Characterizing the Influence of Domestic Cats on Birds with Wildlife Rehabilitation Center Data

Abstract

Depredation of birds by domestic cats is hypothesized to be one of many significant sources of mortality leading to global bird declines. Direct observations are relatively rarely documented compared with large numbers of birds hypothesized to be killed or wounded by cats. We analyzed data from two wildlife rehabilitation centers located in Salem and Grants Pass, Oregon USA, to understand which species were most likely to interact with a cat, and the species traits associated with cat interactions and habitats (urban vs. rural) of rescued birds. Interaction with a cat was the second-most commonly reported cause of admission, representing 12.3% of 6345 admissions. Half to two-thirds of birds were rescued from cats in urban settings and were usually species foraging on or near the ground. Most species were admitted to rehabilitation centers in direct proportion to their regional abundance. An exception was the absence of common species weighing less than 70 g, which we conclude is an effect of sampling bias. We conclude that cats most often interact with regionally common near-ground-dwelling bird species in both urban and rural habitats. Wildlife rehabilitation centers can provide valuable sources of data for cat-bird interactions but potential sources of uncertainty and bias in their data need to be considered carefully.

Trends in Admissions and Outcomes at a British Wildlife Rehabilitation Centre over a Ten-Year Period (2012–2022)

“…Birds dominated admissions to WRCs in Catalonia, Spain (89%; [ 52 ]); Athens, Greece (83.3%; [ 12 ]); Chile (86.0%; [ 36 ]); and South Africa (90%; [ 39 ]). Conversely, in the USA, admissions to WRC in New York State were only slightly higher in birds (51.9%) than mammals (43.7%) [ 33 ], and in two centres in Oregon, birds comprised just 28.0% and 37.1% of admissions [ 11 ]. The number of reptiles and amphibians admitted to WRCs is usually very low: 4.3% in New York State [ 33 ], 0.3% in Catalonia [ 52 ], 1.7% in Chile [ 36 ], and 2% in South Africa [ 39 ].…”

“…A study of WRCs in North America found domestic pets responsible for 14% of admissions and the second most common identifiable cause of wildlife injury [ 10 ]. Interactions with cats represented 12.3% of admissions to two WRCs in Oregon, USA, and were again the second most common reason for admissions [ 11 ]. Attacks by cats accounted for 25.4% of known causes of trauma in birds admitted to a WRC in Florida [ 70 ].…”

“…Most European hedgehogs admitted to WRCs in the Czech Republic were 'hoglets' (59.5%) [63], and most common kestrels were 'nestlings' (34.7%) [64]. In North America, 'orphans' accounted for 37.3% of admissions in New York State (Hanson et al, 2021) and 21.6% in Oregon [11]. In a WRC in Virginia, USA, 23% of grey foxes (Urocyon cinereoargenteus) and 33% of red foxes (Vulpes vulpes) were admitted as orphans [65].…”

“…Reasons for undertaking wildlife rehabilitation are usually welfare-driven but may also include considerations such as providing a public service, interacting with nature, and personal fulfilment [ 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. Furthermore, wildlife rehabilitation is also recognised as having a public educational role regarding specific anthropogenic threats to wildlife [ 10 , 11 , 12 ], as well as a role in monitoring ecosystem health [ 13 , 14 , 15 ] and the impacts of urbanisation [ 16 , 17 ]. Although wildlife rehabilitation has generally been considered to only have indirect impacts on conservation rather than population-level impacts [ 18 ], there is now increasing recognition of the potential for the discipline to have direct impacts on conservation [ 19 , 20 , 21 ].…”

Wildlife Emergency Response Services Data Provide Insights into Human and Non-Human Threats to Wildlife and the Response to Those Threats

“…Often, however, they result in negative impacts on wildlife, including population declines, disruption of social bonds, biodiversity loss, imperilment of threatened species, and harm to individual animals [2][3][4][5][6][7][8]. Globally, wildlife is indeed negatively impacted directly by a range of anthropogenic activities (e.g., vehicle collisions, attacks by domestic pets, entanglements, and gardening incidents) [6][7][8][9][10][11][12][13][14]. Systematic, large-scale and multi-taxonomic approaches to understand what these threats are and how wildlife rescue services might be able to respond to these threats are rare.…”