Activity budgets and group size of caribou during spring migration

1987 ◽  
Vol 65 (1) ◽  
pp. 164-168 ◽  
Author(s):  
Laurel S. Duquette ◽  
David R. Klein
Keyword(s):  
Group Size ◽  
Social Facilitation ◽  
Early Spring ◽  
Spring Migration ◽  
Activity Budgets ◽  
Average Proportion ◽  
Study Sites ◽  
Migratory Movements ◽  
Dominant Activity ◽  
Walking Time

Activity budgets and group size of caribou were described throughout the early spring migration in 1982 and 1983. Pregnant cows were the predominant cohort under observation. Activity budgets and group size of migrating caribou are compared with data from nonmigrating caribou and reindeer to test the hypothesis that the spring migration of pregnant cow caribou will occur with minimal disruption of the normal grazing pattern to ensure maintenance of body condition. The average proportion of time migrating caribou spent feeding, lying, standing, and walking was 61, 28, 1, and 9%, respectively, in 1982 and 64, 24, 1, and 11%, respectively, in 1983. Grazing was consistently the dominant activity throughout migration while lying time was negatively correlated with walking time. Migrating caribou spent more time grazing and walking and less time standing and lying than nonmigrating caribou and reindeer during this season. Discrete caribou groups were difficult to identify because mixing of caribou between groups was common. Groups were identifiable at four study sites and group size ranged from 8 to 393 caribou. At three study sites, caribou were associated with aggregations of 500+ animals. Large social aggregations may be important for stimulating migratory movements through the process of social facilitation.

scholarly journals Seasonal differences in migration strategies of Red Kites (Milvus milvus) wintering in Spain

2021 ◽  
Author(s):  
Jorge García-Macía ◽  
Javier Vidal-Mateo ◽  
Javier De La Puente ◽  
Ana Bermejo ◽  
Rainer Raab ◽  
...  
Keyword(s):  
Spring Migration ◽  
Great Variability ◽  
Autumn Migration ◽  
Seasonal Differences ◽  
North Eastern ◽  
Wintering Areas ◽  
Satellite Transmitters ◽  
Migration Strategies ◽  
Migratory Movements ◽  
Milvus Milvus

AbstractRed Kite shows a great variability in its migration strategies: most individuals in north-eastern Europe are migrants, but there is also a growing number of sedentary individuals. Here, we tagged 49 Red Kites wintering in Spain with GPS/satellite transmitters between 2013 and 2020 to study the autumn and spring migration between the breeding or summering areas in Central Europe and the wintering quarters in Spain. In first place, differences between immatures and adults were found for spring migration. Adults began the spring migration towards the northeast in February–March while the immature individuals began to migrate significantly later and showing a wider date range (February-June). Adults also takes significantly less days to arrive at their destinations (12 ± 5 days) and cover more distance per day (134.2 ± 37.1 km/day) than immatures (19 ± 11 days and 98.9 ± 21.2 km/day). In second place, we also found differences between spring and autumn migration (excluding immatures). Spring migrations were clearly faster and with less stopovers days than autumn migrations. Autumn migration began between mid-October and late November and two different behaviours were observed: most birds made a quick migration direct to the wintering areas with only some days of stopovers, but others prolonged the migration with long stops along the route. These results highlight a great variation in the migratory movements of Red Kite, not only according to age but also between individuals and seasons.

Rays and Skates of Devon and Cornwall. II. A Study of the Fishery; with Notes on the Occurrence, Migrations and Habits of the Species

1932 ◽  
Vol 18 (1) ◽  
pp. 1-33 ◽  
Author(s):  
G. A. Steven
Keyword(s):  
Early Spring ◽  
English Channel ◽  
Adult Fish ◽  
The West ◽  
Full Extent ◽  
Sea Bottom ◽  
Western Area ◽  
Migratory Movements ◽  
Eleven Species ◽  
Inshore Migration

