Discover How to Bring Birds into Your Garden

 

Above: Long-tailed tits (Aegithalos caudatus) feeding on suet balls (image courtesy of Paul Brentnall)

Birds are everywhere.  Just LOOK around; parks, cities, in fact, most places you look (commuters often stumble over frenzied pigeons on their way to work).  But it can be frustratingly hard to see birds when you want to, for instance in YOUR garden.  In this series of posts, I will teach you the secrets of attracting them to your garden.  With these useful tips you can transform your personal 'green space' to a twittering haven for your feathered friends.

In the series:

What do you feed birds?
How do you feed birds?
What do birds drink?

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.

What Do You Feed Birds?

 

Above: Long-tailed tits (Aegithalos caudatus) feeding on suet balls (image courtesy of Paul Brentnall at FreeDigitalPhoto.net)

In this post you will learn how to attract different species of birds to your garden.

Birds eat allsorts; bread, seeds, peanuts, suet and meal worm.  But each bird species has its own food preference.  By providing a variety of different foods, as detailed below, you can attract a good diversity of birds to your garden.

So let’s begin.

Bread is perhaps the easiest and cheapest food to distribute.  In urban areas you are likely to attract crows, magpies and feral pigeons, whilst in more rural settings, bread will also additionally attract wood pigeons.  However, bread is of low nutritional value (lacking the fat and proteins birds need), and so should not constitute a large or sole part of their diet.  Also, make sure ideally that the bread is not too stale (and, therefore, hard), so that it will not choke birds, particularly hatchlings in the breeding season (although, incidentally, I have known magpies to soften stale pieces of bread in our bird bath, before eating it).

Above: Wood pigeon swallowing large chunk of bread, on a garden lawn

It is more ideal to provide birds with seed mixtures.  Good mixtures contain maize, peanut granules and sunflower seeds.  These mixtures will attract a variety of birds including blackbirds, house sparrows, dunnocks and finches. Black sunflower seeds are popular all year round, particularly with tits and greenfinches.  Although these types of seeds can be spread on the ground, you will have more success of attracting birds through distributing these foods via a bird table or hanging feeder.

Nyjer seeds will attract goldfinches to your garden, one of the most colourful British species.  You will need a special type of feeder, however, for distributing these small, black, oily seeds.

Above: a goldfinch (Carduelis carduelis) feeding on Nyjer seeds

Peanuts are also very popular, particularly with greenfinches, tits, and if you're lucky a visiting nuthatch or greater spotted woodpecker.  However, unfortunately not any peanut will do — peanuts can be high in a particular natural toxin which can be lethal to birds, so make sure you buy them from a trusted dealer, such as the RSPB.  Unfortunately left over dry roasted peanuts will not do!

Suet balls and bird cakes are very popular in the winter, due to their high fat content.  They are favourite foods of tits.  However, make sure that you remove the mesh bags they are sold in, which can injure birds, before placing the food on a special feeder.

Meal worm is particularly sought-after by robins, and other insect eating birds, but will also be popular with seed-eating birds during the breeding season, as the emerging chicks will be needing the extra nutrition.  This food type can be distributed on the lawn, on the bird table or in a specialised feeder.

Above: A British robin feeding on a fresh worm it has plucked from the lawn

Do NOT give these to birds: milk (which can result in death), cooking fat and vegetable oils (not good for bird health or feathers), mouldy foods (which can cause respiratory infections).

In the series:

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

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.

How Do You Feed Birds?

 

In this post, you will discover how to feed birds in different ways. Not all birds feed the same way.  So this means you will need to be a little creative.

 

 

Some birds, such as the blue and yellow macaw above, are happy to feed by hand (image courtesy of Khunaspix FreeDigitalPhotos.net).  This post, however will focus on garden birds; birds that you can see and attract without having to go on holiday or visit the zoo.

Some garden birds, such as robins and pigeons, also feed by hand   However, it is far easier to feed them, by putting food onto the ground. Some food items, such as bread and meal worm can be distributed in this way.

Above; feral pigeons (Columba livia) congregrate en masse on a garden lawn (image courtesy of Natara at FreeDigitalPhotos.net)

 

However, not all species of bird (e.g. goldfinches) like to feed on the ground.  Bird tables and hanging feeders are more effective ways of distributing many food items, attracting a greater number of bird species.

