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Sunday, 19 October 2014

What Do Birds Drink?


You should only give birds water.  Liquids such as milk could kill them.

Although many birds get a certain amount of water from their food (particularly those that feed on insects), many will also need a good guzzle of water. Water also helps birds to keep their flight feathers in good working order and a good wash is invaluable to removing unwanted dirt or parasites which will affect flight performance and general health.


Bath Time Stock Photo Paul Brentnall

Above: these starlings (Sturnus vulgaris) enjoy a good soak in a bird bath (image courtesy of Paul Brentnall at FreeDigitalPhotos.net)


Bird baths are the best way of providing birds with water in the garden.  Bird baths come in many shapes and sizes but you don't need anything too fancy, with an expensive fountain or anything which will be difficult to maintain.  However, I do advise flushing out and replacing the dirty water, every few weeks or so.  You may like to replace any ornamental pebbles at the bottom of the bath every few months or so, as green algae tends to build up on them.

Also bear in mind, that bird baths, being nearer the ground than other bird attractors, make visiting birds inherently more vulnerable.  So you may like to consider the safest place to put the bird bath in the garden.


Blue tit standing Tall on ice Tina Phillips

Above:this blue tit (Cyanistes caeruleus) is about to dine on some peanuts; but the bird bath is frozen!   (image courtesy of Tina Phillips at FreeDigitalPhotos.net)

Bear in mind that in the winter, bird baths will freeze.  To help birds out, you can add hot water to melt the ice.  Also, if you line the bath with a polythene sheet, this will help you to remove the ice easier.  However, substances such as antifreeze and salt should not be used, as these are harmful to birds.


In the series:

Introduction
What do you feed birds?
How do you feed birds?

RSPB advice

If you have already created a ‘bird garden’, you may have some useful tips of your own. Please share them through a comment.

Friday, 17 October 2014

What Are Fossil Footprints?

 

Fossil footprints are ancient traces of living animals — termed trace fossils.  Trace fossils also include eggs, faeces (coprolites) and trails and burrows of invertebrates (animals with no backbones). 

You are probably more familiar with the skeletons of extinct animals, such as the iconic dinosaurs, which fill the halls of our museums — these are termed body fossils.  They tend to steal the excitement of children away from footprints, and very often, from scientists too.  In fact, although fossil footprints sparked much excitement with their first discoveries in the early 19th century, it is has only been relatively recently that we are beginning to realise just how important they really are.

Fossil  footprints show us how extinct animals moved; they are geological “movies” of dinosaurs going about their daily business.  They record the dynamic interaction between the animal and the ground upon which it walks.  Fossil footprints also help us to understand extinct animal behaviour (e.g. did they live in herds, did they hunt in packs?);  they help us to understand their ecology (what other animals did they live with?);  they help us to understand their environment (did it contain rivers, lakes or was it near the coast?).   Very often, fossil footprints may be the only traces of extinct animals (in a particular area).

Indeed, as the great Sherlock Holmes quipped in A Study in Scarlet, “There is no branch of detective science which is so important and so much neglected, as the art of tracing footsteps”.

 

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Above: Fossil footprint of a three toed dinosaur.  Such footprints are records of how extinct animals moved; note the claw mark (top, centre) indicating that the toe was dragged through this sediment (photograph from the Middle Jurassic, Yorkshire coast).

 

This is the first in a series of articles aiming to introduce the reader to the study of fossil footprints, with a particular focus on my area of study, dinosaur footprints.

Thursday, 9 October 2014

‘Mutant’ Turtles at Crystal Palace Park? The Story of the Dicynodon

 

As the new Teenage Mutant Ninja Turtles (2014) film pounces onto British cinemas, I thought it timely to introduce you to the strange turtle-like animal statues at Crystal Palace Park — animals that you have probably already passed many times rushing to see the dinosaur statues…

These two strange animal statues (termed Dicynodon) can be found to the right-hand side of the (large) dinosaurs and the marine reptiles.  The statues are actually on the other side of the Primary Island to the Labyrinthodon, (as shown in the photograph below).  But you should be able to see them if you follow the path around.

 

Above: Photograph showing location of Dicynodon on Primary Island.

Above: Photograph showing location of Dicynodon on Primary Island.

 

Dicynodon

Above: Close -up of two Dicynodon statues

 

As you can see from the photographs, these two strange statues have shells like turtles.  But have a closer look, what else do you notice?

