and peak appearance are examined in relation to Manley's central England temperatures, using regression techniques. We predict that, in the absence of confounding factors, such as interactions with other organisms and land-use change, climate warming of the order of 1 °C could advance first and peak appearance of most butterflies by 2–10 days.


Worcestershire Record No. 26 April 2009 pp. 9-11


Mike Williams

As “cold blooded” animals, butterflies are particularly affected by changes in climate. Numbers are influenced every year by weather patterns but increases in mean temperatures over a sustained period can lead to significant changes in range, population size, the rate of colonisation or extinction, phrenology [sic], number of generations each year, choice of larval foodplant and other ecological and evolutionary factors. It is important to understand and monitor change, not just because of its intrinsic interest but because these changes may have considerable implications for conservation management.

Because there is such a good data set and because of their biology, butterflies are very effective indicators of climate change. The Millennium Atlas of Butterflies in Britain and Ireland (Asher et al 2001). which was the most comprehensive and intensive period of butterfly recording ever undertaken in the UK, shows very clearly that butterflies are extending their distributions northwards. Many species, which have been formerly confined to southern Britain, have shown a significant extension to their range margin of 37km over a 21 year study period, nearly 2km per year (Hickling et al 2006). Because Worcestershire, historically, has been on the range margin of a number of these species, it is an exciting place to be and the county is well placed to see at first hand some of these changes in distribution. In any overview, however, it is important to recognise that 72% of British butterfly species have decreased in distribution between 1970-82 and 1995-2004. This is particularly the case with what can be described as habitat specialists which have shown a 93% decrease over this time period compared to the wider countryside species which have only declined by 56% (Fox et al 2006).

As well as expansions in range, there is also evidence that some species that historically have not been able to survive our winters are now doing so increasingly. The best example of this is Red Admiral which is now regularly recorded every month of the year and has been found over a wide area of southern Britain during the winter as both larva and pupa as well as an adult (see Map 1). It is now often the case that in January and February there are more sightings of Red Admiral than any other species on the British list. Good examples of significant range expansion nationally are Comma (see Map 2), Small Skipper, Essex Skipper, Holly Blue and, to a lesser degree, Speckled Wood. Distribution of the Comma, a butterfly that has always been well represented in Worcestershire, has virtually doubled since 1982 and the species is now recorded well into southern Scotland and has been recorded for the first time ever in Ireland. Over the same period, Small Skipper has expanded throughout Wales and has now reached the Scottish border, while the Holly Blue has undergone a similar expansion in both England and Wales and has also really taken off in Ireland.

Essex Skipper is a good example of a species where historically Worcestershire has been on the range margin, the first sighting in the county not occurring until 1997. Over the past 10 years, it has become extremely well established and, while undoubtedly generally under-recorded because of its similarity to Small Skipper, has been reported from the majority of 10km squares (see Map 3). With the Marbled White, when I first moved to the county in 1980, one could have drawn an east-west line through Worcester and say with confidence that the butterfly did not occur north of this line. Now the species is found pretty well throughout the county (see Map 4) occurring on most remaining areas of unimproved grassland not subject to annual cutting. A similar story can be told with the Brown Argus, a species in the early 80s pretty well confined to Bredon Hill, but now found over much of the county with the apparent exception of the north-east (see Map 5). This species has clearly benefited from the introduction of set-a-side and much of the expansion is associated with the utilisation of various species of geranium as an alternative larval food-plant to rockrose. In 1982, when Jack Green published his guide to the butterflies of Worcestershire (Green 1982). the White Admiral was so rare that the author kept the locations where it was found confidential. Now it occurs in virtually every area of woodland in the county right up to the edge of Birmingham.

What is difficult with some species is to distinguish the impact of climate change from other factors. The Brown Hairstreak is a really good case in point. As Maps 5 and 6 illustrate, the last 13 years show a major expansion in range within the county but is this really the result of climate change or is it increased recording effort or the impact of improved hedgerow management on the back of agri-environment schemes? I suspect that all these factors have played their part.

