As spring slowly brings our nature reserves to life you may spot these tiny mounds of earth in the grass or on patches of  bare earth. They are the nests of the Tawny Mining bee which build their nests at this time of year. The nest consists of a vertical shaft 8-12 inches long with several brood cells branching off. The female fills each cell with a mixture of nectar and pollen on which she lays one egg. The larvae quickly develops and begins pupating, to emerge as an adult the following spring.

This all sounds like a good plan however we are not the only ones who notice these nests! Bee flies are notorious for flying over the nests and flicking their own eggs in to the entrance. These eggs then develop into maggot like larvae which wriggle in to the prepared cells to continue developing in comfort. Cuckoo bees, Nomad bees and many solitary wasps have also developed strategies to exploit the Tawny mining bees nest sites. The picture was taken Barnwell West nature reserve.

Spring is definitely on the way, you can hear it!

Not just the sound track of the birds establishing territories but also the friendly hum of Bumblebees.

This time of year it is the queens that you will hear as they emerge from hibernation to start a new colony.  They wake up hungry and thirsty and therefore it is vital that they find early flowers to feed on. The newly emerged queens eat both nectar and pollen. It is actually the pollen that helps her ovaries develop in preparation for all the worker bees she will give birth to. She continues feeding and sheltering at night near the food plants until her body signals her that it is time to find a nest site.

Nests can be underground in disused rodent holes, under sheds or compost heaps. The Tree Bumblebee(Bombus hypnorum)shown in the picture prefers to nest higher up in hollow trees, bird boxes or maybe a house loft. This species is relatively new to the UK, it has been steadily spreading from the European continent and parts of Asia since the start of the 21st century. These Bumblebees prefer habitats that others do not, allowing them to pollinate flowers in areas that many other species do not get to. This has helped with their growing establishment and success.

The city’s waterways seem an unlikely habitat for finding otters in but as always nature can surprise you. Working with the Wildlife Trust the city’s nature reserves were surveyed for otter activity with very pleasing results. Spraint was found at 9 Wells, Logan’s Meadow, Stourbridge Common and Coldhams Common.

According to the Wildlife Trust just 15 years ago the otter population had almost disappeared around Cambridge. But since then the numbers have been steadily rising. Survey statistics gathered from Wildlife Trust staff and volunteers, the Cambridgeshire Mammal Group and the Cambridgeshire and Peterborough Water for Wildlife project have found evidence of a significant increase in Otter numbers.

The Otter survey carried out on the city’s nature reserves was part of a larger initiative which was surveying the whole of the county’s waterways and tributaries. The results are being gathered and will hopefully reveal a similar trend. It is certainly an optimistic picture for Cambridge city.

If you are interested in this project more information can be found at the Cambridgeshire and Peterborough Water for Wildlife Project- 01954 713555.

Since May last year volunteers have been monitoring Cherry Hinton Brook’s River fly larvae populations. Riverflies are an important indicator of the overall health of a water system. Using a monitoring system developed initially by Anglers,  then refined by the Riverfly partnership,  it has been amazing to see what life is present in the brook.

The need for monitoring became apparent after improvements were made to the stream but with no real way to measure the impact these changes had potentially had. Alongside the Riverfly populations the stream’s health is also monitored for other important elements such as: dissolved oxygen, temperature and PH. The aim is to try to build up a picture of the brook’s condition and how well it supports aquatic life.

The monitoring is carried out by volunteers. Their work  not only provides valuable data but also gives them the opportunity to become familiar with their local stream and what lives in it. If you would like to join in with this exciting project please email: parks@cambridge.gov.uk

 

A recent partnership with CPARG (Cambridgeshire and Peterborough amphibian and Reptile group) has reaped some invaluable pond improvements for the city’s nature reserves. Working firstly at Barnwell East pond, as this is one of the city’s most important common toad breeding sites, the volunteers removed overhanging willow and created a large hibernaculum. CPARG are planning to survey the site this coming spring to get an idea of toad numbers. Next to receive some attention were the ephemeral ponds located at the back of Stourbridge Common. The Friends of Stourbridge Common also pitched in offering some important local knowledge about the ponds and associated fauna. These precious seasonal ponds are a welcome haven for our toads but also popular with grass snakes and smooth newts. Finally the pond at Logan’s Meadow reserve was looked at and it’s drainage problems hopefully solved. If the levels of water can be a little more sustained we may see smooth newts breeding there this spring.

If you are interested in doing some volunteering for CPARG or Friends of Stourbridge Common their details are as follows:

CPARG:

candparg@googlemail.com

www.facebook.com/groups/CPARG/

Friends of Stourbridge Common:

http://www.facebook.com/group.php?gid=193283709830&ref=ts

General advice for Amphibians and Reptiles:

http://www.froglife.org/advice/FAQs/index.htm

http://www.arc-trust.org/advice/