18-12-2020

You're probably familiar with classifying photographs of roe deer on MammalWeb, but over the Christmas period look out for the festive version of this species - Rudolph the red-nosed roe deer! We've hidden 10 photos like the one below in the MammalWeb Britain project. If you find one whilst classifying, then take a screenshot of it and either email it to us at This email address is being protected from spambots. You need JavaScript enabled to view it. or message us on Facebook, Twitter or Instagram. Your name will then go into a prize draw to win a camera trap! We'll announce the winner on the 12th day of Christmas (5th January) on social media, as well as in our next newsletter. Good luck!

07-12-2020

Some of you might have noticed that we have changed the name of MammalWeb UK to MammalWeb Britain.  This reflects an exciting change, as we welcome MammalNet Ireland to the group of MammalNet projects.  MammalNet Ireland will be recruiting trappers and spotters from across the whole island of Ireland.  Trappers from Northern Ireland will, thus, be contributing data to that project, rather than to a UK-wide project.  It is fitting, therefore, that we refocus our longest-running project on England, Scotland and Wales.

19-08-2020

It is a shamefully long time since we last posted news on this page. In our defence, (a) if you want more regular news, the best way to get that is to subscribe to our monthly newsletters; and (b) this global pandemic is playing with everyone's lives - and the MammalWeb team are no exceptions.

Rather than post separate updates for the Spotters' League from recent months, we thought it would be interesting to present a single table, showing the league rankings over the past 4 half-month periods (see below). Congratulations to everyone who made it in to the top-20 during one of those periods!

The table emphasises the high turnover in the League. For example, it shows that, of those who have made it in to the top-20 in one or more of the 4 periods, about two-thirds have appeared on only one occasion. It also shows that we have some very consistent contributors. Particular congratulations, then, to PetaSams, Florian, AKStenhouse, sammykwild, vivcoy and Gven, all of whom have made it on to each of the 4 lists shown! And commiserations to PetaSams who, despite being the top contributor over the entire 2-month period, has consistently been denied the top spot!

As always, thanks to all contributors - we hope you are able to keep up the good work!

16-06-2020

Here's the top 20 for the first half of June. Lots of turnover again, with poofinder claiming the top spot for the first time! Seven further spotters were within a handful of classifications of making it on to the table, so even a couple more classifications a day could be the difference between fame and obscurity ...

As always, thanks to all contributors!

16-06-2020 by Roland Ascroft

Many bird and mammal species may be classified as sexually dimorphic (i.e., males and females differ visibly in their appearance) like pheasants or deer, or monomorphic (i.e., the two sexes look alike) like dunnocks or hares. Obviously, terrestrial mammals in Europe are not truly monomorphic because of their external genitalia, but these are only sometimes visible on trail camera images. Secondary sexual characteristics such as antlers in deer or tusks in wild boar make it much easier to separate the sexes for much of the year, but many mammals are sexually dimorphic by size, and this also occurs in birds (particularly some birds of prey). So, for mammals and birds in the UK (merely because this is where we have sufficient data), how often do spotters separate the sexes?

 Percentage of identifications where the spotter gave the sex (for species with more than 100 classifications)

Not surprisingly, deer rank top in terms of sex-separation in mammals, and the top 5 bird species are also ones which are obviously dimorphic, in this case in their plumage. One might expect Pied Wagtail to be included there, but it comes in at number 16, below several sexually monomorphic species. For most species, most of the time, spotters cannot or do not attempt to identify the sex of a bird or mammal.

One of our most dimorphic mammals in terms of size is the stoat with males being much larger than females, and yet there were zero attempts to give its sex. This may be because of the difficulty of estimating size on a picture when only one individual is present. In case you think size does not matter when it comes to sex, most of these species breed seasonally, and the size of their testes changes with season, driven by a hormonal cycle. This has been measured in roe deer, for example (Short R.V. & Mann T. 1966. The sexual cycle of a seasonally breeding mammal, The Roebuck (Capreolus capreolus) J. Reprod. Fert. 12,337-351).