Bad parenting could give zebra finches the evolutionary edge

 Zebra finches may have the potential to become brood parasites. Credit: Keith Gerstung, CC BY-SA

Zebra finches may have the potential to become brood parasites. Credit: Keith Gerstung, CC BY-SA

Species must reproduce to survive, and animals have found unique ways of achieving this. For some, including us, it seems as though producing a few offspring that require extended care is the best strategy. For others, such as many coral reef fishes, many offspring that require little care appears better suited.

Brood parasitism is among the most bizarre breeding strategies in nature. A brood parasite, such as a cuckoo, manipulates another individual into raising its young. Hosts do all they can to stop brood parasites from successfully reproducing, because they usually harm their own young. Brood parasites fight back, and the two species can become locked in a coevolutionary arms race. Continue reading

Early female bonds boost male birds’ mating success

Forming male-female pairs when young has been found vital for mating success

Forming male-female pairs when young has been found vital for mating success

Male zebra finches that fail to socialise with females during adolescence are less successful at courtship later in life, a study says.

This effect mimics the “loser effect” where, after a defeat, an animal is more likely to lose a subsequent fight.

Social friendships at a young age were also found to be more important than physical and social attractiveness.

The findings are reported in Proceedings of the Royal Society B: Biological Sciences.

The loser effect has been well demonstrated in many species, from spiders and fish to birds. After a fight hormonal levels change which negatively affects performance in further fights.

Now scientists have found a similar effect for mating. Adolescent males who failed to pair with a juvenile female were later unsuccessful with females they encountered in adulthood.

Scientists also paired young males as a control in the experiment. They found that if males failed to pair with another male, it had no effect on their later success.

Judging fights

Mylene Mariette, from the University de Saint-Etienne, France, and lead author of the study said: “We know that social interaction is important for some aspects of development, like the role of males to teach youngsters to sing, but so far no study has looked at the effect of how interaction between juveniles affects their behaviour as adults.”

She explained that there are two ways in which the loser effect could be operating.

In the first, losers may judge past experience of their own abilities – of fighting or attractiveness – and adjust their behaviour accordingly “to avoid losing time and energy”.

In the second, knowledge of a past loss or rejection may change the way an opponent or potential mate reacts to a loser, for example, females may be less willing to mate a previously rejected male.

“Like winning a fight, successful mating is a positive social interaction. We know that animals are able to pick up chemical cues from others, so they could potentially detect a change in hormone levels,” Dr Mariette added.

“In the mating context we have good reason to expect the same mechanism to happen. Just like an animal wanting to know how good a male is at fighting compared to others, they may also want to know how attractive he is.”

Not a loser forever

Fortunately for the males, the loser effect does not last forever, sometimes only for a few hours. “He may just court less attractive females. He’s not a loser for life,” Dr Mariette told BBC News.

Two months after rejection by their female companion, the males were no longer less successful with new females, but “better quality males were still preferred”.

The loser effect in mating could be widespread amongst other animals but for now “it’s too early to tell”, she said.

Source: BBC.CO.UK

Finches sing like birds — and their dad taught them how

Singing zebra finch brothers created a new song based on the signature song of their dad.

Singing zebra finch brothers created a new song based on the signature song of their dad.

It goes a little something like this: A young male zebra finch, whose father taught him a song, shared that song with a brother, with the two youngsters then creating new tunes based on dad’s signature sound.

The musical bird family, described in the latest Biology Letters, strengthens evidence that imitation between siblings and similar-aged youngsters facilitates vocal learning. The theory could help to explain why families with multiple same sex siblings, such as the Bee Gees and the Jackson 5, often form such successful musical groups.

Co-author Sébastien Derégnaucourt told Discovery News that, among humans, “infants have a visual preference for peers of the same age, which may facilitate imitation.” He added that it’s also “known that children can have an impact on each other’s language acquisition, such as in the case of the emergence of creole languages, whether spoken or signed, among children exposed to pidgin (a grammatically simplified form of a language).”

Pidgin in this case is more like pigeon, since the study focused on birds. Derégnaucourt, an associate professor at University Paris West, collaborated with Manfred Gahr of the Max Planck Institute for Ornithology. The two researchers studied how the young male zebra finch from a bird colony in Germany learned from his avian dad.

“Young male zebra finches learn to sing during a sensitive period that starts around day 25 post-hatch,” he said. “A phase of intense practice, which recalls human’s babbling phase, lasts for a couple of months. During this time, the young bird is comparing its own vocal output with a song model that he memorizes. The song model is usually its father’s song.”
Derégnaucourt went on to explain that young male zebra finches — when they reach 30 to 35 days — practice on their own, based on memory, since dad likely has literally flown the coop by then.

“Around 90 to 100 days post hatching, song structure stabilizes and no significant changes will occur during the remainder of the bird’s life,” he said.

The researchers housed the young male bird with one of his brothers. That second male — after hearing his brother sing and frequently joining in — learned dad’s tune. Both birds then came up with their own unique versions, which sounded a lot like that of their father, but with some different notes and syllables.

The tunes are love songs, since they are “used in courtship context,” according to Derégnaucourt. He said the songs might also be used “as kin and group signature,” but not in very antagonistic situations, since these birds do not defend territories.

While sibling rivalries are all too common among birds, humans and other animals, there’s a definite benefit to having a brother or sister around, particularly when parents are absent.
Derégnaucourt explained that when dad isn’t available, as often happens in the big bird-eat-little bird world, young finches can then learn from each other.

