Mexican howler monkeys in trouble


This video is called Wild Howler Monkeys at Iberostar Tucan Quetzal Mexico.

From Wildlife Extra:

Howler monkeys increasingly stressed by human disturbance

New research shows that disturbed habitats are resulting in increasingly poor diets for monkeys, and that the additional time and energy required to find food is causing concerning levels of stress in already critically endangered primates.

January 2013. Endangered Mexican howler monkeys are consuming more leaves and less fruit as a result of habitat disturbance by humans which is forcing them to invest much more time foraging for sustenance and leading to increased ‘stress’ levels, as detected through hormone analysis.

The research took place in the tropical rainforests of the Mexican state of Veracruz, which are being deforested and fragmented by human activity – primarily the clearing of forest for cattle raising. It shows that increases in howler monkey ‘travel time’ – the amount of time needed to find requisite nourishment – are leading to increases in levels of stress hormones called glucocorticoids. These hormones are not only indicators of stress, but are also known to relate to diminished reproductive success and lower survival rates.

Researchers believe the study could serve as a model for behavioural change and resulting health implications more generally in primates living in habitats disturbed by human activities, such as deforestation.

Dr Jacob Dunn from Cambridge’s Department of Biological Anthropology, who carried out the research, said “Howlers are arboreal primates, that is to say they spend their wholes lives in the trees. As forests are fragmented, the howlers become cut off, isolated on forest ‘islands’ that increasingly lack the fruit which provide an important component of their natural diet. This has led to the monkeys expending ever more time and effort foraging for food, often increasing leaf consumption when their search is, quite literally, fruitless.”

Fruit cycle

Fruit occurs in natural cycles, and the monkeys will naturally revert to ‘fallback’ foods, including leaves, when fruit is scarce. But as habitats shrink, and fruit is harder to find, leaves from second-choice plants, such as lianas, have increased in the Mexican howlers’ diet.

While leaves may sound like a plentiful resource in a rainforest, many leaves are difficult to digest and can be filled with toxins – a natural defence mechanism in most trees and plants – so the monkeys are actually forced to spend more time seeking out the right foliage to eat, such as new shoots which are generally less toxic.

Fruit is vital to monkey diet

Dunn added “The traditional view was that the leaves exploited by howler monkeys were an abundant food source – but this is not the case. The monkeys rely much more heavily on fruit than previously believed, and when turning to foliage for food – as they are increasingly forced to do – they have to be highly selective in the leaves they consume, visiting lots of different trees. This leads to the increased ‘travel time’ and consequent high levels of stress we are seeing in these primates as their habitats disintegrate.”

Faeces analysed

As trying to catch the howlers to examine them would in itself be highly stressful for the animal, the best way of evaluating stress levels in wild primates is by analysing their faeces for glucocorticoid stress hormones, which are general to all vertebrates. Through statistical modelling, the researchers were able to determine that it is the ‘travel time’ – rather than the increased foliage intake – causing high levels of stress.

“Monkeys in disturbed habitats suffering high levels of stress is in itself unsurprising perhaps, but now we think we know why, the root cause from the primates perspective. Our results also highlight the importance of preserving and planting fruit trees – particularly those species such as figs that can produce fruit during periods of general fruit scarcity – for the conservation of howler monkeys¨ said Dr Jurgi Cristóbal-Azkarate, also from Cambridge, who led the research in collaboration with Dr Joaquim Vea from the University of Barcelona.

The authors say that further studies are required to fully understand the significance of increases in stress in howler monkeys living in disturbed habitats. “Determining the full relevance of our results for the conservation of primates living in forest fragments will require long-term studies of stress hormones and survival”, said Dunn.

The research was published in the International Journal of Primatology.

British moths, new research


This video says about itself:

British Butterflies and Moths

The video includes Duke of Burgandy, Speckled Wood Butterfly, Pearl bordered Fritillary and a Cinnabar Moth.

From Wildlife Extra:

Moths in major 40 year decline in UK – Especially in the south

UK moths suffer 40-year crash

February 2013. The abundance of the UK’s larger moths has crashed during the past 40 years with three species becoming extinct in the last decade, a major scientific report has revealed.

