Sociable

Saturday, 24 August 2013

Health Check and Vegetation

The longer you leave it, the the harder it is to return, but here I am, back at the blogging.


Here is an ink cap, the first I have seen here this autumn.



The branching bur reed (Sparganium erectum) is a common aquatic plant, but I was delighted to see it in the temporarily dried out bit of the big pool in the Wet Wood. It is the first time I have seen it, and so much of it at that, in that area.





The beavers of the Wet Wood are very active now, preparing for winter. This ash (Fraxinus excelsior) was cut earlier in the year and has pushed out abundant coppice shoots, which have be browsed by roe deer.





Our most momentous event took place here in the first days of August, when the RZSS team came to do health checks on beaver here.

This is the article I wrote for the September number of the 'Alyth Voice'.


The swifts flew out one day during the first week of August. That is their wont and it marks the beginning of the end of summer. 

A day or two before the departure of the swifts the Royal Zoological Society of Scotand team came to Bamff on behalf of the Tayside Beaver Study Group to carry out health checks on any of the beavers here that had walked into their traps.  The chip shed had been prepared for the examination: the BBC crew that came to film for the One Show was in place.

'The first beaver to oblige was presented for examination on the 3rd of August. He turned out to be a young male of around 12kg. The high spot of the examination was a laparoscopy to study his liver. There has been some anxiety in official quarters that the beavers in the Tay might might be sources of a tape worm (Echinococcus multilocularis) that has been making its way through Europe. 

After the animal had been brought to the operating table ( it had been caught the previous day and spent the night in a beaver proof pen) and anaesthetised, the vet, Dr. Romaine Pizzi, carried out various procedures, including an ultra-sound scan, and then the laparoscopy. To do this, he cut away the belly wool. Then, after swabbing the area where he was to make the insertion, he made a small cut through the abdominal wall of the beaver and inserted a trocar ( a hollow pipe with a sharp end) and inserted his camera laparoscope through it. The monitor standing next the operating table now revealed live video of the internal organs of the animal. The liver was its proper clean purply  brown (so, no sign of infection by that worm which damages the liver seriously), and between the lobes he pointed out the spleen. As Dr. Pizzi moved the laparoscope around we could see clearly the large intestine. He pointed out the pelvis and the spermatic cord and, when he moved the camera up, we could make out the pulsations of the beating heart. All this was fascinating, made even more so by the commentary as Dr Pizzi answered questions that the interviewer from the One Programme asked. I was impressed above all by the sensitivity and respect with which Romaine carried out his work on the living animal, pointing out interesting adaptations that beavers had evolved to carry on their aquatic way of life. Apart from the laparoscopy, samples were taken of blood, faeces, anal gland secretions (this last for sexing the animal) as well as castoreum. Once all this was over, the mask which delivered the anaesthetic was removed from the beaver’s muzzle and the animal recovered consciousness. It was carried to the pen and left for a few hours to recover before being returned to its wetland home. 

The next day another beaver that had walked into a trap came in for its health check. Judging from his size and colour, I think he may well be the male that came to us from Bavaria in 2004. The same procedures were undertaken and, once again, we were excited to look at the insides of a living animal: the healthy liver, the gentle peristaltic movement of the large intestine with its branching networks of blood vessels. As on the day before, we looked at and handled the scaly tail of the animal and studied the webbed hind paws with the split nail that enables beavers to groom themselves so carefully. The beaver’s tail stores fat for the winter as well as being used as a rudder and diving plane with occasional use for propulsion. Both animals had fed well through the summer and their tails felt firm and strong.

Once the checks were over, the animal was awoken and, after giving him some time to recover,  was taken back to the place where he had been trapped, and released. This beaver, an adult male of 22kg, needed no persuasion to leave the carrying crate in which he had been moved and disappeared quickly into the waters from which he had come, leaving a trail of bubbles behind him.' 


Here are some of the photographs I took at the time.


Milking the anal glands for their secretion. Colour and consistency give a reliable indication of the beaver's sex.





That scaly tail - how did I miss the tip! 



Fur cut away before the laparoscopy.






The dense underfur that so nearly proved the undoing of the species.




The veterinary surgeon at work.




The monitor shows the healthy liver and spleen.




A length of large intestine.





Back to the water!

Thursday, 1 August 2013

A dry spell for a change! Izzy Tween, a fourth year student from St.Andrews, came to survey the invertebrates of the beaver pools in the Burnieshed Burn. She needed a comparable ditch as a control, so I suggested the only ditch that is comparable.

Here are some photographs of the ditch that runs from the ditch that runs along the north side of the Burnieshed field. These photographs were taken when it was already fairly dry - 2 June.








And here are some photographs of the corresponding stretch of former ditch inhabited by beavers on the south side of the Big Burnieshed Field, as we call it with our creative imaginations:


This photo was taken on the 2nd of June, already a time of drought.


As you see from the foxglove on the right, this photo was taken in July.



As was this.

Starting to post again after a gap of more than a month is difficult: so much has happened it is hard to know where to begin.