Factors associated with nest- and roost-burrow selection by burrowing owls (Athene cunicularia) on the Canadian prairies

2005 ◽  
Vol 83 (10) ◽  
pp. 1373-1380 ◽  
Author(s):  
Ray G Poulin ◽  
L Danielle Todd ◽  
Kimberly M Dohms ◽  
R Mark Brigham ◽  
Troy I Wellicome
Keyword(s):  
Ground Squirrels ◽  
Athene Cunicularia ◽  
Canadian Prairies ◽  
Burrowing Owls ◽  
Burrowing Owl ◽  
Factors Associated ◽  
Crop Fields ◽  
Taxidea Taxus ◽  
Spermophilus Richardsonii ◽  
Selection Of

We examined nest- and roost-burrow characteristics from a declining population of burrowing owls (Athene cunicularia (Molina, 1782)) in Saskatchewan. Between 1992 and 2003, 84% of the 584 nests we found were in grassland pastures, even though these pastures constituted only 7% of the potentially available nesting area within our study area. In contrast, less than 3% of nests were in crop fields, despite these fields comprising 90% of the potentially available area. Within grassland pastures, owls selected nest burrows in areas with a higher density of burrows within 75 m (11.1 burrows/ha) compared with non-nest burrows of similar dimensions (5.6 burrows/ha). Richardson's ground squirrels (Spermophilus richardsonii (Sabine, 1822)) and badgers (Taxidea taxus (Schreber, 1777)) are the primary excavators of suitable nesting burrows in prairie Canada. In our study area, burrowing owls chose to nest and roost in badger-sized burrows, selecting those with taller tunnel entrances and soil mounds relative to unused burrows. We suggest that management for burrowing owl nesting habitat in Canada should consider the owls' avoidance of crop fields and their preference for grassland pastures. Managers should also consider the owls' apparent preference for nesting in areas of high burrow densities and their selection of badger-sized burrows for nesting and roosting.

scholarly journals Burrowing Owl (Athene Cunicularia) Population Genetics: A Comparison of North American Forms and Migratory Habits

The Auk ◽  
2005 ◽  
Vol 122 (2) ◽  
pp. 464-478 ◽  
Author(s):  
Nicole M. Korfanta ◽  
David B. McDonald ◽  
Travis C. Glenn
Keyword(s):  
Genetic Differentiation ◽  
North American ◽  
Habitat Structure ◽  
Gene Diversity ◽  
Athene Cunicularia ◽  
Population Declines ◽  
The West ◽  
Burrowing Owls ◽  
Burrowing Owl ◽  
Patchy Habitat

Abstract We assessed the effects of range disjunction, migratory habit, coloniality, and habitat structure on the genetic differentiation of North American Burrowing Owl (Athene cunicularia) populations. Burrowing Owls in North America comprise two forms or subspecies: A. c. floridana in Florida, separated by ∼1,500 km from the western form, A. c. hypugaea, which ranges from Texas to California and north to southern Canada. Burrowing Owls tend to be loosely colonial, and both the Florida populations and southerly populations of A. c. hypugaea from California to Texas are nonmigratory. To assess genetic structure, we examined 201 individuals from nine western and six Florida populations at seven highly variable microsatellite DNA loci. Mean gene diversity (Hexp) was higher in the west than in Florida (0.539 and 0.341, respectively; P < 0.05). Populations within subspecies were essentially panmictic (A. c. floridana: θ = 0.038, ρ = 0.014; A. c. hypugaea: θ = 0.014, ρ = 0.009) and even genetic differentiation across subspecies was modest (θ = 0.051, ρ = 0.014). Nevertheless, the western and Florida forms were easily distinguished by any of several criteria, such as allelic absences in Florida, assignment tests, and well-supported branches on the inferred phylogenetic tree. Genetic differentiation was at least twice as great in resident Florida (θ = 0.038) and California (θ = 0.021) populations as in migratory western populations (θ = 0.012), though 95% confidence intervals of theta estimates overlapped. We found no evidence of a genetic bottleneck that would result in evolutionary disequilibrium within subspecies. In the west, high observed heterozygosity values and evidence of gene flow suggest that population declines and patchy habitat, which currently imperil this species throughout much of its range, have not led to inbreeding or biologically meaningful genetic differentiation among the sampled populations.

Description of Sarcocystis campestris sp. n. (Protozoa: Sarcocystidae): a parasite of the badger Taxidea taxus with experimental transmission to the Richardson's ground squirrel, Spermophilus richardsonii

1983 ◽  
Vol 61 (2) ◽  
pp. 370-377 ◽  
Author(s):  
Richard J. Cawthorn ◽  
Gary A. Wobeser ◽  
Alvin A. Gajadhar
Keyword(s):  
Ground Squirrel ◽  
Prepatent Period ◽  
Ground Squirrels ◽  
Intermediate Hosts ◽  
Patent Period ◽  
Sporocyst Residuum ◽  
Experimental Transmission ◽  
Taxidea Taxus ◽  
Spermophilus Richardsonii ◽  
Large Round

Sarcocystis campestris sp. n. (Protozoa: Sarcocystidae) is an heteroxenous coccidium with badgers (Taxidea taxus) as natural and experimental definitive hosts and Richardson's ground squirrels (Spermophilus richardsonii) as experimental intermediate hosts. Free sporocysts (10.2 × 8.0 μm with a large, round sporocyst residuum consisting of a single refractile granule), obtained from intestinal scrapings of badgers (carcasses frozen 2 years at −20 °C), were orally administered to juvenile Richardson's ground squirrels. Acute fatal sarcocystosis developed in some squirrels at 11–13 days postinoculation (p.i.). Meronts (second generation) were present 9–12 days p.i. in the vascular endothelium of many tissues (especially the lungs). Cysts developed in skeletal muscle, contained metrocytes (7 × 5 μm) 30 days p.i., and beginning 46 days p.i., bradyzoites (12.0 × 3.5 μm) were present. Cysts were macroscopic as early as 258 days p.i. Squirrel carcasses containing cysts (76 days p.i.) of S. campestris sp. n. were fed to Sarcocystis-free badgers. The prepatent period was 9 days and the patent period at least 13 days. Both badgers were ill early in the patent period and passed unformed feces during the patent period. Free sporocysts were 10.2 × 8.0 μm and each had an elongate sporocyst residuum containing numerous small refractile granules.

Killing technique of North American badgers preying on Richardson's ground squirrels

2001 ◽  
Vol 79 (11) ◽  
pp. 2109-2113 ◽  
Author(s):  
Gail R Michener ◽  
Andrew N Iwaniuk
Keyword(s):  
North American ◽  
Prey Size ◽  
Ground Squirrels ◽  
Thoracic Cavity ◽  
Internal Organs ◽  
Small Prey ◽  
Taxidea Taxus ◽  
Spermophilus Richardsonii ◽  
Southern Alberta

Carcasses of 13 Richardson's ground squirrels (Spermophilus richardsonii) cached during autumn by North American badgers (Taxidea taxus) in southern Alberta, Canada, were inspected to determine the capture and killing technique. Regardless of prey size (251–651 g) or torpor status (normothermic or torpid), badgers killed ground squirrels with a single grasping bite directed dorsally or laterally to the thorax. The canines and third upper incisors of badgers generally bruised the skin without puncturing it, but caused extensive hematomas on the thoracic musculature and penetrated between the ribs, with associated breakage of ribs and hemorrhaging in the thoracic cavity. Internal organs and bones other than ribs were usually not damaged. Thoracic bites, rather than nape or throat bites, are used by several mustelids, including North American badgers, when capturing small prey (<10% of the predator's mass).

Investigation of the geographic origin of burrowing owl fleas with implications for the ecology of plague

The Auk ◽  
2019 ◽  
Vol 136 (1) ◽  
Author(s):  
Kara A Navock ◽  
David H Johnson ◽  
Samantha Evans ◽  
Matthew J Kohn ◽  
James R Belthoff
Keyword(s):  
Isotope Analysis ◽  
Geographic Origin ◽  
Breeding Ground ◽  
Athene Cunicularia ◽  
Wintering Grounds ◽  
Burrowing Owls ◽  
Burrowing Owl ◽  
Isotopic Compositions ◽  
Breeding Grounds ◽  
Host Parasite

ABSTRACT Host-parasite relationships between Western Burrowing Owls (Athene cunicularia hypugaea) and the fleas (Pulex irritans, Siphonaptera:Pulicidae) they harbor were studied to understand the extent to which migratory Burrowing Owls translocated fleas from wintering grounds to breeding grounds. This has implications for host-parasite relationships in Burrowing Owls and also potentially for the dynamics of plague, as Burrowing Owl distributions overlap plague foci, owls inhabit fossorial mammal colonies where epizootic outbreaks of plague occur, and owls may harbor species of flea that are competent plague vectors. We used hydrogen stable isotope analysis to help elucidate geographic origins of fleas collected from adults and nestlings in 2 migratory populations of Burrowing Owls in Idaho and Oregon, USA. For adults, we posited that bird-mediated dispersal would impart flea isotopic compositions representative of southern latitudes and be similar to owl toenail tissue recently grown on wintering grounds, but they would differ from contour feathers presumably grown on breeding grounds the previous year. We assumed nestling feathers and toenails would have isotopic compositions representative of the breeding grounds. We analyzed contour feathers and toenails from adults collected shortly after they arrived in breeding grounds following spring migration and from nestlings later in the breeding season, to which we compared isotopic compositions in fleas collected from individuals of both age classes. Fleas on nestlings in both populations had isotopic compositions that did not differ from nestling feathers and toenails, suggesting that nestling fleas had breeding ground origins. Fleas on adults in one population (Oregon) had breeding ground isotopic signatures, as flea compositions did not differ from nestling feathers or toenails. Adult owls in Idaho had fleas that similarly did not express a wintering ground signature, but they were enriched in the heavy isotope (deuterium) relative to nestling feathers and toenails. Therefore, we discuss the possibility that adult owls in Idaho acquired fleas at migratory stopover sites. While the latter indicates that Burrowing Owls have the potential to disperse fleas, there was no evidence of continent-wide movement of fleas by owls from wintering grounds to breeding grounds.

scholarly journals Demography of the Burrowing Owl in Badlands National Park

1991 ◽  
Vol 15 ◽  
pp. 55-58
Author(s):  
Mark Martell ◽  
Patrick Redig ◽  
Jill Nibe
Keyword(s):  
Great Plains ◽  
Management Practices ◽  
Athene Cunicularia ◽  
Prairie Dog ◽  
Burrowing Owls ◽  
Burrowing Owl ◽  
Nest Site Fidelity ◽  
Population Sizes ◽  
Wintering Areas ◽  
Badlands National Park

The burrowing owl (Athene cunicularia), was once widely distributed throughout the western United States and Canada (Bent 1938), and was considered common on the prairie dog towns of South Dakota and Nebraska (Cooke 1888, Over and Thomas 1920). Recently however, concern over the birds status has resulted in its being listed as; "endangered" in two states (MN and lA), "threatened" across its range in Canada, and of "special concern" in seven states (WA, OR, CA, MT, WY, ND, FL) (Martell1990). Land management practices including grazing, shooting, and poisoning on prairie dog colonies, the primary nesting habitat of burrowing owls in the Great Plains, has the potential to greatly affect owl populations. Information on population sizes and trends, the location of wintering areas, and the degree of nest site fidelity is needed to monitor and manage this species on public lands.

scholarly journals Isolation and characterization of 7 microsatellite loci for the Florida Burrowing Owl (Athene cunicularia floridana)

2016 ◽  
Author(s):  
Alison Laxer ◽  
Maureen Krause ◽  
Ann Marie Clark ◽  
Melissa M Grigione ◽  
Ronald Sarno
Keyword(s):  
Microsatellite Loci ◽  
Random Mating ◽  
Athene Cunicularia ◽  
Burrowing Owls ◽  
Burrowing Owl ◽  
Isolation And Characterization ◽  
Special Concern ◽  
Key Aspects

Despite long-term scientific interest in the Florida Burrowing Owl, little is known about key aspects of its ecology that likely influence population persistence. This is a cause of alarm considering that the Florida Burrowing Owl has been designated a “Species of Special Concern” since 1979. Therefore, seven microsatellite loci were developed and characterized for 48 Florida Burrowing Owls. All loci were polymorphic and six of them differed significantly from Hardy-Weinberg expectations. Although preliminary, the number of loci out of HW equilibrium may result from low population size and resultant non-random mating that could be caused by habitat fragmentation as development has ensued.

scholarly journals Survival and Movements of Juvenile Burrowing Owls During the Postfledging Period

The Condor ◽  
2006 ◽  
Vol 108 (2) ◽  
pp. 282-291 ◽  
Author(s):  
J. Morgan Davies ◽  
Marco Restani
Keyword(s):  
Brood Size ◽  
Cynomys Ludovicianus ◽  
Adult Survival ◽  
First Year ◽  
Juvenile Survival ◽  
Athene Cunicularia ◽  
Prairie Dog ◽  
Burrowing Owls ◽  
Burrowing Owl ◽  
First Year Of Life

AbstractBurrowing Owl (Athene cunicularia) populations have declined extensively throughout much of North America, and modeling demography may assist conservation. However, few studies have estimated adult survival, and fewer still have determined juvenile survival. In 2003 and 2004 we monitored survival of 40 radio-tagged juveniles during the postfledging period in the Little Missouri National Grassland, North Dakota, where owls nested in black-tailed prairie dog (Cynomys ludovicianus) colonies. Survival averaged 0.57 (95% CI: 0.41–0.73) prior to autumn migration. Mortality was highest during the first two weeks after nest departure when juveniles were flightless, and two to three weeks later when juveniles became independent. Predation or starvation was implicated in most deaths. Distribution and abundance of escape cover (number of prairie dog burrows within 30 m of nests and size of the natal prairie dog colony) did not affect survival. Body condition and brood size at the time of radio-tagging also did not influence survival. Juvenile owls exhibited nest-centered dispersal, and averaged 108 ± 21 (SE) m and 82 ± 17 m from nests at initiation of migration in 2003 and 2004, respectively. Mean dates of departure from the study area were 2 September (± 3 days) 2003 and 24 August (± 2 days) 2004. Mortality during the postfledging period accounted for approximately two-thirds of mortality in the first year of life.

scholarly journals Evaluating cropland in the Canadian prairies as an ecological trap for the endangered Burrowing Owl Athene cunicularia

Ibis ◽  
2019 ◽  
Vol 162 (1) ◽  
pp. 162-174
Author(s):  
Corey A. Scobie ◽  
Erin M. Bayne ◽  
Troy I. Wellicome
Keyword(s):  
Ecological Trap ◽  
Athene Cunicularia ◽  
Canadian Prairies ◽  
Burrowing Owl

Nest stage, wind speed, and air temperature affect the nest defence behaviours of burrowing owls

2004 ◽  
Vol 82 (5) ◽  
pp. 707-713 ◽  
Author(s):  
Ryan J Fisher ◽  
Ray G Poulin ◽  
L Danielle Todd ◽  
R M Brigham
Keyword(s):  
Wind Speed ◽  
Air Temperature ◽  
Reproductive Investment ◽  
Weather Conditions ◽  
Nest Defence ◽  
Athene Cunicularia ◽  
Burrowing Owls ◽  
Burrowing Owl ◽  
Air Temperatures ◽  
The Impact

The effect of nest stage on nest defence responses has been fairly well established but the impact of weather conditions has been largely ignored. We examined the effects of nest stage, number of previous visits, wind speed, and air temperature on burrowing owl (Athene cunicularia (Molina, 1782)) defence of nests from a human intruder. We found that burrowing owls changed nest defence tactics from retreat behaviour to more confrontational behaviour once eggs hatched. Aggressiveness was significantly reduced as wind velocity increased and when temperatures were warmer. We found no evidence for a change in owl defence behaviour with the number of previous visits to a nest. Although not statistically significant, there was a tendency for burrowing owls to allow closer approaches and to not retreat as far once eggs had hatched. Wind speed did not have an effect on retreat or approach distances, and owls allowed us to get significantly closer to the nest before retreating when air temperatures were warm. There are a multitude of factors that could affect nesting success and thus fitness of birds, but our study shows that routine climatic events such as warm weather had a measurable impact on how a bird defended its reproductive investment.

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