As well as range expansion, perhaps the other most striking impact of climate change has been with regard to emergence dates and flight periods. Generally species are being first reported much earlier in the year and are seen over a longer time period (Roy & Sparks 2000). Back in the 1980s, the first Orange Tip was generally not seen until May, now it is unusual if it is not seen by mid-April and in some seasons e.g. 2005 it is recorded before the end of March. In recent years, there have been examples of normally single brooded species like White Admiral and Dingy Skipper apparently producing a partial second generation in southern Britain. Similarly, with normally doubled brooded species like Small Copper, there have been increasing records of specimens being on the wing in October suggesting a partial third generation.

It is perhaps easy to get carried away with the positive effects of climate change, perhaps even envisaging new species of butterfly queuing up at the channel tunnel to make the crossing, but it is not all good news. There has been a lot of concern in recent years about the collapse in numbers of the Small Tortoiseshell in Britain. Once one of our commonest and familiar garden butterflies, it has now suddenly become rather scarce. Research has suggested that this decline is linked with the arrival into the UK of a tachinid fly Sturmia bella which is a well known parasite of Small Tortoiseshells and other Nymphalidae on the continent. It first arrived in Britain in 1999 and has since spread to most areas having a major detrimental effect on Small Tortoiseshell populations. Certainly a less welcome impact of climate change on butterflies.

It will be interesting to see what the future has in store for Worcestershire’s butterflies. Developing our knowledge of the continuing impact of climate change will be key to ensuring that the right priorities and land management decisions are taken which makes recording and monitoring butterflies all the more important in the years ahead – so keep on recording! 2009 is the final year of the latest 5 year survey undertaken by Butterfly Conservation into the changing distribution of Britain's butterflies. Recording forms can be downloaded from the regional BC website


ASHER, J, WARREN, M, FOX, R, HARDING, P, JEFFCOATE, G, JEFFCOATE, S, 2001. The Millennium Atlas of Butterflies in Britain and Ireland. Oxford University Press, Oxford
FOX, R, ASHER, J, BRERETON, T, ROY, D, WARREN, M. 2006. The State of Butterflies in Britain and Ireland. Pisces Publications
GREEN, J. 1982, A Practical Guide to the Butterflies of Worcestershire. Worcestershire Nature Conservation Trust
HICKLING, R, ROY, DB, HILL, JK, FOX, R, THOMAS, CD. 2006 The distribution of a wide range of taxonomic groups is expanding polewards. Global Change Biology 12, 450-455
ROY, DB, SPARKS, TH. 2000. Phenology of British butterflies and climate change. Global Change Biology 6, 407-416.


Effects of climatic change on the phenology of butterflies in the northwest Mediterranean Basin

Global Change Biology (2003) 9, 1494–1506


Phenological changes in response to climatic warming have been detected across a wide range of organisms. Butterflies stand out as one of the most popular groups of indicators of climatic change, given that, firstly, they are poikilothermic and, secondly, have been the subject of thorough monitoring programmes in several countries for a number of decades. Here we provide for the first time strong evidence of phenological change as a consequence of recent climatic warming in butterflies at a Spanish site in the northwest Mediterranean Basin. By means of the widely used Butterfly Monitoring Scheme methodology, three different phenological parameters were analysed for the most common species to test for trends over time and relationships with temperature and precipitation. Between 1988 and 2002, there was a tendency for earlier first appearance dates in all 17 butterfly species tested, and signficant advances in mean flight dates in 8 out of 19 species. On the other hand, the shape of the curve of adult emergence did not show any regular pattern. These changes paralleled an increase of 1–1.51C in mean February, March and June temperatures. Likewise, a correlation analysis indicated the strong negative effect of spring temperature on phenological parameters (i.e. higher temperatures tended to produce phenological advances), and the opposite effect of precipitation in certain months. In addition, there was some evidence to indicate that phenological responses may differ between taxonomic lineages or species with similar diets. We discuss the consequences that these changes may have on species’ population abundances, especially given the expected increase in aridity in the Mediterranean Basin caused by current climatic warming. We predict that varying degrees of phenological flexibility may account for differences in species’ responses and, for multivoltine species, predict strong selection favouring local seasonal adaptations such as diapause phenomena or migratory behaviour.

