I confess that it is my interested in bumblebees that draws me to Fox Rosehill Garden each winter. The garden's various varieties of Mahonia are pretty well guaranteed to attract winter active buff-tailed bumblebees from November through to the end February. While a bumblebee visit to a Mahonia flower is almost certain, some days entail quite a lot of waiting for a visitor to arrive. This allows me to take a look at its other attractions.
The garden is home to a variety of exotic plants from around the world. Quite a few of these flower during in the winter. I am not very knowledgeable on ornamental plants but with help from Robbie Blackhall- Miles from Fossil Plants and Helen Brown at Little Ash Gardens I have managed to put a name to the plants in my photos.
Bumblebee on Mahonia flowers
Fuchsia microphylla
Amaryllis belladonna
Impatiens tinctoria
Sparmannia africana
Correa glabra var. turnbullii
Salvia corrugata
brugmansia x Lutea
Clerodendrum trichotomum - these are fruits not its flowers
It was an accidental discovery while I was looking for early flowering wildflowers at the beginning of January. I spotted a few Scarlet Pimpernels flowing in my garden and picked one to photograph. Only when I looked through the camera's viewfinder did I notice something unusual. Where the stamens and pistil should have been, small leaves were to be seen.
Normal Scarlet Pimpernel Flower
My not so normal Scarlet Pimpernel Flower
This phenomena was observed in roses by the German writer and polymath, Johann Wolfgang von Goethe and he named it, Metamorphosis. Today it is usually known as Phyllody (leaf like) and it is generally caused by infections although adverse environmental conditions may also cause an imbalance in a plant's hormones producing the same effect. With this plant flowering so early environmental stresses could be a possible cause. However Scarlet Pimpernel is also a known host for aster yellows phytoplasma. This disease can infect over 300 species in 38 families of herbaceous plants, symptoms are variable and include phyllody. Phytoplasma are one of the smallest living organisms and cannot be seen through an optical microscope nor can they be cultured like many other types of bacteria. Little wonder that they were not discovered until 1967 by Japanese Scientists. If the phyllody in the flower was caused by a disease it was mostly likely infected by a sap sucking insect such as a leafhopper. Interestingly the phytoplasma in the sap once ingested by a female leafhopper can extend the insect's lifespan and increase the number of eggs it lays. While this benefits the insect it also increases the opportunities for the bacteria to infect other plants. An unusual start to year to be sure, I had not seen anything like it before or heard of Phyllody. I will keep my eye on this patch of pimpernels during the spring to see if I can see any recurrences.
It is a magical spectacle of the autumn, swarms of the cranefly Dicranomyia chorea dancing in patches of sunlight towards sunset. These were filmed in Fox Rosehill Gardens in November and I have also seen them in the old parts of the cemetery above Swan Pool in early October. Could they be mistaken for faeries or pixies? I think it likely that they are one natural phenomena that may have supported the folklore.
November can seem like a rehearsal for winter as the
days shorten, temperatures fall and deciduous trees make their final
preparations for shedding their leaves. It is not though a month entirely of
gloom with Nature snuggling down to sleep through the long nights. A few wild flowers can still be found adding colour to the landscape in the milder
parts of Britain.
The plants I discovered on a walk at the beginning of
the month can be divided into four groups. The first would be the last remnants
of species that mainly flower in September and October such as Ivy and bramble
flowers. The second group are those species that take advantage of
Falmouth’s mild coastal climate to flower for much of the year, examples of
these would be Red Campion and Ivy-leaved Toadflax. A few individual
plants of spring flowering species can be enticed into flowering in autumn by
mild weather, the primroses and wood sorrel flowers I saw for example. Finally there are the winter flowering species that tend to be garden escapees for example Winter Heliotrope.
In all I spotted twelve species flowering, a reasonable count for early November.
