Extravagance explained: Why birds-of-paradise are the way they are 24 September 2013 www.BirdWatchingDaily.com

I saw one of the most handsome birds in the world not too long ago.

It was a male about the size of a jay, generally rust-colored with a yellow head and emerald chin and throat. Most striking were its white and yellow flank feathers, which were twice as long as the bird’s body and trailed far behind it. They were fluffy and lace-like.

When a female landed nearby, the male transformed himself into a hyperactive billboard. He spread his flank feathers above his back, shimmering, and jumped wildly around the female for ten minutes. It was spectacular.

In time, he landed on the same branch as his intended. Shaking his side feathers over his back and flapping his wings slowly below, he moved close to her. Then, when her bill touched his chest, he preened her hindneck. She crouched and fluttered her wings, signaling that his courtship displays had won her over, and they mated.

The scene took place in New Guinea, and, no, I didn’t witness it. I learned about the bird, a Greater Bird-of-Paradise, while watching a National Geographic television program about the work of field biologist and photographer Tim Laman and Cornell University ornithologist Ed Scholes, who recorded all 39 species during 18 expeditions over eight years.

Found only in New Guinea and on surrounding islands as well as in a corner of Australia, birds-of-paradise are an extraordinary group of birds. Most wear vivid colors and have lacey feathers or feathers modified into flags, disks, wires, or ribbons. To these traits add tantalizing displays and dances — some even transform their bodies from a typical bird-like silhouette to one that is very non-bird-like — and you have the most spectacular and complex courtship of all avian groups.

Europeans first learned of the birds-of-paradise in 1522, when Magellan’s only surviving ship returned home after its around-the-world voyage. In it were gifts for the King of Spain, including specimens of the Greater Bird-of-Paradise.

Naturalists Alfred Russel Wallace and Charles Darwin visited New Guinea in the 1850s. Both were awestruck by the beauty of the birds and how different they were from one another. It was the wild colors and the enlarged feather plumes that piqued Darwin’s interest, since they seemed at odds with his developing theory of natural selection, which favors traits that confer survival value to the individual. How could all of this gaudiness offer survival value?

Darwin was thinking of the upper tail covert feathers of the Indian Peafowl, which are grossly overgrown and loaded with eyes. The peacock’s tail couldn’t be explained by natural selection, and neither could the plumages of the birds-of-paradise.

Darwin believed the colors, modified plumes, and dances were intended to help males gain favor with females and had nothing to do with survival. Years later, he explained that male “beauty” was a result of sexual selection, a concept that was ahead of its time.

Sexual selection is favored when food is abundant, predators are few, and males mate with several females, but no pair bonds are formed (a mating system known as polygyny). A male, therefore, can spend almost all of his time displaying, while the female can easily build a nest for her clutch of one, incubate the egg, and have no problem finding enough food for her and the youngster.

The zoogeographical requirements for sexual selection are not common, but New Guinea and its surrounding islands are perfect: They are filled with fruit trees, but

no monkeys or other primates compete for fruit, no squirrels vie for seeds, and no avian or mammalian predators threaten the adult birds, especially the “billboard” males.

As long as females select the males for mating, and as long as the females prefer the “sexiest” plumages and displays, male birds-of-paradise will amaze us with vivid colors, incredible feather plumes, and tantalizing displays and dances.

Blackcaps Change Their Migration Patterns…But Why?By SUE ANNE ZOLLINGER23 September 2009www.indianapublicmedia.org "Moment of Science" podcast

Blackcaps are small songbirds that breed in Central Europe. Fifty years ago, most blackcaps went south for the winter to Spain or Portugal. But since the 1960s more and more blackcaps have started wintering in Britain and Ireland.

By 2003, blackcaps were seen perched at one in every three backyard bird feeders in Britain! But why did so many blackcaps change their winter vacation location?

Lost Genes?The direction birds migrate is coded in their genes. Each population of birds has an average direction they will go, but individuals can vary as much as forty degrees from the average.

Although historically, the average direction for blackcaps was towards Portugal, a few birds’ genes pointed them in a slightly different direction and they ended up in Britain.But for the numbers of blackcaps wintering in Britain to change so dramatically, there must be some significant advantage to fly north rather than south.