You should be able to see tusks, giving them a strange sabre-toothed appearance (in photo, can only be seen in one animal, but they both have them).  It is from these features, that they were named Dicynodon (from the Greek words meaning “two tusks or canine teeth”).  Now if you are a fan of prehistoric animals you have probably seen many strange creatures; the four legged carnivore with a huge sail on its back (Dimetrodon), the exotically frilled Triceratops and its kin, or the prehistoric shark with an ‘ironing board’ like spine on its back (Stethacanthus).  But you are unlikely to have seen sabre-toothed turtles. But did these animals really exist?   In order to answer this question, we need to take a look back at the history of the Dicynodon models.

The famous sculptor of the models, Benjamin Waterhouse Hawkins, built the models under the scientific guidance of famous British anatomist, Richard Owen.  Richard Owen was particularly good at solving palaeontological puzzles, a few years earlier being able to predict the existence of a giant flightless bird (later described as the moa) from a single bone fragment alone1,2,3.  However, in the case of these strange Dicynodon, all he really had to work with were a few skulls he was sent from South Africa (along with a few vertebrae)4,5.  These heads were very strange indeed, showing a combination of tusks, but with the toothless beak of turtles.  So what did the rest of the bodies look like?  It seems that Owen was unwilling to reconstruct an entire body, however, judging from the lack of such reconstructions, though he did speculate that the animals were amphibious5.

 

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Above: The skull of Dicynodon lacerticeps (from Owen 18455).

 

Now, in order to breathe life into these extinct animals, and reconstruct the bodies, Hawkins would have to edge further into the dark of the “speculation zone”, even if Owen was not prepared to.  So, it seems Hawkins gave these Dicynodon statues shells.  Exactly why he did this, we can really only speculate.  This could be due to Owen’s interpretation of the animals as amphibious, or from his description of the turtle-like beaks.

We know now, that Hawkins was incorrect in giving these animals shells — the Dicynodon turns out to be more closely related to mammals (“mammal-like reptiles”).  However, perhaps we should not judge Hawkins too harshly, as what we must bear in mind is that he was working with very fragmentary material known at the time (we now have more complete material for the Dicynodon and closely related species).  More importantly, the Hawkins’ reconstructions, still standing 160 years later, are ‘living’ testaments to the changing process of science — reconstructions change with new discoveries and theories, so we can go back and question older reconstructions, or ideas critically. We can say “we have got it less wrong now”.  Ideas, like animals, evolve too.

The sabre-toothed Dicynodon, ‘mutant’ turtles no more.

 

For my more comprehensive historical look at the Dicynodon, visit the Friends of Crystal Palace Dinosaurs website, where this research was first published.  I would be happy to answer any questions related to this topic, so please leave a comment.

 

References

1. Owen, R. (1840). On the bone of an Unknown Struthious Bird from New Zealand, Meeting of November 12, 1839. Proceedings of the Zoological Society of London (Vol. 7, pp. 169-171).

2. Owen, R. (1843).  On the Remains of Dinornis, an Extinct Gigantic Struthious Bird.  Proceedings of the Zoological Society of London (pp. 8-10).

3. Dawson, G.  On Richard Owen’s Discovery, in 1839, of the Extinct New Zealand Moa from Just a Single Bone. BRANCH: Britain, Representation and Nineteenth-Century History. Ed. Dino Franco Felluga. Extension of Romanticism and Victorianism on the Net. Web. [Last accessed 20 September 2014].

4. Bain, A. G. (1845). II.—On the Discovery of the Fossil Remains of Bidental and other Reptiles in South Africa. Transactions of the Geological Society of London, 53-59.

5. Owen, R. (1845). III.— Report on the Reptilian Fossils of South Africa: Part I.  — Description of Certain Fossil Crania, Discovered by AG Bain, Esq ., in Sandstone Rocks at the South-Eastern Extremity of Africa, Referable to Different Species of an Extinct Genus of Reptilia (Dicynodon), and Indicative of a New Tribe or Sub-order of Sauria. Transactions of the Geological Society of London, 59-84.

Monday, 1 September 2014

What Are Butterflies?