 

Bird Tables

Distributing food items on a bird table will attract smaller species, such as robins, tits and greenfinches. Bird tables come in all shapes and sizes, though one with a roof will provide shelter for visiting bird guests. Ensure that there are no sharp edges which will harm your avian visitors.

Make sure that the bird table is a suitable height (at least a metre) above the ground and away from anything obvious that a cat could use as a platform to pounce onto the bird table and unsuspecting bird guests.  If your bird table is made of wood, then by fitting an inverted plastic bucket at the top of the pole, at the base of the table platform, this should stop scaling cats and squirrels (squirrels, though they will not harm birds, have a tendency to completely raid the food bounty!).  Additional tip: you will need to fit some wiremesh around the base of the bucket to stop squirrels gnawing it away.

Larger species, such as pigeons, will also try and devour everything on the table in sight, so you may like to consider winding some string around the centre, a couple of inches above the platform of the table, in order to prevent this. Alternatively, a 4 cm wiremesh around the table will also keep out the larger birds. 

You also need to clean the table regularly and avoid letting old food accumulate, which will lead to the buildup of harmful bacteria.

 

Above: A bird table, showing modifications restricting squirrel and pigeon access

'Hanging' Feeders

In my experience, hanging food feeders are a better way of attracting small birds, at least to our sub-urban garden.  Because these feeders have a mesh or small access point they inherently keep out squirrels or larger birds, such as pigeons, and depending on where you live, may be a better investment than a bird table.  Ideally place them on the branches of a tree, where birds would be sheltered by overhanging foliage (offering protection from both the rain and prospecting sparrow hawks).

Hanging peanut feeders consist of a wiremesh, between which dining bird guests can access the goodies via pecking.  The mesh is typically about half a centimetre apart, allowing birds to get their beaks in without letting the peanuts slip out. These feeders will attract tits, greenfinches, ring-necked parakeets, and sometimes greater spotted woodpeckers.

Above: greater spotted woodpecker (Dendrocopos major) feeding on peanuts (image courtesy of Tina Phillips at FreeDigitalPhoto.net)

Some specialised peanut feeders have a spring-loaded metal sheath around them, so that when prospecting squirrels land on the feeders, they inadvertently pull the sheath down around the peanuts and block their passage to them.  The agility of squirrels never fails to amaze me, and they always seem to get onto the feeder no matter how far it is from the trunk of the tree — but this spring-loaded sheath always seems to do the trick and leaves the little critter more than a little disappointed.

Above: A hanging peanut feeder, designed to keep squirrels out with spring-loaded sheath

Hanging seed feeders consist of cylindrical transparent tubes which have one or more access points for the bird. They also have a platform for the bird to perch on, while they dine.  Sunflower seeds can be distributed in this way (in addition to on a bird table), and it's quite common to see a tit or greenfinch leisurely sitting on the feeder while it strips the shell of the kernel.

Above: Great tit (Parus major), left, and coal tit (Periparus ater), right. (Image courtesy of Tina Phillips at FreeDigitalPhotos.net)

Nyjer seeds can be distributed through a specialised Nyjer seed feeder. Depending on how many perching points you have, you can attract several goldfinches all leisurely feeding at the same time (unless you startle them, they are happy to dine, unhurriedly, for 5, 10 minutes or more, and with their spectacular coloured plumage make a marvellous addition to your garden!)

Above: A goldfinch (Carduelis carduelis) feeding on a hanging Nyjer seed feeder

Suet ball feeders consist of hanging baskets or cages, in which the food is placed.  But do remember to remove the mesh packaging from the balls first, as this is harmful to birds.  In our garden anyway, this food is very popular with blue tits and sometimes if we are lucky we get a large group of feeding long-tailed tits.

Above: Long-tailed tits (Aegithalos caudatus) feeding on suet balls (image courtesy of Paul Brentnall)

 

Mealworms can be dispersed via a hanging tray, which the robin is quite happy to swoop down on to grab its dinner, before immediately flying off again. However, open trays can be raided by starlings — which have the habit of consuming every last remaining scrap.  Therefore, there are specialised mealworms feeders you can purchase which have adjustable height roofs, which only allow smaller birds, such as robins, in. 

In the series:

Introduction
What do you feed birds?
What do birds drink?

