Stratford Park Biodiversity Newsletter. April 2013

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1 Stratford Park Biodiversity Newsletter April 2013 Hi All, As the end of March approaches, winter refuses to release its icy grip on the park. Despite this there have been glimpses of spring. Last month we placed nesting material on the island for our pair of resident swans and they have now built their new nest. Adrian Watts and I were lucky to observe our two swans on the lake, engaging in their courtship display which was absolutely fascinating to watch. A successful encounter no doubt, as the female bird is now sitting on eggs. The mortality rate for our young swans is quite high. Some succumb to predation soon after hatching, some are accidentally washed over the river waterfall and occasionally they are taken by predators. Despite this, each year the park usually sees 3 swans reach maturity. Even when the birds reach the juvenile stage their troubles are not over because the following year as another breeding season approaches, the adult swans become very territorial and will drive the young swans from the lake. After a few weeks the young swans will wander in an attempt to leave the park and this creates new dangers for them, mainly road traffic. When the birds become anxious and a danger to road users they need to be relocated. Adrian has had previous experience with swans and ducks from previously working with the Wetlands and Wildfowl Trust, so it s left to him to relocate them. In this month s newsletter you will see a picture of park staff with their annual catch. Elsewhere in the park the momentum of spring and warmer weather is eagerly anticipated by the writer, and to another season of new discoveries and

2 Observations. Our first bird walk is scheduled through the Museum in the Park this month by which time birds will be in abundance as the nesting season is in full swing. Enjoy the park this April. Mike News from the Supervisor s Trap Giving the Swans a helping hand Stratford Park receives many thousands of visitors each year and most of these will walk around and enjoy its beautiful lake. There is no doubt that the swans are the main attraction along with the large number of Mallards which exploit a never ending supply of bread and other scraps. For many decades there has always been a resident pair of Mute swans on Stratford Park Lake. As Royal birds they are afforded special protection but this does not always help them when they are sometimes subjected to vandalism and cruelty. In these instances it is usually a lack of education that causes such mindless acts. Thankfully, these occurrences are infrequent and isolated and by and large, the birds remain safe and are enjoyed by the many visitors who come to the park each year. As staff working in the park 12 months a year, we see the full breeding cycle of swans on the lake, their habits, ecology and behaviour. Mute swans are relatively adaptable birds but require large areas of water to feed and exercise. They also require safe and secure areas to nest and raise their young. As the lake has gone through several structural and aesthetic changes during the last 40 years, their natural nesting sites have been lost. Pre-1970s the present concrete retaining wall which encases a sewer pipe was a natural grass bank with vegetation. This provided the swans with nesting sites. Since the construction of this and the removal of extensive reed fringes, the swans have lost all but one nesting site the small island on the lake. However, even here there is no suitable vegetation to construct a nest and this is where park staff plays their role in helping the birds. Every autumn during annual hedge and shrub maintenance, staff cuts back the ornamental grasses by the leisure centre and store this during the winter to provide nesting material for the swans each spring. This is placed on the island in February and March where shortly afterwards, the swans use it to build their new nest. It s clear to say that without this material the swans would not breed and therefore a new brood of swans would not be produced. When this material is not available the swans will be seen scratching and pulling at any piece of vegetation that is around them. The frustration in them is clear to see. Getting the material to the island is another challenge, and staff have to negotiate the material over a ladder (see photo). The birds will start using the material and build a nest with

3 out hesitation and once eggs are laid the female bird will incubate these for a period of around 35 days. It is crucial that she sits on the eggs during cold and wet weather, and will only leave the nest to feed. The spring weather of 2012 was exceptionally wet and as a result of this 1 egg from that year s clutch remained un-hatched. The eggs are large one of the largest of British birds. We removed this egg from the nest at the end of the nesting season which is photographed (below). On hatching the young cygnets take to the water and will often travel on the backs of the adult swans. There is another problem facing the small cygnets; due to the slippery mud around the island, they have great difficulty scrambling back onto the nest. This proved fatal for one cygnet in Whilst trying to climb onto the island, one of the adult swans became territorial and killed the young cygnet. Park staff then constructed a small wooden ladder which now provides a safe and easy access ramp onto the island. As mentioned mortality rates are high, and the first two weeks are crucial to survival for the young birds. Marauding dogs, Herring gulls, adverse weather and other factors all play a part in the fate of small cygnets. Once the cygnets grow past the downy stage, they are relatively safe and will mature to adult birds throughout the summer and autumn. The juvenile swans can be quite feisty when approached, although over time they start to recognize park staff. When the cycle of growth is completed they will be driven from the lake by the parent swans and will then start another brood. At the time of writing our swans are sitting tightly on eggs during one of the coldest March months for 50 years, and this time last year we were soaking up 22 degrees. Relocating a juvenile swan Adrian negotiates the island with nest material