Perhaps the benefit is simply from the shorter, less taxing flight to Britain. Or maybe it’s because Britain has many bird lovers that stock backyard birdfeeders.

This Nest Is Taken!But researchers from Germany and the UK believe the key difference is the shorter winter days in Britain. Shorter days affect migration and breeding behavior, so British birds return to summer breeding grounds about ten days earlier than birds that went south.

This ten-day head start lets British migrants claim the best territories and start breeding sooner. Females paired with British males laid more eggs and hatched more chicks than those mated to southern birds.

Each year, blackcaps with genes orienting them towards Britain pass on those genes to more chicks. And so the number of blackcaps with the disposition to fly to Britain steadily increases.

Milk bottle-raiding birds pass on thieving ways to their flockDecember 4, 2014 "Science & Technology," www.theconversation.comNeeltje Boogert, University of St Andrews

Great tits (Parus major) are opportunistic copycats. Entire populations can be found performing the same arbitrary behaviour simply because birds copy one another, following a fashion. And it’s this behaviour, reported in a paper published in Nature, which explains the great milk bottle raids that baffled milk drinkers in Britain almost a century ago.

Back in 1921 residents of the small town of Swaythling in Hampshire found their milk bottles vandalized on their doorsteps, the foil caps pierced. The culprits turned out to be birds of the tit family (blue tits, Cyanistes caeruleus) and this milk thievery spread quickly, with people all over Europe noticing tits pecking through the foil caps of the milk bottles on their doorsteps to reach the cream underneath.

How could this novel behaviour spread so quickly? It’s unlikely so many different populations of different species of tits figured it out all by themselves at once. A faster way to solve a complex puzzle is to copy someone else’s solution – it was assumed that tits learned by copying each other.

The Nature paper published by Lucy Aplin and her collaborators provides the first experimental evidence of persistent cultural variation in new feeding behaviours in great tits in the wild.

Watching tits behaving wiselyThe authors' study of eight populations of tits in Wytham Woods involved using a unique bird feeder to establish whether the tits would copy each others' habits in the wild – a puzzle box with a sliding door that could be opened using two distinct, but equivalent, ways. The bird’s reward: a yummy mealworm.

Using two birds from each of the study populations, the authors used some pairs as controls which received no training, while other pairs were trained to use the device in one of two ways – either to push the blue side of the door rightward, or the red side leftward. These birds were then returned to their original flocks, where it was hoped they would demonstrate their trained puzzle-solving skills to others.

Training, as any pet owner or parent knows, does not necessarily lead to performance. But here the experiment worked beautifully: when a trained bird was present to demonstrate, around 75% of their flock-mates solved the puzzle at least once – and the overwhelming majority of them copied the solution that the demonstrator bird had been trained to perform. By contrast, birds in the control populations (where the demonstrators received no training) took a long time to solve the puzzle and ended up with different solutions.

The great tits were keen to fit in: the number of birds learning and repeating the puzzle solution that matched the demonstrator bird’s increased by an average of 14% per day. Further evidence comes from 14 birds that migrated from an untrained control population to a population where birds had been trained on one solution. Of these, 10 switched to solving the puzzle using the method demonstrated by the trained bird.

Passing it onAmazingly, the knowledge of how to solve the puzzle re-emerged as a learned “tradition” even more strongly when the puzzles were taken away for nine months and then returned. Although less than half the original birds who had learned the technique remained, they and the new naïve birds demonstrated an extremely pronounced preference toward using the original solution that had spread previously, rather than finding alternative solutions.

This study raises various new questions – the two alternative puzzle solutions gave exactly the same reward and were equally difficult to solve, so why are most tits so keen to fit in? And when are the few birds that do not comply, referred to by the authors as “mavericks”, at an advantage?

It seems symbolic that, just as a major British dairy company announced it would close down its last glass milk bottle factory, great tits turn out after all to be the pervasive copycats they were thought to be almost a century ago. Having provided the first experimental evidence of persistent cultural variation in new feeding techniques – once thought only to exist among primates – these common or garden birds are still full of surprises.