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.

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.

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.

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.

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”.

 

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.

‘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: 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 alone^1,2,3.  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.

 

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.

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.

Join the Big Butterfly Count 2014

 

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

 

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.

 

 

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.

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

 

 

  

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. 

 

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.

 

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

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…

Above: 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.

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.

 

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!

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

 

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.

What Are Butterflies and How Can I Enjoy and Attract Them?

Their wings with azure, green and purple gloss'd,

 

Studded with colour'd eyes, with gems embossed,

 

Inlaid with pearl, and marked with various stains

 

Of lively crimson through their dusky veins —

Mrs Barbauld
(from Newman 1887)

At some point, most of us have seen a butterfly. Perhaps one has silently fluttered past us in our garden or a park, and we may or may not have paid attention. Many children are at least aware of the complete, almost magical transformation from that worm-like caterpillar, to the magnificent splendour of the fully-winged adult. But if you are reading this blog, and are fascinated by butterflies as much as I am, then you will probably want to know more. 

• What exactly are butterflies?
• Where can I see butterflies?
• How can I attract butterflies to my garden?

are some of the questions this blog answers. This page is predominantly about British and European species, though many of the facts are also applicable to butterflies worldwide.

 

What Exactly 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.

What is a Butterfly's Life Cycle?

There are four distinct stages in the life-cycle. The life of a butterfly begins with an egg (ovum), laid by an adult female, usually on a specific species of plant.

After a period ranging from a few days to several months, the caterpillar (larva) emerges — a stage which dominates the life-cycle of most species — and it begins to devour the leaves of its surroundings, in order to grow. Eventually, it becomes too big for its own 'skin' and like all insects, needs to undergo the process of shedding its skin (moulting or ecdysis), before continuing to grow. The caterpillar will undergo this process several times (usually five).

Ultimately, the caterpillar will form a chrysalis (pupa), a stage which varies between a few weeks to up to 10 months. This is where complete change (metamorphosis) occurs, and the fully winged adult (imago) emerges, albeit with small and floppy wings. The wings are now expanded and hardened by pumping fluid through their veins — in some species in a matter of minutes — and now the adult is ready for its first flight.

Many species will then seek to find a mate almost as soon as they have emerged, with males following the scent plumes, or pheromones, released by the females. After mating, the process begins all over again, with an egg.

Why are Butterflies Important?

Butterflies are vital components of ecosystems. Caterpillars, as herbivores, recycle nutrients back into the food chain. Adults are also important plant pollinators. Both stages are important food sources for animals higher in the food chain (e.g. birds, other insects).

Butterflies also respond rapidly to changes in the environment, so monitoring populations of butterfly species is a good indication to the overall health of the ecosystem — a decline in butterfly species is an indicator of other wildlife losses.

When Can I See Butterflies?

In Europe, you're most likely to see the adults during their flight period, during the spring and summer, when they have emerged from hibernation to reproduce and feed. And you are most likely to see them on a sunny and warm day.

However, you may be able to see hibernating butterflies during the winter. Butterflies hibernate in different states, though most European species hibernate as larvae. If you're lucky, you may be able to see an adult Peacock (Inachis io) hibernate in hollow spaces, such as oak trees, which they have been known to do in large numbers. Some species such as the Painted Lady (Vanessa cardui), cannot survive our cold winters and migrate southwards to North Africa, where they remain until spring.

Below: Peacock (Inachis io) specimen. This species has been known to hibernate in oak trees.

 

Where Can I See Butterflies and Can I Attract Them?

Perhaps the best way to be guaranteed to see large numbers of butterflies is to visit a dedicated butterfly centre. For example, the Natural History Museum's Sensational Butterfly Exhibition hosts over 50 species of tropical butterflies and moths, among tropical plants, within its vast marquee set on the lawn outside the museum. Another great example of this kind of environment is the Stratford Butterfly Farm, where one can stroll leisurely through an exotic rainforest surrounded by tropical butterflies and splashing waterfalls.

If you want a greater challenge, you can go out into the country to seek butterflies. As certain species prefer different environments, you can be more choosy about which species you want to seek out. For example, the Adonis Blue (Lysandra bellargus) and Chalkhill Blue (Lysandra coridon) butterflies prefer flower-rich grassland on limestone or chalk. Thus walking along a chalk ridge running through the middle of the Isle of Wight is a great place to see these species (and this is one of the many recommended routes suggested by the National Trust).

