The tree that kills birds

I spend a lot of my time on trains and prefer reading books to the newspapers. Last night I was enjoying a section on how some flowering plants disperse their seeds using animals:
 "Perhaps the most one-sided relationship of all is that which sometimes occurs with the Pisonia tree. This grows on coral islands, in almost pure sand; it has a very sticky fruit and if this becomes attached to a relatively small bird, like a noddy tern, the bird may be unable to free itself and dies, so providing the seedling with excellent compost to start its growth in the barren habitat."1

A tropical shearwater in trouble. The seeds can also kill white and noddy terns. Source: https://seychellesseabirdgroup.wordpress.com/2013/06/02/pisonia-grandisa-grand-problem/

It was so interesting I missed my stop and had to take another train back again.

I looked the story up today. It's true that the sticky seeds can kill birds, sometimes in unsustainable numbers. But someone pointed out that this might not actually benefit the tree: 
"according to current research in the Seychelles Island of Cousins... the germination of the pisonia seeds is not facilitated by being within the carcass of a seabird"2.

 

As a reference, they link to a page by the Seychelles Bird Group3 which in turn (tern) references one unpublished report and two papers. I've looked at the papers, and one mentioned that another paper discussed noddy terns and Pisonia seed dispersal, but I looked that up too and can see nothing about germination in carcasses. So whether the seeds' deadliness is beneficial to the tree or effectively accidental is still a mystery.

References 
1 The Story Of Life. Richard Southwood, Oxford University Press
2 http://neotrigonia.blogspot.co.uk/2016/01/the-bird-killing-tree-of-great-barrier.html
3 https://seychellesseabirdgroup.wordpress.com/2013/06/02/pisonia-grandisa-grand-problem/

Organising fossil tetrapods

For the second and final day of curation experience, I was working with a palaeontology curator and someone, I think, from the pest management team who was nevertheless also a palaeontologist. Aptly, the day's activities involved pest management and general organising of fossil tetrapods.

In the morning we finished off what yesterday's students had worked on. We were in the museum's quarantine area, inspecting a new collection that had been donated, funnily enough, by someone who once taught me. It was boxes and boxes of Triassic synapsids, the group that gave rise to mammals, including little Diictoton that would have looked something like this:

Source: https://commons.wikimedia.org/wiki/File:Diictodon-A72-01.jpg

 The boxes were very well organised, though we had to swap out most of the packing material. Over the long term, things like fleece wrap and South African newspapers from the 70s don't make good packaging because they can break down, release chemicals that can harm specimens (most paper is acidic) or be eaten by pests. Another part of the job was looking for said pests. They might not be able to eat fossils, but just having them in the same building as more edible materials is risky. Fortunately we only found a few, and those were very dead, so the collection was pronounced clean and hauled into the museum proper. It's currently languishing in a sub-basement, on shelves and pallets lest there be another flood, waiting for shelf space in the proper stores. But at least its new packing materials will keep it safe.

The proper location for Triassic synapsids is a cupboard in the palaeontology building that a previous curator had instead filled with moas.

Classic moas vs. eagle. This eagle had a wingspan just shy of three metres.
Source: https://upload.wikimedia.org/wikipedia/commons/2/2d/Giant_Haasts_eagle_attacking_New_Zealand_moa.jpg

 These were quite important, though often not much to look at: they were all type or figured specimens. Figured ones have been illustrated in a publication, so should be publicly available for anyone to see. Type specimens are very special. These are the specific objects that carry the name of a species. The type specimen of an organism represents that specimen in the eyes of taxonomy, and is what you'd use to identify a specimen if you thought it was of the same species. Unfortunately, many extinct species were defined on just odd scraps of bone. Fortunately, that means they fit in museum drawers.

Moa sizes. Summary: would not fit in drawers.
Source: https://commons.wikimedia.org/wiki/File:Dinornithidae_SIZE_01.png

 The previous curator had collected together all of the type and figured moa specimens into one cupboard, so that if the building was at risk (it apparently floods alarmingly often) someone could quickly rescue them all, rather than having to search through dozens of cupboards and over a hundred drawers. But that one cupboard happened to be where the Triassic synapsids should have gone, so we spent the afternoon emptying out the moas and squeezing them back in their original drawers.

After we'd finished, we stood back from this cupboard and realised that there was no way the new fossils could possibly all fit in there anyway. But the collection was a little more organised than before. Success.

Organising a herbarium

Today was day one of curation experience. We effectively became volunteers, helping out with tasks to get an idea of what the job is like. I was in the flowering and seed plant division of botany today. After a brief tour, I spent the morning sorting out herbarium sheets a bit like these:

Source: https://commons.wikimedia.org/wiki/File:Joseph_Banks%E2%80%99_herbarium_sheet,_Treasures_Exhibition,_Natural_History_Museum_08.jpg

Each specimen should be representative of the plant. Very small plants can be pressed whole, but for anything bigger than a miniature daffodil it's usual practice to just sample a twig or branch, incorporating a leaf, stem section and reproductive parts. Often, any flowers are pressed on the sheet and fruits and seeds are stored loose, either in a little envelope stuck to the sheet or in a separate box for the big ones. One of the biggest seeds in their collection is the scandalous Lodoicea maldivica (worthy of an image search); that clearly wouldn't dry flat. The NHM has certainly hundreds of thousands of the sheets, probably more, with some dating back to about 1700. But these aren't the oldest: those sheets are stored in another part of the building, in the historical collection, and they date from more like 1550. Fortunately, the sheets I was manhandling were only on the order of decades old(!).

