Airport skylark survey

Airport skylark survey 2012. Photo by Mick DrydenOn Wednesday, 27th June, we conducted our annual survey of the skylarks Alauda arvensis and meadow pipits Anthus pratensis at Jersey Airport. This is one of the hardest monitoring exercises we undertake each year as, even after we’ve gone through security clearance and been scanned before going out onto the grass, we have to trudge through the long grass left by the airport’s management regime. The airport is obliged by law to manage its entire site to dissuade large birds from coming into proximity of the aircraft and the length of the grass throughout the area is very important. All bird-friendly plants are discouraged too but strangely both skylarks and meadow pipits seem to thrive here. In fact, Jersey airport is now the major site for breeding skylarks in the Channel Islands.

27-6-2012. Photo by Mick DrydenThe skylark team, Tony Paintin, Mick Dryden, Hester Whitehead and Glyn Young set out to walk in a line the grassy areas of the airport either side of the runway but must be very visible at all times and keep in radio contact with air traffic control throughout. There are very sensitive areas that the team cannot enter and we all have to withdraw to a safe point when an aircraft is landing, taking off or taxiing. Quite what passengers and air crew think of the team sitting patiently in the grass is anyone’s guess!

Airport skylark survey. Photo by HGYoungWe walk out in a line and record each lark and pipit, typically flushed from under our feet or high above our heads singing. It is pretty obvious though that the larks can land in the grass and not budge as we walk past (or over?) them. Whatever the failings in our technique are though, we have used the same methodology since 2006, and we are beginning to see a trend in numbers developing. This year we counted 30 larks, our lowest figure but future counts will show the exact significance of this more clearly as in other years, particularly 2011, we may have recorded young birds of the year whereas this year the weather has been so bad that there may have been little breeding or the season may be delayed.

Once again we are indebted to the airport authorities for allowing us to count the birds and for helping with security clearance and for providing radios and high-visibility vests etc.

Date

Singing males

Flushed birds

Total

skylarks

Meadow pipits

15th June 2006

14

22

36

5

12th June 2007

12

22

34

8

5th June 2008

14

50

64

16

24th June 2009

12

32

44

2

9th June 2010

12

34

46

3

27th July 2011

4

85

89

32

27th June 2012

9

21

30

21

 

Chough report: May 2012

On the 1st Issy laid a fourth egg and remained sitting on the two dummy eggs and one real egg. This was the last egg of her clutch. During the incubation period the choughs managed to reposition the camera obscuring the view of the nest. On the 21st it seemed as if the birds were taking insects to the nest, but there were no observations of the parents feeding. Over the next two days their foraging time on the ground increased and there were more trips to the nest.

The keepers checked the nest on the 23rd by opening the hatch at the side: one chick was seen along with the two dummy eggs and one real egg. The chick was accessioned as B7021 and named ‘chick A’. A photo was taken at the nest and sent to Paradise Park who estimated the chick to be three to four days old.

Chough 'chick A' with 2 dummy and 1 egg May 2012. Photo by Liz CorryThe keepers continued to give several ‘chick feeds’ each day using a variety of insects including ants and ant larvae. On the 27th the keeper discovered the dummy eggs, hatched eggshell, and a cracked egg at the front of the aviary and it was assumed the parents had just cleaned out the ‘debris’ from the nest, as some birds do, and continued with the  feeds. However, two days later both birds were out of the nest-box preening first thing and not showing interest in insects. The inner lining of the nest was spotted at the back of the aviary so the keeper went straight to the nest box to check. The nest was empty and a search of the aviary found the decomposing body of chick A at the very back on the ground. The body was submitted for post mortem; however, it was too autolysed for useful examination.

The two eggs placed in the artificial incubator at the end of April were monitored closely through weight loss graphs and egg candling. Initially the eggs were set at 37.6°C and 50% humidity, but the eggs were not losing enough weight so the humidity had to be reduced accordingly. A passerine egg should lose approximately 15% of its initial weight when laid by the time it hatches. It is possible to calculate how much weight an egg should lose each day if the incubation period of the species is known.

On the third day of incubation the eggs were candled and found to be fertile because blood vessels were visible. However, they continued to struggle with weight loss throughout the incubation period. On the 14th the eggs were candled and placed in an egg heart monitor machine and both confirmed to be dead. A post mortem showed that both eggs had suffered early embryonic death. One egg was noted to have a haemorrhage around the embryo and suspected trauma indicating blood loss as the cause of death.

Arthur will nicely healed bill, May 2012. Photo by Liz CorryArthur and Gwinny continued to show little interest in breeding. They would occasionally move twigs around in the nest-box but spent most of their time away from the nest. Arthur’s bill has healed well and now both upper and lower mandibles are the same length.

Captive breeding at Paradise Park

Paradise Park have parent-reared three chicks this season; two chicks from one nest and a single chick from another. The chicks are due to fledge in June. Another nest has failed this year, probably through naivety of a new pair and heavy rain during incubation.

Display flock at Durrell

Nothing of note has occurred with the display flock this month.

General notes

Both adult chough pairs continue to show an interest in the cameras. Tristan and Issy spend a considerable amount of time attacking their camera and we will look at addressing this next season. We do not have access to software to view back any footage recorded from the camera and this too will also be addressed in time for next season.

Rare orchid found

Bee orchid. Photo by Tim WrightThe first record of a bee orchid Ophrys apifera in Jersey was in 1912. Following that there were only four records, the last in 1947, all from Les Quennevais and St Ouen’s Bay. In 2005 some visitors to the Island sent a photograph of a bee orchid to the Eric Young Orchid Foundation that they said they had found in St Ouen’s Bay but were unable to say exactly where. Local botanists have tried to locate the plants every year since but only succeeded in June this year when Tina Hull and Anne Haden found three bee Bee orchid. Photo by Anne Hadenorchid plants north of Le Braye slip in St. Ouen’s Bay. The bee orchid is a protected plant inJersey.