 

Butterflies are insects, which like all arthropods (also including spiders, scorpions, millipedes, lobsters) have jointed legs and a 'shell' on the outside of the body (an exoskeleton), enclosing the soft parts. Like all insects, butterflies have three major body parts; a head, thorax and abdomen. Like insects, butterflies have three pair of legs, though in some groups the first pair of legs has been reduced so much that they are virtually useless for walking and are only apparent on closer examination.
 
Butterflies belong to the order Lepidoptera — Greek for 'scale wings', as their thin membrane wings are covered by loose scales. Actually, only about 12% of this order (Lepidoptera comprising more than 165,000 species) are butterflies, the rest being moths. Butterflies and moths have two pairs of wings, originating from the thorax; 2 forewings, 2 hindwings, which are cut by complex patterns of veins, varying between the different species.

Below: Small Tortoiseshell (Aglais urticae), showing characteristic butterfly features discussed



Unlike most moths, butterflies are active during the day, usually only when it is sunny and bright. When butterflies rest, their wings are pressed or folded together in a vertical plane, above the body (abdomen) so that the lower surfaces of the wings are exposed — most moths rest with their wings held flat, concealing the abdomen. Unlike moths, the two antennae end in clubs.

Below: Red Admiral (Vanessa atalanta), feeding on buddleia, showing resting position with wings closed.

The bright colours and spectacular markings which often adorn butterfly wings are either due to presence of pigments in the wing-scales, or may be due to the way the microscopic structure of the scale interferes with light (the diffraction of incidence light), the latter of which produces the metallic colours of butterflies, as in the group known as the 'blues' (Lycaenidae). Colour may serve several functions: to avoid predation through camouflage (normally visible on the under-surfaces of the wings), for attracting a possible mate (visible on wing upper-surfaces), and may also be used to raise body temperature, as the butterfly basks in the sun.

Saturday, 19 July 2014

Join the Big Butterfly Count 2014

 

Sunny days like today are perfect for heading out into your garden or park, and butterfly spotting.

 

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Above: Small Tortoiseshell (Aglais urticae) on buddleia (Crewkerne 2013)

The spectacular summer last year saw a dramatic rise in many species of butterfly, including a significant recovery of Small Tortoiseshell, to almost 4 times the population of the previous year (recorded in the Big Butterfly Count 2012).  Peacock butterflies increased by an amazing 3500% on the previous year.  Will this summer see comparable numbers?

This is something that you can really help to assess, with this Big Butterfly Count 19th of July-10th of August 2014.

Why is this survey important? Well, because butterflies react so quickly to any changes in their environment, they are extremely good biodiversity indicators and help to assess the overall health of our environment.

By participating in this nationwide survey, run by the charity Butterfly Conservation, in association with Marks & Spencer, you can help build up a picture of butterfly numbers, and environmental health.

How can I take part?  It's really simple.  Firstly download the identification chart which gives you a list of butterflies with corresponding pictures.

 

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Give yourself 15 minutes when it's sunny, in the garden or park and start counting butterflies.  Binoculars are useful if you have them, but not necessary.  Count the maximum number of each species that you can see at a single time — for instance if you see four Small Tortoiseshell then record that as four.  If you have certain butterfly attracting plants, such as buddleia, then you may be very busy, as butterflies are known to swarm on these!  Read more about attracting butterflies to your garden.

Then submit your sightings online at http://www.bigbutterflycount.org/ or by using the app which you can download for your smartphone.

It's that easy!  So start butterfly spotting and see what you can find!

For more information about the survey please visit The Big Butterfly Count.


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Above: Peacock (Nymphalis io) butterfly on buddleia (Crewkerne 2013)


 

 

  

Wednesday, 18 June 2014

Crystal Palace ‘Park Life’: What Animals Can You Spot?


A recent visit to Crystal Palace Park, at Sydenham, reveals some rather unexpected animals…

When most people think of Crystal Palace Park, the iconic images of the dinosaur statues looming over visitors are conjured in the mind. But, part of the Park experience is the living animals too.  Although they might seem somewhat out of place in these essentially prehistoric scenes, they help to breathe life into the Park — a sense of animation — and provide us with an extra sense of scale to help us marvel at the antediluvian stars. 

 

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Above: a duck swimming casually by the marine reptile statues at Crystal Palace Park.