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Species’ traits predict phenological responses to climate change in butterflies

Ecology 92:1005–1012

Sarah E. Diamond, Alicia M. Frame, Ryan A. Martin, Lauren B. Buckley


How do species’ traits help identify which species will respond most strongly to future climate change? We examine the relationship between species’ traits and phenology in a well-established model system for climate change, the UK Butterfly Monitoring Scheme (UKBMS). Most resident UK butterfly species have significantly advanced their dates of first appearance during the past 30 years. We show that species with narrower larval diet breadth and more advanced overwintering stages have experienced relatively greater advances in their date of first appearance. In addition, species with smaller range sizes experienced greater phenological advancement. Our results demonstrate that species’ traits can be important predictors of responses to climate change, and suggest that further investigation of the mechanisms by which these traits influence phenology may aid in understanding species’ responses to current and future climate change.


Effect of Regional Climate Warming on the Phenology of Butterflies in Boreal Forests in Manitoba, Canada

Environmental Entomology 39(4):1122-1133, 2010

A. R. Westwood and D. Blair


We examined the effect of regional climate warming on the phenology of butterfly species in boreal forest ecosystems in Manitoba, Canada. For the period 1971–2004, the mean monthly temperatures in January, September, and December increased significantly, as did the mean temperatures for several concurrent monthly periods. The mean annual temperature increased ~ 0.05°C/ yr over the study period. The annual number of frost-free days and degree-day accumulations increased as well. We measured the response of 19 common butterfly species to these temperature changes with the date of first appearance, week of peak abundance, and the length of flight period over the 33-yr period of 1972–2004. Although adult butterfly response was variable for spring and summer months, 13 of 19 species showed a significant (P < 0,.05) increase in flight period extending longer into the autumn. Flight period extensions increased by 31.5 ± 13.9 (SD) d over the study period for 13 butterfly species significantly affected by the warming trend. The early autumn and winter months warmed significantly, and butterflies seem to be responding to this warming trend with a change in the length of certain life stages. Two species, Junonia coenia and Euphydryas phaeton, increased their northerly ranges by ~150 and 70 km, respectively. Warmer autumns and winters may be providing opportunities for range extensions of more southerly butterfly species held at bay by past climatic conditions.


[PDF through university access to scientific database only]


Ecology 85(1):231–241, 2004

Lisa Crozier
Department of Biology, Box 351800, University of Washington, Seattle, Washington 98195-1800 USA


As the climate warms, many species are moving to higher latitudes and elevations. However, range shifts can be caused by many factors. These factors are unknown in most cases. The specific role of climate in these dynamics needs study to better predict future consequences of global warming. This case study evaluates whether warming is driving the northward range expansion of a skipper butterfly (Atalopedes campestris). Recently colonized areas have warmed 2–4°C over the past 50 years. To assess the importance of climate change for population persistence in these areas, I compared population dynamics at two locations (at the current range edge and just inside the range) that differ by 2–3°C. Population growth rate at these two locations over two years was positively correlated with January mean and annual mean temperatures. To determine whether larval overwinter survivorship could explain this correlation, I transplanted larvae over winter to both sites. Larval survivorship was very low at both locations, but significantly lower at the range edge, probably because lower lethal temperatures frequently occurred there. To estimate the direct effect of cold stress on larval survivorship, I applied a previously derived hazard-rate model based on laboratory experiments. With input from field-measured daily mean temperature, the model accurately predicted transplant survivorship at both locations over two winters. Combined results from population and larval transplant analyses indicate that winter temperatures directly affect the persistence of A. campestris at its northern range edge, and that winter warming was a prerequisite for this butterfly's range expansion.


