Blackcap males sing differently to females than to other males


This video is about singing male blackcap.

This morning, Hans Slabbekoorn, who does research on bird songs at Leiden university, was interviewed on Dutch Vroege Vogels radio.

He told about research into songs by blackcap males. It turns out that, if a blackcap male sings to a female, there are more softer notes in the song. While, if he sings to another male, a potential rival, the songs have more louder notes.

Glass art and marine animals exhibition


This video says about itself:

Selections from the the film Proteus, a documentary concerning the life, work, and philosophy of Ernst Haeckel, a 19th century naturalist. The film tells of the man’s character and influences while using his detailed engravings of Radiolaria, single-celled marine organisms, to make animated progressions.

On Saturday 28 June 2014, a new exhibition will start in Naturalis museum in Leiden in the Netherlands.

The museum writes about it (translated):

Summer at Naturalis is dominated by marine animals. Meet the fascinating underwater world of Professor Ernst Haeckel. His brilliant scientific illustrations are the basis for cooperation between the National Glass Museum and Naturalis.

Until September 6, 2014

The exhibition Marine Animals brings nature, science and art together in an event with drawing activities, a special design contest and live glassblowing. The glass objects by artists and designers such as Andries Copier and Jan Taminiau are presented in addition to the natural history objects of Naturalis, surrounded by Haeckel’s drawings. Are you inspired as well? Draw a jellyfish, starfish or seashell and marvel at your lifelike drawing!

Tyrannosaurus rex fragments pieced together by museum visitors


This is a Dutch TV video about the Tyrannosaurus rex discovery in Montana, USA, in 2013.

Last year, an expedition from Naturalis museum in Leiden, the Netherlands, discovered a Tyrannosaurus rex skeleton in Montana. If there will be enough money, this dinosaur will become part of the Naturalis collection.

Some of the bones of this tyrannosaur are very fragmented. Small pieces were found among lots of sand.

The museum wants to piece cervical vertebrae and cervical ribs of the dinosaur together.

To do that, they need many people.

The museum asks visitors to help.

On 7,8 and 9 June, paleontologist Anne Schulp will tell them about the discovery of this Tyrannosaurus rex. Then, visitors will try to fit bone fragments together.

Sessions will be at 11am, noon, 1pm, 2pm and 3pm; with a maximum of 24 people per session.

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Zebra finches sensitive to human speech, new research


This video is called Wild Zebra Finches in Australia.

From Proceedings of the Royal Society B in Britain:

Zebra finches are sensitive to prosodic features of human speech

Michelle J. Spierings
1,2
and Carel ten Cate
1,2

1
Behavioural Biology, Institute Biology Leiden (IBL), Leiden University, PO Box 9505, Leiden 2300 RA, The Netherlands
2
Leiden Institute for Brain and Cognition (LIBC), Leiden University, PO Box 9600, Leiden 2300 RC, The Netherlands

Variation in pitch, amplitude and rhythm adds crucial paralinguistic information to human speech. Such prosodic cues can reveal information about the meaning or emphasis of a sentence or the emotional state of the speaker.

To examine the hypothesis that sensitivity to prosodic cues is language independent and not human specific, we tested prosody perception in a controlled experiment with zebra finches.

Using a go/no-go procedure, subjects were trained to discriminate between speech syllables arranged in XYXY pat-
terns with prosodic stress on the first syllable and XXYY patterns with prosodic stress on the final syllable. To systematically determine the salience of the various prosodic cues (pitch, duration and amplitude) to the zebra
finches, they were subjected to five tests with different combinations of these cues.

The zebra finches generalized the prosodic pattern to sequences that consisted of new syllables and used prosodic features over structural ones to discriminate between stimuli. This strong sensitivity to the prosodic pattern was maintained when only a single prosodic cue was available. The change in pitch was treated as more salient than changes in the other prosodic features.

These results show that zebra finches are sensitive to the same prosodic cues known to affect human speech perception.

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More flowers and birds on biodiversity day


Red clover, 31 May 2014

After the small water animals on the biodiversity day, we returned to birds and flowers. Like this red clower flower.

White clover, 31 May 2014

White clover grew along that bicycle track as well.

White clover again, 31 May 2014

While a white stork was as its nest.

English plantain flowers, 31 May 2014

English plantain flowers again.

Broadleaf plantain as well.

A male pheasant near a ditch behind them.

Broad-leaved dock, 31 May 2014

Broad-leaved dock flowering.

