In preparing for winter many beekeepers will reduce hive entrances to enable the bees to better thermoregulate. It is also a practice in our region to place shrew guards on our hives. This week we enter the debate about whether or not these are necessary.
The 2020 blueberry harvest is complete, and we are getting some general idea of the success of this year's crop. We have some comments below from our provincial blueberry specialists.
Blueberry Update
Prince Edward Island
"Initial assessment of the 2020 harvest shows an expected lower than the five year average for the blueberry crop this year. The 5-years average is about 23 million pounds and the last couple years have been below this as a result of frost events, drought, and lower inputs due to the low blueberry price. I expect the significant drought this year to cause a low total crop year once again"
Cameron Menzies (PEI Dept. Agriculture)
Nova Scotia
"As we are heading towards the end of September, wild blueberry harvesting is completed for this season. This has been a challenging year across the regions. We had a very good bloom during the pollination season, and anticipated a great yield. However, mother nature likes to bring challenges to agriculture and the dry and hot conditions affected wild blueberry production aw well as insect pressures.
We are seeing yield reduction by drought in the Parrsboro and Amherst areas. Colchester blueberry fields seemed to do fine but still below the expectation. Up to this point, we do not have the final number of total wild blueberry yields for this year yet, but we are expecting less than the anticipated 50 million lbs."
Hugh Lyu (Perennia Inc.)
New Brunswick
"Although exact weights are not yet available, early indications are that the 2020 crop is down significantly. This is due to a combination of frost in the spring followed by summer drought conditions. The season had good news with favorable fruit set but finished with less than optimal smaller and lighter berries."
Michel Melanson (NB DAAF)
Once the final weights are available we will follow up with information on how this years crop compared exactly with previous years.
Are You a Shrewd or “Shrewed” Beekeeper?
Beekeepers know that honey bees need to be protected against opportunistic omnivores and insectivores. Bears and skunks will hungrily enter our apiaries in search of a meal. On the other end of the size scale, but none the less dangerous to honey bees, are the smallest mammals in our region: the shrew. There are seven species of shrew found in eastern Canada. One of these, the Maritime Shrew (Sorex maritimensis) is the only endemic mammal to our region. Other species include the venomous Northern Short-tailed Shrew whose bite delivers deadly toxins! Also, our region hosts the smallest of the shrews, the aptly named Pigmy Shrew.
 |
| A shrew found in a dead-out hive in spring. Note the feces which differs from that of a mouse. Without studying the dentition of this individual, it can only be stated, due to the size, that it is likely a Common Shrew (Sorex cinereus). |
Dr. Donald McAlpine, Curator of Zoology in the Department of Natural History of the New Brunswick Museum, has extensive knowledge of and research experience with our region’s shrews. He suggests that, when it comes to eating honey bees, the Common Shrew (Sorex cinereus) is the most likely culprit followed by the Smoky Shrew and possibly Short Tailed Shrew. The Pigmy Shrew is uncommon and so less likely, although equally willing, to attack beehives. The Maritime Shrew and the Eastern Water Shrew, due to their habitat and distribution, are unlikely to attack beehives. He also notes that, aside from the easily identifiable Short Tailed Shrew, it is difficult to visually differentiate one species from another, especially with juvenile animals.
Table 1. Shrew species found in eastern Canada
|
Common
Name |
Binomen |
Unique
Characteristics |
Hive
invader |
|
American
Pigmy Shrew |
Sorex hoyi |
Smallest of
our region’s shrews, scarce |
Yes |
|
Maritime Shrew |
Sorex
maritimensis |
Endemic to
our region |
Unlikely |
|
Common Shrew |
Sorex
cinereus |
Most numerous
and widespread |
Yes |
|
Northern
Short-tailed Shrew |
Blarina
brevicauda |
Venomous,
largest of our region’s shrews |
Possibly |
|
Smokey Shrew |
Sorex fumeus |
Odorous |
Yes |
|
Long tailed
Shrew |
Sorex
dispa |
Uncommon |
Unlikely |
|
Eastern Water
Shrew |
Sorex albibarbis |
Forages in
water |
No |
Shrews have a very high metabolic rate and, unlike many small mammals, are not dormant or hibernating through the winter months. The result is that these voracious insectivores will almost double their food intake to keep warm and active during winter. For these reasons, beehives must be protected against shrews while the bees are clustered and most vulnerable! The Chief Apiary Inspector for the province of New Brunswick, Fletcher Colpitts, feels that the shrew is a very common problem for overwintering honey bees in our region. He has written an excellent fact sheet with further background information and suggestions of how to protect your hives during the winter. You can access this factsheet on the New Brunswick Beekeepers Association website.
There are a couple of key points to consider when protecting your hives against shrews. The Pigmy Shrew, although less common than the others, can fit through any space larger than 1cm. Therefore, guards used to protect hives must have a screen opening size of no larger than 6mm. Also, it must be noted that the small size of the screening will remove pollen from the bees as they enter the hive. This may deprive them of important early spring nutrition. This leads to Mr. Colpitts recommendation to put the screen in place in December and remove it prior to spring pollen foraging by the bees.
If you are a beekeeper concerned about shrews, make sure to subscribe
to our blog. We will be talking about
shrews again soon and provide details of a study we are establishing with local
researchers to determine the presence and species of shrew in individual
apiaries. Stay tuned for upcoming details
and contact us if you want to ensure your place on this project. More to follow!
Connecting with ATTTA Specialists
If you’d like to connect with ATTTA specialists or learn more about our program, you can:
visit our website at https://www.perennia.ca/portfolio-items/honey-bees/
Email abyers@perennia.ca
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