Regional and temporal distribution of Selasphorus rufus in Texas.
MARK KLYM, Texas Parks & WiId. Dept, Austin, TX.
We have all heard the question: "Aren't the Rufous Hummingbirds early this year?" Casual observation in a limited setting would seem to indicate these migrants arrive and depart at similar times each year, but data acquired through 11 yr of observations at various sites across the state indicate that these birds arrive at diverse times across the state and that there is little or no standard time in any one region. Arrival dates averaged week 32 (wk 2 in Aug, SD = 6.8, SE = 3.6) statewide. Regional arrivals varied from an average week 29 (wk 4 JuI, SD = 7.6, SE = 1.2) in the Trans Pecos to week 36 (wk 2 in Sep, SD = 5 2, SE = 0.99) in south Texas. Departure dates showed even less consistency with the average departure week 9 (wk 1 in Mar, SD = 15.4, SE = 0.87). Early average departure was seen in the Oaks and Prairies region with the birds leaving during week 2 (wk 2 in Jan, SD = 12.4, SE = 3.1). There were three regions of the state where the birds consistently left prior to the winter months, those being the Rolling Plains (week 38 - wk 4 in Sep), the High Plains (week 36 - wk 2 in Sep) and the Trans Pecos (week 38 - wk 4 in Sep).