1. Until the beginning of the present century there was little demand in this country for Rays and Skates. This fishery is now of major importance both nationally and within the Devon and Cornwall area.2. Of the eleven species of Raia present in the western area of the Channel, R. clavata makes the greatest numerical contribution (37%) to the total landings in Devon and Cornwall. The composition of the catches obtained by different methods of fishing varies greatly.3. R. clavata is the most widely distributed species in the Channel area at all depths and on all kinds of sea bottom.4. In a series of trawl hauls off the west coast of Ireland R. clavata was most numerous in the catches down to about 100 fm. From that depth down to about 170 fm. (the greatest depth fished) R. fullonica was most numerous.5. Unispecific and even unisexual shoals of at least three species of Raia—R. clavata, R. brachyura, R. fullonica—occur.6. When more than one species of Raia is present within the same area at the same time, the members of the different species have been found not to mix indiscriminately.7. R. clavata appears to hatch out in shallow water close inshore and gradually move seawards into deeper water as it grows.8. Adult R. clavata show definite migratory movements, though the full extent of their wanderings is not yet known. There is an inshore migration in early spring of adult fish to a small part of the coast near Plymouth. The first fish to appear are females, males appearing later.9. There is evidence of somewhat similar migratory movements by R. brachyura.10. R. clavata—and possibly also R. brachyura and R. batis—at times may feed almost entirely on Herrings.11. Large R. batis feed to no inconsiderable extent on other species of Eaia.12. In foraging for their food Rays and Skates depend upon some sense other than sight.13. There has been in recent years a steady decline in the landings of Rays and Skates from the English Channel—probably due to depletion of the available stock of fish.

scholarly journals Seasonal activity of the Denali caribou herd, Alaska

Rangifer ◽  
1985 ◽  
Vol 5 (2) ◽  
pp. 32 ◽  
Author(s):  
Rodney D. Boertje
Keyword(s):  
Nutritional Status ◽  
Food Availability ◽  
Nutritional Stress ◽  
Early Spring ◽  
High Availability ◽  
Late Winter ◽  
Seasonal Activity ◽  
Activity Budgets ◽  
West Greenland ◽  
Rest Periods

<p>Activity of female and young caribou in the Denali herd was studied from June 1978 through April 1980 to help assess the food availability/nutritional status of this reduced population. No nutritional stress was evident as inferred by the greater activity of Denali caribou in late winter compared with starving caribou in West Greenland and by the low proportion of time spent grazing in spring compared with reindeer on overgrazed ranges in Norway. Also, low proportions of time were spent running from insects due to relatively few insects and a high availability of insect-relief sites. A low proportion of time was spent cratering due to windswept conditions. Activity budgets calculated from complete active-rest cycles and accompanied by the duration of active and rest periods may be useful indicators of relative food availability/nutritional status, particularly in late winter/early spring. Duration of active periods is presumably most strongly related to rumen fill, and, thus, food availability. Duration of rest periods was not significantly different among seasons (P&lt;0.05), except when insects, rutting bulls, and, presumably, mushroom-searching altered active-rest cycles.</p><p>Sesongmessige svingninger av aktiviteten i Denali karibu-flokk, Alaska.</p><p>Abstract in Norwegian / Sammendrag: Aktiviteten hos simler og ungdyr i Denali karibouflokk ble studert fra juni 1978 til utgangen av april 1980 som hjelpemiddel for &aring; bestemme n&aelig;ringstilbud/ern&aelig;ringsstatus i denne reduserte karibustamme. Ingen ern&aelig;ringsmessig stress var &aring;penbar, noe som kan utledes av den st&oslash;rre aktivitet hos Denali karibu p&aring; senvinteren sammenlignet med sultende karibu i Vest-Gr&oslash;nland samt den lave andel av beiting sammenlignet med rein p&aring; overbelastede beiter i Norge. Videre ble en lav andel av tiden brukt til &aring; r&oslash;mme fra insekter, fordi insektplagen var relativt liten og at det var lett adgang til omr&aring;der der dyrene kunne befri seg fra insektene. Graving krevde ogs&aring; liten andel av tid takket v&aelig;re vindbl&aring;ste sn&oslash;forhold. Aktivitetsbudsjetter beregnet ut fra totale aktivitets-/hvilesykluser kan v&aelig;re nyttige indikatorer p&aring; relativ n&aelig;ringstilbud/ern&aelig;ringsstatus, s&aelig;rlig p&aring; senvinter og tidlig v&aring;r. Varigheten av aktive perioder er sannsynligvis mest knyttet til vomfylde og, derfor, til n&aelig;ringstilbud eller n&aelig;ringstilgjengelighet. Varigheten av hvileperioder var ikke signifikant forskjellig mellom sesonger (P&lt;0.05), unntatt n&aring;r insekter, brunstige bukker og, sannsynligvis ogs&aring;, sopps&oslash;king forandret aktivitet-/hvilesykluser.</p>

scholarly journals Migrating bison engineer the green wave

2019 ◽  
Vol 116 (51) ◽  
pp. 25707-25713 ◽  
Author(s):  
Chris Geremia ◽  
Jerod A. Merkle ◽  
Daniel R. Eacker ◽  
Rick L. Wallen ◽  
P. J. White ◽  
...  
Keyword(s):  
New Technology ◽  
Empirical Support ◽  
Early Spring ◽  
Bison Bison ◽  
Small Scale ◽  
Large Aggregate ◽  
Decadal Shift ◽  
Grassland Ecosystems ◽  
Engineer Plant ◽  
Migratory Movements

