Less snow from climate change pushes evolution of browner birds

7 09 2017
© Bill Doherty

© Bill Doherty

Climate changes exert selective pressures on the reproduction and survival of species. A study of tawny owls from Finland finds that the proportion of two colour morphs varies in response to the gradual decline of snowfall occurring in the boreal region.

Someone born in the tropics who travels to the Antarctic or the Himalaya can, of course, stand the cold (with a little engineering help from clothing, however). The physiology of our body is flexible enough to tolerate temperatures alien to those of our home. We can acclimate and, if we are healthy, we can virtually reside anywhere in the world.

However, modern climate change is steadily altering the thermal conditions of the native habitats of many species. Like us, some can live up to as much heat or cold as their genetic heritage permits, because each species can express a range of morphological, physiological, and behavioural variation (plasticity). Others can modify their genetic make-up, giving way to novel species-specific features or genotypes (evolution).

When genetic changes are speedy, that is, within a few generations, we are witnessing ‘microevolution’ — in contrast to ‘macroevolution’ across geological time scales as originally reported by Darwin and Wallace (1). To date, the detection of microevolution in response to modern climate change remains elusive, and many studies claiming so seem to lack the appropriate data to differentiate microevolution from phenotypic plasticity (i.e., the capacity of a single genotype to exhibit variable phenotypes in different environments) (2, 3). Read the rest of this entry »





Spring asynchrony in migratory birds

15 05 2017
CB_ClimateChange5_BirdLateMigratoryArrival_Photo

Brent geese flock in the Limfjorden (Denmark)courtesy of Kevin Clausen. The Brent goose (Branta bernicla) is a migratory goose that breeds in Arctic coasts, as well as in northern Eurasia and the Americas, starting from late May to early June. Adults are about 0.5 m long, weigh some 2 kg and live up to 30 years. Their nests are placed in the ground, where reproductive pairs incubate a single clutch (≤ 5 eggs) for a couple of months. They are herbivores, feeding on algae (mainly Zostera marina in Limfjord) and seagrass in estuaries, fjords, intertidal areas and rocky beaches during fall and winter. During summer they feed on tundra herbs, moss, lichens, as well as aquatic plants in rivers and lakes. The species is ‘Least Concern’ for the IUCN, with a global population at some 600,000 individuals.

Migratory birds synchronise their travel from non-breeding to breeding quarters with the seasonal conditions optimal for reproduction. Above all, they decide when to migrate on the basis of the climate of their wintering areas while they are there. As climate change involves earlier springs in the Arctic but not in the wintering areas, there is a lack of synchronisation that leads to a demographic decline of these birds in the polar regions where they breed.

When I think about how species respond to climate change, the song from the ClashShould I stay or should I go” comes to mind. As climate changes, species eventually have to face an ultimate choice: (i) stay and adapt to novel conditions or become locally extinct if adaptation fails, (ii) or move to other regions where climatic conditions should be more suitable. Migratory species have to face this decision every time they have to move back and forth from non-breeding to breeding grounds.

Migration is a behavioural strategy shared by different animal groups like sea turtles, mammals, amphibians, insects or birds. Species move from one area to another usually to feed and reproduce in the best climatic conditions possible. For birds, migration is a common phenomenon that typically entails large movements between breeding and wintering grounds. These vertebrates boast some of the longest migratory distances known in the animal kingdom, particularly seabirds like Artic terns, which can complete up to a round-world trip in a single migratory event between the UK and the Antarctic (1). There are several theories about the mechanisms triggering bird migration, including improving body condition and fitness through unexploited resources (2), reducing parasite load (3), minimizing predation risk (4), maximizing day-light (5), or reducing competition (6, 7). Whatever the cause, birds have to decide when the best moment to migrate is, counting only with the (usually climatic) clues they have at the departure site. Read the rest of this entry »





To feed or to perish in an iceless world

1 02 2017
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Emaciated female polar bear on drift ice in Hinlopen Strait (Svalbard, Norway), in July 2015 – courtesy of Kerstin Langenberger (www.arctic-dreams.com)

Evolution has designed polar bears to move, hunt and reproduce on a frozen and dynamic habitat that wanes and grows in thickness seasonally. But the modification of the annual cycle of Arctic ice due to global warming is triggering a trophic cascade, which already links polar bears to marine birds.

Popular and epicurean gastronomy claims that the best recipes should use seasonal veggies and fruits. Once upon a time, when there were no greenhouses, international trade routes, or as much frozen and canned food, our grandparents enjoyed what was available at the time. So in some years we had plenty of cherries, while during others we might have feasted on plums. Read the rest of this entry »





The Evidence Strikes Back — What Works 2017

16 01 2017
Bat gantry on the A590, Cumbria, UK. Photo credit: Anna Berthinussen

Bat gantry on the A590, Cumbria, UK. Photo credit: Anna Berthinussen

Tired of living in a world where you’re constrained by inconvenient truths, irritating evidence and incommodious facts? 2016 must have been great for you. But in conservation, the fight against the ‘post-truth’ world is getting a little extra ammunition this year, as the Conservation Evidence project launches its updated book ‘What Works in Conservation 2017’.

Conservation Evidence, as many readers of this blog will know, is the brainchild of conservation heavyweight Professor Bill Sutherland, based at Cambridge University in the UK. Like all the best ideas, the Conservation Evidence project is at once staggeringly simple and breathtakingly ambitious — to list every conservation intervention ever cooked up around the world, and see how well, in the cold light of evidence, they actually worked. The project is ongoing, with new chapters of evidence added every year grouped by taxa, habitat or topic — all available for free on www.conservationevidence.com.

