Latest Videos

Hovering on a high fructose diet: hummingbirds can fuel expensive flight with glucose or fructose

Uploaded November 2013

Unlike humans, some animals evolved on a sugar diet equally rich in glucose and fructose. Hovering hummingbirds are rare among vertebrates in their ability to rapidly make use of ingested sugars to fuel energetically expensive hovering flight, powering up to 100% of their metabolic needs with the sugars they drink, while humans athletes max out at around 30%. Until now, we haven't understood to what extent hummingbirds can use the 50% of the sugar in their nectar meals that is glucose versus the 50% that is fructose. Our study shows that hummingbirds begin using newly ingested sugars to fuel hovering flight within minutes and can fuel as much as 100% of their intense hovering metabolism with either glucose or fructose. This suggests that hummingbirds may even be able to oxidize fructose in flight muscle tissues at rates high enough to satisfy metabolic demands that are, pound for pound, 10 times those of an elite human athlete.
By relying on newly ingested sugars to fuel flight hummingbirds can reserve precious fat stores to see them through the overnight fasting period, or to power migratory flights. These results hint at unique adaptations for fructose use in hummingbird muscles and demonstrate the remarkable convergence of diet, behaviour, and most notably, physiology that enables their high energy lifestyle.
You can read the paper free online Chen, C. C. W., Welch, K. C. (2013), Hummingbirds can fuel expensive hovering flight completely with either exogenous glucose or fructose. Functional Ecology. doi: 10.1111/1365-2435.12202 or the lay summary here.

 

The effects of weather on dispersal behaviour of free-ranging lizards in tropical Australia

Uploaded November 2013

Animals move within natural habitats in complicated ways, in response to many aspects of the environment. To understand those patterns of movement, we need new methods to gather highly detailed information on exactly where a free-ranging animal spends its time; and new methods of analysis to extract maximum insight from those data. Advances in the technology available for recording and analysing animal movements enabled us to ask and answer questions that were inaccessible with previous methods. We attached miniature GPS transmitters to large lizards- bluetongue skinks, Tiliqua spp. in the Australian wet-dry tropics, to examine how weather conditions, such as temperature, air pressure, precipitation, humidity and wind speed influence a lizard's behaviour. Our transmitters provided over 60,000 records of lizard location from 49 individuals monitored for a mean of 65 days each.
Lizards primarily moved between widely scattered patches of core-habitat under fine, hot, clear weather conditions. Thus air pressure tended to predict lizard dispersal more accurately than did more commonly-analysed variables such as temperature and precipitation.
You can read the paper free online Price-Rees, S. J., Lindström, T., Brown, G. P., Shine, R. (2013), The effects of weather conditions on dispersal behaviour of free-ranging lizards (Tiliqua, Scincidae) in tropical Australia. Functional Ecology. doi: 10.1111/1365-2435.12189 or the lay summary here.

 

Garden plants for flower-visiting insects-- quantifying variation in attractiveness

Uploaded October 2013

Bees and other pollinating insects are declining in many countries. One way that the general public can help is via their gardens, by growing ornamental plants that are also attractive to flower-visiting insects. But which plant varieties are attractive to flower-visiting insects? Given the great public interest, many lists of recommended plants have recently been produced, but where did this information come from? On a closer look, it appears that these lists are based largely on personal experiences, opinions and anecdotes. This study is an attempt to put these recommendations on a firmer scientific footing. < br />You can read the paper free online Garbuzov, M., Ratnieks, F. L. W. (2013), Quantifying variation among garden plants in attractiveness to bees and other flower-visiting insects. Functional Ecology. doi: 10.1111/1365-2435.12178
Or the lay summary here

 

Does forest colour tell how much carbon dioxide is absorbed by deciduous trees?

Uploaded January 2013

In an oak-dominated forest in Hampshire UK, photographs of the forest canopy were taken every half an hour over two years. The transition of colours showed the seasonality of the forest: when budbreak started, the green sharply increased, gradually decreased in summer, and returned to the original level when leaves were shed; the rise of red colour was shown when oak leaves turned yellow in autumn. Mizunuma et al modelled the photosynthesis of the forest using the extracted colours to compare with the flux measurements. Recent global warming has made the arrival of spring earlier, and leaves appear sooner. How does this influence the carbon cycle in forests?