 

I have visited the Park many times, and I am accustomed with mallard ducks, geese and coots, casually swimming by (irreverent to the prehistoric marine reptiles, seemingly frozen in time, next to them) or pigeons cheekily dropping into picnics and unsuspecting visitors.  The chatter of goldfinches, great tits and robins (albeit with the occasional cry of a child) form the ambience.  But during a recent visit, I came across some rather unexpected inhabitants…

Lazily perched across a large branch, was a series of five terrapins.  One behind the other, all with their right foot stretched backwards (like they were following a choreographed dance routine in a show).  They were clearly enjoying basking in the sun — and why not, it was a beautiful day.

 

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Above: terrapins at Crystal Palace Park basking lazily in the midday sunshine..why not?

 

Separated from the terrapins by an expanse of water, I could only zoom in so far with my optical lens.   So identifying them was tricky.  But squinting through the glimmering sun, I could just about make out the bright red and yellow markings adorning their faces.  I surmised that they were probably red-eared terrapins (Trachemys scripta elegans).  But what are they doing at Crystal Palace Park?

According to a post by the Guardian (2011), thousands of the species were let loose in UK waterways after the Teenage Mutant Ninja Turtles craze faded away.  Yes, they were sadly bought as pets, no longer loved and then dumped…why people do this I really don't know.

… But at least these have survived and are currently enjoying the UK summer of 2014.  Actually, due to these types of pet releases, these terrapins have become an invasive species in many areas of the world. Read more.

So, this summer, when you visit the Park, don't just look at the dinosaur statues — see what other living animals you can observe.  And, if you spot something interesting, then I would be interested to know! 

Reply to Naturalcuriositycorner@Gmail.com or on Twitter, @DrSimonJackson

Wednesday, 11 June 2014

Can You Spot the ‘Missing’ Footprints at Crystal Palace Park?



There is a curious note in the Crystal Palace Park guide; Geology and Inhabitants of the Ancient World1, about a series of footprints, which was installed with the extinct animal models in the Crystal Palace Park, in 1854. However, whereas the dinosaurian behemoths, such as the iconic Megalosaurus and Iguanodon, loom over captive audiences, and are impossible to miss, the footprints are nowhere to be seen....but perhaps we have found a clue…

clip_image002Above: A series of footprints like these (Chirotherium) was supposedly installed in the Park2.



Well, firstly, you might ask, who cares about footprints? In scientific circles today, fossil footprints are considered invaluable tools to unlocking secrets about the way extinct animals moved, behaved and interacted within their environment. They are essentially a window into the past. By the mid-19th century, the study of footprints was an exciting new frontier of palaeontology. Discoveries had recently come to light from Dumfriesshire, Scotland3; Hildburghausen, Germany4; Cheshire and Merseyside5 (UK) and the Connecticut Valley, US6. With so few bones and complete skeletons described worldwide at the time, footprint discoveries represented, in some cases, the only clues of the animals; the only real means by which the intangible past could become tangible; the only way we could make that connection to strange bygone eras and understand the seemingly invisible creatures7.

This Victorian fascination with fossil footprints was reflected in the large number of museum displays at the time; for instance, footprint slabs on display at the, then, British Museum galleries8 (now part of the Natural History Museum collection). Casts of footprint slabs were also available for purchase from Ward's 1866 Catalogue of Casts of Fossils9; there was clearly a demand to display and marvel at these natural curiosities.


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Left: Image from Ward's (1866) Catalogue of Casts of Fossils, showing a cast of what is labelled as Chirotherium, on sale for $10.

So it's not surprising then that Benjamin Waterhouse Hawkins would include footprints as part of his prehistoric landscape at Crystal Palace Park. Following the "sanction and approval" of the celebrated British anatomist, Richard Owen10, guiding the creative hand of Hawkins, these footprints (then, under the name of Cheirotherium) accompanied their presumed animal creators; three models of Labyrinthodon; essentially giant amphibians which Owen interpreted and described from fragmentary material in Warwickshire11.

 

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Above: The 'Labyrinthodons' are the first animal models which one discovers in the Park, if one works their way through the geological time sequence reconstructed by Hawkins (photograph  taken in 2014).

So, where are the footprints now?  I have spotted what we think may be the only surviving footprint, or pair of footprints12  in a photograph  taken by Professor Joe Cain in 2013.  However, strangely, I have only spotted it in just one photograph, and in numerous other photographs of the same models... well, it's just not there!