Winter warming facilitates range expansion: cold tolerance of the butterfly Atalopedes campestris

Oecologia (2003) 135:648–656

Lisa Crozier


Our ability to predict ecological and evolutionary responses to climate change requires an understanding of the mechanistic links between climate and range limits. The warming trend over the past half-century has generated numerous opportunities to develop much needed case studies of these links. Species that are only limited by climatic factors are likely to shift range quickly during periods of warming. Such species directly impact recipient communities and indicate trends that will become more widespread. Because minimum temperature (T min) is rising at twice the rate of maximum temperature, species with this range-limiting factor may be especially responsive to global warming. In this study, I test the hypothesis that rising T min has directly affected the range of a skipper butterfly. Atalopedes campestris has moved northward rapidly this century, recently colonizing eastern Washington where January T min has risen 3 C in 50 years.


The NABA Counts and Climate Change

by Leslie Ries and Lisa Crozier
American Butterflies, Winter, 2009

One of the most important research areas right now is the quest to track and predict not only climate change, but how both human society and the ecological community are responding to it. Many studies have shown how natural populations of many animal and plants are already shifting their distributions or timing to align to new climate realities (Parmesan and Yohe 2003). For European butterflies, poleward shifts have been shown to be associated with regional warming (Parmesan et al. 1999). Is a similar analysis possible with NABA’s butterfly count data? A recent project looking in detail at the distributions of Sachems suggests that it may be.

Sachems are common throughout much of their range, and are found largely in open, often disturbed, areas. Sachems were the focus of co-author Lisa Crozier’s dissertation work where she conducted an intensive study (both field and lab) of cold tolerances within an area in eastern Washington into which the Sachems’ range had recently expanded. Lisa’s research showed that Sachems are strongly limited by minimum winter temperatures, and their expansion was into an area that only recently had experienced minimum winter temperatures within their cold tolerance (Crozier 2004).

After compiling all of the eco-physiological data, Lisa and colleague Greg Dwyer used the data collected in a small area of Washington State to predict the range of Sachems throughout all of the United States, as well as predict how their range might shift under various climate scenarios (see Crozier and Dwyer 2006). In that paper, they used historical occurrence records from the Butterflies and Moths of North America project to see how well their model did at predicting the range of this common species. The range predictions fit very well with documented occurrences in the western US, but not the east (see Fig. 1a). However, occurrence records can be highly misleading since only one observation needs to be made to be counted as “present.” It would be better to know where Sachems are able to maintain consistent populations. That is where NABA’s count data comes in. Together, we have been examining the count data to see how accurate Lisa and Greg’s model was, and whether we can use those results to make reasonable predictions

To do this, we mapped the likelihood of observing a Sachem throughout all the count locations surveyed over the history of the count program. Only count locations with at least three years of data were used. Our results showed that consistent observations of Sachems occurred up to the predicted range limit, even in the east, and then dropped sharply after that (Fig. 1b). Although some observations occurred north of the predicted limit, other than a pocket along the border of Iowa and Nebraska, those observations were rare and usually only a single individual was seen over the life of the survey. These results suggest that range limits can be predicted using basic physiological tolerances to temperature, at least for some species.

What else can we learn from the Sachem’s distribution throughout its range? One thing we noticed is how variable its distribution is throughout its range. Since the predicted range is mainly constrained by minimum winter temperatures, something else must be controlling local habitat quality. Look at a graph at the top of page 36, of actual Sachem abundance compared to the predicted growth rate from Lisa and Greg’s model, which is largely based on minimum winter temperatures. This graph clearly illustrates that population sizes begin to grow just after the model predicts self-sustaining populations (where growth rates are equal to one). However, at the high-end growth rates (where the populations should be largest), actual populations fall precipitously. We are still exploring different possibilities, but one possibility we have noted is that populations are limited not only by winter temperatures that are too low, but winter temperatures that are too high!

