Predator Guard Pros & Cons

Comparing (Pros and Cons) Various Predator Guard Styles

• No predator guard invented to date is 100% effective against all predators in all situations. Know which predators you’re dealing with to prevent attacks. A combination of guards may be required to protect against multiple predators.
• If boxes are mounted near or under trees or fences, climbing predators may be able to gain access to boxes from the roof despite pole mounted guards. Cats can jump as high as 6 feet to get on a nestbox roof.

Style	Protects From	Pros	Cons	Picture	More Info
Conical Baffle (galvanized sheet metal / hardware cloth)	Raccoons Snakes < 5ft. Cats Rats Squirrels	– Cheap to make – Can be installed without disturbing nestbox, anytime, remain year-round – Suitable for 4×4 wood post – Durable – Can see hornet/ wasp nest starts underneath	– May not stop snakes over 5 feet long – Tricky to mount on EMT? – Some raccoons learn to defeat – Sharp edges on hardware cloth can cut hands		How to make – traditional – tennis ball mount (LBBS)
Stovepipe (Kingston), wobbling or wobbling PVC tube/bucket	Raccoons Cats Squirrels Chipmunks Mice and rats	– Effective against wide range of predators – Can remain year-round – Durable	– Can rust if not painted – Not suitable for 4×4 wood post mount – More expensive – Need to install when mounting box – May bang in windy conditions if not installed with hanger iron per instructions – Hornets or wasps may nest underneath if top is solid (vs. hardware cloth) – open top on conduit pipe fills with water – if it freezes it can split the pipe. Cap with a leftover wine cork – Conduit connector (connecting conduit to rebar) requires a longer screw to catch rebar to prevent spinning around – sometimes it slips down or spins. Duct tape will stop spinning.		How to make
					Above: bucket with rims removed
Noel	Raccoons Cats Squirrels	– Cheap to make – Can be used with any mounting method – Easy to remove	– Sharp edges can cut hands – May deter birds -Should be placed on box after first egg – Must be deep enough & strong enough to deter coons		How to make
Krueger (mesh) Trap	Snakes	– Works on any pole type and tree mount	– Snakes not released will die.		How to make
Wooden block over entrance	Large avian Squirrels (prevents enlarging)	– Cheap to make – Slows down hole enlargement (e.g., by squirrels or woodpeckers) – Easy to replace – Can install anytime – For any mounting method	-? deeper entrance may be attractive to HOSP? – Can interfere with front opening box that opens from top (change to open from bottom/use screw that allows swiveling down of block during monitoring) – Can cause a bit more wear and tear on feathers – Can make it a bit harder for parents to dip head in to feed older nestlings/for nestlings to stick head out for food. – probably does not deter raccoon predation		1.5″- 2″ thick block screwed over hole
Hole Restrictor/ Guard	Squirrels Woodpeckers (prevents enlarging hole) Avian (keeps larger cavity nesters out)	– Inexpensive – Durable – For any mounting method	– Can get expensive to purchase for large trail – If used as restrictor, wait for first egg.		– About – Purchase – Size tests
Carpet Tack Strips	Raccoons Snakes Cats Squirrels	– Suitable for 4×4 wooden post – inexpensive	– Unattractive
Hanger	Bears Cats (jumping) Humans	– Inexpensive – Durable (Combine with deeper box and large overhanging roof to deter access via roof)	– Need tree (location may attract squirrels/House Wrens) – Not suitable in areas with tree snakes – If high up, requires system to raise and lower		– Purvis Hanging Systems (p.12) – Violett
Greased Pole	Snakes Raccoons	– Inexpensive	– Not suitable for wooden posts unless covered with duct tape first – Lithium grease accumulates dirt, must be re-applied regularly		Rub with steel wool, then apply a generous coating of carnauba car wax or lithium grease
Hutchings Coon Guard	Raccoons Cats	– Cheap to make – For any mounting method – Durable	– May not be accepted, although 4″ PVC may be better accepted than Bird Guardian – Wait for first egg		How to make
Bird Guardian	Raccoons Cats Large avian	– Easy to install – Any mounting method – Durable – inexpensive	– Not well accepted by birds; may deter nesting; thus not recommended – Wait for first egg if you decide to use – then verify next afternoon that a second egg has been laid – if not, remove. – must be purchased		for purchase (two styles)

More Information:

• Predator ID and Solutions
• DIY:
  • Conical Baffles
  • Wobbling Stovepipe
  • Noel Guard
  • Hutchings Coon Guard
• Hanging boxes:
  • Linda Violett
  • Purvis Hanging Systems, Southern California
  • David Gwin’s hanger
• Hole Restrictors
• Hole Size Tests
• Human Vandalism – Deterring
• Suppliers
• Can I mount a box on a tree?
• Photo Credits: Conical Baffle – Jay Brindo; Kingston Baffle – Ron Kingston; Purvis Hanger – from Southern California Bluebird Club, Wobbling bucket – Dottie of Indiana; Hutchings from The Bluebird Monitor’s Guide