4 Adult swan sitting on eggs an infertile egg from last year s clutch (All photos: Mike McCrea) Apple trees for the Park On a cold morning last month members of Transition Stroud joined park staff to plant new fruit trees along the top fields. A total of 12 apple trees were planted in rough grass along the top perimeter. 2 greengage trees were planted in the orangery and 2 cherry trees planted in rough grass adjacent to the outdoor sports pitch. As part of this year s edible Britain theme for Britain in Bloom, it ticks boxes for the park and its biodiversity.

5 Cold weather affects wildlife Everyone reading this newsletter will be well aware of the recent cold weather experienced throughout the UK. The weather has dominated the news everywhere during what has been the coldest March since 1947 and now, officially the coldest Easter on record. In comparison to the northern part of the country, we have not experienced the ice-age conditions, snow and winds that have caused those regions unparalleled disruption. Although these extremes of weather hit us all hard, it hits wildlife harder. As someone who has grown up through many seasons at the park, never before have I known a colder spring. For the first time ever, my moth trap has not left the sanctity of its storage box once since January 1 st. normally I would have at least 7 weeks recording under my belt and a good park list building up. In comparison last March we recorded Hummingbird hawk moth in the park and record numbers of resident species were being recorded every night. Of our hibernating species of butterflies, only Small tortoiseshell has been seen this spring. Although our butterflies and moths are adaptable to weather trends and can bounce back over time, I really think that this prolonged cold spell will have a damaging effect which will see a large decline in even the commonest of species. Nesting birds are also suffering. This year there is no where near the activity seen last spring in our nest boxes throughout the park, as small birds delay breeding due to a shortage of insect food. Although Nuthatches have been numerous in the park this month, they have not been seen investigating the boxes. Last season they were mudding up their nest holes in late March. Mallards on the lake and along the river are just not laying eggs. Even our resident little owl has disappeared, all very concerning. Let s just hope that the weather for the second half of April warms up enough for wildlife to recover. To conclude I did have a glimmer of hope on April 3 rd when a sunny afternoon saw celandines reaching out for some welcome sun on a bank by the sports pitch (back page) and a Blackbird was sitting on a nest in our works compound. (See photos below). Blackbirds next with eggs in the works compound Hungry chicks hatched on 10 th April

6 Little owls update In the previous feature of this newsletter I mentioned that our owls had disappeared during the recent cold weather. I was therefore pleased to see the male back in the walnut tree on the morning of 11 th April. I was delighted the next day to locate along with Adrian Watts, the female owl in the adjacent oak tree. This is very encouraging as the owls start nesting next month. That both birds are back in the park and appearing in good health could hopefully be a prelude to breeding. We know that the birds have not yet selected a nest site as they have been seen fighting with Jackdaws for cavities in the walnut tree. The female was spotted very close to the owl box in the oak tree, so I intend visiting the park at dusk over the coming month to monitor their movements more closely. Whilst weeding by the Bowling Green recently, I was amazed at how tame the park s robins have become. They have been exploiting the free food that we are digging up, especially worms. At times the birds were coming within 2ft of us and one morning I was able to catch one on my phone (below). Robins are currently doing well in the park and we have located several nest sites. They are mainly concentrated around the shrub beds by the bowling green and leisure centre where they fiercely protect their territories from other birds. At the time of writing Greenfinches are also showing in good numbers around the Bowling Green and can be seen calling from the tops of the conifers there.

7 Wildlife to see now in Stratford Park Birds: Common Buzzard (over the woodland), Little owl (on the main field) Green woodpecker (A pair on the main field most days), Great-spotted woodpecker (woodland very vocal at this time of year), Treecreeper (around the orangery and woodland fringe), Nuthatch (Showing very well this month and can be heard calling in the woodland and around the orangery), Greenfinch & Goldfinch (both around the Bowling Green). Other birds nesting around the green Dunnock and Robin. Kingfisher (lake) Song thrush, Mistle thrush Blackbird (all throughout the arboretum). Butterflies: The season has started late for spring butterflies. Only Small tortoiseshell has been seen. EVENTS Bird walk in Stratford Park Sunday 21 st April 9.30am (Meet at the Museum) Further information visit CONTACT: Mike McCrea Tel: USEFUL LINKS: (British Trust For Ornithology) (The Amateur Entomologists Society) (Celandines by the woodland a welcome sign of spring)