Mice in the Netherlands, new research


This video is about yellow-necked mice.

Translated from the Dutch Mammal Society:

Tuesday, March 3rd, 2015

For years the yellow-necked mouse in the Netherlands was only known from the extreme southeast of Limburg province. Since 2005 from the German border they are expanding to the west. Meanwhile, the species is known from all our provinces bordering on Germany. The question now is: are yellow-necked mice taking over, or may they occur in the same habitats together with common wood mice?

In Northwest Europe two species of wood mice live, common wood mice and yellow-necked mice. The yellow-necked mouse is clearly larger, but in terms of food spectrum it is virtually identical to the ordinary wood mouse.

So far, research has not yet established clearly whether yellow-necked mice supplant wood mice.

Red squirrel in tawny owls’ nestbox, video


Before the tawny owl couple of my earlier blog post started nesting in their nestbox in Oisterwijk in the Netherlands, a red squirrel visited that box; as seen in the video here.

Squirrels And Snowballs Will Make You Love Winter Again: here.

Good long-eared owl news


This video is about long-eared owls.

Vroege Vogels TV in the Netherlands reports that this year, more long-eared owls than ever have been counted in Friesland province. 1740 owls at 143 resting places. Last winter, there had only been 800 birds.

Extremely probably, this is because 2014 has been a good year for rodents. Other owl species have profited from this as well. 90-95% of long-eared owl food are common voles. In a bad rodent year, they eat some small birds as well.

Beaver cleans itself, video


This is a video about a beaver cleaning itself, in nature reserve Rhoonse Grienden in the Netherlands.

René Sluimer made the video.

Red squirrel in garden, video


This video is about a red squirrel in a garden in the Netherlands, feeding on bird feed.

Greetje Sibon made the video.

Norwegian lemmings, new study


This video says about itself:

Norway Lemmings Norske Lemen

10 October 2013

Lemmings in all their cuteness, with the beautiful Norwegian mountains as a backdrop.

I also bust one of the great lemming myths; the one [propagated by Walt Disney] that claims they commit mass suicide by throwing themselves off cliffs and drowning in the Arctic seas.

From Wildlife Extra:

Norwegian Lemmings stand out in a crowd and scream to deter predators

Conspicuous, boldly coloured fur and loud barks warn would-be predators that little Norwegian Lemmings are not to be messed with, researchers have discovered.

The findings of the team headed by Malte Andersson from the University of Göteborg in Sweden appears in Springer’s journal Behavioral Ecology and Sociobiology.

The Norwegian Lemming (Lemmus lemmus) is endemic to northern Finland, Norway, Sweden, and the Kola peninsula in Russia.

The animals have a red-brown back, yellow flanks, white breast, chin and cheeks and a large black patch on the head, neck and shoulders.

They are unique among small rodents in their ferocity, and will readily fight back the aerial attacks of predators such as the Long-tailed Skua with loud screams, lunges and bites.

Most smaller rodents rarely aggressively protect themselves from predators; a willingness to have a go, therefore, is worth advertising.

Through five field tests, Andersson noted that the Norwegian Lemming’s remarkable traits can be ascribed to aposematism: the use of warning colours and other methods to signal to predators that the potential prey has some form of defence, for example being toxic.

Aposematism is unusual in herbivorous mammals, however, being much more common among insects, snakes and frogs.

In one of the experiments, 18 observers found it easier to spot Norwegian Lemmings in their natural habitat than their main rodent neighbour, the Grey-sided Vole.

In another test, Andersson noted that Brown Lemmings only gave anti-predatory warning calls in one out of 39 instances when a human (seen as a potential predator) was near.

Norwegian Lemmings, on the other hand, did so in 36 of 110 cases.

Black and white or yellow are classic warning colorations, which some birds instinctively know to avoid.

Andersson explains that such calls and coloration are often useful at close range, where a lemming is likely to be discovered even if silent.

They signal to a predator that the rodent will put up a fight if attacked.

“The Norwegian Lemming combines acoustics with visual conspicuousness, probably to reduce its risk of becoming prey,” says Andersson, who believes that such aposematism could help explain why the long-distance movements of Norwegian Lemmings are so conspicuous.

Rat poison kills birds, partial ban


This video is about a kestrel nest on a balcony in Poland.

Translated from Vroege Vogels radio in the Netherlands today:

Vermin fighters may no longer use mouse and rat poison anymore in the open air from early this year on. That was decided by the board for the authorization of plant protection products and biocides (Ctgb). The main reason for the partial ban of these rodenticides is that many mice and rats have become immune to the poison. It is also to reduce the risk of other animals being exposed to the substances.

Research by ecotoxicologist Nico van den Brink of Alterra research institute in Wageningen shows that a large part of our raptors get rat poison in their food. The chance of barn owls and kestrels dying from this is plausible.

Rodenticides are not completely prohibited. Inside buildings they may still be used. Also, the Ctgb offers the possibility to obtain an authorization under strict conditions for outdoor use.