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Fifty-six cats identified by their owners as known hunters
completed the study, which took place in Perth, Western Australia
over a six-week period in November/December 2005 (southern
hemisphere late spring/early summer). Each cat spent a period of
three weeks wearing a CatBib and three weeks without it and the
number of prey brought home during each period was recorded.
Participating cats caught a total of 13 bird species, five mammal
species, and 11 herp (reptile and frog) species. The mammal the
Southern Brown Bandicoot was the only prey species of conservation
concern. CatBibs stopped 81% of cats from catching birds, 45% of
cats from catching mammals, and 33% of cats from catching
herptofauna.
CatBibs of both colours were equally effective at reducing
predation. There was no statistically significant evidence that
adding bells conferred additional protection. Most cats (86%)
adjusted almost immediately to wearing a CatBib, 10% took a day or
so and only 4% took longer.
BACKGROUND
Cat ownership is declining in Australia in contrast to the
increased popularity of pet cats in Europe and the United States (REARK
1994, Perry 1999, Chaseling 2001, McGreevy et al. 2002).
One significant reason may be a widely held view in Australia
that pet cats are bad for wildlife either by roaming and hunting in
remnant bushland or by excluding wildlife from domestic gardens (Baldock
et al. 2003, Grayson et al. 2002, Grayson and Calver 2004, Lilith et
al. in press). Reducing the incidence of predation by pet cats would
benefit wildlife conservation and enhance the image of pet cats.
Several collar-worn devices are marketed to reduce predation by
pet cats. Recent detailed studies of their effectiveness suggest
that bells reduce prey captures by 34 - 48% (Ruxton et al. 2002,
Nelson et al. 2005) and that electronic warning devices achieve a 38
- 51% reduction (Nelson et al. 2005).
However, one device not yet tested is the CatBib, a lightweight
neoprene bib worn on a collar. It functions both as a visual warning
to prey and a barrier to paws when pouncing, reducing hunting
success.
This study assessed the effectiveness of the CatBib, a product
marketed by Cat Goods Inc. (Oregon, USA) in reducing predation of
birds by pet cats in an Australian context.
METHODS
The study took place in Perth, Western Australia over a six-week
period in November/December 2005 (southern hemisphere late
spring/early summer). In October 2005, 63 volunteers were accepted
from 82 respondents to advertisements in local newspapers seeking
assistance from owners of cats which were active hunters.
Respondents whose cats did not catch on average one prey every three
weeks were declined. Most volunteers came from the outer suburban
foothills where cats have ready access to native bushland. All cats
were neutered and there were almost equal numbers of males and
females.
The CatBib is made of neoprene, a light, strong and tear
resistant synthetic fabric used in wetsuits. It attaches to a collar
via hook and loop pads (velcro), which can release if the CatBib snags. Although there is only one size, varying the point of
attachment of the CatBib allows some size adjustment for large or
small cats. Bibs are available in five colours, two of which were
tested in this study. The retail price is $8.95 (US), without a
collar. While cats can carry out all activities while wearing a
CatBib, the manufacturer suggests that bibs are only worn when the
cat is outside. During this study owners were asked to ensure that
their cats always wore bibs when outside during treatment weeks.
Male and female cats were allocated randomly to four treatments:
teal CatBib only, teal CatBib plus a bell, purple CatBib only and
purple CatBib plus a bell. Half the cats in each treatment were
fitted with the device for three weeks followed by three weeks
without the device, while the others were monitored for three weeks
without the device followed by three weeks with it. This design
ensured that all cats spent a period with and without the device as
well as controlling for possible effects of the sequence of
treatments or changes in prey availability over time. All collars
and CatBibs were fitted initially during a home visit. If the cat
was not already wearing a collar, it was given at least one week to
adjust to the collar before the CatBib was fitted. Only safety
collars were used.
Owners collected the bodies of any dead prey brought home by
their cats and reported instances where live prey were rescued and
released. All cases where the prey was dead or was released only
after intervention by the owner were recorded as captures. If the
owner saw a cat with a prey animal but it escaped without the
owner's intervention, no capture was recorded. Prey bodies were
identified to species. Most prey released after owner intervention
were classed simply as mammals, birds or herps (reptiles and frogs)
unless the owner provided a clear description identifying the
species conclusively.
