by Brad Kubecka, Graduate Research Assistant
Quail are sedentary birds, but in good years, displacement and dispersal are common. Old literature referred to these mass dispersals as “migrations,” and noted that they indeed coincided with years of extraordinary population abundance (Bennitt and Nagle 1937). This year we had multiple reports of bobwhites (and scaled quail) banded on RPQRR being harvested by hunters well off-site. Three instances stood out in particular as they were harvested in Kent and Jones counties up to 28 miles away (Figure 1). All of these birds were hatched in 2015, making them about 1.5 years of age upon harvest.
These reports mark our farthest documented dispersals from RPQRR, but aren’t unusual in the grand scheme. In 1968, a bobwhite banded by Val Lehmann and colleagues was harvested 65 miles south of the initial banding location only 2 months after being banded. In 1961, Campbell and Harris reported a scaled quail dispersing 61 miles.
Interestingly so, recent studies have found little variation in genetic diversity among 24 subpopulations of bobwhites in South Texas (Deyoung et al. 2012, Miller et al. 2012). This along with similar research findings in the southeastern United States (Evans et al. 2012) suggest that bobwhites have the ability to disperse much better than once thought.
Whether dispersal is good, bad, important, or indifferent depends on context. For example, we might prefer that birds stick around on a translocation site to establish a viable population. In 2013 and 2014, an estimated 90% of translocated bobwhites in the eastern Rolling Plains moved less than 2.5 miles from their release site (Downey et al.). This type of short-term site fidelity is what researchers like to see from a translocation effort. On the other hand, dispersal from productive populations can be extremely important for rescuing declining populations from extinction (Townsend et al. 2003, Sands et al. 2012). Dispersal distances typically depend on age with juveniles dispersing greater distances than adults (Fies et al. 2002). Fies et al. (2002) showed that juvenile males were more likely to disperse than any other age/sex group whereas adult males were the least likely to disperse. Townsend et al. (2003) did not document a differential proclivity to disperse among age/sex classes, but supported that juvenile dispersers moved significantly farther than adult dispersers. Cook et al. (2009) suggested that habitat quality dictated dispersal probability, but this effect depends on age. Old males in this study were more likely to disperse from closed canopy pine stands which are associated with poor quality habitat. Current evidence suggests dispersal does not influence survival, and that dispersers have higher nest initiation rates than that of non-dispersers (Townsend et al. 2003).
Though radio-telemetry technology has been a valuable tool for almost 4 decades, comprehensive dispersal information still lacks for bobwhites. With the arrival of new GPS technology in the past decade, it’s only a matter of time before researchers unravel just one more mystery in bobwhite ecology. Until then, we’ll rely on a much less expensive technology, i.e., aluminum leg-bands, as our “message in a bottle.” Currently we’ve leg-banded over 12,000 quail since 2008, and each increases our opportunity for a “return on investment.”
Knox Co. Blue Quail Restoration update
by Becky Ruzicka, doctoral student, Colorado State University
Last week we started trapping again to support the second year of our scaled quail translocation efforts in Knox County. We trapped two sites: one in the Rolling Plains Ecoregion and one in the Edwards Plateau. These birds were transported to the release site where they were placed in surrogators and will be held on site until their release in late-April. As part of this study we are comparing survival, reproduction, and dispersal of birds from different source populations (i.e., Rolling Plains vs. Edwards Plateau). We will also be evaluating the effects of a ‘soft release’ treatment to find an optimal amount of time to hold quail prior to release. A soft release means the birds are held on site for a length of time prior to release. Previous research has indicated that a soft release is preferable to a hard release (i.e., releasing birds immediately after capture) for scaled quail. For a comparison, this year we will release birds after holding them for 8 and 9 weeks, 4 and 5 weeks, and 1 and 2 weeks.
The scaled quail we released last year (393 in total) have exhibited survival and reproduction comparable to estimates of non-translocated scaled quail in the scientific literature. They have also exhibited a remarkable fidelity to the release site. Hens that had dispersed beyond our study site during the summer returned to the release site in the fall and several of them returned with chicks in tow. The first year’s results are encouraging to say the least. This year we hope to duplicate the effort in terms of number translocated.
Impact of La Niña vs. El Niño weather patterns on RPQRR coyote diets
by Cade Bowlin, Graduate Research Assistant, Texas Tech University
Adaptive, resilient, and relentless with acute senses of smell, vision, and hearing are traits seldom packaged together in one individual, but the coyote can lay claim to each of the above. Coyotes can make a living just about anywhere, eating just about anything. This prolific North American canid resides in all states of the union except Hawaii. Populations of coyotes occur in remote wilderness and urban jungles such as Chicago and San Francisco.
Coyotes are a common sight on the RPQRR; they comprised 49% of mammalian predators spotted during camera trapping efforts on the ranch during June 2016. Coyotes have been credited with preying on quail and depredating quail nests in the Rolling Plains of Texas. However, it is not known how large of an impact coyotes have on quail populations.
Previous research concerning coyote diets and prey selection on the Rolling Plains has warranted further investigation. Mark Tyson studied coyote diets on RPQRR in 2009-11 as his master’s thesis at Texas Tech University. Tysons’ research was conducted during La Niña weather patterns, with 2011 being one of the hottest, driest years in Texas’ recorded history. The subsequent drought had dramatic effects on the flora and fauna on the ranch and statewide. Bobwhite quail abundance on the ranch reached the lowest numbers since monitoring efforts began on RPQRR.