Newly emerging plants provide the best forage for herbivores. To exploit this fleeting resource, migrating herbivores align their movements to surf the wave of spring green-up. With new technology to track migrating animals, the Green Wave Hypothesis has steadily gained empirical support across a diversity of migratory taxa. This hypothesis assumes the green wave is controlled by variation in climate, weather, and topography, and its progression dictates the timing, pace, and extent of migrations. However, aggregate grazers that are also capable of engineering grassland ecosystems make some of the world’s most impressive migrations, and it is unclear how the green wave determines their movements. Here we show that Yellowstone’s bison (Bison bison) do not choreograph their migratory movements to the wave of spring green-up. Instead, bison modify the green wave as they migrate and graze. While most bison surfed during early spring, they eventually slowed and let the green wave pass them by. However, small-scale experiments indicated that feedback from grazing sustained forage quality. Most importantly, a 6-fold decadal shift in bison density revealed that intense grazing caused grasslands to green up faster, more intensely, and for a longer duration. Our finding broadens our understanding of the ways in which animal movements underpin the foraging benefit of migration. The widely accepted Green Wave Hypothesis needs to be revised to include large aggregate grazers that not only move to find forage, but also engineer plant phenology through grazing, thereby shaping their own migratory movements.

Group size and activity patterns of belugas (Delphinapterus leucas) and narwhals (Monodon monoceros) during spring migration in Lancaster Sound

1991 ◽  
Vol 69 (6) ◽  
pp. 1630-1635 ◽  
Author(s):  
Susan E. Cosens ◽  
Larry P. Dueck
Keyword(s):  
Group Size ◽  
Predator Avoidance ◽  
Additional Data ◽  
Activity Patterns ◽  
Size Variation ◽  
Spring Migration ◽  
Delphinapterus Leucas ◽  
Interspecific Differences ◽  
Monodon Monoceros ◽  
Grouping Patterns

Aerial surveys of belugas (Delphinapterus leucas) and narwhals (Monodon monoceros) were conducted in Lancaster Sound and northern Admiralty Inlet, N.W.T., during spring migration in 1987. Interspecific differences in grouping patterns and associated behaviour were observed. Group size and behaviour varied with ice type and state of breakup but patterns of variation differed between species. Behaviour of narwhals but not of belugas varied significantly with group size. Variation in group size and activity suggests that aggregation patterns are not related to predator avoidance strategies. Additional data are needed to test hypotheses about grouping patterns and behaviour in relation to prey distribution.

Trumpeter swan behaviour at spring-migration stopover areas in southern Alberta

2001 ◽  
Vol 79 (11) ◽  
pp. 2036-2042 ◽  
Author(s):  
Jalene M LaMontagne ◽  
Robert MR Barclay ◽  
Leland J Jackson
Keyword(s):  
Time Budget ◽  
Spring Migration ◽  
Energy Reserves ◽  
Cygnus Buccinator ◽  
Behavioural Study ◽  
Southern Alberta ◽  
Wintering Areas ◽  
Trumpeter Swan ◽  
Trumpeter Swans ◽  
Dominant Activity

The use of breeding and wintering areas has been a focus of studies on trumpeter swans (Cygnus buccinator), but the importance of migration stopover areas has been overlooked. We conducted a behavioural study to assess trumpeter swans' use of spring-migration stopover areas in southern Alberta, Canada. Adult swans foraged for 48% of the day, preened for 12%, rested for 26%, and were involved in locomotion for 14% of the time. Cygnets foraged for 49% of the day, preened for 15%, rested for 19%, and were involved in locomotion for 18% of their time. Temperature had a significant effect on the time budget of trumpeter swans: below –4°C, foraging diminished and sleeping was the dominant activity. The dominant activity of trumpeter swans in spring-migration stopover areas was foraging. We therefore suggest that these stopover areas are important for building the energy reserves required for successful migration and breeding.

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