What Works in Conservation’ is a book that summarises the key findings from the Conservation Evidence website, and presents them in a simple, clear format, with links to where more information can be found on each topic. Experts (some of us still listen to them, Michael) review the evidence and score every intervention for its effectiveness, the certainty of the evidence and any harmful side effects, placing each intervention into a colour coded category from ‘beneficial’ to ‘likely to be ineffective or harmful.’ The last ‘What Works’ book included chapters on birds, bats, amphibians, soil fertility, natural pest control, some aspects of freshwater invasives and farmland conservation in Europe; new for 2017 is a chapter on forests and more species added to freshwater invasives. Read the rest of this entry »





Game bird madness

4 11 2015

Gamecart_largeI just returned to Paris after a brief visit to the University of Aberdeen over the weekend. My hosts, Xavier Lambin and Beth Scott, were not only marvellously welcoming, I also learned a lot about the travesty that is game bird management in the United Kingdom, and especially in Scotland.

As you might already know, the Great Britons are a little cuckoo for birds — I’d even wager that the country produces more twitchers than any other country on Earth. The plus side is that there are few national taxa better censused and studied that British birds, because so many non-scientists get into the spirit of data collection. Hell, I’ve even had a play with some of their datasets.

The other side of this bird madness is not so good — I’m talking about the massive biomass of game birds reared, released and shot every year in the United Kingdom. It’s not the hunting per se with which I take issue, it’s the insane manipulation of an entire ecosystem for the benefit of a few species. Read the rest of this entry »





Help Hawaii’s hyper-threatened birds

6 01 2015
Puaiohi or small Kaua'i thrush. Photo by Lucas Behnke

Puaiohi or small Kaua’i thrush. Photo by Lucas Behnke

You wouldn’t want to be a bird in Hawaii. There are more avian species threatened with extinction there than anywhere else in the USA. After humans arrived, some 70+ species have become extinct, and 31 are listed as threatened with extinction. In addition, 43% of 157 species are not native; among land birds, 69% are introduced species.

My friend, Cali Crampton asked me to promote their new crowdfunding project to reduce the threat of feral rats on Hawaiian birds. Please help if you can.

The Kaua‘i Forest Bird Recovery Project, a collaborative project of the Hawaii Department of Land and Natural Resources, Division of Forestry and Wildlife, the University of Hawaii Pacific Cooperative Studies Unit, and Garden Island Research and Development, has announced the launch of a crowdfunding and outreach campaign to generate support for protecting the native birds of Kaua’i by controlling rats with humane, self-resetting rat traps.

The campaign, named “Birds, not Rats!” runs through to 31 January 2015, with goals of increasing awareness of the threats that rats pose to birds and native ecosystems, and raising at least $10,000 for rat control through many small, individual donations.

Hawai’i is at the epicentre of the current global extinction crisis. Of the original 130+ native Hawaiian bird species, many have been lost forever, and only 11 are not yet endangered. Today, Kaua’i is home to eight native forest bird species, three of which are federally listed as endangered: the puaiohi or small Kaua’i thrush, the akeke’e or Kaua’i akepa, and the akikiki or Kaua’i creeper. Populations of these birds have plummeted as much as 90% in the last five years; the akikiki and the puaiohi now number fewer than 500 individuals, and the akeke’e numbers fewer than 1000 individuals. The Kaua’i Forest Bird Recovery Project’s goal is to reverse these declines. Read the rest of this entry »





Give some flair to your scientific presentation

18 11 2014

Smoko3

As the desert spring came to the great Centre Red,
Scores of sandalled folk from tin birds descend-ed.
Alice Town had been invaded,
Bearded alike and unshorn-legged.
 
They sat and stared at words and the odd trend.
Billies boiled to get them through to day’s end
They swapped bush stories that made good sense,
Trying to understand Aussie environments.
 
One bloke‘s tales caught the punters’ attention,
So this bush poet deserves special mention.
To standard rules he would not kowtow,
So his special science verse I present to you now.

If none of that made any sense, then let me help you out. At the last Ecological Society of Australia meeting in Alice Springs, I witnessed a rather unique way to give a scientific presentation – via bush poetry. Dr. Dale Nimmo of Deakin University was particularly engaging, and he agreed to have his presentation poem reproduced here. Who said scientists were boring? Honourable mention too to Simon Watson for another audience-engaging, bush-poetry seminar (but I don’t have that to reproduce here). There also might be a slidecast of Dale’s presentation coming soon. For now, please enjoy the poetic delivery of science in text.

The Old Grey Box of Heathcote Town

Dale Nimmo

Down around old Heathcote town, just east of Bendigo,
A big old grey box tree casts an eye.
The sallee fills the understory bright as sunlights glow,
As the silvereyes and thornbills flitter by.
 
This landscape, bruised and battered from 200 years of change,
Holds the secrets of a time lost somehow.
One of Jaara land, where lowan dug and dingoes howled,
The latter two, here, just distant memories now.
 
The gold rush came like bushfire, ring barked trees fell like boughs
Of the red gums scattered on the old flood plains,
That made way for sheep and cattle, while, fighting a losing battle,
rufous bettongs were never seen again.
 
When a man of English gentry, Professor Bennett was his name,
Found the woodlands to his aristocratic tastes.
Many days he’d venture in, binoculars under his chin,
He never let a single bird call go to waste.
 
While at the old St Arnaud Inn, over a couple pints of gin,
Bennet and a bloke called Radford got to talking.
Stealing horses was his game, but he’d give it all away,
To join Bennett in woodlands, bird walking

Read the rest of this entry »