Abstract
BackgroundHummingbirds are frequently presented to California wildlife rehabilitation centers for medical care, accounting for approximately 5% of overall admissions. Age, sex, and reason for admission could impact hummingbird survivability, therefore identification of these factors could help maximize rehabilitation efforts.MethodsMixed-effects logistic regression models were used to identify specific threats to the survival of 6908 hummingbirds (1645 nestlings and 5263 non-nestlings) consisting of five species (Calypte anna, Calypte costa, Selasphorus rufus, Selasphorus sasin, Archilochus alexandri), found in urban settings, and admitted to California wildlife rehabilitation centers over 26 years.ResultsIn total, 36% of birds survived and were transferred to flight cage facilities for further rehabilitation and/or release. Nestlings were more likely to be transferred and/or released compared to adult hummingbirds. After accounting for age, birds rescued in spring and summer were twice as likely to be released compared to birds rescued in the fall. A high number of nestlings were presented to the rehabilitation centers during spring, which coincides with the nesting season for hummingbirds in California, with the lowest number of nestlings presented in fall. Reasons for presentation to rehabilitation centers included several anthropogenic factors such as window collisions (9.6%) and interactions with domesticated animals (12.9%). Survival odds were lower if a hummingbird was rescued in a “torpor-like state” and were higher if rescued for “nest-related” reasons. Evaluation of treatment regimens administered at wildlife rehabilitation centers identified supportive care, including providing commercial nutrient-rich nectar plus solution, to significantly increase hummingbird survivability.DiscussionOur results provide evidence of threats to hummingbirds in urban habitats, based on reasons for rescue and presentation to rehabilitation centers. Reasons for hummingbird admissions to three California wildlife rehabilitation centers were anthropogenic in nature (i.e., being associated with domestic animals, window collisions, and found inside a man-made structure) and constituted 25% of total admissions. There was a clear indication that supportive care, such as feeding a commercial nectar solution, and medical treatment significantly increased the odds of survival for rescued hummingbirds.
Highlights
Hummingbirds, found only in the Americas, are often presented to wildlife rehabilitation centers (Greenewalt, 1990; Heyden, 2005)
Wildlife rehabilitation centers play a vital role in rehabilitation efforts and provide valuable data for wildlife commonly found in urban habitats (Griffith et al, 2013; Kelly & Bland, 2006; Molina-López & Darwich, 2011) through standardized medical records documenting success or failure for each wildlife rescue (Heyden, 2005; Kelly & Bland, 2006; Mazaris et al, 2008; Molina-López & Darwich, 2011; Wimberger & Downs, 2010)
A total of 6908 hummingbirds rescued from 192 city/town areas were presented to the three Californian rehabilitation centers involved in this study over 26 years
Summary
Hummingbirds, found only in the Americas, are often presented to wildlife rehabilitation centers (Greenewalt, 1990; Heyden, 2005). Evaluation of rehabilitation centers’ medical records can identify admission trends, key reasons for admission, anthropogenic threats (Deem, Terrell & Forrester, 1998; Griffith et al, 2013), and pathogen prevalences (Harris & Sleeman, 2007) for a wide variety of wildlife species. This vast availability of data brings a greater understanding of human-wildlife interactions in our urbanized world, as well as determines the overall impacts and outcomes of rescued wildlife following rehabilitation efforts (Molina-López & Darwich, 2011). Evaluation of treatment regimens administered at wildlife rehabilitation centers identified supportive care, including providing commercial nutrient-rich nectar plus solution, to significantly increase hummingbird survivability
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.