So, how does this all relate to global climate change? Based on the results of our analysis, we show that minimum winter temperature appears to be a major driver in the range of the Sachem (although other factors are obviously important). Since minimum temperature is one of the metrics calculated by global climate models, we can make some predictions of how Sachem distributions will change under different climate scenarios. Then, as NABA count data continue to be collected, we can test those predictions and continue to learn from the data. Although the types of intensive field studies conducted by Lisa are not common, we can also use current climate information to determine if there are other species whose range seems limited by temperature (or other climate-related) regimes. This will allow us to make specific predictions about how the ranges of species such as the Sachem should shift given certain climate outcomes. Tracking responses under the framework of models such as these makes understanding observed patterns much more possible and increases the value of the data being collected by volunteers in the count program. So keep up the good work!

Crozier, L. 2004. Warmer winters drive butterfly range expansion by increasing survivorship. Ecology 85: 231-241.

Crozier, L. and G. Dwyer. 2006. Combining Population-Dynamic and Ecophysiological Models to Predict Climate-Induced Insect Range Shifts. American Naturalist 167: 853-866.

Parmesan C. and many others. 1999. Poleward shifts in geographical ranges of butterfly species associated with regional warming. Nature 399: 579-583.

Parmesan C. and G. Yohe. 2003. A globally coherent fingerprint of climate change impacts across natural systems. Nature 421: 37-42.


Climate change and the effect of increasing spring temperatures on emergence dates of the butterfly Apatura iris (Lepidoptera: Nymphalidae)

Eur. J. Entomol. 102: 161–167, 2005



Data on pupation and emergence dates for the nymphalid Purple Emperor butterfly Apatura iris have been collected at Basel, Switzerland, between 1982 and 2002. The butterfly has been shown to emerge on average 9 (males) to 12 (females) days earlier per decade, 19 and 24 days earlier respectively over the study period. Emergence dates relate strongly to spring temperatures, particularly with daily maximum temperatures for the months March to May. Temperatures for these months have increased significantly during this period (0.7°C to 1.8°C per decade). Three factors suggest that the strongest influence of the rise in spring temperatures has been on late larval instar growth and development: (i) May temperatures dominate emergence date models and larvae are feeding faster and for longer periods during this month, (ii) Salix caprea flowering date, a surrogate for bud burst, is excluded in stepwise regression models with temperatures and years suggesting that tree phenology may be less important than temperature effects on later development, and (iii) convergence of female and male emergence dates over time points to limits on earlier feeding in protandrous males. A negative consequence observed with earlier emergence dates is lethal extra broods.


Climatic trends and advancing spring flight of butterflies in lowland California

Global Change Biology (2003) 9, 1130-1135

[Climatic trends and advancing spring flight of butterflies in lowland California.png]


[PDF through university access to scientific database only]

Elevational trends in butterfly phenology: implications for species responses to climate change

Ecological Entomology (2012), 37, 134–144



1. Impacts of global change on the distribution, abundance, and phenology of species have been widely documented. In particular, recent climate change has led to widespread changes in animal and plant seasonality, leading to debate about its potential to cause phenological mismatches among interacting taxa.

2. In mountainous regions, populations of many species show pronounced phenological gradients over short geographic distances, presenting the opportunity to test for effects of climate on phenology, independent of variation in confounding factors such as photoperiod.

3. Here we show for 32 butterfly species sampled for flve years over a 1700 m gradient (560–2260 m) in a Mediterranean mountain range that, on average, annual flight period is delayed with elevation by 15–22 days per kilometre. Species mainly occurring at low elevations in the region, and to some extent those flying earlier in the year, showed phenological delays of 23–36 days per kilometre, whereas the flight periods of species that occupy high elevations, or fly in late summer, were consistently more synchronised over the elevation gradient.