Among coho salmon, strategy beats brawn in mating game Sophia Yin, DVM 3 July 2004 www.sfgate.com

This is a story of sex, deceit and the desperate struggle for survival. And it plays out every year like a Greek tragedy, starting with romance and ending in death. It is the saga of what you probably once thought of as just another fish. It is the saga of the coho salmon.

Hatched in freshwater, salmon eat, grow and practice their survival skills in the creeks and river systems in which they are born for one to two years before they journey to the ocean. They swim the seas for six months to five years. Then, those lucky and skilled enough to survive to maturity tenaciously trek upstream back to their place of birth, where males diligently court females, the two sexes spawn, and then regardless of their success or failure, they ultimately die shortly thereafter.

Sounds dramatic, and rightly so. In all animals, ranging from tiny insects to the largest mammal, sex is the prime directive, the meaning of life, the only way for most animals to pass on their genes. And not everyone gets the opportunity.

Who's the most successful? Common sense dictates that the strongest competitors, the largest males with greatest might, win the most females, whereas the little guy finishes last, but for some species, such as various fish, the plot takes some interesting twists. There are a number of strategies for passing on one's genes, from fish that start out as females and change into males when they are large enough to defend a harem, to species in which big, burly males duke it out for access to females and then smaller males sneak in under their radar to mate undetected.

Coho salmon go for the strategy involving two types of males. The large, fierce hooknoses directly compete for females and the smaller, cryptically colored jacks rely somewhat on stealth. For many years, researchers couldn't help but view the large, muscular males as the superior style; however, recent research by Jason Watters, a behavioral ecologist at UC

Davis,

indicates that this may not be the case.According to Watters, the little jacks were once the largest, most successful juveniles. "Jacks grew more quickly as juveniles and then headed out to sea first. Then they returned to spawn at least a year earlier than hooknoses."

Jacks developed from juveniles, referred to as territorials, that were chose and best able to defend a low-flow area of the shallow part of a stream called a riffle. These territories contained abundant food, allowing these juveniles to grow quickly compared with other young salmon in less abundant areas. So they headed out early as the largest juveniles and matured in a short six months to a small, camouflage-colored jack. The less successful, smaller juveniles waited longer to go out to sea, then spent more time there. When it was their turn to head home, they came back large and with a flashy red hue to their normally silvery scales.

Based on the hypothesis that says females choose males with features that indicate they have good genes, this early success is highly significant. "It takes a proven winner to become a jack," says Watters, "so females have plenty of reason to prefer jacks."

By choosing to mate with jacks, not only would they get the male that played a better strategy early on, but they would also get the male who might pass on traits leading to a shorter maturation time in the offspring. Theoretically, that means females who mate with jacks could be able, over many generations, to produce more offspring than those who mated with hooknoses.

To see whether females did indeed prefer jacks over the masculine hooknose, Watters observed salmon spawning in the wild. He watched the large hooknoses fight for access to females, with these salmon suitors lining up in a row in order of dominance right behind the female.

Cryptically colored jacks also stationed themselves close by and were often closer to the female than any of the hooknoses.After countless hours of spying on the spawning, Watters found that 75 percent of the jacks got to mate while only 58 percent of the hooknoses got the chance. Also, while the flashy hooknoses nudged, bit and coerced females into mating while chasing competitors away, jacks were gentler with the females. Their quiet,

gentler strategy paid off not only in more matings, but also in longer spawnings. Females spent more time laying eggs when jacks were present.

Overall, both the hooknose and the jack strategies are effective, and having two strategies increases the genetic variation in the salmon population.

Food: optimal foraging models www.sparknotes.com Behavioral Ecology

Theories of optimality involve a mathematical model of cost and benefit analysis that can give quantitative predictions about an animal's behavior. By no means are these models fully accurate; each comes with certain assumptions... But we can often use the models to predict behavior to a reasonably certain degree.

To some degree, animals display the ability to modify their behavior so that they receive an optimal balance of benefits and costs. Costs can include danger, loss of valuable time, and wasted energy. Benefits are usually counted in terms of net energy intake (consumed calories) per unit time or number of offspring produced. In this section, we will focus on optimal foraging methods to achieve the highest net energy intake.