RESULTS
The results below are summaries of detailed statistical analyses
of the data.
Characteristics of cats and cat husbandry
The 63 cats accepted had a mean age of 5 years (females) and 4.5
years (males). Most were not pure breeds, but there were some pure
breed Russian Blues and Burmese, one pure breed Persian and one pure
breed Abyssinian. 13% lived entirely outdoors, while the others were
allowed indoors at least some of the time. Only six cats were
occasionally restricted indoors. Fighting was common, with two cats
wearing bibs and nine cats not wearing bibs suffering fight-related
injuries (scratches, bites, abscesses) over the six-week trial. Four
cats, none of which was wearing a bib, disappeared from their homes
for at least two days at some point during the trial.
Most cats (86%) adjusted almost immediately to wearing a CatBib,
10% took a day or so and only 4% took longer. Seven cats lost their
CatBib at least once during the trial and one lost its CatBib six
times.
Prey capture and effectiveness of treatments
Over the six weeks of the trial the participating cats caught 13
bird species (11 native), 11 herp (reptile and frog) species (all
native) and five mammal species (two native). The mammal the
Southern Brown Bandicoot was the only species of conservation
concern (Lower Risk, Near Threatened: Maxwell et al. 1996). On
average, each cat caught 2.93 mammals, 1.11 birds and 1.20 herps.
Male and female cats caught similar numbers of prey.
Alone or in conjunction with a bell CatBibs stopped 81% of cats
from catching birds and 45% of cats from catching mammals.
The effects for birds and mammals are strong, but the effect for
herps is weak. CatBibs of both colours were probably equally
effective at reducing predation. Bells are unlikely to cut predation
beyond the reductions already caused by CatBibs.
CONCLUSIONS
1. The CatBib is especially effective in reducing predation on
birds. Predation on mammals is also reduced, but not to the same
extent. There may be limited protection for herps.
2. There was no statistically significant evidence that
differently coloured CatBibs varied in their effectiveness.
3. There was no statistically significant evidence that cats
wearing a bell as well as a CatBib caught fewer prey than cats
wearing a CatBib alone.
4. Most cats (86%) adapted almost immediately to the CatBib, 10%
took a day or so and only 4% took longer.
5. Direct comparisons of the relative effectiveness of CatBibs,
bells and electronic warning devices must be made cautiously because
no researcher has tested them all simultaneously. However, the
reductions in total numbers of prey caught by cats wearing CatBibs or CatBibs and bells in this study are similar to or better than
those reported for the other devices in the UK by Ruxton et al.
(2002) and Nelson et al. (2005). The 72% reduction in the numbers of
birds caught by cats fitted with a CatBib compares favourably to the
figures of 34% for bells alone and 38% for electronic warning
devices alone (Nelson et al. 2005). The 44% reduction in the numbers
of mammals caught by cats fitted with a CatBib or a CatBib and a
bell is similar to the figures of 38% for bells alone and 51% for
electronic warning devices alone (Nelson et al. 2005).
6. While the sample size was small, only two of the 11 cats
injured in fights were wearing CatBibs. Possibly the CatBibs make a
cat look larger and more formidable, discouraging aggression.
Alternatively, cats wearing them may be less inclined to pick a
fight.
7. Overall, the CatBib is a safe and effective means of reducing
predation by pet cats, especially when birds are the prey. Cat
owners can use the product with confidence.
ACKNOWLEDGEMENTS
We are grateful to the many owners who kindly volunteered their
cats for the study. Cat Goods Inc. supplied the CatBibs, Mr Ray Dunn
of Symonds donated the safety collars and bells and Dr Karen
Johnstone of Hills Pet Nutrition provided sample bags of cat food to
reward the volunteer cats. Dr Ric How, Mr Ron Johnstone, Ms Claire
Stevenson and Mr Brad Maryan of the Western Australian Museum
identified the prey. Mr Ian Davis, Environmental Programs Manager
for the City of Melville, and Mr John DeJose, manager of the Cat
Haven in Perth, provided encouragement and advice. The City of
Melville and the Murdoch University Research Excellence Grants
Scheme provided financial support.
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