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Baby salamanders, baby fish, flatworm and beetles


Flatworm on egg spoon, 31 May 2014

After the birds and flowers on the biodiversity day on 31 May 2014, to small animals living in water. Like the flatworm on this photo. This worm was photographed on a small egg spoon with water on it. A macro lens was really necessary to photograph a tiny animal like this. Research still has to find out which flatworm species this is.

Many small animals were caught with a landing net in the ditch near the allotment gardens. Water is rather clean there, so much biodiversity.

There were various leech species. Like Erpobdella octoculata, which was named in 1758 by Linnaeus. And Theromyzon tessulatum; which lives in ducks’ bills. One female Theromyzon tessulatum had eggs.

Bugs included specimens of water boatman; a species which may survive in polluted water. There was also the lesser water boatman. And a much smaller related species: Plea minutissima.

And a saucer bug as well.

There were nymphs of various damselfly species.

Crustaceans were represented by an aquatic sowbug.

Common bladder snail, 31 May 2014

And mollusks by a common bladder snail.

Meanwhile, a reed warbler sang.

There were various, still small, common newt larvae.

Among the very smallest animals were Cyclops and Daphnia crustaceans.

Not in the ditch, but in reed beds along the ditch: a beetle species, Donacia vulgaris.

Edible frog sound.

One very small fish is caught. Too young still to say which species. Among fish species living in this ditch are: northern pike, perch, ninespine stickleback and spined loach.

A water mite. One of scores of species in this ditch.

Finally, a great silver water beetle larva.

After the research, all animals went back into the ditch.

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Birds and plants on biodiversity day


Marsh woundwort, 31 May 2014

On 31 May 2014, there was biodiversity day in Cronesteyn park in Leiden, the Netherlands. One symptom of biodiversity there then were these marsh woundwort flowers.

As we started walking along the old woodland, originally belonging to medieval castle Cronesteyn, a blackcap sang.

In a ditch, a gadwall duck couple.

An Egyptian goose on a fence in a meadow. Below it, on the meadow: gray leg geese, domestic geese and Canada geese.

In a schoolchildren’s garden, plastic bottles protected plants from being eaten by pheasants.

A greenfinch singing.

Bishop’s weed flowering.

A chiffchaff on a tree.

In Cronesteyn, there are about forty grey heron nests. Three spoonbill couples nest among them.

After some years of absence due to harsh winters, this year fortunately there is a kingfisher nest again.

Black-tailed godwit, redshank and northern lapwing nest year after year on the meadows.

On the other side of the ditch, an Egyptian goose couple and three pheasants.

Mites' gall on sycamore maple leaf, 31 May 2014

On a sycamore maple leaf, red spots: mites have caused galls.

Marsh woundwort flowering, 31 May 2014

Next to it, flowering marsh woundwort, mentioned already.

We pass a nestbox where blue tits have nested. Other blue tits had their nest in a hole in a tree not far away.

A jay on the other side of the ditch.

11:20: we hear a great spotted woodpecker.

Grass flowering, 31 May 2014

Along the bicycle track, many flowers. Like this grass species.

Tall oat-grass close-up, 31 May 2014

And this tall oat-grass.

English plantain, 31 May 2014

And this English plantain.

Greater yellow-rattle and large earth bumblebee, 31 May 2014

And this greater yellow-rattle; visited by a large earth bumblebee.

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Bird anatomy art, lecture by Katrina van Grouw


This video from London, England says about itself:

The Unfeathered Bird at Nature Live

13 February 2013

Katrina van Grouw appeared at Nature Live at the Natural History Museum. In this short video, she describes the audience she had in mind as she wrote The Unfeathered Bird.

Learn more about The Unfeathered Bird here.

Read the New York Times review here.

On 25 May 2014, in Naturalis museum in Leiden, there was not only a lecture on extinct birds.

There was a lecture by Katrina van Grouw as well, because of the publishing of the Dutch edition of her book The Unfeathered Bird, called De ontvederde vogel.

She said her inspiration were two artists: John James Audubon and George Stubbs. Stubbs paid much attention to the anatomy of horses which he painted. Anatomy, what is below the feathers of birds, their muscles and bones, is also important for depicting birds, Ms van Grouw said.

Katrina van Grouw, toco toucan and violet touraco, 25 May 2014

Like in these pictures in her book, of a toco toucan, and a violet touraco. Ms van Grouw said that, though these two species are not really related, they are both good at climbing branches, and their somewhat similar skeletons show why.

