Saturday, 27 February 2016

The Nightjar project, from the summer of 2015

As a third year student at The University of Nottingham, I have been studying the impact of human disturbance on the breeding of the European nightjar (Caprimulgus europaeus). In the summer of 2015 we surveyed the recreational trail usage in the forest, the wildlife abundance, and breeding success of the nightjar. The surveying of the trails was carried out by myself and a masters student Jack Rayner under the supervision of Dr. Kate Durrant, while the monitoring of nightjar breeding was led by the Birklands Ringing Group.
A little friend we met on one of our surveys
We spent June and August surveying the forest and monitoring the nightjar from around 7am until anywhere between 7pm and 11:30pm five days a week. We cycled around, with our food for the day packed in our bags, and a rake threaded between our rucksack straps. The looks we got from local cyclers was quite amusing, wondering if we were hopelessly trying to garden the forest of Sherwood Pines. We spent half an hour at each survey point, counting all the traffic passing, and the wildlife spotted. The rake was used on the earth paths to track any traffic crossing paths over a 24 hour period, rather like Sherwood Pines CSI. The rest of the time we spent cautiously searching for nightjar nests, and ringing the chicks born in that season. If the weather was suitable, we would set up nets to catch the birds at around 7:30pm. It was fantastic on those evenings to hear the nightjar males making the churring territorial call, and watch the nightjar gliding past us before being caught in the net. The caught nightjar could then be identified, and carefully released back to continue their evening hunt. I thoroughly enjoyed carrying out the field work, and was inspired to find out what is affecting the distribution of these birds.
One of the many bees that were pollinating the heather in
the forest
In previous years from 2001 to 2014, the nightjar of Sherwood pines have been shown to prefer a breeding habitat incurring less frequent human disturbance, however in 2015 we found the nightjar have shown no preference between more or less disturbed areas of the forest. Furthermore, in 2015 there has been a higher portion of nests that fledge chicks, as well as an altogether greater number of nests going on to fledge chicks in areas incurring higher levels of disturbance. Through wildlife surveying we established that predators threatening nightjar breeding such as Corvids and Birds of Prey live in greater densities in the area of the forest incurring a lower level of disturbance. Corvids predate on the nightjar nests, while the Birds of Prey are thought to predate on the adult nightjar. This difference in risk of predation could provide explanation for a lower success in nightjar nests.
A moth we came across quite frequently, not sure which species though? (Please comment if you know!)

A mother nightjar, who is rather  insulted at being disturbed from her afternoon nap

The same mother nighjtar, whatching us with a glaring eye
Historically, nightjar have been shown to be less successful in breeding where human disturbance is greater. In recent years however, we may have found that the nightjar in this forest may have become more habituated to human disturbance, impacting the consideration of the suitability of nightjar habitat in the future.
A buzzard in the early morning, keeping a careful eye on us at work. 

After seeing that Jack and I were carrying out the surveying well, the buzzard left us for more important duties for the day

To Find out more, please take a visit on the Sherwood Pines website!

Thursday, 25 February 2016

The Crafty Cormorant

Last week I took a visit to the university lake where I met a Great Cormorant. His face looked like the cross between that of a dinosaur and a gnarly troll. Given that previous description, it seems impossible for me to like this bird, but given his crafty and wily nature, his phenomenal resilience, and incredible hunting skills I could not help but enjoy the company of this prehistoric animal.

I first caught sight of the cormorant at the side of a lake, basking with his wings welcoming the sun. It is easy not to wonder why the cormorant undertakes the task of drying his wings, but I could not help but think this myself. As his looks would suggest, the Great grey Cormorant is one of the most prehistoric species, along with the Shags. Unlike the more recently evolved water bird species, the cormorants have not evolved a waxy coating on their feathers, and so understandably will get rather wet after a hunt for his fish or whatever meal is available. After becoming sodden from a hopefully successful attempt to catch dinner, the cormorant will stand on a perch for an hour if needed to dry off any water that may not be shaken off. While this characteristic is reasonably interesting, the wing drying behavioural quirk provided scientists with the ability to carry out an experiment revealing something rather more intriguing.
One of the Coromorant standing minding his own business

A cormorant looking back very disapprovingly at me after folding back his wings, and ceasing
to dry his feathers
Recent research has been undertaken to study the migration behaviours of Roach fish. Through use of the cormorant feeding behaviour, evidence has been gathered to demonstrate the reasoning behind migrations. Once a cormorant has caught a fish, he will regurgitate spit balls at the perch on which he is drying his feathers on. If a fish has been pit tagged (a form of microchip-like identification), all morphometric measurements can be taken of that fish, and so we can understand what size fishes are being eaten by the cormorant. It was found that fish spending more time outside a lake would be less likely to be eaten by the cormorants, but will also be less likely to find plentiful food. In addition to this, it was found that the bigger fish were more likely to get caught. Using this information, and the information of when the fish left the lake to migrate, they found that when the risk of being predated outweighed the food benefit provided by a lake over another stream, the fish would leave the lake. Bigger fish were more likely to leave the lake, and especially so when predation pressures were high and less food was available in the lake.