We hear about La Nina and El Nino on a regular basis. But what causes these phenomena and what exactly are they? The El Nino-Southern Oscillation (ENSO) cycle is comprised of two contrasting phases, La Nina and El Nino weather patterns. Put simply, ENSO describes the fluctuation between sea temperatures in the equatorial region of the Pacific Ocean and atmospheric temperature above this area. El Nino patterns occur when sea surface temperatures are above average. Oceanic temperatures below the mean induce La Nina conditions. Fluctuations in the ENSO can have worldwide weather implications. In our part of the world, El Nino weather patterns typically result in below normal temperatures and above average rainfall. Conversely, La Nina results in hot, dry weather like we experienced from 2010 to mid-summer 2015 (Nielson-Gammon 2016). We are currently in an El Nino phase that has been in place in the Rolling Plains since summer 2015.
A follow up project replicating Tyson’s work during an El Nino, wetter weather pattern is underway on the ranch. This study will assess how major weather patterns affect coyote’s diets and how their diets shift through changing environmental conditions. How do these weather patterns affect coyote diets on a landscape managed strictly for quail such as RPQRR?
Coyote scats have been collected, since Fall 2015, in order to analyze the diets of coyotes on RPQRR focusing on consumption of quail, vegetative mast, and small mammals. Data attained from scat samples will allow analysis of coyote dietary composition. The scat collection route is a 20-mile, continuous loop on the Texas Quail Index (TQI) route on the RPQRR. Coyote scats are collected once monthly with a total of 30 scats collected per month. Scats will be analyzed in the laboratory using a biomass calculation model and frequency of occurrence techniques. Data derived from scat analysis will be used to determine coyote dietary composition on the RPQRR. Using small mammal and quail trapping data, arthropod sampling, as well as monthly vegetation surveys, a determination of food item selection versus availability will be made.
Tyson’s study on RPQRR showed only one quail consumed by coyotes (n=1080 scats). However, quail numbers were also well below historic average on the ranch during the study period. Spring trapping data showed 45.3, 34.1, and 32.2 quail per 100 trap nights during 2009, 2010, and 2011 respectively. Efforts from spring 2016 trapping on the ranch indicated 331.2 birds/100 trap nights (a 10-fold increase from Tyson’s time period). The purpose of this follow-up study is to ascertain whether coyotes are important predators of quail and quail nests during a period when quail and additional coyote food sources are abundant. Additionally, the study will investigate dietary differences of coyotes on RPQRR during La Niña and El Niño weather cycles.
In Tyson’s study, quail were found in less than 1% of coyote scats. Remains from mammals and mast were found in 63% and 67% of scats, respectively. Mast is the edible vegetative or reproductive part produced by woody species of plants and is a key component of coyote’s diets. During the fall of 2011, 96% of scats analyzed by Tyson contained mast. Vegetation surveys have been conducted throughout the duration of the study. Twenty-four, 100-m permanent transects were established along the TQI. Once each month for the duration of the study, all transects were walked and mast assessed. The top five most consumed mast-producing plants from Tyson’s study were monitored (mesquite, prickly pear, hackberry, chittam, and lotebush). The same individual plants were monitored each month to establish mast availability in the study area. Land management practices that encourage growth of mast-producing plants important to coyotes could help relieve pressure on coyote prey species.
In a similar study, Meinzer et al 1973 looked at coyote diets in nearby Knox and King counties. Rodents were the top-ranked prey item consumed by coyotes during the study. The study area is well known for large cow-calf operations; astonishingly no livestock were reported depredated during the study period. Small mammals comprised 24.5% of mean annual diet of coyotes on their study area. Birds and bird eggs made up 1.1% of diets. Meinzer et al (1973) suggested coyote diets vary in a large part due to climactic conditions and patterns. Trapping data on the ranch will help give an abundance estimate of small mammals during the study period.
Preliminary analyses of scats collected Fall 2015 show an abundance of small mammal remains and hair whereas mast is appearing in low abundance in scat samples. No novel items have been found in analysis of scats thus far. Statistical analysis is currently being conducted on vegetation survey data for the study period. It appears low mast production was experienced on RPQRR during 2016. But small mammals (especially cotton rats) have boomed since 2015. A total of 1152 small mammals were captured during summer 2016 trapping efforts on the ranch. These results are drastically different than the 167, 285, and 78 small mammals trapped during 2010, 2011, and 2012 respectively. But winter trapping efforts (still underway on the ranch as of this week) suggest a major crash in small mammal population. The effects on coyote diets, and ultimately quail abundance, are yet to be determined.
Operation Idiopathic Decline: Search for the Smoking Gun
The role that disease and parasites may play in quail dynamics has been largely ignored since the 1920s. After the (in our opinion) inexplicable decline of quail in the Rolling Plains, the Board of RPQRF “got serious” about disease and funded a comprehensive project dubbed “Operation Idiopathic Decline.” Currently (as of Feb 2014), the RPQRF has invested $3.4 million into this ground-breaking study of disease and parasites. This webisode explains OID in more depth.