Manipulation of photoperiod perception advances gonadal growth but not laying date in the great tit

Manipulation of photoperiod perception advances gonadal growth but not laying date in the great tit

Abstract

In seasonal environments, organisms use biotic and abiotic cues to time various biological processes that are crucial for growth, survival and reproductive success. Photoperiod is the best‐known cue used to regulate gonadal development, migration and moult of many animal species. In birds, the relationship between photoperiod and gonadal development is clearly established, but we have little understanding on whether photoperiod also regulates actual timing of egg laying under natural conditions. Elucidating the link between photoperiod and timing of breeding is however key to understand whether an evolutionary change in sensitivity to photoperiod is a possible mechanism through which organisms could adjust their seasonal timing in response to climate warming. Here, we investigated the causal relationship between photoperiod, gonadal growth and laying date in wild female great tits. We experimentally increased the photoperiod perceived by the birds in spring by clipping head feathers, and we subsequently monitored gonadal development in the lab and egg laying dates in the wild. We show that our manipulation increased the photoperiod perceived by the birds to a level that approximately corresponds to an advancement of ten calendar days. 

This increase in perceived photoperiod led to an acceleration of gonadal development, but not to an advancement of egg laying dates. Our results indicate that photoperiod sensitivity is not constraining the advancement of laying date under current environmental conditions and suggest that evolution of sensitivity to other supplementary cues is necessary to advance reproduction under global warming.

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The radiation around Mukaino-daijuu park of Hitachinaka city, Ibaraki pref, Japan. I monitored 0.54 micro Sievert per hour in air at 50cm high from the park ground level, 2.86 on the road side mud. 
Moniroring point is in a housing area in Hitachinaka city. The city is going to remove surface soil of the park to reduce the radiation level.Measuring instrument is made of Ukraine. ECOTEST MKS-05. 120 from Fukushima Daiichi.

Alerta por una filtración química al Yangtsé en China

SHANGHÁI, China (Reuters) - Las autoridades de Shanghái están en alerta tras una filtración química que ha contaminado el río Yangtsé, la principal fuente de agua de la ciudad más poblada de China, aunque parecía que no hay una amenaza sanitaria, dijo el diario Shanghái Daily el miércoles.

Responsables en Zhenjiang, en la provincia de Jiangsu, dijeron que habían hallado en sus aguas fenol, un compuesto ácido usado para fabricar nailon y detergentes. El diario dijo que la causa era una filtración de un barco surcoreano.

Según el Shanghái Daily, las autoridades de Jiangsu dijeron que no suponía una amenaza a la población. 

Pero Chen Wei, director de la oficina de protección ambiental, dijo que la ciudad estaba preparada para cerrar su principal reserva de agua cerca del Yangsé si se detectan niveles anormales de químicos.

El agua embotellada se ha agotado en Zhenjiang y las poblaciones vecinas, ya que los residentes denunciaban un mal olor del agua del grifo, según el diario.

Una fuga de cadmio, que causa cáncer, de una compañía minera contaminó un largo trecho de dos ríos en el sur de China el mes pasado, obligando a las autoridades a advertir a unos 3,7 millones de habitantes de Liuzhou en la región de Guangxi que evitaran beber agua del río, informaron los medios estatales.

La contaminación y la seguridad alimentaria son asuntos candentes en China, donde las numerosas operaciones en el sector alimentario del país han tenido poco efecto, ya que continúa asediado de escándalo de contaminación y toxinas que han minado la confianza de los consumidores.

bird hair

Pigeons Are Brilliant in Math

Pigeons may be ubiquitous, but they’re also brainy, with surprising numerical competence.

Pigeons may be ubiquitous, but they're also brainy, according to a new study that found these birds are on par with primates when it comes to numerical competence.

The study, published in the latest issue of the journal Science, discovered that pigeons can discriminate against different amounts of number-like objects, order pairs, and learn abstract mathematical rules. Aside from humans, only rhesus monkeys have exhibited equivalent skills.

Could pigeons then be the Einsteins of the bird world?

"It would be fair to say that, even among birds, pigeons are not thought to be the sharpest crayon in the box," lead author Damian Scarf told Discovery News. "I think that this ability may be widespread among birds. There is already clear evidence that it is widespread among primates."

Scarf, a postdoctoral researcher in the Department of Psychology at the University of Otago, and colleagues Harlene Hayne and Michael Colombo began the study by first teaching pigeons how to order the numbers 1, 2 and 3.

To do this, they presented the pigeons with three images containing one, two, or three objects. All three images appeared at once on a touch screen and the pigeons pecked the screen to make a response. If they correctly accomplished the task -- pecking the images in ascending order -- they received a wheat snac

more discovery news

 By Jennifer Viegas

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canary oyster mushrooms

J.Sagreras El colibrì

Carlos Rubén Gómez plays a new version of El colibrí of Julio Sagreras 
 El Colibrí, J. Sagreras/ David Mozqueda
 El colibrí - Sagreras - Jaime Landini 
 Eliot Fisk y el Colibri de Sagreras 
 Julio Sagreas: El Colibri 
 Ruben Dario Lopez - El colibri





EL COLIBRI BY JULIO SAGRERAS FROM THE CD ''EL SECRETO'' AXIOTIS PANAGIOTIS

El Colibri in Istanbul 

 Victor Castro "El Colibri" Sagreras

 Julio Sagreras, El Colibri by Irina Kulikova

 El colibrí (Sagreras) by Carlos Ruben Gomez 

 J.Sagreras El colibrì by Fabio Montomoli

Men and birds / O Homem e as aves/ Lo Hombre y los pajaros

Elisabeth SCHUMANN - Nightingale Song

Soprano Elisabeth Schumann

Albanian Folk Iso-polyphony

Traditional Albanian polyphonic music can be divided into two major stylistic groups as performed by the Ghegs of northern Albania and the Tosks and Labs living in the southern part of the country. The term iso is related to the ison of Byzantine church music and refers to the drone accompanying polyphonic singing. The drone is performed in two ways: among the Tosks, it is always continuous and sung on the syllable e, using staggered breathing, while among the Labs, the drone is sometimes sung as a rhythmic tone, performed to the text of the song.

Rendered mainly by male singers, the music traditionally accompanies a wide range of social events, such as weddings, funerals, harvest feasts, religious celebrations and festivals such as the well-known Albanian folk festival in Gjirokastra. 

Albanian iso-polyphony is characterized by songs consisting of two solo parts, a melody and a countermelody with a choral drone. The structure of the solo parts varies according to the different ways of performing the drone, which has a great variety of structures, especially in the popular style adopted by all groups performing this music. 

Over the last few decades, the modest rise of cultural tourism and the growing interest of the research community in this unique folk tradition have contributed to the revival of Albanian iso-polyphony. However, the tradition is adversely affected by poverty, the absence of legal protection and the lack of financial support for practitioners, threatening the transmission of the vast repertoire of songs and techniques. 

The rural exodus of young people to the bigger cities and abroad in search of jobs compounds this danger. Given these conditions, at the present time, the transmission of this tradition is maintained through professional folk artists, rather than within the family structure.