3 moths extinct in UK

The State of Britain’s Larger Moths 2013 found that the Orange Upperwing, Bordered Gothic and Brighton Wainscot had all become extinct in the UK in the last 10 years; these follow the extinctions of an additional 62 species during the 20th Century.

2/3rds larger moths in decline – Especially in south

The report by Butterfly Conservation and Rothamsted Research revealed that two-thirds of common and widespread larger species (macro-moths) declined in the last 40 years. The losses in abundance were much greater in the southern half of Britain than the north.

Once common moths on the edge

Some once common garden species such as the V-moth, Garden Tiger and the Spinach have decreased by more than 90% from 1968-2007 and now face the real threat of extinction in the future. On-going habitat loss and the deteriorating condition of the countryside are believed to be the major factors behind these declines.

Top five losers and winners in terms of abundance

Losers
1. V-moth Macaria wauaria 99% decrease
2. Garden Dart Euxoa nigricans 98% decrease
3. Double Dart Graphiphora augur 98% decrease
4. Dusky Thorn Ennomos fuscantaria 98% decrease
5. Hedge Rustic Tholera cespitis 97% decrease

Winners
1. Least Carpet Idaea rusticata 74,684% increase
2. Blair’s Shoulder-knot Lithophane leautieri 7,878% increase
3. Treble Brown Spot Idaea trigeminata 4,312% increase
4. Buff Footman Eilema depressa 3,884% increase
5. Scarce Footman Eilema complana 3,590% increase

The longest running national population insect study in the world

The report is based on continuous records running from 1968 to 2007 on common and widespread species. These records represent the longest running national population trends of insect species known anywhere in the world.

Some two-thirds of the species recorded declined over the 40-year study, 37% of species decreased by at least 50%.

40% decline in all moths in southern Britain

In the southern half of Britain, larger moth populations decreased by an average of 43% in comparison to an average 11% decline in northern Britain. Total abundance of moths decreased by 40% in southern Britain but showed no overall change in the north, where declines of some moth species were balanced out by other moths faring well.

The reason for the disparity between the two regions is likely to be due to higher levels of habitat loss in the south and the beneficial effect of climate warming on some moths in the north.

Key indicator species

Moths are key indicator species for assessing the health of the environment. These findings point strongly to a wider insect biodiversity crisis and mirror declines of butterflies and bees and carabid beetles. The declines could have a knock-on effect for plant pollination and animals reliant on moths for food, such as garden and woodland birds, bats and small mammals.

New moth species influx – 100 new species recorded

While moth populations have declined substantially in the last few decades, the period has also seen an unprecedented influx of new moth species to Britain.

More than 100 species have been recorded for the first time in Britain this century and 27 species have colonised Britain from the year 2000 onwards. Climate change is seen as a major driver for these new colonisers as conditions become more suitable for continental species.

Butterfly Conservation Surveys Manager and lead author of the new report, Richard Fox said: “This report paints a bleak picture about Britain’s biodiversity. Much has been made of the decline of butterflies and honey bees but moths represent the massive, but largely un-noticed diversity of insects that form the vast majority of animal life in Britain.

“The severe declines of once common garden moths and overall decrease in moth abundance that we found are a damning indictment of how recent human activity has devastated our native wildlife.”

Chris Packham, Butterfly Conservation Vice-president said: “Larger moths are key indicator species that let us know how our environment is faring in a period of unprecedented environmental change.

Vital cog in food chain

“As well as being important pollinators, moths are an absolutely vital cog in the food chain for other species such as birds and bats. The dramatic and ongoing loss of moth abundance highlighted in this report signals a potentially catastrophic loss of biodiversity in the British countryside.”

David Brooks, an ecologist at Rothamsted Research who analysed the data, said: “This study highlights the value of long-term investment in monitoring of species populations, for discovering fundamental changes taking place in the ecology of the British landscape. The study would also not have been possible without the help of numerous volunteers and amateur naturalists, who increasingly make invaluable contributions to ecological research.”

Milestone for this blog, 150,000 visits


Blogging, cartoon

Today is a milestone for Dear Kitty. Some blog.

Ever since my blog moved to WordPress in December 2011, there are now over 150,000 visits.

I do not know who visitor #150,000 was.

However, all visitors are welcome. Thank you!