However, perhaps the most rewarding experience is to proactively attract butterflies to your own garden, so that you can enjoy them at your own leisure. But how do you do this?

Attracting a particular species of butterfly means you need to consider both the caterpillar and adult (winged) stages. Most adult females are particularly choosy about where they lay their eggs, and certain species of plants are selected which will provide the source of food for the ever-growing caterpillars (these may be referred to in books as larval or host foodplants). For instance, Large and Small White butterflies (Pieris brassicae, Pieris rapae) often lay their eggs on leaves of cabbages (Brassica), where their caterpillars emerge. Peacocks (Inachis io) and Small Tortoiseshell (Aglais urticae) leave their eggs on nettles (Urtica). The Holly Blue (Celastrina argiolus) leaves it eggs on either ivy (Hedera) or holly (Ilex). So by growing certain types of plants, you can attract certain species of butterfly caterpillar, which will ultimately develop into its often spectacular adult form.

When the adults emerge, you then want to keep them on site, by providing them with food. Flowers rich in nectar are at the top of their menu... a butterfly uses its set of mouthparts (proboscis) to suck it up. Flowers such as the buddleia (Buddleia), iceplant (Hylotelephium spectabile) are great for attracting large numbers of butterflies, particularly Small Tortoiseshell. Choose a nice sunny spot, ideally protected from the wind.

If you can combine these two factors together, then you stand an excellent chance of attracting certain butterfly species to your garden.

The picture below is from a large buddleia bush in Crewkerne, Somerset, which is near an allotment rich in nettles and other larval foodplants — caterpillar food. Two species can be seen here: a specimen of Painted Lady (Vanessa cardui) and a specimen of Small Tortoiseshell (Aglais urticae). I have, however, observed at least five other species feeding on this buddleia, including: Large and Small Whites (Pieris brassicae, Pieris rapae), Peacocks (Inachis io), Red Admiral (Vanessa  Atalanta), Commas (Polygonum c-album).

 

Can I Identify Butterflies?

When you spot a butterfly in your garden, or in the country, you may like to work out what it is, may be even keeping a record of it in a notebook (with a date and locality).But how can you identify one?

The most striking parts of a butterfly are the colour markings on its wings.These may be eyespots (as in the Peacock) or contrasting bands (as in the Small Tortoiseshell or Red Admiral).These colours are normally most developed on the upper wings, visible during flight, but you will also need to look at the colouration of the lower surfaces of the wings, visible when they are pressed together during feeding — blues (Lycaenidae), for instance, can be best distinguished in this way.

This shape of the wings is also another important feature; for instance, the edge of a Comma is scalloped or jagged, whereas that of the Swallowtail (Papilio machaon britannicus) has characteristic tails protruding from the hindwings.

Size may also be an important feature to distinguish species, though in the field this can sometimes be hard to determine. It's also worth noting that the morphology varies between the different sexes (male, female) within the same species: for instance, in some blues, the upper wings of males are blue, whereas those of females are dark brown.

 

What Will I Need to Identify Butterflies?

Unless you are an experienced entomologist, you will need a nature guide book, or ideally a dedicated butterfly guide to identify butterflies.Through matching the butterfly to the picture and description in the book you will then be able to identify the butterfly in two ways.Each species of butterfly has a common name, for instance, Large White, which is quite easy to remember.However, it also has a more formal scientific name, which is often a mixture of Greek and Latin (Large White =Pieris brassicae).

For only £3 you can get the "Guide to the Butterflies of Britain", which is a fold out pamphlet with full-size illustrations of butterflies — excellent for identification purposes — with general information about butterflies on the back.

For a bit more (£6) you can get the highly illustrated Pocket Nature Butterflies and Moths which is an excellent introduction to the groups with a picture and summary for every common species. A great feature of this book is that it also shows an image of the caterpillar of each species.

The Collins Butterfly Guide is a much more comprehensive (but more expensive) guide, with similar species listed for Europe, aimed at the more serious butterfly spotter.

Is it Legal to Collect Butterflies?