4. Elevational patterns in phenology appear to reflect a narrowing phenological window of opportunity for larval and adult butterfly activity of high elevation and late-flying species.

5. Here, we speculate as to the causes of these patterns, and the consequences for our ability to predict species responses to climate change. Our results raise questions about the use of space–time substitutions in predicting phenological responses to climate change, since traits relating to flight period and environmental associations may influence the capacity of species to adapt to changing climates.


Some Butterfly Species Particularly Vulnerable to Climate Change

June 1, 2012 — A recent study of the impact of climate change on butterflies suggests that some species might adapt much better than others, with implications for the pollination and herbivory associated with these and other insect species.

The research, published in Ecological Entomology, examined changes in the life cycles of butterflies at different elevations of a mountain range in central Spain. They served as a model for some of the changes expected to come with warming temperatures, particularly in mountain landscapes.

The researchers found that butterfly species which already tend to emerge later in the year or fly higher in the mountains have evolved to deal with a shorter window of opportunity to reproduce, and as a result may fare worse in a warming climate, compared to those that emerge over a longer time period.

"Insects and plants are at the base of the food pyramid and are extremely important, but they often get less attention when we are studying the ecological impacts of climate change," said Javier G. Illan, with the Department of Forest Ecosystems and Society at Oregon State University.

"We're already expecting localized extinctions of about one third of butterfly species, so we need to understand how climate change will affect those that survive," he said. "This research makes it clear that some will do a lot better than others."

Butterflies may be particularly sensitive to a changing climate, Illan said, and make a good model to study the broader range of ecological effects linked to insects. Their flight dates are a relevant indicator of future responses to climate change.

The research was done by Illan's group in the Rey Juan Carlos University in Madrid. It examined 32 butterfly species for five years at various elevations in a Mediterranean mountain range, and the delays in flight dates that occurred as a result of elevation change.

Journal Reference:
Javier Gutiérrez Illán, David Gutiérrez, Sonia B. Díez, Robert J. Wilson. Elevational trends in butterfly phenology: implications for species responses to climate change. Ecological Entomology, 2012; 37 (2): 134-144


Climate Change Affects the Flight Period of Butterflies in Massachusetts

Feb. 12, 2013 — In a new study, Boston University researchers and collaborators have found that butterflies show signs of being affected by climate change in a way similar to plants and bees, but not birds, in the Northeast United States. The researchers focused on Massachusetts butterfly flight periods, comparing current flight periods with patterns going back more than 100 years using museum collections and the records of dedicated citizen scientists. Their findings indicate that butterflies are flying earlier in warmer years.

"Butterflies are very responsive to temperature in a way comparable to flowering time, leafing out time, and bee flight times," says Richard Primack, professor of biology and study co-author. "However, bird arrival times in the spring are much less responsive to temperature." As a result, climate change could have negative implications for bird populations in the Northeast, which rely on butterflies and other insects as a food source. The team, which includes Caroline Polgar (Boston University), Sharon Stichter (Massachusetts Butterfly Club), Ernest Williams (Hamilton College), and Colleen Hitchcock (Boston College) will publish its findings in the February 12 online edition of the journal Biological Conservation.

While the effect of climate change on plant and bird life cycles in eastern North America has been well examined, studies of the effects of climate change on insects are rare, so these findings represent an important contribution. This new study investigated whether the responses to climate warming in Massachusetts of ten short-lived butterfly species known as elfins and hairstreaks are similar to responses seen in plants, birds and bees. Another unique feature of this study is its use of data from museum collections as well as data gathered by the Massachusetts Butterfly Club, a group of dedicated citizen scientists who love butterflies. Use of this data gave the researchers an opportunity to compare butterfly flight periods dating back to the late 1800s.

