Estimating Survival and Determining Causes of Mortality of Golden Eagles in South-Central Montana

There is concern for golden eagles (Aquilla chrysaetos) in the West as a result of contradictory population trend estimates and a likely increase in threats including but not limited to expanded wind energy development.  Estimating survival of golden eagles and identifying causes of mortality can be used to assess the viability of nesting golden eagle populations and to direct mitigation efforts if necessary.  To date, little information exists on golden eagle survival in western North America.  In addition, identified causes of golden eagle mortality are often associated with an opportunity to find dead birds, creating a potential bias that may be minimized with the use of satellite telemetry.  We outfitted 17 adult and 13 nestling golden eagles with satellite transmitters during the 2011-2014 nesting seasons near Livingston, Montana to estimate survival and determine causes of mortality.  We used multi-state models to estimate survival over discrete-time periods for both adults and nestlings.  Preliminary results showed our survival estimates were consistent with similar long-lived, slow reproducing raptors.  Golden eagle mortalities in our study were a result of poisoning, intraspecific interaction and poaching.  Our survival estimates are consistent with the stable density of breeding golden eagles in our study area and the primary causes of mortality differed from repository-based studies

50-Year Golden Eagle Nesting Trends In South-Central Montana

Golden Eagle (Aquila chrysaetos) migration counts in the western North America have shown a significant negative trend in recent years. However, the causes of these declines are unknown and it remains unclear if declining migration counts correlate to a declining population or changes in migratory behavior. Long-term research on nesting Golden Eagle populations is lacking and is needed to properly assess the current Golden Eagle population status in many areas. In 1962, intensive monitoring efforts were initiated in a roughly 1200-mi2 study area in south-central Montana. The objectives were, among other things, to determine density and productivity of Golden Eagles. This area was re-surveyed in the mid 1990s to begin looking at long-term population trends. In 2009, we initiated a multi-year effort to investigate potential changes in the nesting trends in the same study area over a half a century. The data collected to date indicate an increase in the nesting density, similar nest success rates, and a decrease in productivity when compared with both the 1960’s and 1990s studies. The longevity of data collected in this study area allows for one of the longestterm comparisons for Golden Eagle nesting density and success in the West and provides invaluable insights into the status of nesting Golden Eagles in this region

Avian Scavengers And Lead Rifle Ammunition: Where We’re At, Challenges, And Solutions

Birds have long been recognized at risk of lead poisoning from ammunition sources, but only in recent years has rifle ammunition been identified as a source of lead toxicity in raptors and other scavenging birds. Several studies have indicated increased lead exposure in eagles but the implications to population dynamics remain unclear. We have monitored blood lead levels of Common Ravens (Corvus corax), Bald Eagles (Haliaeetus luecocehpalus), and Golden Eagles (Aquila chrysaetos) in Jackson Hole, Wyoming, since 2004 to investigate effects of spent rifle ammunition on avian scavengers. Data from ravens and Bald Eagles indicated a strong relationship between big-game hunting seasons and elevated blood lead levels. In 2009, we initiated a voluntary non-lead ammunition program in collaboration with Grand Teton National Park and the National Elk Refuge. Free, non-lead ammunition was distributed to hunters in the area. Hunter surveys indicated that 24 percent of successful hunters on the Park and Refuge used non-lead ammunition and we detected a 28-percent drop in the mean lead levels of ravens monitored from previous years after the harvest totals were controlled for. We continued the voluntary program in 2010 by selling reduced-priced non-lead ammunition, and there was greater participation in the voluntary non-lead program (33%). Further, we have outfitted 13 Bald Eagles with satellite transmitters to document the potential geographic impact our local hunting season has on the continental eagle population and found that 90 percent of eagles outfitted during the big-game hunting season breed/ summer in central Canada

A novel camera trapping method for individually identifying pumas by facial features

Camera traps (CTs), used in conjunction with capture-mark-recapture analyses (CMR; photo-CMR), are a valuable tool for estimating abundances of rare and elusive wildlife. However, a critical requirement of photo-CMR is that individuals are identifiable in CT images (photo-ID). Thus, photo-CMR is generally limited to species with conspicuous pelage patterns (e.g., stripes or spots) using lateral-view images from CTs stationed along travel paths. Pumas (Puma concolor) are an elusive species for which CTs are highly effective at collecting image data, but their suitability to photo-ID is controversial due to their lack of pelage markings. For a wide range of taxa, facial features are useful for photo-ID, but this method has generally been limited to images collected with traditional handheld cameras. Here we evaluate the feasibility of using puma facial features for photo-ID in a CT framework. We consider two issues: 1) the ability to capture puma facial images using CTs, and 2) whether facial images improve human ability to photo-ID pumas. We tested a novel CT accessory that used light and sound to attract the attention of pumas, thereby collecting face images for use in photo-ID. Face captures rates increased at CTs that included the accessory (n = 208, χ2 = 43.23, P ≤ 0.001). To evaluate if puma faces improve photo-ID, we measured the inter-rater agreement of 5 independent assessments of photo-ID for 16 of our puma face capture events. Agreement was moderate to good (Fleiss' kappa = 0.54, 95% CI = 0.48–0.60), and was 92.90% greater than a previously published kappa using conventional CT methods. This study is the first time such a technique has been used for photo-ID, and we believe a promising demonstration of how photo-ID may be feasible for an elusive but unmarked species.Funding provided by: Community Foundation of Jackson HoleCrossref Funder Registry ID:Raw detections of pumas were collected using camera traps with and without an 'attention caller device' (ACD) to capture puma face images. Data include the time and camera site ID of detection, and whether the detection was at an ACD site. Detection data was further processed to include if the puma's face was captured, as well as behavioral reactions of pumas. To generate the daily detection data, raw image data was processed in R to create a sitewise record of capture counts for each day of deployment. Columns also include whether the site used an ACD, whether the site was a community scrape site, and the age in days of the scent lure placed at sites. The interrater agreement data was collected with an online application that was distributed to 5 independent users who rated 120 puma face image comparisons, giving each comparison a same (1) or different (0) rating

Big game harvest and eagle blood lead levels.

<p>Total big game harvest (lead and non-lead) by year (black bars, 2005–2008, 2009–2010) and harvest of big game using only lead-based ammunition (white bars) in Jackson Hole, Wyoming. Log transformed mean seasonal blood lead levels of bald eagles (gray line). Note the x-axis is not time contiguous since eagles were not sampled during the 2008 hunting season.</p

Bald eagle fall migration routes.

<p>Fall migratory (August 2010– January 2011) routes of bald eagles captured the previous fall (2009) in Jackson Hole, Wyoming. Four of the five eagles returned to Jackson Hole during the big game hunting season a year after being tagged.</p

Percentage and number (N) of bald eagle samples in four exposure categories captured between November – January in Jackson Hole, Wyoming, USA from 2005–07, 2009–10.

<p>Blood lead levels <10 µg/dL = background, 10–59 µg/dL = exposed, 60–99 µg/dL = clinically affected, and >100 = acute lead exposure (guidelines based on Redig 1984 and Kelly et al. 2011).</p