Ashy Mining Bee - Kimberley Park, Falmouth

Nature in Falmouth - Kimberley Park

The first in a series of short videos showing wildlife, flora and fauna, in and around Falmouth.

Bumblebee count No.2

My timetable and dismal weather during my free time this week prevented me returning to the bumblebee nest until a week after my last count. Not that the weather was inviting as I began walking to the site, the dark clouds suggested rain and the strong wind was cold. Not surprisingly I saw no honeybees, hoverflies or solitary bees about. Bumblebees generally shrug off bad weather, they are tough determined little beasts.

The only other bee seen was this queen Bombus
terrestris (Buff-tailed bumblebee) feeding on
heather near to the nest.

As I approached the nest the first question in my mind was, would it still be active? No one knows with certainty how long these winter colonies last. Within a couple of minutes a bee arrived and entered the nest so I began setting up my tripod and camera to film the nest.

Filming the bees entering or leaving the nest offers a number of advantages. From the perspective of personal comfort it is preferable to watch a video in the warm than stand outside conducting the count. If my comfort is of no concern, it also offers greater accuracy as the video can be replayed and examined frame by frame. Having video also offers the possibility of recounts and the availability of other people to view it.

It had rained earlier in the morning and bumblebees have a tendency not to collect wet pollen. Out of the forty bees that returned to the nest only one carried pollen. It was debatable whether the bee had collected the pollen, it was spread on its hind legs rather than rolled into a ball as usual. It returned in the last few minutes of filming and may indicated that the flower's pollen was drying out and some stuck to the hairs on the bee's leg.

The other notable observation was that one worker exited the nest but rather than flying away, turned round and re-entered the nest - see video.

Compared to last week, there were less bees seen in a similar time span. This may be due to several possible reasons. The colony size may have decreased or possibly the bee's foraging activity may have been less due to the adverse weather, wet pollen or the difference in the time of day between the two observations.

The only certainty gained by comparing both day's counting is that more data is needed. It seems I have a new task for next week's to do list.

Bombus terrestris nest - Falmouth 3rd March 2017 11.14hrs+
P/N? = unable to distinguish whether bee had pollen due to hind legs obscured 

DUR MINS	BEES IN	BEES OUT	POLLEN	NECTAR	P/N ?	TOTAL
10	6	6	0	6	0	12
13	8	7	0	8	0	15
10	5	5	0	5	0	10
11	6	5	0	6	0	11
14	5	6	0	5	0	11
11	7	6	0	7	0	13
7	3	4	1	2	0	7
76	40	39	1	39	0	79

Falmouth Cemetery: a haven for wildlife

Possibly the last population in Cornwall of the Red-girdled

Mining bee lives and nests in Falmouth cemetery.

When I discovered the old parts of Falmouth cemetery on a casual walk in 2014 I had no idea of its importance as a sanctuary for wildlife. It was clear that there had been minimal maintenance for quite some time. The County Council was responsible for the general upkeep but maintenance of the graves and monuments was the responsibility of the family. Clearly many had been left by the families to go back to Nature. As a result Falmouth had been left a legacy that contained a wide variety of wildlife.

The small copper butterfly has declined by 75% in urban

locations between 1995 - 2014. Another important

species found in the cemetery.

For the past two years I have been recording the species of wild bees to be found in the cemetery. While some species can be found elsewhere in Falmouth the scarcer ones seem limited to both living and nesting in the cemetery. Many solitary bees species only forage short distances from their nests, usually a distance of about 50-200 meters depending on the size of each species. So far I have discovered 37 species of solitary bees within the cemetery, some are rare or scare both nationally and in Cornwall.

Newly emerged Queen Red-tailed bumblebee. Raised in a nest
in Falmouth cemetery she visited nearby flowers to build her
reserves before hibernating

The key element why the old parts of the cemetery is able to support such a rich variety of wildlife are the range of wildflowers that grow in the cemetery. From early spring to late autumn they provide both nectar and pollen. The fact that the ground is largely undisturbed also benefits ground nesting species such as most bumblebees. 

The value of these parts of the cemetery to both wildlife and the local community is clearly something to be safeguarded. For this reason I have written the document you can download below. It is a guide to some of the species that can be found there together with an overview of the ecology. 

Click to Download PDF

  

While compiling my records for the old parts of the cemetery responsibility for its maintenance passed from Cornwall County Council to Falmouth Town Council. This brought about substantial changes in the way in the way the cemetery is managed. As a response I included a section on maintenance and its importance in ensuring the conservation of the wildlife in the cemetery. Having received a reply from the town council to an earlier draft I have now revised the maintenance section to reflect this.

It is my hope that this will open a debate on how best to manage the cemetery. The maintenance changes are significantly changing both the character of the old parts of the cemetery and its value to wildlife. The degree to which these are desirable are open to discussion. It is important that as many voices as possible are heard in deciding its future.

The current document should be seen as an introduction to the cemetery's biodiversity. During this year I hope to be adding more records to the list of species. I also hope to build a better picture of its butterfly species and also include hoverflies. As its flora plays such a vital part in its ecology I hope to build a seasonal list of its wildflowers. This blog will keep you up to date with my progress.

If you have any photos of wildlife in Falmouth that you would like to share you can be post them on the Falmouth Nature Facebook page or to Twitter including @FalmouthNature.

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Bumblebees - A Winter's Tale

Nature loves variation; evolution can be thought of as playing, let’s try something different and see if it works. Not only has this produced an astonishing variety of species it also results in variations within specie. Nature plays dice and making general statements is often a bit of a gamble. Quite often there are exceptions that complicate matters.

The bumblebee is a good example of this for while most have a life cycle of one generation in a year there are exceptions. Generally new queens emerge in late summer, they will mate and then forage for food to build up their reserves before digging a burrow that they hibernate in.