Mizunuma, T., Wilkinson, M., L. Eaton, E., Mencuccini, M., I. L. Morison, J., Grace, J. (2012), The relationship between carbon dioxide uptake and canopy colour from two camera systems in a deciduous forest in southern England. Functional Ecology. doi: 10.1111/1365-2435.12026

Running lizards provide climate clues

Uploaded July 2012

Although climate change is heating polar and temperate areas faster than the tropics, evidence is mounting that tropical ectotherms (animals that don't produce their own heat) will be negatively affected by the relatively mild warming they do experience. Duke researchers tested this idea at a fine scale with the Puerto Rican crested anole, Anolis cristatellus, by combining data on the lizard's current habitat temperature and physiology with predictions of future air temperatures to estimate how the lizards will be affected. They found that warming will likely be detrimental to lizards inhabiting the dry scrub forests, as future temperatures will often exceed their upper physiological temperature threshold. However, lizards found in moist shaded forests may be little affected by warming.

 

 


Find out more, you can read the
lay summary or full article: Alex R. Gunderson and Manuel Leal, Geographic variation in vulnerability to climate warming in a tropical Caribbean lizard

 

Hide and seek in the rainforest: how do bats tell food from foliage?

Uploaded July 2012

Many bats use echolocation to find insects and other arthropods for food. They emit ultrasonic calls and listen for the returning echoes to detect and localize their snack. In cooperation with Prof. Tigga Kingston from Texas Tech University and Prof. Rosli Hashim from The University of Malaya, Dr. Björn Siemers and Daniela Schmieder from the Max Planck Institute for Ornithology plunged deep into the Malaysian rainforest to investigate how bats tell food from foliage. This is an especially demanding task as in the dense vegetation of the jungle bats are bombarded by echoes from leaves, trees and vines. Embedded in this acoustic confusion there just might be a weak echo from an insect or spider.


Find out more, you can read the lay summary or full article: Daniela A. Schmieder, Tigga Kingston, Rosli Hashim, Björn M. Siemers Sensory constraints on prey detection performance in an ensemble of vespertilionid understorey rain forest bats

 


Behaviour & stress physiology in fish

Uploaded 10 May 2012

Gabrielle Archard and colleagues describe their study with freshwater fish, the Panamanian bishop (Brachyrhaphis episcopi), in which they predicted that individuals from populations with predators would release less stress hormone and be behaviourally more robust than those with no predators.

To access the paper click here: Archard, G. A., Earley, R. L., Hanninen, A. F. and Braithwaite, V. A. (2012), Correlated behaviour and stress physiology in fish exposed to different levels of predation pressure. 


Does ecotourism influence shark behavior?

Uploaded 7 March 2012

Hammerschlag and colleagues conducted the first satellite telemetry study to examine the long range movement patterns of tiger sharks (the largest apex predator in tropical waters) in response to dive tourism.  In this video Neil Hammersclag describes their study in more detail.
 
To access the paper click here: Hammerschlag, N., Gallagher, A. J., Wester, J., Luo, J. and Ault, J. S. (2012), Don’t bite the hand that feeds: assessing ecological impacts of provisioning ecotourism on an apex marine predator. 

 

Setting the trap

Uploaded 30 November 2011


Thornham et al describe in this video highlight how ants' cleaning behaviour maintains the effectiveness of a pitcher plant's prey capture mechanism in a novel form of myrmecotrophic mutualism.

To access the paper click here: Thornham, D. G., Smith, J. M., Ulmar Grafe, T. and Federle, W. (2011), Setting the trap: cleaning behaviour of Camponotus schmitzi ants increases long-term capture efficiency of their pitcher plant host, Nepenthes bicalcarata. 


The foraging tight-rope

Uploaded 10 November 2011

 


The foraging tight-rope is a matter of concentration for free-ranging bushbabies choosing the right plants to eat whilst avoiding their enemies. In this video McArthur and colleagues explain strategies used by bushbabies to keep safe.

To access the paper click here: McArthur,C., Orlando,P., Banks, P.B. and Brown, J.S. (2011) The foraging tightrope between predation risk and plant toxins: a matter of concentration

 

Life in the really slow lane

Uploaded 11 October 2011

 

 

 

In this video Scott et al talk about how they researched the age of maturity for loggerhead sea turtles by tracking the journey of young juveniles across the North Atlantic and measuring their growth rate.

To access the paper click here:
Scott, R., Marsh, R. and Hays, G. C. (2011), Life in the really slow lane: loggerhead sea turtles mature late relative to other reptiles.