Contingency TheoryContingency Theory, also called the prey choice model, predicts what an animal will do when it encounters a particular food. Should the animal eat what he has, or search for a more profitable food item? We do not often imagine animals refusing to eat the food in front of them to search for other items, but this does occur. Shore crabs, for instance, eat mussels that become increasingly difficult to crack open as their size increases. Crabs will pass up large mussels, which would take too much time and energy to crack, to search for smaller mussels. This way, the crab can spend less time and energy handling their food, and, even though they pass up the massive meals, will increase their net food intake.

Models similar to that just described for the shore crab can include several food choices… We will focus on a simpler version with two food types. For the purpose of the model, we will define the following terms:

Energy (E) is the net number of calories obtained by consuming the food item.Handling time (h) is the amount of time required to handle the food between the time it is encountered to the time it is consumed. Handling time can include cracking a shell, digging it out of the ground, or manipulating the item.Search time (s) is the mean expected time between encounters of items of the same food type. Search time depends on the abundance of the item and the ease of locating it.Total time foraging (T) is the sum of searching and handling times.

The model we are building is concerned with profitability, the energy gained divided by the time spent handling it (E/h) for a single food source, and the maximum energy gained per total time foraging (E/T) when there are multiple food sources.

Using the Model

Food choice 1 is scarce, but is highly profitable, meaning it will yield a high amount of energy with a low handling time. E/h for food 1 is therefore quite high. However, because we are trying to maximize both E/h and E/t, we must also take into account the time it takes to find the very scarce food choice 1. Food choice 2 is abundant, but less profitable than food 1. E/h for food source 2 is not very high, but it takes much less effort and time for the animal to find food choice 2.

The model assumes the animal is holding food 2, meaning that there is no search time involved for food choice 2 since the animal has already found it. The animal stands over the food and must debate whether to eat it: is the immediate consumption of food choice 2 a better action than moving on and looking for some of that fine food choice 1? We can put this debate into mathematical terms:

If E2/h2 > E1/(s1 + h1) then the animal should eat food 2.

If the profitability of food choice 2 is greater than the energy of food choice 1 divided by the sum of the search and handling time of food source 1, then eating food 2 is the better move. If the energy per time gained by going in search of food source 1 is higher, then the animal should pass by food choice 2 and keep searching for food type 1.

Think about the problem posed if the animal was standing above food choice 1 rather than food choice 2. Because food type 1 is more profitable, the animal should always eat it if it comes upon it. Therefore, for the model's purposes, we only consider food type 2 because type 1 is hard to come by.

From the model for contingency theory, we can see that inclusion of a food type in an animal's diet is dependent only on the abundance of better food choices, and is independent of that food type's own abundance. The model predicts that when all food types are abundant, diets are restricted to fewer types, because the animal can afford to be choosier. With this model, we can often predict an animal's optimal diet. However, the animal itself will not always be able to predict his own ideal diet because the model assumes the animal has perfect knowledge of available resources. In order to know the benefits of two food types, the animal must consume both and observe the relative abundance of both types. And so, what we see in nature does not follow the model exactly, but it does come close.

ADAPTATIONS THAT LIONS USE TO CARE FOR THEIR YOUNGby Norma Roche, Demand Media www.animals.mom.me

Half of all the cubs born to African lions (Panthera leo) will die before they are 2 years old. Some will starve, others will fall prey to predators like hyenas, and infanticide will claim some 25 percent or more of the unfortunate cubs. Adaptations linked to their social lifestyle give the lions a better chance of protecting their young, and help them provide sufficient food in the grassy plains, scrub and open woodlands of sub-Saharan Africa.

Creches and Synchronized Reproduction

Lions live together in prides made up of a male, or a coalition of males, and females with their dependent young. Synchronized reproduction, where females come on heat at the same time, is common in lion prides. As the cubs are around the same age, they can be raised together in creches, in which the females help to look after the young, and will nurse cubs belonging to other lionesses. An important function of forming creches is to defend the cubs. If the pride is taken over by invading males, the invaders will attempt to kill young who are still suckling. The females will come back into estrus within a few weeks, and the invaders can father their own offspring. Females from nearby prides will also try to kill cubs -- a quarter of cubs are lost to infanticide. The bonds created in a creche cause mothers to defend all the cubs, not just hers; as a group they can be more successful at protecting the young.