That’s no small effort for this particular species, whose vocal repertoire comprises about 10 different calls. Females produce calls too, but they do not sing.

Ofer Tchernichovski, a professor of psychology at Hunter College, told Discovery news that, prior to this new study, “The role of siblings in vocal learning, both in humans and in song birds, was not studied much. The current results demonstrate, at least in songbirds, that birds can tutor each other very efficiently, so as to allow rapid propagation of vocal culture horizontally (meaning among peers). These results are very exciting, and will surely lead to additional discoveries.”

He added, “Cumulative vocal culture is shared across songbirds and humans, and the capacity to rapidly propagate vocal culture horizontally is highly significant.”

source: science.nbcnews.com

UI researcher studying birds in urban, rural settings

Master naturalist Nancy Snellen takes one of the captured birds out of a mist net set up on William Street in Champaign, on Wednesday June 5, 2013.

Master naturalist Nancy Snellen takes one of the captured birds out of a mist net set up on William Street in Champaign, on Wednesday June 5, 2013.

CHAMPAIGN — Just how are finches and sparrows faring in urban environments?

University of Illinois graduate student Jason Fischer is trying to answer that question.

If you’ve been out and about in Champaign-Urbana in recent days, you may have seen Fischer and his team of volunteers capturing and tagging birds like American Goldfinches and northern cardinals as they visit area bird feeders.

“I’m really interested in learning how people and nature come together and interact in cities,” Fischer said.

Fischer is a Ph.D. candidate — he has one year to go — in an interdisciplinary degree program called PEEC, the Program in Ecology, Evolution and Conservation Biology. His dissertation focuses on how urbanization affects bird populations, including their behavior and population dynamics.

He’s doing this by studying activity at bird feeders. With the help of volunteers around Champaign County, he captures birds when they come to feed, checks their health and attaches a radio frequency identification tag (RFID) to them. He connects a scanner to the feeder and will later download data that will help him learn more about the bird’s behavior. When the bird returns to the feeder, the tag, which is similar to chips inserted into pets to monitor and track their movements, will show Fischer when they land and how often they return.

“I can see how they’re surviving in different parts of the county or city, how often they forage and what their condition was,” he said.

This is his fourth summer of field work, his third year putting RFID tags on the birds and second year of having the scanners on feeders.

Throughout those years, he’s had student and community volunteers assist him in his efforts to capture and tag the birds, which in addition to goldfinches and cardinals have included house sparrows and house finches.

“The reason I like urban ecology is the ability to integrate people into the research — the citizen-science approach — which educates the public and gives them a unique experience with nature,” Fischer said. “And it benefits science because we will be able to have a much larger number of birds to be processed.”

On Wednesday, Fischer and his volunteers cast what are called mist nets, which are made of fine mesh, to capture the birds. Fischer blew on the birds’ feathers to look at their body fat. He examined their throats and abdomens to get a sense of how much energy they have in reserve.

He’s monitoring 14 feeders at sites within Champaign and Urbana, on the edge of the cities, and on farms. One is at the Anita Purves Nature Center in Urbana, another is at the Homer Lake Interpretive Center, and the rest are on private property. He anticipates catching birds through August or September and will continue to gather data on the tagged birds. This fall, he will transition to studying the data and writing his thesis.

So far, he’s been surprised by some of the preliminary results: The birds’ “condition does not seem to be linked to the degree of urbanization of an area,” he said.

There are many ways to study the effects of urbanization, such as reproductive performance and survival rates, but when measuring body condition, birds living near farms appear to be doing just as well as birds living in the city, he said.

Fischer enjoys talking about his research, and if you’re interested in learning more or being involved, you can email him at fischer9@illinois.edu.

source : news-gazette.com

Ron Pittaway’s Winter Finch Forecast 2012-2013

image_previewTeam eBird is pleased to once again host Ron Pittaway’s Winter Finch Forecast. While the focus of this piece is on Ontario, we believe it has interest to a wider audience. From Ron: This winter’s theme is that a fair number of species–especially Red and White-winged Crossbills, redpolls, Pine Grosbeaks, and Evening Grosbeaks–are likely to be on the move this year due to widespread crop failure of fruiting and cone-bearing trees in Canada. Three irruptive non-finch passerines are also discussed.

First, please read the Red Crossbill section and click the map link. This species is on the move throughout the US, with Red Crossbills reaching the Central California Coast, Kansas, Maryland, and New England. Many of these are proving to be Type 3 (from California to New England!), suggesting that their particular ecological niche–primarily Western Hemlock forest in the Pacific Northwest–is undergoing very hard times this year. As always with Red Crossbills, audio-recording their calls is invaluable. The below section gives instructions on reporting Red Crossbill sounds. Look for Matt Young’s guide to Red Crossbill types to come out on eBird next week and please do report any Red crossbills that you can audio record to the specific type on eBird. Matt Young (may6 AT cornell.edu) is even willing to help identify any recordings you are able to get, even cell phone recordings! Here’s a  Red Crossbill (Type 3) map from eBird.

Second, Red-breasted Nuthatches are all over right now and are on the move in all provinces and all 48 states. Please make sure to report them to eBird too so we can to continue to document this invasion.

Finally, although not mentioned in the finch report below, Boreal Owls are expected to move south this year. Think about good owl groves, or consider doing nighttime surveys in good evergreen areas near you to try to detect one. When Boreal Owls move, it is often just the lucky birders who detect them. But concerted effort might pay off, as there are surely always more out there than are seen.

Without further ado, here is Ron Pittway’s forecast:

source http://ebird.org/content/ebird/news/ff2012