 

Do nectar guides influence foraging?

Uploaded 6 July 2011

 


This video by Anne Leonard and Daniel Papaj describes their recent research on whether nectar traps guide the foraging preferences of bumblebees,

To access the paper click here: Leonard, A. S. and Papaj, D. R. (2011), ‘X’ marks the spot: The possible benefits of nectar guides to bees and plants.

 

Does the immune system change with age?

Uploaded 1 June 2011

 

 

 

An audio slideshow from a recent paper by Ujvari and Madsen published in Functional Ecology. This paper shows how the common assumption of a decline in the immune system with age does not hold true in Australian Pythons. Rather, some components of the immune system improve with age, whereas other aspects decline, suggesting a complex interplay between age and the physiological strategies that these snakes use to maintain health.

To access the paper click here:
Ujvari, B. and Madsen, T. (2011), Do natural antibodies compensate for humoral immunosenescence in tropical pythons?

 


A micro-view of thermal stress in snails

Uploaded 10 May 2011

 


Recent research by Chapperon and Seuront shows how snails experience significant and variable thermal stress in shoreline habitats.  Their audio slide show and lay summary explain their findings.

To access the paper click here:
Chapperon, C. and Seuront, L. (2011) Space–time variability in environmental thermal properties and snail thermoregulatory behaviour


Ageing in lizards

Uploaded 8 March 2011

 

 

 

In this study published in Functional Ecology, Massot et al use a wild population of common lizards to show ageing variation in females. Integrative studies are a challenge in free-living populations and here 14 years of study are used to report on multiple aspects of female maturation.

To access the paper click here: Massot, M., Clobert, J., Montes-Poloni, L., Haussy, C., Cubo, J. and Meylan, S. (2011) An integrative study of ageing in a wild population of common lizards..


Bats Heads and Jaws in 3-D

Uploaded 15 February 2011

 

 

 

A CT-SCAN movie showing morphological variation among bat species in their jaw, head and teeth dimensions. This is based on a recent paper by Santana, Strait and Dumont recently published online in Functional Ecology. This paper shows that teeth complexity, measured using sophisticated mapping techniques, varied according to diet in bats, suggesting that evolution has proceeded to more complex morphology in some species as a function of dietary choices.

To access the paper click here: Santana, S. E., Strait, S. and Dumont, E. R. (2011), The better to eat you with: functional correlates of tooth structure in bats.


Reproduction and death in beetles

Uploaded 20 January 2011

 

 

 

Video highlights for a recent article in Functional Ecology by Cotter et al. examining relationships between reproduction and death in beetles. A great read!

To access the paper click here:
Cotter, S. C., Ward, R. J. S. and Kilner, R. M. (2010) , Age-specific reproductive investment in female burying beetles: independent effects of state and risk of death.


Whale Sharks do the math to avoid sinking

Uploaded 25 November 2010

 

 

 

Video highlights from a recent paper by Gleiss et al published in Functional Ecology. This important new work shows how the majestic whale shark uses basic geometry to minimize energy expenditure during swimming

To access the paper click here:
Gleiss, A. C., Norman, B. and Wilson, R. P. (2010), Moved by that sinking feeling: variable diving geometry underlies movement strategies in whale sharks


Fish shrink in winter

Uploaded 26 November 2010

 

 

 

Video highlights of a recent study by Huusko et al published in Functional Ecology

To access the paper click here:
Huusko, A., Maki-Petays, A., Stickler, M. and Mykr , H. (2010), Fish can shrink under harsh living conditions


Grasshopper escape performance

Uploaded 28 September 2010

 

A visual summary of research on grasshopper jumping and development.
To access the paper click here:
Hawlena, D., Kress, H., Dufresne, E. R. and Schmitz, O. J. (2010) Grasshoppers alter jumping biomechanics to enhance escape performance under chronic risk of spider predation


Modelling bat feeding

Uploaded 28 September 2010

 

A CT-SCAN movie showing morphological variation among bat species in their jaw, head and teeth dimensions. This is based on a recent paper by Santana, Strait and Dumont recently published online in Functional Ecology. This paper shows that teeth complexity, measured using sophisticated mapping techniques, varied according to diet in bats, suggesting that evolution has proceeded to more complex morphology in some species as a function of dietary choices.

To access the paper click here:
Santana, S. E., Dumont, E. R. and Davis, J. L. (2010), Mechanics of bite force production and its relationship to diet in bats

 

 

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