The researchers obtained over 5000 records of butterflies in flight using museum collections (1893-1985) and citizen science data (1986-2009), then analyzed the data using statistical models to determine how butterfly flight times are affected by temperature, rainfall, geographic location, and year.

The researchers found that the start of the butterfly flight period advances on average by two days for each degree Fahrenheit increase in temperature. The response of these butterfly species to temperature is similar to plant flowering times and bee flight times and is significantly greater than bird arrival times, which increases the likelihood of ecological mismatches with migratory birds arriving after the first spring flush of their insect food.

The researchers also found that observations by citizen science groups such as the Massachusetts Butterfly Club were an effective and largely untapped source of information that could be used to investigate the potential impacts of climate change on butterflies. Such data provides an opportunity to inform conservation policies on these species and associated habitat. While data from museums was helpful, it was less abundant and therefore less useful than the citizen science dataset.

Journal Reference:
Caroline A. Polgar, et al., Climate effects on the flight period of Lycaenid butterflies in Massachusetts. Biological Conservation, 2013; 160:25


Butterflies and Birds Unable to Keep Pace With Climate Change in Europe

Jan. 18, 2012 — Butterflies and birds are no longer able to keep up with climate change. Compared with twenty years ago, butterflies are now 135 kilometres behind the shifting climate zones and birds more than 200 kilometres. This is one of the findings from a study by European researchers published Jan. 9, 2012 in the journal Nature Climate Change.

A lack of reliable long-term data makes recording the effects of climate change on biodiversity a huge challenge. The data for butterflies and birds, however, is available. This week, an article in Nature Climate Change published by a European research team including a number of Dutch scientists, shows that populations of birds and butterflies are no longer able to keep track of the northward shift in their living environment caused by global warming. A partial explanation can be found in the fact that fragmentation of intensively-used European land is making it very difficult for species to colonize new areas. But the relative abundances of resident species are also proving slow to change. This applies less to butterflies, which have a short lifecycle, than to birds.

The research, in which Dutch Butterfly Conservation [De Vlinderstichting], SOVON Dutch Centre for Field Ornithology [Vogelonderzoek], Statistics Netherlands [CBS] and Wageningen University are taking part, is focusing on changes in the relative abundance of species in the total butterfly and bird community, where previous studies concentrated on individual species. The findings constitute the first evidence that climate change is causing entire groups of animals to accrue a ‘climatic debt’ on a continental scale. Over the last twenty years, this debt has risen to 135 km for butterflies and a staggering 212 km for birds. In other words, butterfly and bird populations have a more northern character than one would expect on the basis of the climate. It is currently difficult to predict the long-term implications. The difference in the shifts between the two groups of species may disturb their interdependence. A good example of this is the pied flycatcher, whose young only hatch after the peak period for caterpillars in warm years.

The researchers have devised a simple method for determining the consequences of climate change for entire groups of species. The unique amount of data is largely due to the efforts of thousands of volunteers in seven countries, who spent more than 1.5 million hours collecting the information.

Journal Reference:
Vincent Devictor, et al., Differences in the climatic debts of birds and butterflies at a continental scale. Nature Climate Change, 2012; DOI: 10.1038/nclimate1347


Animal phenology (CLIM 025) - Assessment published Nov 2012

Key policy question: How is climate change affecting the seasonal cycle of animals in Europe?

Key messages

Many animal groups have advanced their life-cycles in recent decades, including frogs spawning, birds nesting and the arrival of migrant birds and butterflies. This advancement is attributed primarily to a warming climate.

The breeding season of many thermophilic insects (such as butterflies, dragonflies and bark beetles) has been lengthening, allowing more generations to be produced per year.

The observed trends are expected to continue in the future but quantitative projections are rather uncertain.

Past trends

Several studies have convincingly demonstrated a tight dependency of life-cycle traits of animals with ambient temperatures, both in terrestrial and aquatic habitats[i]. Mostly, the observed warming leads to an advanced timing of life history events. For example, temporal trends for appearance dates of two insect species (honey bee, small white: Pieris rapae) in more than 1 000 localities in Spain have closely followed variations in recorded spring temperatures between 1952 and 2004 [ii].

