>Feeding habits and trophic niche overlap of two sympatric
>mustelidae, the polecatMustela putorius and the beech martenMartes
>foina
>A. Baghli1 , E. Engel1 and R. Verhagen2
>Summary  The diets of the polecat
>
>Mustela putorius (Linnaeus, 1758) and the beech martenMartes foina
>(Erxleben, 1777) in Luxembourg were investigated by using faecal
>analysis and determination of gut contents. Data of the polecat (121
>scats and 16 guts) were collected around the country where the
>populations of this species have been sharply declining over the past
>decades. 112 scats of the more common and widespread beech marten were
>collected in those areas where both mustehds were known to be present.
>Standard techniques were applied for analysing the data. In winter,
>small mammals, especially rodents, were the most abundant food for
>both species. Amphibians dominated the summer diet of the polecat
>whereas fruits were the most important resource for the beech marten
>during that season. The pattern of resource partitioning between the
>polecat and the beech marten is based on the common use of small
>mammals. The niche overlap of food items is however limited and
>appears only during winter. The adaptation allowing the use of
>alternative food sources might avoid the competition for food.
---

>Austral Ecology
>Volume 25 Page 223  - June 2000
>doi:10.1046/j.1442-9993.2000.01024.x
>Volume 25 Issue 3
>Functional response and area-restricted search in a predator:
>seasonal exploitation of anurans by the European polecat, Mustela
>putorius
>T. Lode
>
>Abstract
>
>A study of the feeding habits and movements of 11 radiotracked
>polecats Mustela putorius in western France revealed that seasonal
>predation upon agile frogs, Rana dalmatina, was directly influenced by
>prey abundance and distribution. Although dietary structure showed the
>importance of mammalian prey (71.5%), polecats exploited nocturnal,
>terrestrial anurans in spring (31.6%). The periodic activity of
>anurans at spawning sites led both to a maximum density in spring and
>to a patchy distribution. The monthly variations in anuran dietary
>occurrences were associated with changes in frog availability. The
>functional response of polecats to frog density was sigmoidal shaped
>(type 3 response). Frog consumption rate increased more slowly than
>prey density but frogs were actively removed at higher density. It is
>therefore suggested that frog populations were moderately affected by
>the predator and this density dependent effect tends to stabilise
>anuran populations. Predation upon anurans was also correlated with a
>prey dispersion index as revealed by a polynomial regression. Polecats
>concentrated their predation on spawning congregations of the breeding
>adult frogs. Movements were smallest in spring and polecats changed
>their track length by increasing the difference between a succession
>of small movements and of longer journeys towards profitable sites.
>Changes in movements correlated with the anuran dispersion index and
>the response was sigmoidal (polynomial regression) revealing an
>area-restricted search. This response may be regarded as an
>'aggregative response' according to the first part of the definition
>of Begon et al. (1996). Functional and area-restricted search
>responses to the frog abundance and dispersion constitute an original
>example of predator-prey coexistence strategies among vertebrates. I
>suggest that such predation could be favoured by the individualistic
>habits of the mustelid.
> ---

>Hystrix, (n.s.) (1995): 69-72
>It. Symp. on Carnivores
>DIET OF THE POLECAT MUSTELA PUTORZUS L. IN RIVERINE
>HABITATS (NORTHERN ITALY)
>
> Claudio PRIGIONI* & Anna Maria DE MARINIS**
>
> *Dipartimento di Biologia Aninzale, Universita di Paviu, Piazza Butta
>  9, 27100 Pavia
>
> **Museo di Scienze Naturali, Sezione Zoologica, Universita di Firenze,
>  via Romana 17, 501 25 Firenze
> 
> ABSTRACT
> - Food habits of the polecat (Mustela putorius) were studied by the
>analysis of 50 scats collected in riverine habitats of northern Italy
>from 1985 to 1988. Data were expressed as percent frequency of
>occurrcncc (F%) and relative pcrcentage of frequency (Fr%). Rodents
>(Fr%H.4), mainly Apodemus sp. (Fr% %.0) and Clethrionomys glareolus
>(Fr% = 15.6), lagomorphs (Fr% #.4) and birds (Fr%.5) wcrc the main
>components of the diet. Falconiformes, probably consumed as carrion,
>and Ralliformes wcrc recorded for the first time in the polecat diet
>in Europe. Fruit, amphibians, and reptiles were scarcely exploited...