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Above: Labyrinthodon with footprint, or pair of footprints, highlighted (taken in 2013)

 

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Above: Photograph taken from same angle (2008): where is the footprint?

 

During a recent visit to the Park, I was still unable to spot the footprints, even using my binoculars and a powerful optical zoom camera (I could not get onto the islands without special permission from Park officials).  Unfortunately, the spot has overgrown with plants, frustratingly obscuring any possible footprints.

It's well known to scientists who study footprints (known as ichnologists) that footprints can be highly elusive to the human eye. The slightest change in lighting, for instance, can unveil or shroud these prehistoric enigmas. This is because they are often of low relief and, paradoxically, if you're staring straight down at one...you could likely miss it.

The secret to spotting footprints, which any ichnologist will tell you, is to look for them when the sun is at a much lower angle, for instance, at daybreak or dusk. Then, get down as low as possible, and look across the surface (bedding plane) to spot the 'newly' emerging footprints.

We do know that our image was taken only in 2013, and no conservation work has been undertaken around the models since then. So it's possible that the footprint has been infilled with loose sediment or dirt. So we need to get out there with a brush....(under the watchful eyes of Rangers of course).

So, if you have had the fortune to visit the fantastic Crystal Palace Park, look at your photographs....  If you spot anything that looks like a footprint then tweet the Friends of Crystal Palace Dinosaurs at @cpdinosaurs or add a post on the Friends’ Facebook page. Or, if you happen to visit the Park again, don't just visit the dinosaurs....give the 'Labyrinthodons' some of your time; start footprint spotting....

"There is no branch of detective science which is so important and so much neglected, as the art of tracing footsteps" — Sherlock Holmes, A Study in Scarlet.

 

(Note: I have posted a virtually identical piece earlier on the Friends of Crystal Palace Dinosaurs website).

 

References and Notes

1 Owen, R, and Hawkins, B. W. (1854). Geology and Inhabitants of the Ancient World. Crystal Palace Library. 39 p.

2 From Kaup, J. J. (1835). Das Tierreich 1. Johann Philipp Diehl, Darmstadt: 116 p.

3 Duncan, H (1831) An Account of the Tracks and Footprints of Animals Found Impressed on Sandstone in the Quarry of Corncockle Muir in Dumfriesshire. Transactions of the Royal Society of Edinburgh,11:194-209.

4 Kaup, J. J. (1835). Mitteilung über Tierfährten von Hildburghausen. Neues Jahrbuch für Mineralogie, Geologie und Paläontologie, 1835:327–328.

5 Cunningham, J. (1838) An Account of the Footsteps of the Chirotherium and Other Unknown Animals Lately Discovered in the Quarries of Storeton Hill, in the Peninsular of Wirrall between the Mersey and the Dee. Proceedings of the Geological Society of London, 3: 12-14.

6 Hitchcock, E. (1836) Ornithichnology-Description of the Footmarks of Birds, (Ornithichnites) On New Red Sandstone in Massachusetts. American Journal of Science, Series 1. 29:307-340.

7 For an example of how footprint evidence may be the only proof of an animal's existence, in the geological record, see Tresise, G. R. (1989) The Invisible Dinosaur. National Museums and Galleries on Merseyside. Eaton Press, Wallasey, Merseyside. 32 p.

8 Mantell, G. A. (1851) Petrifactions and Their Teachings; or, a Handbook to the Gallery of Organic Remains of the British Museum. Henry G Bohn, London.

9 Ward, H. A. (1866). Catalogue of Casts of Fossils: From the Principal Museums of Europe and America, with Short Descriptions and Illustrations. Benton & Andrews, printers.

10 Hawkins, B. W. (1854). On Visual Education As Applied to Geology. Journal of the Society of Arts, 2: 444-449.

11 Although Cheirotherium is the correct spelling in Greek for hand beast, Chirotherium (the incorrect spelling) was used first and therefore, under the provisions of the International Code of Zoological Nomenclature, is the valid name, used now. It is now thought that this type of footprint was made by animals more closely related to crocodiles, than to amphibians (see Tresise 1989, above for more details).

12 There is a short note in McCarthy and Gilbert (1994) (full reference below) that one of these footprints still survives.

McCarthy, S. and Gilbert, M. (1994) The Crystal Palace Dinosaurs: The Story of the World's First Prehistoric Sculptures. Crystal Palace Foundation.