The predicted egg-laying date for the Pied flycatcher (Ficedula hypoleuca) showed significant advancement between 1980 and 2004 in western and central Europe, but delays in northern Europe, both depending on regional temperature trends in the relevant season (see Figure 1) [iii]. Data from four monitoring stations in south to mid-Norway that include nest-boxes of Pied flycatcher from 1992–2011 show in contrary to the regional temperature estimated trends that there are no significant delays in egg-laying date for the Pied flycatcher, but an annual fluctuation making a rather flat curve for the median over these years [iv]. A study in the Netherlands covering the period between 1932 and 2004 found that half of the investigated bird species are now overwintering significantly closer to their breeding site than in the past, most likely due to warmer winters [v]. A long-term trend analysis of 110 common breeding birds across Europe (1980–2005, 20 countries) showed that species with the lowest thermal maxima showed the sharpest declining trends in abundance[vi]. In other words, cold-adapted species are losing territory most quickly.

A study from the UK found that each of the 44 species of butterfly investigated advanced its date of first appearance since 1976 [vii]. Recent studies on birds, butterflies and amphibians not only confirmed previous findings that there is a coherent fingerprint of climate change in the pattern of phenological changes [viii], but also indicated that average rates of phenological change have recently accelerated in line with accelerated warming trends [ix]. There is also increasing evidence about climate-induced changes in spring and autumn migration, including formerly migratory bird species becoming resident [x].


Projections for animal phenology are rarely carried out, except for species of high economic interest[xi]. Quantitative projections are hampered by the high natural variability in phenological data, particularly in insects[xii]. The projected future warming is expected to cause further shifts in animal phenology and can lead to an increase of trophic mismatching, unforeseeable outbreaks of species, a decrease of specialist species and changes in ecosystem functioning[xiii].

[i] DB Roy and TH Sparks, „Phenology of British butterflies and climate change“, Global Change Biology 6, Nr. 4 (2000): 407–416, doi:10.1046/j.1365-2486.2000.00322.x; C. Stefanescu, J. Penuelas, and I. Filella, „Effects of climatic change on the phenology of butterflies in the northwest Mediterranean Basin“, Global Change Biology 9, Nr. 10 (2003): 1494–1506, doi:10.1046/j.1365-2486.2003.00682.x; D. Dell, T H Sparks, and R L H Dennis, „Climate change and the effect of increasing spring temperatures on emergence dates of the butterfly Apatura iris (Lepidoptera: Nymphalidae)“, European Journal of Entomology 102, Nr. 2 (2005): 161–167; C. Parmesan, „Ecological and evolutionary responses to recent climate change“, Annual Review of Ecology, Evolution, and Systematics 37 (2006): 637–669, doi:10.1146/annurev.ecolsys.37.091305.110100; C. Hassall et al., „Historical changes in the phenology of British Odonata are related to climate“, Global Change Biology 13, Nr. 5 (2007): 933–941, doi:10.1111/j.1365-2486.2007.01318.x; Niels J Dingemanse and Vincent J Kalkman, „Changing Temperature Regimes Have Advanced the Phenology of Odonata in the Netherlands“, Ecological Entomology 33, Nr. 3 (Juni 1, 2008): 394–402, doi:10.1111/j.1365-2311.2007.00982.x; M.H. Schlüter et al., „Phenological shifts of three interacting zooplankton groups in relation to climate change“, Global Change Biology 16, Nr. 11 (2010): 3144–3153, doi:10.1111/j.1365-2486.2010.02246.x; P. Tryjanowski et al., „Does climate influence phenological trends in social wasps (Hymenoptera: Vespinae) in Poland?“, European Journal of Entomology 107, Nr. 2 (2010): 203–208.

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Last updated: 2013 September 25