Be sure to see also:
http://ead.univ-angers.fr/~ecologie/Polecat_project.html

Not an article:
http://animaldiversity.ummz.umich.edu/site/accounts/information/Mustela_putorius.html

>Food Habits
>
>Mustela putorius is carnivorous and generally preys on rodents and
>rabbits. It is a testament to the polecat's ferocity that it can and
>will take down a rabbit that is much larger than itself. Should food
>become scarce, polecats also eat insects and fruit, though they are
>much less able to handle the digestion of these foods than either
>canids or ursids.
>
>Primary Diet: carnivore (eats terrestrial vertebrates).
>
>Animal Foods: birds; mammals; amphibians; reptiles; eggs; insects;
>terrestrial non-insect arthropods.
>
>Plant Foods: fruit.

But the last of the full articles w abstract quoted mentions in the
article itself insects in the diet. Notice the flexibility and variety!

[Part 2 (posts combined by moderator)]
Here is the end of the polecat diet refs post, put here to make the
post short enough. Yesterday it got lost in the ether and today it
bounced back as too long.

It seemed that it would be of interest, though, how flexible the diet
is within which boundaries.

Here:
If you are getting the idea that there is some flexibility in wild
polecat diets welcome to the club. Does the flexibility extend much
beyond what is eaten in the wild (including prey gastrointestinal
contents which may play a minor(?) part at times) and at what level
does such an extension of flexibility pose a problem? Are any of the
foods in the grouping actually better for the polecats than others, or
is the combination most useful? If in careful study it does pose a
problem beyond a certain point, then what are reasonable alternatives
to digestible animal sources for ferrets who need protein restriction
or nutrient balance changes due to aging organs or disease compromised
organs such as kidneys? Well, some of that is part of what people who
are investigating teeth and gums are looking at, and hopefully, at some
point there will be the sort of funding needed to do a decent very
carefully designed *****actual endocrinological study***** and then
follow-up studies to do more to take a real look at insulinoma and
diet, rather than just look at a portion (or hopefully all -- to
avoid prejudicing results since there is a lot of conflict) existing
pancreatic and carbohydrate studies, keeping in mind that most existing
studies are about diabetes rather than insulinoma and are in different
species, plus the existing studies show conflicts rather than simply
confirmation.
---

Closing comments:

Vastly important are that:
any diet be balanced, the people know the risks associated with their
choice of diet, and that people are honest with the vets on what is
given.

Those are my main points beyond that I personally don't care what is
fed as long as those things are remembered. The failure to include
downsides of one's own choices seems to be more inclined to happen when
raw foods are discussed than when kibble is. It seems like people are
well aware that kibble isn't perfect.

Going to CDC and searching on salmonella didn't seem to uphold a
statement made in today's FML but I am completely willing to believe
that I could be missing a new and essential ref so, *****please, give
CDC ref for raw eggs (a definite salmonella risk) being more of a
salmonella risk than raw meat and proportions involved to round out my
resources*****, because articles exist which give pause such as:

http://www.cdc.gov/foodborne/publications/45_dechet_2006.pdf
http://wonder.cdc.gov/wonder/prevguid/m0039761/m0039761.asp
http://www.cdc.gov/pulsenet/pathogens_pages/salmonella.htm
http://www.cdc.gov/foodborne/publications/338-kimuraa.pdf

The CDC would apparently like to start irradiating more meat and
poultry as well as some other foods (which does *NOT* make meat
radioactive, though I know of people who assume that) as is done
in many other parts of the world but there has often been a strong
opposition to it here in the states for reasons I have not grasped.
Some irradiation is finally done now here to improve safety as it has
been in many parts of the world for a much longer time:
http://www.cdc.gov/foodborne/publications/209-p_frenzen_consum_accept_irradmeatJFP2001.pdf

Yes, there is a hypothesis that carbohydrates may lead to insulinoma
(and certainly also one that they may lead to diabetes). There are
dental and gum concerns.

On the other hand, there are increased disease risks with raw foods
(shown to be valid by the vet replies about treating such cases), and
the vet write-ups about treating them in texts such as _Biology and
Diseases of the Ferret_. Low risk does not equal no risk; there is a
world of difference when a ferret does get sick with a severe disease.
Please, note that I have been consistently careful to not exaggerate
the threat by pointing out that ferrets often have resistance because
I think that it is best to be most fair in these discussions and to
not exaggerate despite some trying to ignore that I have regularly
mentioned resistance. Fair is fair.

So, all it boils down to is to never assume that any one food choice
is going to be perfect. All have upsides and all have downsides.

Sukie (not a vet)
Reminder: THE FERRET HEALTH LIST IS MOVING.
To join, click on the joining link at

http://groups.yahoo.com/group/ferrethealth and then follow the
directions.

OR just send a blank mail to the automated joining address:
[log in to unmask] and then follow the directions.

Recommended ferret health links:
http://pets.groups.yahoo.com/group/ferrethealth/
http://ferrethealth.org/archive/
http://www.afip.org/ferrets/index.html
http://www.miamiferret.org/fhc/
http://www.ferretcongress.org/

[Posted in FML 5431]