It is important to note that certain species are protected (in the UK, by the Wildlife and Countryside Act 1981), and there are certain protected sites such as nature reserves.A licence would be necessary to collect under these conditions. Having said that, it is legal to collect unprotected species of butterfly.However, in this day and age, as our understanding of butterfly conservation and wildlife protection increases, this practice is frowned upon. Collecting can have a detrimental effect on populations of butterflies, with specimens often collected before they have reproduced.For instance, a colony of Large Blues (Maculinea arion) in Northamptonshire never fully recovered after 200 butterflies were collected by one dealer in 1860. Now the Large Blue is protected by law.

Unlike museum and university collections, private collections are usually only accessible to a limited number of people, and therefore often only make a very limited contribution to further our scientific knowledge. (Read more about the legalities of collecting).

With advances in digital photography and video, members of the general public can effectively collect 'virtual specimens' of butterfly, flying and feeding in all their glory, without the need to capture or kill them for identification or collection purposes.

Can I Become Involved in Butterfly Conservation?

If you would like to become more involved with conservation work and species recording, or to take part in evening meetings and talks, then you may like to become involved with the UK charity, Butterfly Conservation. For instance, the 'big butterfly count' is a nationwide survey, launched in 2010 and has become the world's biggest survey of butterflies.

References

Lewington, R and Bebbington, J.(2005) Second Edition. Guide to the Butterflies of Britain. Field Studies Council Publications, Telford.

Newman (1887) An Illustrated Natural History of British Butterflies and Moths. Hardwicke and Bogue, London.

Sterry, P. and Mackay, A (2004) Pocket Nature Butterflies and Moths. Dorling Kindersley. London.

Tolman, T and Lewington, R (2009) Collins Butterfly Guide: The Most Complete Field Guide to the Butterflies of Britain in Europe. Harper Collins

What Are Sea Urchins?

Sea urchins, or echinoids, are small, seafloor dwelling invertebrates (they have no backbones), that are spiky, often brightly coloured and either globular (e.g. the edible sea urchin), disc-shaped (e.g. sand dollars) or heart-shaped (e.g. heart urchins).  There are over 900 living species, with an evolutionary history that stretches back 450 million years.

 

Above; Fragile pink sea urchins (Strongylocentrotus fragilis) live in communal groups off the west coast  of North America. (Picture courtesy of all-free-download.com)

Sea urchins, comprise the class Echinoidea and are echinoderms, a group which also includes starfish, brittle stars, sea cucumbers and sea lilies.  A familiar feature of echinoderms, particularly the sea urchins, is their spines or sharp projections — a feature which many unwary swimmers are painfully familiar with (Echinodermata is derived from the Greek and Latin for 'prickly skin').

The spines of a sea urchin connect via tubercles to its rigid skeleton (known as a test).  In most species, the test is circular when viewed from above, with the anus on top, and the mouth at the bottom (do sea urchins feed through their bottoms?)

Unlike starfish, sea urchins lack arms.  However, the test of a sea urchin consists of a series of plates which are arranged into pairs of columns, or 'bands', which radiate outward from the top (apex) of the skeleton and have a star-shaped configuration.

Five of the star-shaped 'bands' (termed ambulacra) bear tiny pores.  Through each pore, a tube-like structure extends, each one ending in a circular disc — these are called tube feet, and a sea urchin can move them, by controlling the pressure of water within them.  This system, unique to sea urchins and other echinoderms, allows a sea urchin to move, feed and in some species, respire.

Above: a specimen of Echinus esculentus, with spines removed, showing key features of sea urchins (Courtesy of UCL, Grant Museum of Zoology_specimen S174).

In addition to spines and tube feet, a sea urchin possesses tiny pincer-like structures (pedicellariae).  These help to keep it clean and to avoid parasites (such as marine larvae settling on it).  Many species of sea urchin also bear venom glands, within pedicellariae, which can be used to ward off predators or subdue prey.

In summary, a sea urchin can be thought of as a small rounded ‘box’, consisting of many small plates connected together, which uses its specialised projections (spines, tube feet, pedicellariae) to interact with its environment.

You may like to read:

What Are the Main Types of Sea Urchin?
How and What Do Sea Urchins Eat?
How Do Sea Urchins Move? 
How Do Sea Urchins Reproduce and Grow?
Where Do Sea Urchins Live?

What are the Main Types of Sea Urchin?