Shared GenesMost female lions stay in the same pride as their mothers. Because all the females are related to each other -- mothers, daughters, aunts, sisters -- they share the same genes. This is another reason to collectively ensure the survival of all the cubs. Male coalitions are generally formed from pairs of brothers who have left their natal prides. They sometimes get together with half-siblings or cousins. So they share genes with the cubs, even if they are not parental, and this provides an incentive to protect all the cubs in the pride.

Early WeeksMothers leave the pride to give birth in a secluded spot. The newborns' coats, covered with dark spots until they are about 3 months old, probably help to protect them, acting as camouflage as they hide amongst the undergrowth. The new cubs won't join the others until they are 5 to 6 weeks old. This may be because they feed only on milk during this period, and older cubs might prevent them getting enough. A study by Anne Pusey and Craig Packer from the University of Minnesota found that cubs under 2 months were easily supplanted by older ones when they were trying to suckle. Cubs older than 2 months didn't have this problem.

The Role of MalesCoalitions of males play a major role in protecting the cubs. If they can maintain control of their prides, preventing takeover by other males, the cubs are at a lower risk of being killed. A coalition with three or more males will usually keep control of their pride longer than a single male or pair, and this allows them to produce more offspring who are able to survive. While the females do most of the hunting, males are able to bring down prey too large for lionesses. An animal like a buffalo can feed the whole pride. The males take their share of the kill first, but they will make sure the cubs, who often arrive late, are able to feed from the carcass, as females will take meat from the cubs.

Moral Mazewww.bbc.co.uk Science & Nature - 17 September 2014

Why should you risk your own life to save another human being? Your genes are the most precious things in the whole world and you must protect them at any cost.

Jumping into a pool to save a drowning swimmer, or pulling a road accident victim out of a burning car just isn't a risk worth taking.

That person is your rival - for food, for resources, maybe even for a mate. Helping them should be the last thing on your mind.Most human beings simply don't think like this. Yet this is how many people believe evolution explains human nature. If the twin goals of survival and reproduction are our reason for being, then we must all be selfish

under the skin.

Yet every day, people across the world demonstrate their capacity to be moral, to be just. And far from being the by-products of civilization, the instinct to put others first may be as basic as our urges to compete, to survive and to replicate our genes.

You scratch my back...There is a rare form of co-operation in nature, practiced by only a handful of animals, which could lie at the roots of our instinct to put others first.

Reciprocal altruism is a form of sharing or kindness that results in mutual benefit. To

exist, it requires other animals to return the favor regularly and for an animal to be able to grant a large benefit to another at a small cost to itself.

Please give bloodOne species that demonstrates reciprocal altruism is the vampire bat. These nocturnal mammals feed on the blood of larger animals while they are sleeping. But food is relatively scarce and bats regularly return home to their roosts hungry. If a bat goes more than 48 hours without blood, it will begin to starve.If this happens, other bats will regurgitate blood into its mouth until it is nursed back to health. For this system to work, bats that have received blood must return the favor when the roles are reversed.

Squeak clique"These animals seem very capable of keeping track of associations over long periods of time," says Gerald Wilkinson, a zoologist at the University of Maryland.

Wilkinson has also shown that bats will not share blood easily with new members of their group, suggesting that these blood-sharing associations are built up over time.This suggests that bats may be able to keep track of their blood donations. The most obvious benefit of this skill would be to detect and recognize cheats, in order to make sure that they are denied blood in future.

Wilkinson suggests that blood sharing

between vampire bats may owe its origins to the extinction at the end of the last ice age of several important species of North American mammal.

The disappearance of the horse, camel and giant sloth from the continent would have drastically reduced the food supply for vampire bats. These conditions may have favoured the survival of bats that shared.

I can see for milesIt's just possible that a similarly monumental period of environmental upheaval was responsible for the emergence of human altruism.

Around two million years ago, climatic change caused widespread deforestation in central and eastern Africa, creating a wide belt of open Savannah where once there were trees as far as the eye could see.The primates that lived in the forests now had to adapt to living on hostile open plains, where they would have been easy prey for formidable predators - including 20 species of big cat.

Forced to use increasingly sophisticated hunting methods on these dangerous grasslands, it is thought that our early ancestors must also have evolved advanced forms of co-operation and sharing, especially of food...