While the cormorant is currently causing great concerns with regards to impact on current biodiversity, given past distributions I cannot help but admire the resilience of this species. Historically, cormorants were regarded as an irritating competitor for fish by fishermen, and so were nearly hunted to extinction. Since, the Great Cormorant has escalated in numbers to the 1.2 million individuals in Europe today. The Great Cormorant is now thriving in the UK, and now the species is predicted to cause incredible changes in our aquatic and terrestrial ecosystems. There are great concerns over the impacts that cormorants may have on ecosystems, with relocation of matter and microbial agents between ecosystems, and the possible food web modifications that may follow the cormorant’s population growth. It is true that in the future we may need to control cormorant populations, however it is still fantastic to see such a prehistoric creature on our doorstep, and I thoroughly enjoyed admiring the bird in the sun all the same.

This isn't much to do with the blog, however I did think the gulls looked 
brilliant sitting in a line along the concrete posts

Saturday, 20 February 2016

Wollaton's Wacky Wildlife

So I have been rather quiet over the last few weeks, putting together a video from the last few months of footage I have gathered from Nottingham. I had so much fun making it, and I hope you have as much fun watching it with the few surprises I have edited in (not your normal wildlife video I promise you!)

Thanks a lot, and thank you to Fat Freddy's Drop for the music, and to the wonderful wildlife who helped create it!

Sunday, 7 February 2016

A trip to Brighton, with a mesmerising murmuration!

A starling murmuration is always a fascinating sight to see, and I was lucky enough on my trip to Brighton to see one at dusk from the pier. The wind was howling, the skies were grey, and the sea was whipping up an angry and salty mist into the air, and I didn’t want to leave as these birds danced in the sky in perfect unison. I also could not help but wonder how these birds coordinated themselves so well. Luckily, I have since found that a group of scientists has managed to provide us with part of the answer.
A Black and White of the Brighton Beach looking from the new pier
A colour picture of the beach at Brighton
A Starling murmuration is a swarm of Starlings that forms at dawn and dusk, as a mass of thousands of birds swoop through the skies. The best time to view these swarms are between November and March, all across the UK. Although piers such as the one at Brighton are particularly good for viewing Starling murmurations, they can also be seen over wetlands and farmlands, so almost anyone could be lucky enough to see one. It is simply a case of being in the right place at the right time.
A black and white of the murmuration, looking from the new pier towards the old pier in the distance
There are many theories behind the existence of these murmurations, ranging from predator defence, to maintenance of warmth, to the development of information exchange. It is well known that animals will group in large numbers as a form of predator defence, and creating these mesmerising illusions of fluidity could confuse dangerous predators such as peregrine falcons, or short eared owls. Animals are also known to gather to decrease heat loss, and to exchange information between individuals. At the moment information is being gathered on Starlings all over the country, but data is not complete enough to fully understand what is going on.
The Starling murmuration powered by the winds created by the crashing waves in the sea
The murmuration, echoing the movement of the waves
While the reason behind the Starling murmurations is not fully understood, recent research has given a fascinating insight into who coordinates the movement of these flocks. A study amazingly managed to develop a tracking algorithm to reconstruct three-dimensional trajectories of each of the individuals in the flock during a turning event. This allowed the researchers to analyse the indivitdual change in movement of each starling as the turns of the murmuration were occurring. From this, it was found that the birds on the outside initiated the steering of the entire flock. With this kind of technology that can be used to analyse Starling murmuration movement, it may only be a few years until we may understand the evolutionary reasoning behind this beautiful phenomena.

While the murmurations really were breathtaking, I can't take a trip to the beach without acknowledging the Herring Gulls that of course were in a great abundance. While they are seen as quite a nuissance by many, I find them really quite entertaining. Its great to be able to get so close to them, and meant I had a great opportunity to get some bird close-ups. Of course I may have had a very different view on the beggars if I had a sandwich in my hand I am sure! 
A juvenile Herring Gull who was sitting on Brighton Pier

An adult Herring Gull, with its mature plumage
A Herring Gull going for a stroll next to the pier, keeping an eye out for lunch