birds

Photography and Bird Identification

Submitted by Gitie on 1 April, 2011 - 19:34

by Jerry Liguori (Author and Bird Photographer)

Barn Owl Equipment Advances:

Camera equipment has advanced in many ways in recent years, the biggest advancement has been in digital photography. Yes, film cameras can take beautiful photos, especially medium and large format landscapes and the like, but for overall image quality and usefulness regarding bird photography, particularly in-flight, digital equipment is far superior (see images on left). One of the most valuable features of digital photography is the ability to review images on-the-spot through the rear viewfinder. I remember having to wait at least 2 weeks to get a roll of slides back, only to be disappointed with the results. Nowadays, you can review your images instantly to get a feel for the exposure, contrast, sharpness, or composition. The ability to adjust tone, contrast, saturation, and sharpness on-the-spot as conditions change is another valuable option offered by the newer digital cameras. However, overdoing certain adjustments may result in a negative effect. High quality digital cameras also perform better in low light and at high ISO settings than film. Manufacturers try to make improvements each year regarding the precision of the auto-focus and other functions, and this is evident when comparing older model film or digital cameras to new models. Another advantage of digital images is that they are much easier to store and archive than are prints or slides. Some digital cameras offer video recording, and I'm sure most or all will in the future.

Just a note about shooting JPEG vs. RAW. The image size and resolution of JPEG (high quality setting) and RAW photos are the same (but the file size of a JPEG image is smaller). There are advantages to both settings, but the overall advantage of shooting JPEG is greater. This issue can be argued to death, as opinions differ, and alone is worthy of an entire article, which I don't have the energy or time for...but I have tested both settings and compared the results. On most cameras, there is an option to shoot both JPEG and RAW simultaneously, but there are drawbacks in doing so. I just don't prescribe to the theory of shooting RAW "just in case" because a strong enough case has not been made.

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Mothers' Problems Affect Even Bird Kids

Submitted by Gitie on 6 January, 2011 - 20:04

Baby magoue Wendy being fed mother magpie Vicky

A recent study has found that the social environment of mother quails has a direct influence on the growth and the behaviour of their young.

The research was performed by Floriane Guibert and Cecilia Houdelier at the CNRS-Universite de Rennes 1 in France, together with researchers at the INRA in Nouzilly, France and with Austrian scientists including Erich Mostl of the University of Veterinary Medicine, Vienna.

Some people are surprised to hear that quails (see picture of a family of quails in our back yard below) are able to distinguish one another, let alone that they form close relationships with other quails. From our observations here at WingedHearts.org, we've found that birds as small as thornbills, pardalotes and wrens have no trouble recognising each other,

While many have known for a long while that disruption of the birds' social environment causes them stress. The researching team has shown that changing the composition of groups of quails housed together causes the birds to behave more aggressively towards one another. The level of steroid hormones (corticosterone) in their blood also increases when their group composition is disrupted. When the mothers were subjected to social stress of this kind the eggs they lay were found to have significantly higher levels of testosterone.

These results are consistent with previous findings from other groups, which showed that House sparrows, American quail family

coots and Common starlings lay eggs with more testosterone when they breed in dense colonies than when they nest in isolation.

But the new work has also shown that the eggs of females under social stress hatch later and the chicks grow more slowly after hatching, at least for the first three weeks.

We've noticed with magpie and butcherbird clutches that when our mother birds friends Vicky (see top picture where baby magpie Wendy is being fed by mother Vicky magpie), Harrie & Butchie have been going through a period stress they eggs hatched much later than their counterparts across the valley and their chicks were also slower in developing. The stress can be caused through harsh climate, strained relations with neighbouring clans, death in the family of a child, or partner. Once when we were away for five weeks during their normal breeding period, even though we had organised carers to refresh their water bowls and feed them once a day (so they would not go without in the winter drought), our bird so stressed by our absence that they delayed having their clutch till after we returned. Their joy and relief at seeing us return was unmistaken.

Sources:

http://www.medindia.net/news/Even-Bird-Kids-Affected-By-Mothers-Social-L... by Tanya Thomas

Veterinärmedizinische Universität Wien (2010, December 28). Parents' social problems affect their children -- even in birds. ScienceDaily. Retrieved January 6, 2011, from http://www.sciencedaily.com/releases/2010/12/101227083745.htm

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