Katrina van Grouw, trumpet manicode, 25 May 2014

She also made a picture of a trumpet manucode. This bird-of-paradise species is not as colourful as its relatives. But it has a very loud voice. The trumpet manucode has a loud voice because of its very long trachea or windpipe, which an anatomical drawing can show.

Katrina van Grouw, domestic animals, 25 May 2014

Katrina van Grouw announced that in 2018 her next book, Unnatural Selection, about domestic animals, will be published.

Katrina van Grouw, domestic pigeons, 25 May 2014

Katrina’s husband Hein van Grouw, formerly taxidermist of Naturalis, was present as well.

All photos in this blog post are mobile phone photos.

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Extinct birds, lecture


Great auk and dodo bones, Naturalis

On 25 May 2014, in Naturalis museum in Leiden, there was a lecture about extinct birds. It was by René Dekker. He had brought some rare stuffed birds, usually invisible for the public because exposure to light might damage them. His material at the lecture included the great auk and dodo bones on this photo.

All photos of this blog post are mobile phone camera photos.

The museum has 37 million objects: stuffed animals, rocks, plants, etc. Some of them are very rare extinct bird specimens.

Many of the bird species which became extinct used to live on islands. Often, island birds eventually lost much or all of the ability to fly, as there were often no or few predators on the islands.

For example, the closest relative of the now extinct dodo is today’s Nicobar pigeon. Nicobar pigeon-like ancestors of the dodo flew from Asia to Mauritius island. There they gradually lost their ability of flight. A drought in Mauritius about 4,000 year ago had already been a disaster for dodos. When about 1600 sailors arrived on Mauritius, bringing rats, cats and dogs, that meant soon the end for these flightless birds.

The dodo at Naturalis museum is not real. It is a reconstruction with rhea feathers. There are no dodo feathers left. An Oxford museum has the only bit of dodo skin left. Other museums, including Naturalis, do have bones.

Naturalis has the only Tahiti sandpiper specimen, collected in 1774 during a Captain Cook expedition.

And it has a great auk: there are 80 museum specimens left in the world; two of them in Naturalis.

Other rare extinct birds in the collection: Cuban macaw; Labrador duck; Himalayan quail; and Hawaiian rail.

Passenger pigeon, Naturalis

Another species present at Naturalis is the passenger pigeon. Not a flightless species. Not an island species. Not a rare species: millions used to live in North america. However, even a species like that was exterminated by humans.

More species: Carolina parakeet, formerly in the USA; paradise parrot, formerly in Australia; Delalande’s coua, formerly in Madagascar.

Also from Madagascar, Naturalis has bones of extinct elephant birds. These birds, and their bones, were so big that museum people wrongly put them among elephant bones. The mistake was discovered later.

There are 48 Javanese lapwings at Naturalis, and only two elsewhere in the world.

Passenger pigeon and pink-headed duck, Naturalis

The collection also includes this pink-headed duck.

Pink-headed duck, Naturalis

And a glaucous macaw; probably extinct.

And an ivory-billed woodpecker; also probably extinct.

Spix’s macaw is probably extinct in the wild, but alive in captivity.

Polynesian megapode, Naturalis

René Dekker concluded his lecture with the Polynesian megapode; a non-extinct species, which he himself had helped to prevent from becoming extinct. For many years, these birds were restricted to Niuafo’ou island. That made the birds vulnerable. So, fifty eggs were transported to Fonualei island. Fonualei is a volcanic island, with hot soil, the right temperature for megapode eggs. Being megapodes, the chicks were able to hatch and survive there without parental care. So, a few years later, over 300 megapodes lived on Fonualei.

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Swifts in an old city


This video says about itself:

Swifts inspecting a nest box

I put a swift nest box up this year, which was completely ignored until today.

On 21 May 2014, walking in the city center of Leiden, the Netherlands; looking for swifts.

On the medieval Hooglandse Kerk church, there is artificial nesting opportunity for these birds. Swifts are flying around. Close to the church, there is an antique shop in a building from the sixteenth century. The owner has taken various measures to help the birds nest.

As we walk to the castle, a greenfinch sings in a treetop.

From the castle, we can see the nestbox for peregrine falcons at the E.ON electricity building.

There are wood pigeons in a tree. And a stock dove, rare for a city center.

Most swifts in Leiden nest near the old harbour.

There is a swift nest above the praline shop as well.

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