There are two types of sea urchin: regular and irregular urchins.

Regular sea urchins (regular echinoids) are more common.  Regular echinoids are radially symmetrical (a vertical cut from one side of the animal to the other, across the centre, in two or more places will produce two halves that are mirror images of each other).  These sea urchins are hemispherical in shape (crudely resembling the top half of a sphere).  There is no front or back and these urchins can move equally easily in all directions. 

Other key features include: an anus which is in the centre of an urchin’s upper surface; a mouth which is in the centre of its lower surface; and long, pronounced spines.

Regular sea urchins live on the surface of the seabed and graze on seaweed.

Above: a specimen of Echinus esculentus, with spines removed, showing key features of sea urchins as seen on upper surface (Courtesy of UCL, Grant Museum of Zoology_specimen S174).

Above: a specimen of Echinus esculentus, with spines, showing mouth (with Aristotle's Lantern) on lower surface (Courtesy of UCL, Grant Museum of Zoology_specimen S251).



Irregular sea urchins, or irregular echinoids, include the sand dollars and heart urchins.  These have a distinct front and back, because of their bilateral symmetry (only one vertical cut, from front to back, through the centre, will produce two halves which are mirror images of each other).

In sand dollars, the mouth is still on the lower surface, and is either central or nearer the front.  The position of the anus is variable, but is nearer the back end. In heart urchins (e.g.  Echinocardium), the anus is right at the back of the urchin, whereas the mouth is near the front.

Irregular sea urchins have a flattened body, and either live partly or completely buried in soft sediment, such as sand.  Heart urchins live in burrows within the sediment, using secreted mucus to stabilise it.  Specialised tiny beating projections (cilia) on the spines draw in currents of water, containing fresh oxygen, for respiration, and food particles.




Above: specimen of Echinocardium, showing its upper surface (Courtesy of UCL, Grant Museum of Zoology_specimen NON2391)

Above: specimen of Echinocardium, showing its lower surface (Courtesy of UCL, Grant Museum of Zoology_specimen NON2391)

(Note that some people constrain the term "sea urchins" to the regular echinoids, but usage here of the term "sea urchins" also includes irregular urchins (sand dollars and heart urchins) — a usage which broadly follows the Natural History Museum Echinoid Directory).

 

Read more:

What Are Sea Urchins? 
How and What Do Sea Urchins Eat?
How Do Sea Urchins Move? 
How Do Sea Urchins Reproduce and Grow?
Where Do Sea Urchins Live?

How Do Sea Urchins Move?

Most sea urchins (particularly regular sea urchins) move using their tube feet.  These are tube-like projections, extending from their body (from the star-shaped ambulacral regions), which end in sucker-like projections.

Tube feet are extensions of a complex set of canals within each sea urchin — a water-vascular system.  Each tube foot can be extended when the urchin pumps fluid into it, allowing the foot to reach out.  The suction cup, at the end of each small foot, sticks to an object, or an adjacent part of the seafloor.  The sea urchin is then pulled towards the object, as the feet contract, when the water pressure within them is decreased.

In regular urchin species, such as Echinus esculentus, the tube feet allows the animal to grip onto rocks, within turbulent marine zones (down to depths of about 50 m), so that it is not detached by waves.  It is able to climb steep rocks and, being radially symmetrical, it is well adapted to moving equally well in all directions.

This method of locomotion — hydraulic powered tube feet — is unique to sea urchins and other echinoderms (which also includes starfish, sea cucumbers, sea lilies and brittle stars).

 

 

Above: a simplified vertical cross-section through a regular sea urchin, showing the tube feet (M = madreporite; GP = genital pore)

 

Irregular sea urchins, such as sand dollars and heart urchins, are adapted to moving in a different environment.  They move using their small, almost fur-like covering of spines, rather than tube feet.  Irregular sea urchins have a distinct front and back end (being bilaterally symmetrical) and they use their lower (oral) spines to move only in a forwards direction.  The urchin, Echinocardium uses it spines in a 'rowing' motion to move forwards within its burrow.

 

Read more:
What Are Sea Urchins?
What Are the Main Types of Sea Urchin?
How and What Do Sea Urchins Eat? 
How Do Sea Urchins Reproduce and Grow?
Where Do Sea Urchins Live?