Upon emerging the queens feed on nectar while their ovaries mature and then begin to search for a suitable nesting site. Once she has established a nest she will lay the first batch of eggs to produce female workers. Bees can determine the sex of their eggs as fertilised eggs produce females and non-fertilised eggs males. The queens sit on their eggs and it is thought that temperature can influence the size of the workers. Warmer eggs producing larger larvae. The amount of food they consume is also likely to determine their adult size.

The queens forage for nectar and pollen to take back to the nest for their larvae to feed on. The larvae eventually spin a cocoon from which they will emerge as adult worker bees. Once enough workers have been produced to bring an adequate amount of pollen and nectar back to nest the Queen no longer leaves it.

 

Eventually the point is reached where the queen starts to lay male eggs and females to become queens not workers. Up to this point the queen has been releasing pheromones to suppress the female workers from becoming fertile and laying their own eggs. As she now wants to produce eggs that will develop into fertile queens she ceases to produce the phoromones. Without them the social order of the nest breaks down and some of the workers will attempt to lay their own unfertilised eggs to produce males. In many cases the unrest within the nest will lead to the workers stinging the queen to death.

The adult males leave the nest in search of queens to mate with. With their own nest in a state of turmoil they are homeless and fend for themselves. If on a rainy late summer’s day you see a wet bedraggled bee it is likely to be a male. In their search for newly emerged queens from other colonies they can travel up to 10km from their original nest.

This brings us back to where we started and the general life cycle of a bumblebee colony is completed - now for some exceptions.

Let us start with the Early Bumblebee (Bombus pratorum) as in this country there is geographical divide in the behaviour of queens. In the North pratorum follows the life outlined above. In the South though some of the new queens produced in a year rather than hibernate will establish nests to produce a second generation in the same year. It would be easy to assume that the difference is due to the climate. That spring arrives earlier in the South and frosts later. It sounds sensible but some bumblebees in Norway challenge that idea.

The Hearth Bumblebee (Bombus jonellus) is found both in this country and Norway. In this country like Bombus pratorum in the south it can produce two generations in a year and the same is true in Norway. Not only that but the subspecies, Bombus jonellus sub borealis occasionally produces two generations in Troms county, Norway that is north of the Artic Circle. Length of season does not of itself seem to be determining whether a queen produces a second generation or hibernates.

In the U.S.A. it seems three species in Oregon can produce a second generation in a single year. These are the yellow faced bumblebee (Bombus vosnesenskii), the fuzzy-horned bumblebee (Bombus mixtus) and the black-tailed bumble (Bombus melanopygus).

Studies in Norway and the U.S.A. suggest mild and dry summer that result in an abundance of suitable flowers species in late summer is a key factor in motivating some bumblebee species to produce a second generation.

Winter active bumblebees are another exception to the general behaviour of bees in this country. These are queens who establish a colony with workers that are foraging through the winter months. For several years winter active Buff tailed Bumblebees (Bombus terrestris) colonies have been recorded mostly in southern urban locations but with outliers as far north as Hull. In locations where this occurs it seems to become a regular occurrence. This is the third year where I have recorded winter active terrestris in Falmouth. This year for the fist time I also found Garden Bumblebee (Bombus hortorum) workers on the same Mahonia flowers as terrestris workers. This mirrors evidence from New Zealand where we exported both species in the 19th Century. There terrestris is the most common winter active species with hortorum less frequently seen. Another exported species Bombus ruderatus has also been recorded as being winter active there, it will be interesting to see if this eventually happens in this country.

It is not known what prompts a new queen to hibernate. Most enter hibernation before the arrival of cold weather, so temperature appears not to be a trigger. It may be that once a queen has built up her reserve being in a burrow is the safest place for her. Combining the time spent in their hibernation burrow with that spent in their nest suggests that queens have a preference not to be out in the open. Most of a queen’s life is spent sheltered and protected.

Generally the instinct to hibernate after mating and building up their reserves is strong in queens of all species. As the exceptions show the strength of the instinct is variable in at least a few species. Going against the norm is a gamble. For example a queen that begins a colony in the late autumn will be reliant on the availability of flowering plants throughout the winter. In the right urban location the odds of survival are favourable elsewhere they are bleaker. 

Another potential problem faced by a bumblebee colony that breaks the widespread timings of their species' lifecycle is finding mates for their males and queens when most of their species are unavailable. A small isolated population can be susceptible to inbreeding.

Variability within a species offers the possibility of adapting to change and taking advantage of new opportunities. If all of life is a gamble then spreading your bets is the safest option.

An introduction

This blog is mainly about Nature in Falmouth. That is the coastal town in Cornwall. Nature though is interconnected so some posts will cast a wider eye. Generally though I will be photographing, filming and writing about Nature and wildlife in Falmouth.

If you have not visited Falmouth, here is a short glimpse of Falmouth Bay as the moon rises and darkness falls.

From walking the coastal path, visiting one of its nature reserves or looking into a rock-pool, Nature can be seen and experienced in a variety of ways in and near to Falmouth.

Resident species benefit from its mild coastal climate while its southwest location attracts a variety of migrating species from birds to insects. The possibility of seeing a new visitor that has flown in or perhaps seeing a seal or dolphin in the bay adds to the excitement of exploring Nature in Falmouth. 

The town is one of the special places in the UK where Buff-tailed bumblebees are active through the year. During the winter months they can often be seen visiting the Mahonia flowers in Fox Rosehill Garden.

As well as this blog you can also follow Falmouth Nature on Twitter, this is the most active social media channel. As well as regularly posting photos and tweets I also look out for Falmouth wildlife related photos and videos to share.

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