The herbarium had been housed in the Waterhouse building until 2008, the building you probably think of when you imagine the NHM, then moved to the Darwin Centre. Rather than just move the collection across, the curators decided it would be a good opportunity to update their classification system. It's primarily based on taxonomy, which for many organisms underwent massive changes when molecular phylogenetics came on the scene. Flowering plants were no exception. There are still specimens that have yet to be put away in the correct cupboards, though whether most of them are left over from the move or just new specimens coming in I'm not sure. So, our job was to look up the family and genus of these lost souls in the museum's shiny mostly-taxonomically-correct-for-the-time-being index and write, in very careful handwriting, an index number on each that designated which cupboard it belonged in. Handwriting really was crucial: just reading the information labels is a skill in itself, especially with elaborate old-timey cursive.

After lunch, we did another curator a big favour by sticking hand-sized blocks of foam in the backs of cupboards. Unfortunately, these (many many many) cupboards were the wrong size. As you removed stacks of herbarium sheets in their paper folders from the cupboard shelves, the corners could very easily catch on the metal rim of the door, causing a surprising amount of damage. After much deliberation, they decided that the most reasonable solution was to stick these foam blocks behind where the folders sit, shoving them forwards by a centimetre or so, so they don't slip behind the metal rim. But this wouldn't work for the top, bottom or very middle shelves because the sticking-out folders would then stop the door from closing. To make matters worse, the cupboards are stacked, so each line contains two rows. The top row needs a stepladder to get to. Because the folders require very careful handling, a lone curator would need to climb the ladder, take out one shelf's worth of folders (with ten shelves per cupboard), climb down the ladder, put down the folders, climb back up the ladder with the foam, stick the foam in the back, climb back down the ladder, pick up the folders, then climb back up, put the folders away and start again. Because there were six of us we could do this in pairs, the extra hands making a real difference. It was actually great fun.

Finally, we watched a demonstration of the exciting upside-down herbarium scanner, used in their massive digitising project. The NHM is home to a huge number of type specimens, the individual organisms that represent their species. Researchers from all over the world can ask to see the type specimens, usually to help with identifying their own specimens and seeing whether things might be new species. Digitising makes high-quality images of specimens available over the Internet, so researchers don't need to fly across the world to see them. There's been an ongoing project to digitise all of the botanical type specimens for several years.

You can get high-quality scanners easily. The problem with herbarium sheets is that the plants often aren't attached to the paper very well, so turning them upside down is the stuff of botanical nightmares. Someone at Kew solved this problem by building a rig where the sheet sits on a foam platform that can be raised up towards an inverted scanner. They patented it, sold it at very high prices and are apparently now very rich indeed. Unfortunately, to be contrary, the NHM uses a slightly bigger sized herbarium sheet than Kew (and indeed, the rest of the world), so sometimes you need to scan the same specimen twice to get both the top and bottom. At the time of writing, 136,775 NHM specimens have been digitised and uploaded to the JSTOR library (http://plants.jstor.org).

Tomorrow I'll be in palaeontology. They have recommended we wear clothes that can get dirty. Should be fun!

Spotted

My normal routine is to catch a very early off-peak train and spend the first part of the morning in the university library, before lectures start at the museum. The library is currently undergoing some building work. I assumed that a student was behind this nice addition:

...but since the university suffered a rather scathing report into equality and discrimination recently, I'd like to think it was a senior manager turning over a new leaf.

Meanwhile, in a dusty corner of a museum courtyard, I found these:

I imagine some poor grad student spending hours and hours scraping all of the fungus off the world's largest arachnid.

Back to the museum

I'm very happy to be back at the NHM this week. My commute is an hour each way instead of two, and there's no hanging round for the best part of another hour waiting for transport. I was last here in December, and there have been some changes since then.

The Hintze hall (the main bit) is mostly closed off for the dismantling of Dippy and, erm, mantling of the blue whale:

Note the blatant disregard for rules that a staff badge brings

The tunnel isn't huge, so staff are strongly encouraged to take alternative routes across the site. This means I've been exploring the basement between lectures. There are maps on most junctions. It's not unlike Ikea.

Someone was about to come through those doors. I took this, shoved the camera into my pocket and tried to act natural, not like a weirdo who takes photos of basements.

Plus, one of the many many cafes has been re-done as "The T. rex Grill". I was pleasantly surprised to see the correct name format, at least on the web page, though not the banners. A palaeontologist said last term that there was a debate going on among the staff over whether the decoration should have a feathery T. rex or not. It doesn't. But I suppose that's still open to discussion.

 

Staff member anonymised by a generic basal ornithopod, who is far too boring to ever have a grill named after it.

In other news, this week's topic is palaeontology. There's still some difficult computing but the lectures have been good. Last year's class went on a field trip, but this year there are over forty of us including visiting students from the other campus (their turn to take a bus) instead of seven, so that's out. I'm not disappointed. It would probably be more than a day and I have a strong history of hating fieldwork.

Instead, I've been in contact with a palaeontologist friend who runs fossil walks at the very same site. I'm hoping that the dozen or so of us interested can get down there for an unofficial field day with no write-up. Organisation will be a challenge, but the course hasn't been perfectly organised so far so I like to think we have low standards.

Finally, a strange biological phenomenon: a collection of fresh insect bites up my leg. In January. It's either global warming or fleas.