While the Met Office starts Spring on the first day of March that usually seems premature to me. Yes, there can be days that feel spring-like but others still require winter clothing. The vernal equinox and the changing of the clocks seem about the right time to start raising expectations that Winter is coming to an end. My two favourite early spring flowers are Lesser Celandine for their bright splash of colour and the more bland Alexander for the reason that it attracts a variety of newly emerged insects to its flowers.
Male Tawny Mining Bee on Alexander flower
Mid-March is also when Queen bumblebees will awaken from their hibernation feeling in need of a good meal or several after their long sleep. One of the first to appear is the aptly named, Early Bumblebee (Bombus pratorum) but other species were also quick off the mark.
Top: Queen Early Bumblebee Middle: Queen Buff-tailed Bumblebee Bottom: Queen Tree Bumblebee
I spotted my first solitary bee species on the 17th March, with more appearing as we moved into April. The first Cuckoo bee to appear was Nomada fabriciana, a striking bee with a red abdomen and black stripes.
From Top: Hairy footed flower bee Yellow legged Mining Bee Cliff Mining Bee Cuckoo Bee Nomada fabriciana
We start this spring with a heightened concern over our butterflies that are showing a decline nationally and in urban areas in particular. There were also indications last year that bumblebee numbers were down and in Falmouth there seemed to be less red-tailed bumblebees about in particular. Fingers crossed that we have better weather this year to help numbers to recover. It is also essential that there will be a continuing source of pollen available to them throughout the spring, summer and autumn. To end on an optimistic note the number of Queen Common Wasps seem to have increased this spring.
Top: The first Holly Blue Butterfly spotted on 01/04/17 Middle: Queen red-tailed bumblebee Bottom: Queen Common Wasp
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
After watching buff-tailed bumblebees (Bombus terrestris) visiting flowers for the last three winters in Falmouth I have gained some insights into their behaviour but many questions remain. Discovering a nest a week ago will help extend that knowledge a little further. By counting the bumblebees leaving and returning to the nest it is possible to speculate how many bees are in the nest.
Friday 24th February 2017 Bombus terrestris nest - Falmouth, UK P/N? = unable to distinguish whether bee had pollen due to hind legs obscured
TIME
DUR MINS
BEES IN
BEES OUT
POLLEN
NECTAR
P/N ?
TOTAL
14.36
12
16
10
5
8
3
26
14.49
10
9
9
4
5
0
18
15.01
10
6
7
1
4
1
13
15.12
10
16
9
5
6
5
25
15.26
10
5
6
0
3
2
11
15.40
11
5
4
2
2
1
9
15.54
11
5
6
4
0
1
11
16.06
6
6
0
1
3
2
6
TOTALS
80
68
51
22
31
15
119
The first thing to consider when looking at the numbers is that about 60% of the worker bees in the colony will remain in the nest doing such things as helping care for the young. A rule of thumb guide is to take the number seen in ten minutes and times that by four. Taking the peak result would give us 104 bees in the colony with about 42 of these involved in foraging. As can be seen the activity decreased over the time of observations illustrating how varied foraging activity can be. Taking an average of the 10+ minute numbers gives a colony size of 66 bees with 26 workers foraging. As a ballpark figure we have a colony size of 66 to 104 bees from the initial observations. Edit 17th December 2017 - Having reflected on these figures I feel they are probably too low. Given that there are fewer flowering plants in winter it is likely foraging flights take longer. Also the frequency of bees visiting plants in various locations suggests a larger colony size although the possibility of there being more than one colony must be considered. The question is only really going to be answered with a spade once a colony has completed its lifecycle and is disused. Examining winter active nests and looking at its cells where the larvae turn into adult bees will not only give accurate numbers but also answer how many males and queens were produced. If you are imagining me standing over the nest for eighty minutes counting the bees while examining each to see if they were carry pollen, possibly wearing a deerstalker hat and smoking a pipe you are mistaken. I filmed the nest - the breaks between counts was due to moving the camera and reframing. Counting was done in the warm, watching and replaying the video while drinking copious cups of tea. Of course I could not resist making another bumblebee video from 80 minutes of footage - don't worry it is only 2 minutes long.
