Behneyel al. • RAPTOR AND LESSER PRAIRIE-CHICKEN INTERACTIONS 
335 
FIG. 1. Species and species group-specific raptor encounter rates (birds/hr) and female Lesser Prame-Chicken 
visitation rate (females/day) for 2-week intervals throughout the lekking season in the Texas Southern High Plains, 2007- 
2008. Two-week interval start dates were: 1 = 9 March, 2 = 23 March, 3 = 6 April. 4 = 20 April, and 5 — 4 May. 
Raptor Approach Types .—Coursing was the 
most commonly observed approach type (44% of 
encounters) used by raptors, followed by perching 
(24%), fly by (16%), and predation attempt 
(16%). We detected 15 predation attempts on 
Lesser Prairie-Chickens, primarily by Northern 
Harriers (n = 7), Swainson’s Hawks (/» = 3), and 
falcons (n = 2). Accipiters, other buteos, and 
unknown raptors accounted for one predation 
attempt each. Northern Harriers were the most 
common raptor observed coursing whereas buteo 
hawks were more commonly seen perching. 
Approach type was related to raptor species (X f , 2 
~ 17.25. P = 0.008). Northern Harriers perched 
less than expected. Swainson’s Hawks attempted 
to prey upon prairie-chickens more than expected, 
and other buteos perched more than expected. 
Lesser Prairie-Chicken Response Types.— 
Some or all Lesser Prairie-Chickens flushed in 
62% of all raptor encounters. However, prairie- 
chicken response was associated with raptor type 
(Northern Harrier, buteo, or falcon; X 6 ~ = 14.5, P 
= 0.02). Harriers and buteos were more likely to 
elicit flushing responses (75 and 73% of all 
responses, respectively). In contrast, three of five 
falcon encounters elicited squat responses from 
prairie-chickens (Fig. 2). This is likely a low 
estimate because flushes often occurred only after 
bl 
<2 iq 
® o ~ 
o 6 , 
Northern Harrier (n 
Buteo (n = 20) 
Falcon (n = 5) 
= 30) 
All flush 
Partial flush 
Squat 
Response 
No response 
FIG. 2. Lesser Prairie-Chicken response to Northern Harriers (n = 30), buteos (including Swainson’s Hawks, n - 20), 
a nd falcons (n = 5) encountered at leks in the Texas Southern High Plains, 2007-2008. 
