Cygnus olor Scorecard

Species:  Cygnus olor

Common Name:  Mute swan

Scorecard created on
Last Updated on

Results

Impact Total:15 / 35Impact = ( Spread + Damage - Benefit )

Ability to Respond Total:15 / 25Ability to Respond = ( Ease of Response + Tools in Place )

Confidence:High

Confidence Notes:

Impact

SpreadNotesScore
Spread RateMute swans are native to northern and central Eurasia and have been domesticated in Western Europe since the 12th century. Mute swans were introduced to the eastern United States from Western Europe during the late 1800s and have spread across the USA. 5
Spread AmountCan occupy many CA watershed habitats (city parks, lakes, delta, ponds, estuaries).4
DamageNotesScore
EcologicalCan aggressively displace native waterfowl species and, once established, can severely damage wetlands by consuming large amounts of submerged aquatic vegetation that other species depend on for food and shelter. 4
AgriculturalWill frequent agricultural crops if other food sources are limited. Mute swans may serve as a vector or reservoirs for diseases of agricultural significance including avian influenza and Newcastle disease viruses. 1
Infrastructure0
CulturalPotential to displace many species of cultural importance due to their damage to habitats and direct aggressiveness to other waterfowl. They are also considered a nuisance in some areas due to their abundant fecal droppings.1
HealthCan alter water quality by disturbing sediment during feeding and by fouling water. Are they are so aggressive that they may attack humans/pets during their breeding season. They also have potential to transmit salmonellosis, swimmer's itch, and E. coli.1
BenefitNotesScore
Ecological0
Agricultural0
Infrastructure0
CulturalSome people like these birds for asthetic reasons.1
Health0
Total15

Ability to Respond

Ease of ResponseNotesScore
DetectionEasily seen due to striking white coloration and size. Juveniles could be mistaken for other native swan species, but the yellow bill of adults makes them easily recognizable. 5
ControlSome difficulty due to politically limited control measures and negative public sentiment to control.3
Tools in PlaceNotesScore
EntryProhibitions are publicized and enforced by CDFG.3
ControlHazing using audio pyrotechnics and other visual deterrents can be successful at reducing local Mute swan abundance. The use of dogs to chase birds and exclusionary fencing to limit their access to habitat or removing available habitat can be successful. 3
OutreachLow awareness of CA public.1
Total15