homosexual wetland birds

[Dogghound]

Originally Posted by Kayleigh

I would be none the wiser as I cant tell male from female swans.

Adult males have a larger black knob on the base of the bill than females.

[Kayleigh]

So I can safely say this is a female..



and this is a male and female..though the difference is not that noticeable with these two..



Thank you again Dogghound for your endless valuable wildlife knowledge..

[Dogghound]

Yep male is the closer of the two. No worries Kayleigh

[Meta menardi]

I really hesitate to post this, when my older brother was at school, he stole a 1 lb. bottle of mercury. We played with it for years, and in the end I couldn't say where it went. We dropped some, we played with scraping aluminium and painting it with mercury and watching the oxides grow before your eyes. We seem to be OK (aged 60+), though he is a little overweight and I don't like crowds, but it has to go through your mind, why did a school lab have that quantity of mercury? It was a known toxin and even for demonstrations a very small amount would have been adequate.

Darn, had to edit to remove transposition of letters in " would". Perhaps it is kicking in.

[thunder]

Originally Posted by Meta menardi

I really hesitate to post this, when my older brother was at school, he stole a 1 lb. bottle of mercury. We played with it for years, and in the end I couldn't say where it went. We dropped some, we played with scraping aluminium and painting it with mercury and watching the oxides grow before your eyes. We seem to be OK (aged 60+), though he is a little overweight and I don't like crowds, but it has to go through your mind, why did a school lab have that quantity of mercury? It was a known toxin and even for demonstrations a very small amount would have been adequate.

Darn, had to edit to remove transposition of letters in " would". Perhaps it is kicking in.

We had large quantities at school (1960s), and thought nothing of using it. I even had a maze puzzle given me for Christmas which had mercury in it instead of tiny ball bearings. Getting all the mercury into the centre of the maze was relatively easy - getting one blob in each outer corner was more of a challenge. How times change!

henrya

[Cygnet]

Originally Posted by Kayleigh

So I can safely say this is a female..



and this is a male and female..though the difference is not that noticeable with these two..



Thank you again Dogghound for your endless valuable wildlife knowledge..

The size of the knob or berry should only be taken as a guideline to the sex of a swan. The North West Swan Study has recorded numerous females with berries larger than their partners. In addition the berry only really grows to full size in breeding birds, and in our study area only around 10% of swans ever pair up. So a female that has bred in the past may well have a berry larger than a young male which has no breeding history.

The only positive way to determine the sex of a swan is to perform a cloacal examination as males have a penis which in adults is quite large making it possible to be 100% certain. However male cygnets are less developed and considerable experience is required to be accurate.

In the first photo, using berry size alone, the bird could quite possibly be a sub-adult male as well as a female. Having said that the experience I have gained handling these wonderful birds would make me say her general head shape looks as if she is a female. We have been trying to formulate a method of sexing swans using head measurements, but have not come up with a positive method, so we still rely on cloacal examination. Which on ringing days means that someone goes without lunch!

Wes Halton NWSSG Coordinator

[wanlock dod]

The most concerning form of the mercury is methylmercury, and whilst the metallic form certainly isn't going to be good for you, it may not be as bad (or as available) as the methylmercury.

Mercury tends to accumulate in the sediments, and can be converted into the methylmercury form by bacteria. This methylmercury is then taken up into the food chain.

Healfdan - if you get them to take any samples then make sure that they take samples for the sediment and invertebrates/fish, because water samples are not really suitable for these kinds of contaminants.

[Burko]

I've always had my doubts about Flamingos.

[fairplay]

As I understand it Flamingoes are pink because of the crustaceans they eat which eat algae containing carotinoid pigments, and it is these same pigments that turn the flesh of trout and salmon pink.

With farmed trout and salmon they have to be fed with artificially produced pigments to make the public buy them.

Neil.

[The Woodman]

The natural carotenoid Canthaxanthin pigments wild Atlantic Salmon and migratory trout species from the prey it eats, mainly krill and small crustaceans.

Synthesised Canthaxanthin E161G is as said, used in farmed fish food to give flesh that attractive colour along with a similar product Astaxanthin E161J.