Spatiotemporal Patterns of Decline of the Loggerhead Shrike in Virginia
Lance Morrow and Jill Morrow
Loggerhead Shrikes (Lanius ludovicianus) have declined for decades and are a threatened species in Virginia. To understand when and where shrike population losses have occurred in Virginia, we analyzed Breeding Bird Survey (BBS) data for Loggerhead Shrikes from 1966-2013 (n= 29 routes). The highest number of shrikes was reported by BBS in the central region (n= 7 routes with 71 shrikes), south central region (n= 4 routes with 90 shrikes) and southeast region (n= 2 routes with 41 shrikes), accounting for 77% of total shrikes reported. Beginning in the late-1970’s Loggerhead Shrikes began disappearing from BBS routes where their numbers had been highest. Losses of shrikes swept from east to west, with the last BBS reported shrike in the western region of Virginia in 2012. We compared BBS results to other sources of data on shrike distribution: the first Virginia Breeding Bird Atlas (VABBA) (1985-1989), Christmas Bird Count (CBC), bird banding records, and shrike sightings reported in Virginia Birds. The CBC shows exponential decline of Loggerhead Shrikes, with Virginia losing approximately half its wintering shrikes every 10 years. We discuss possible causes for the decline of Loggerhead Shrikes and present recommendations for shrike conservation.
First Evidence that Paired Roseate Terns Travel Together During Spring Migration
Jeffrey A. Spendelow and Gabriel Lugo
A mated pair of color-banded Roseate Terns (Sterna dougallii) from the Northwest Atlantic Ocean breeding population was photographed on 12 May 2010 while staging near Mayagüez, Puerto Rico. This represents the first evidence that mated pairs of this species may travel together during their northward migration.
Rapid 3-week Transition from Migration to Incubation in a Female Roseate Tern (Sterna dougallii)
Jeffrey A. Spendelow
A female Roseate Tern (Sterna dougallii) photographed on 10 May 2008 as it staged in Puerto Rico on its migration north was first observed in the nesting area at Bird Island, Buzzards Bay, Massachusetts, on 21 May. It was incubating a complete clutch of two eggs by 1 June and likely had initiated laying within 20 days of having been in Puerto Rico.
Body Masses of Some Cloud Forest Birds in Costa Rica
Spencer Sealy and Diane L.H. Neudorf
Masses are presented for 918 individuals of 55 species of tropical resident birds and 54 individuals of seven species of Neotropical migrants. Individuals were color-marked and released in a cloud forest (2360 m asl) located at the northern end of the Cordillera de Talamanca in central Costa Rica, during eight netting periods . between mid-Jan and early May, 1987-1993, and also including 29 Jul-6 Aug 1988