It is unlikely all male sage‐grouse are detected during lek counts, which could complicate the use of lek counts as an index to population abundance. Understanding factors that influence detection probabilities will allow managers to more accurately estimate the number of males present on leks. We fitted 410 males with global positioning system and very high frequency transmitters, and uniquely identifiable leg‐bands over 4 years in Carbon County, Wyoming. We counted male sage‐grouse using commonly used lek‐count protocols and evaluated variables associated with our ability to detect marked males using sightability surveys on 22 leks. We evaluated detection probabilities of male sage‐grouse based on factors related to bird characteristics such as age or posture, lek and group size, lek characteristics such as vegetation cover or aspect, light conditions, weather, and observer. We then applied the detection probabilities to more accurately estimate male counts on leks. Detection probabilities were generally high (x¯ = 0.87) but varied among leks from 0.77 to 0.93. Male sage‐grouse detection declined with increasing sagebrush height and bare ground and increased with more snow cover. Detection probabilities were also lower when observers counted from a higher elevation than the lek. Our sightability models predicted detection well and can be used to accurately estimate male abundance on leks from lek counts, which is especially useful where accurate abundance estimates are required or inference about population status is based on only 1 count. Further, it is important to consider lek attendance as a component of counts on leks because it affects availability of male sage‐grouse for detection during lek counts. Detection can be maximized by conducting lek counts from 30 minutes before sunrise to 30 minutes after sunrise, although current protocols recommend lek counts can be performed up to 1 hour after sunrise. Detection can also be maximized by conducting lek counts ≥2 days after snowfall, which maximizes attendance and detection. © 2015 The Wildlife Society.

Little is known about the incidence and management of dermatofibrosarcoma protuberans (DFSP) in children. We conducted a retrospective review of all patients younger than 18 years of age treated for DFSP over a period of 11 years (2000-2011) in Madrid, Spain. The sample consisted of 13 children. The average annual incidence of DFSP in the pediatric population corresponded to 1.02 cases per million person-years (95% confidence interval 0.55, 1.73). Sites of involvement were diverse, with 15.3% of tumors found in acral locations. The median tumor size was 3.5 cm × 3 cm and the median time from apparent onset to diagnosis was 36 months. Histopathologic examination revealed conventional (77.0%), pigmented (15.4%), and myxoid (7.6%) variants. The mitotic index was consistently <5 per 10 high-power fields. All lesions were removed using surgical excision. One patient developed a local recurrence because of initial affected margins; none developed metastases. The median duration of clinical follow-up was 70.5 months. This study estimated the average annual incidence rate of DFSP in a population of patients younger than 18 years and reviewed the experience of several hospitals in the management of this tumor.

Movements among leks by breeding birds (i.e., interlek movements) could affect the population's genetic flow, complicate use of lek counts as a population index, and indicate a change in breeding behavior following a disturbance. We used a Bayesian multi‐state mark‐recapture model to assess the daily probability of male greater sage‐grouse (Centrocercus urophasianus) interlek movements and estimate factors influencing movements among leks. We fitted 145 males with solar Argos global positioning systems platform transmitter terminals over 4 years (2011–2014) in Carbon County, Wyoming, USA. The daily probability of a male sage‐grouse moving among leks ranged 0.003 (95% CI = 0.000–0.010) in 2011 to 0.010 (95% CI = 0.001–0.021) in 2013, indicating high daily lek fidelity throughout the season, although there was a 5–42% chance annually a male would move at least once to another lek throughout the season (x¯ days analyzed/M = 55 ± 3.3 days [SE]). Interlek movement probabilities were strongly affected by day of year, peaking early in the lek season. Interlek movements were positively associated with elevation. Seasonal interlek movements occurred more frequently than previously reported, and can bias lek counts in early spring as males move from low to high elevation leks, which reinforces interlek movements as a critical component of lek ecology. © 2016 The Wildlife Society.

Greater sage-grouse (Centrocercus urophasianus) occupy sagebrush (Artemisia spp.) hab

For lek-breeding birds, lek attendance can be correlated with mating success. Variability in lek attendance could confound interpretation of male reproductive effort and complicate the use of lek counts as an index to monitor abundance. We assessed the daily probability of male Sage Grouse Centrocercus urophasianus lek attendance and explored implications of attendance on lek counts. We fitted 145 males with global positioning system (GPS) transmitters over 4 years in Carbon County, Wyoming. We evaluated influences of lek size and topography, date, weather, and bird characteristics such as age on daily morning lek attendance. The daily probability of attendance ranged considerably each year, from 0.120 ( x, 95% CI 0.051-0.259) in 2012 to 0.917 (95% CI 0.844-0.957) in 2013 with peak attendance dates ranging from 8 April (2012) to 11 May (2011). Attendance decreased with increasing precipitation on the observation day. Only 44-79% of lek counts occurred on days without precipitation and with high attendance (i.e. within 0.1 probability of peak predicted attendance). Although lek counts and population abundance, predicted using attendance rates, followed a similar trend, the relationship was not significantly correlated. We provide empirical evidence supporting current lek-count protocols: managers should avoid counting leks on days with precipitation because attendance is reduced. Although managers sometimes only complete one to two lek counts per year on active leks, completing at least three lek counts as recommended in protocols increases chances for higher male counts and improves the relationship between counts and abundance. Attendance varies annually, making it challenging to use lek counts to assess regional population trends over short time periods unless attendance is accounted for.

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