Navigation Links
For birds, the suburbs may not be an ideal place to raise a family
Date:3/3/2011

There comes a time in life for every bird to spread its wings and leave the nest, but for gray catbirds, that might be the beginning of the end. Smithsonian scientists report fledgling catbirds in suburban habitats are at their most vulnerable stage of life, with almost 80 percent killed by predators before they reach adulthood. Almost half of the deaths were linked to domestic cats.

Urban areas cover more than 100 million acres within the continental the United States and are spreading, with an increase of 48 percent from 1982 to 2003. Although urbanization affects wildlife, ecologists know relatively little about its effect on the productivity and survival of breeding birds. To learn more, a team of scientists at the Smithsonian's Migratory Bird Center studied the gray catbird (Dumatella carolinensis) in three suburban Maryland areas outside of Washington, D.C.Bethesda, Opal Daniels and Spring Park.

The team found that factors such as brood size, sex or hatching date played no significant role in a fledgling's survival. The main determining factor was predation, which accounted for 79 percent of juvenile catbird deaths within the team's three suburban study sites. Nearly half (47 percent) of the deaths were attributed to domestic cats in Opal Daniels and Spring Park. The deaths were either witnessed by the scientists or determined to be cat-related by the condition of the fledgling's remains, such as a decapitated bird with the body left uneatendefining characters of a cat kill. Domestic cats were never detected during predator surveys in the third suburban study site, Bethesda.

"The predation by cats on fledgling catbirds made these suburban areas ecological traps for nesting birds," said Peter Marra, Smithsonian research scientist. "The habitats looked suitable for breeding birds with lots of shrubs for nesting and areas for feeding, but the presence of cats, a relatively recent phenomenon, isn't a cue birds use when deciding where to nest."

Technology made tracking the fledgling catbirds possible. The team fitted 69 fledglings with small radio-transmitters. Scientists tracked each individual and recorded its location every other day until they died or left the study area. This detailed type of field research was very limited until recently when transmitters were made small and light enough for songbirds.

Tracking the fledglings revealed that the vast majority of young catbird deaths occurred in the first week after a bird fledged from the nest. This was not surprising to the team, given that fledglings beg loudly for food and are not yet alert to predatorsmaking fledglings in suburban environments particularly prone to visual predators such as domestic cats. Domestic cats in suburban areas that are allowed outside spend the majority of time in their own or adjacent yards, so they are likely able to intensely monitor, locate and hunt inexperienced juvenile birds. Rats and crows were also found to be significant suburban threats to fledgling catbirds.

"Cats are natural predators of not just birds but also mammalskilling is what they are meant to do and it's not their fault," said Marra. "Removing both pet and feral cats from outdoor environments is a simple solution to a major problem impacting our native wildlife."

The scientists' findings were published in the Journal of Ornithology, January 2011.


'/>"/>

Contact: John Gibbons
gibbonsjp@si.edu
202-633-5187
Smithsonian
Source:Eurekalert

Related biology news :

1. 98.6 degrees Fahrenheit ideal temperature for keeping fungi away and food at bay
2. Study shows real partners are no match for ideal mate
3. Coral off Puerto Ricos coast ideal case study for Gulf oil spills impact
4. Creating ideal neural cells for clinical use
5. Canadas role grows amid looming world water shortages in some places, more flooding in others
6. MU researchers believe discovery could lead to testing that displaces colonoscopies
7. Weikang Bio-Technology Announces Completion of $5.0 Million Private Placement
8. Air pollutants from fireplaces and wood-burning stoves raise health concerns
9. Weikang Bio-Technology Announces Completion of $5.0 Million Private Placement
10. Goji berries have the same nutrients as fruits and vegetables and a placebo effect
11. Cinnamon can replace harmful chemicals used to create nanoparticles
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:8/15/2017)... , Aug. 15 2017   ivWatch LLC , a ... intravenous (IV) therapy, today announced receipt of its ISO 13485 Certification, ... by the International Organization for Standardization (ISO®). ... ivWatch Model 400 Continuous Monitoring device for the early ... "This is an ...
(Date:5/23/2017)... the first robotic gym for the rehabilitation and functional motor sense evaluation ... Genoa, Italy . The first 30 robots will be available from ... . The technology was developed and patented at the IIT laboratories ... Technology thanks to a 10 million euro investment from entrepreneur Sergio Dompè. ... ...
(Date:4/19/2017)... April 19, 2017 The global ... landscape is marked by the presence of several large ... held by five major players - 3M Cogent, NEC ... accounted for nearly 61% of the global military biometric ... in the global military biometrics market boast global presence, ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... Oct. 10, 2017 International research firm Parks Associates ... speak at the TMA 2017 Annual Meeting , October 11 in ... the residential home security market and how smart safety and security products ... Parks Associates: Smart ... "The residential security market ...
(Date:10/9/2017)... , Oct. 9, 2017  BioTech Holdings ... mechanism by which its ProCell stem cell therapy ... limb ischemia.  The Company, demonstrated that treatment with ... of limbs saved as compared to standard bone ... molecule HGF resulted in reduction of therapeutic effect.  ...
(Date:10/9/2017)... ... October 09, 2017 , ... ... journal, Epilepsia, Brain Sentinel’s SPEAC® System which uses the surface electromyography (sEMG) ... tonic-clonic seizures (GTCS) using surface electromyography (sEMG). The prospective multicenter phase III ...
(Date:10/6/2017)... ... October 06, 2017 , ... The HealthTech Venture ... sector at their fourth annual Conference where founders, investors, innovative practitioners and collaborators ... ELEVATE pitch competition showcasing early stage digital health and med tech companies. , ...
Breaking Biology Technology: