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301 result(s) for "Hendricks, Paul"
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CANADA JAY PREDATION OF WINTER TICKS (DERMACENTOR ALBIPICTUS)
In this note, I report on my observations of a pair of Canada Jays (Perisoreus canadensis) gathering live engorged female Winter Ticks (Dermacentor albipictus) from the recent bed of a yearling Moose (Alces alces) and flying into the adjacent woods to cache the ticks before returning for more. The Moose bed was on snow and contained loose hair and blood-stained snow as well as the engorged ticks. I found 12 additional beds on snow during the next 48 h within 250 m of the original bed, and all contained loose hair and blood-stained snow, but no ticks. Jays may routinely visit Moose beds on snow in spring because they recognize them as a potential source of food. Moose, however, may not be present during spring in many jay territories, so access to engorged ticks at beds is probably opportunistic and unreliable.
On the incubation behavior of Evening Grosbeaks (Coccothraustes vespertinus)
Knowledge of the breeding behavior of Evening Grosbeaks (Coccothraustes vespertinus) is based largely on a multiyear study in Colorado during the 1980s. In Colorado, the duration of full incubation bouts by female grosbeaks had a mean of 26.6 min, a value repeated since then in the literature. For one nesting pair of grosbeaks I studied in Montana, full incubation bouts (n = 5) by the undisturbed female during 22 h of direct nest watches on 7 d in June 2018 had a mean of 112.6 min (range = 45–202 min), much longer than the value reported in the Colorado study. Incomplete incubation bouts (female already incubating on my arrival or at my departure) by the undisturbed Montana female (n = 11) during the same observation period had a mean of 56.2 min, 4 of which were a minimum of 94–146 min, further suggesting that longer duration incubation bouts may be the norm for this species. Duration of incubation bouts for Evening Grosbeak in the Colorado study appear to be brief relative to other North American fringillids, but my limited data suggest that Evening Grosbeaks are typical in this regard. Mean duration of 10 nest absences by the undisturbed Montana incubating female was 9.7 ± 7.6 min (range = 3–26 min), similar to the Colorado study (10.1 ± 10.7 min). Male behavior during incubation also appeared similar to results from Colorado (no attending the eggs, frequent exchange of vocalizations with the nesting female, escorting and feeding the female only when off the nest). I conclude that the duration of nest watches (60–80 min) in the Colorado study was inadequate to determine the length of many longer incubation bouts by female Evening Grosbeaks.
SHARP-SHINNED HAWK FEEDING BEHAVIOR ON EURASIAN COLLARED-DOVES AT A WINTER-FEEDING STATION
We describe Sharp-shinned Hawk (Accipiter striatus) feeding behavior on Eurasian CollaredDoves (Streptopelia decaocto) at our backyard bird feeding station during winter 2024-2025. Collared-doves are large avian prey for Sharp-shinned Hawks to subdue, and considerable time is spent by hawks processing and feeding on carcasses once collared-doves are captured (at least 129 min and 262 min in 2 cases), which increases the exposure of hawks to potential prey theft and injury from other predators attracted to bird feeding stations for the same prey species. We also observed hawks retuming over multiple days to collared-dove kills, indicating hawks remembered where carcasses were left and that motion by avian prey is not necessary to attract a hawk's attention. In 2 cases, once the collared-dove carcass was stripped of much of its meat, the hawk carried the carcass to another location out of view, possibly caching the remains in a more protected location for future feeding visits. We anticipate that Sharp-shinned Hawks will attack collared-doves with greater frequency as the 2 species continue to encounter each other at winter feeders.
BLACK-BILLED MAGPIES (PICA HUDSONIA) CACHING FOOD IN SNOW
I observed Black-billed Magpies (Pica hudsonia) in a residential backyard in Montana during November-December 2019 and February 2020, as they cached food 10 times in a snow cover 10- to 12-cm deep and recovered 3 caches from the snow. The magpies carried food items up to 7 m from a food source before caching them, and tended to cache more closely to the food source when alone rather than in the presence of other magpies. Most of the snow caches were on the ground, but 1 cache was made 1.5 m above ground in a snow-covered vine thicket, and a 2nd cache at the same height in snow accumulated on the roof of a parked trailer. Cached foods included chicken scratch (grains and cracked corn), sunflower seeds, crab apples, dried mealworms, and commercial suet. These observations appear to constitute the 1st report of Black-billed Magpies caching food in snow.
Anting Behavior by the Northwestern Crow (Corvus caurinus) and American Crow (Corvus brachyrhynchos)
Anting is one of the more peculiar behaviors performed by birds, and is widespread among Passeriformes. During this activity, birds deliberately introduce ants (Hymenoptera: Formicidae) into the plumage. Hendricks and Norment describe cases of anting by wild Northwestern Crows (Corvus caurinus) and a wild American Crow (Corvus brachyrhynchos), species for which anting by wild individuals has been infrequently reported. They also describe the context of the anting behavior. They further provide a brief review of anting behavior by North American Corvus and discuss common patterns.
The History and Politics of the Teachers' League of South Africa's Transformative Praxis
Hendricks examines the history and politics of the Teachers' League of South African's (TLSA) transformative praxis. Particular focus is given on the contribution of the TLSA to the educational and political landscape of the country. Africa, to the educational and political landscape of the country. It examines the organization's pedagogical politics of resistance, in particular the social theory of non-collaboration, which guided the organization from the mid-1940s, and how it influenced the League's strategic engagement with the educational politics embodied in teacher unionism and the emergent educational reforms during South Africa's transition of the l990s and the beginning of the twenty-first century.
Predatory Attack by a Western Terrestrial Garter Snake on a Nestling Dark-Eyed Junco
I observed a Western Terrestrial Garter Snake (Thamnophis elegans) attacking a large (approximately 9-d-old) nestling Dark-eyed Junco (Junco hyemalis) on 7 July 2018 near Rattlesnake Creek, Missoula County, Montana. The snake held the stillliving nestling by its head (the head was mostly enveloped by the snake's jaws) and continued to do so for 3 min before it released the now-dead nestling when disturbed by my presence. The dead nestling exhibited skin wounds on the neck but no other superficial injury. Predation on birds by Western Terrestrial Garter Snakes is infrequently reported, and I found only 2 other reports of predation on juncos by this snake species.
PREDATORY ATTACKS BY BLACK-BILLED MAGPIES (PICA HUDSONIA) ON CASSIN'S FINCH (HAEMORHOUS CASSINII) AND OTHER ADULT BIRDS
On 12 April 2021, we observed a Black-billed Magpie (Pica hudsonia) kill an apparently-healthy adult female Cassin's Finch (Haemorhous cassinii) in an urban backyard near a feeding station in Missoula, Montana. The magpie landed on a chain-link fence above the finch before dropping to the ground 1–2 s later where it grabbed the finch with its bill and pinned it to the ground with a foot, then delivered several blows of the bill to the finch's neck, back, and breast. The entire attack, from arrival of the magpie to its departure with the apparently-dead finch held in its bill, lasted no more than 60 s. We found only 2 prior reports of Black-billed Magpies capturing adult birds, and none for the Yellow-billed Magpie (Pica nuttalli). There are several published cases of the closely-related Eurasian Magpie (Pica pica) attacking and killing adult birds, indicating that magpies are quite capable of subduing birds if so motivated when given the opportunity. Black-billed Magpies and Eurasian Magpies tended to attack adult birds during winter through spring (non-breeding season), and most often in urban environments where small birds aggregate near concentrations of food or potential roost and nest sites, resources also attractive to magpies. These circumstances may afford magpies more close encounters with potential adult avian prey than might occur in rural locations, and may encourage them to hunt adult birds more frequently.
Context of rattle-call use by adult Belted Kingfishers (Megaceryle alcyon) near their nests
We documented use of rattle calls when adult Belted Kingfishers (Megaceryle alcyon) approached or departed active nest burrows, and contrasted rattle-call use during incubation and nestling phases of nesting. Adults rattled on 92.7% of 109 nest approaches and 56.2% of 105 nest departures (P = 0.021) combining both phases of nesting. During the incubation phase rattling occurred on 81% of 36 approaches and 28% of 32 departures (P < 0.001), and during the nestling phase rattling occurred on 99% of 73 approaches and 69% of 73 departures (P < 0.001). Overall, a significantly lower amount of rattling occurred during the incubation phase, both when approaching and departing the nest. Males and females exhibited similar patterns of rattle-call use at nest burrows during both phases of nesting. We suggest that use of rattle calls is more prevalent when approaching the nest burrow, despite drawing attention to the nest location, to advertise a mate's or parent's presence prior to entering the burrow and to avoid injury from the tending adult or nestlings defending themselves against an unknown intruder. We also suggest that adults are more secretive near the nest burrow during the incubation phase, especially when departing, because of a reduced need to communicate with their mate while tending the eggs during lengthy bouts of nest attendance. Nevertheless, it remains unclear why adults use rattle calls as much as they do when departing from the nest, which appears to unnecessarily advertise the nest location.
PREDATORY ATTACKS BY BLACK-BILLED MAGPIES AND OTHER ADULT BIRDS
On 12 April 2021, we observed a Black-billed Magpie (Pica hudsonia) kill an apparently-healthy adult female Cassin's Finch (Haemorhous cassinii) in an urban backyard near a feeding station in Missoula, Montana. The magpie landed on a chain-link fence above the finch before dropping to the ground 1-2 s later where it grabbed the finch with its bill and pinned it to the ground with a foot, then delivered several blows of the bill to the finch's neck, back, and breast. The entire attack, from arrival of the magpie to its departure with the apparently-dead finch held in its bill, lasted no more than 60 s. We found only 2 prior reports of Black-billed Magpies capturing adult birds, and none for the Yellow-billed Magpie (Pica nuttalli). There are several published cases of the closely-related Eurasian Magpie (Pica pica) attacking and killing adult birds, indicating that magpies are quite capable of subduing birds if so motivated when given the opportunity. Black-billed Magpies and Eurasian Magpies tended to attack adult birds during winter through spring (non-breeding season), and most often in urban environments where small birds aggregate near concentrations of food or potential roost and nest sites, resources also attractive to magpies. These circumstances may afford magpies more close encounters with potential adult avian prey than might occur in rural locations, and may encourage them to hunt adult birds more frequently.