scholarly journals Natural history, population dynamics, and habitat use of humpback whales over 30 years on an Alaska feeding ground

Ecosphere ◽  
2017 ◽  
Vol 8 (1) ◽  
pp. e01641 ◽  
Author(s):  
Christine M. Gabriele ◽  
Janet L. Neilson ◽  
Janice M. Straley ◽  
C. Scott Baker ◽  
Jennifer A. Cedarleaf ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Natural History ◽  
Habitat Use ◽  
Humpback Whales ◽  
Feeding Ground

Modeling cetacean habitat use in an urban coastal area in southeastern Brazil

2020 ◽  
Vol 642 ◽  
pp. 227-240
Author(s):  
L Lodi ◽  
R Tardin ◽  
G Maricato
Keyword(s):  
Habitat Use ◽  
Protected Areas ◽  
Linear Models ◽  
Anthropogenic Activities ◽  
Buffer Zone ◽  
Humpback Whales ◽  
Southeastern Brazil ◽  
Major Influence ◽  
Cetacean Species ◽  
Few Data

Most studies of cetacean habitat use do not consider the influence of anthropogenic activities. We investigated the influence of environmental and anthropogenic variables on habitat use by humpback Megaptera novaeangliae and Bryde’s whales Balaenoptera brydei off the coast of the Brazilian city of Rio de Janeiro. Although there are 2 marine protected areas (MPAs) in this area, few data are available on cetacean habitat use or on the overlap of different cetacean species within these MPAs. Our aim was to evaluate the effectiveness of the MPAs and propose a buffer zone to better protect the biodiversity of the study area. We conducted systematic surveys and developed spatial eigenvector generalized linear models to characterize habitat use by the species in the study area. Habitat use by humpback whales was influenced only by depth, whereas for Bryde’s whales there was the additional influence of anthropogenic variables. For Bryde’s whales, which use the area for feeding, sea surface temperature and the distance to anchorages had a major influence on habitat use. We also showed that neither of the MPAs in the study area adequately protects the hotspots of either whale species. Most of the humpback whale grid cells with high sighting predictions were located within 2 km of the MPAs, while areas of high sighting prediction of Bryde’s whales were located up to 5 km from the MPAs, closer to beaches. Our findings provide important insights for the delimitation of protected areas and zoning of the MPAs.

scholarly journals Population abundance, natural history, and habitat use by the arboreal marsupialDromiciops gliroidesin rural Chiloé Island, Chile

2012 ◽  
Vol 93 (1) ◽  
pp. 134-148 ◽  
Author(s):  
Juan L. Celis-Diez ◽  
Jennifer Hetz ◽  
Paula A. Marín-Vial ◽  
Gonzalo Fuster ◽  
Pablo Necochea ◽  
...  
Keyword(s):  
Natural History ◽  
Habitat Use ◽  
Population Abundance

Age-specific behavior and habitat use in humpback whales: Implications for vessel strike

2021 ◽  
Author(s):  
JEF Stepanuk ◽  
EI Heywood ◽  
JF Lopez ◽  
RA DiGiovanni Jr ◽  
LH Thorne
Keyword(s):  
Habitat Use ◽  
Humpback Whales ◽  
Specific Behavior

Modelling climate influences on population dynamics and diurnal time budget of the Shelduck (Tadorna tadorna) wintering in Ramsar wetlands of Algeria

2019 ◽  
Vol 12 (3) ◽  
pp. 77-95 ◽  
Author(s):  
Adel Bezzalla ◽  
Moussa Houhamdi ◽  
Mohamed Cherif Maazi ◽  
Haroun Chenchouni
Keyword(s):  
Population Dynamics ◽  
Habitat Use ◽  
Generalized Linear Models ◽  
Linear Models ◽  
Time Budget ◽  
Climate Variables ◽  
Conspecific Density ◽  
Lack Of Information ◽  
International Importance ◽  
Important Bird Area

Several North African wetlands are classified as wetlands of international importance (Ramsar sites and Important Bird Area) because thousands of Shelducks ( Tadorna tadorna) winter in these habitats. However, Shelduck’s patterns of habitat use in these protected wetlands during the wintering season are still hindered by lack of information in arid and semi-arid regions regarding population dynamics and the effects of climate variables. This ornithological survey aims to study population dynamics and temporal patterns of diurnal activities of the Shelduck at two Ramsar and Important Bird Area sites (Chott Tinsilt and Sebkhet Ezzemoul) with respect to the effect of climatic parameters of the habitat in order to deepen our understanding of wintering strategies and habitat use. Populations were weekly censused from 06:00 to 19:00 during the entire wintering season (September 2015–May 2016). Diurnal behavioural activities were monitored at the same rate, and then the variation of time budget was tested using generalized linear model to determine the effects of climate variables and conspecific density dependence. The Shelduck was observed at both sites from the end of November and remained there until the total desiccation of both lakes in early May. Trends of Shelduck’s population dynamics differed between the two sites. Generalized linear models revealed the significant effects of temperature, wind speed and number of snowy days on population dynamics. Feeding was the main diurnal activity of the Shelduck at both sites with 80.2% of time budget at Chott Tinsilt (mainly feeding at lake shores) and 82% at Sebkhet Ezzemoul (mainly feeding in water). The generalized linear models showed that the variation of time budget allocated to different diurnal activities was not density-dependent, but rather it was negatively affected by the increase of air temperature. Significant effects of the interaction between population size and some climatic variables were found and discussed. During the whole wintering season, Chott Tinsilt and Sebkhet Ezzemoul play an important ecological role since they offer a wide-ranging diurnal forging habitat and a shelter for thousands of this waterfowl.

scholarly journals Low latitude habitat use patterns of a recovering population of humpback whales

2018 ◽  
Vol 98 (5) ◽  
pp. 1087-1096 ◽  
Author(s):  
Maria Isabel Carvalho Gonçalves ◽  
Renata Santoro De Sousa-Lima ◽  
Niel Nascimento Teixeira ◽  
Maria Emilia Morete ◽  
Gustavo Henrique De Carvalho ◽  
...  
Keyword(s):  
Habitat Use ◽  
Cost Effective ◽  
Humpback Whales ◽  
Anthropogenic Activity ◽  
Small Scale ◽  
Nursery Ground ◽  
Social Strategies ◽  
Low Latitude ◽  
Use Patterns ◽  
Key Factor

The coast of Brazil is an important low latitude nursery ground for humpback whales (Megaptera novaeangliae). The number of humpback whales in this region has increased and its population is reoccupying areas where it has been depleted during the whaling period. The goal of this study was to conduct land-based observations during 2014 and 2015 to characterize patterns of habitat use and relative abundance of humpback whales that migrate to one of these reoccupation areas: Serra Grande, Bahia state. The observed mean group size was 2.12 ± 0.96 individuals and did not vary through the reproductive season nor between years. Dyads (32.9%) and singletons (26.7%) were more frequently observed, and groups with calves represented 21.2% of the sightings. The mean number of whales counted per hour increased from 2014 (3.44 ± 3.35) to 2015 (5.12 ± 4.18). Habitat use varied during the season; whales used shallower waters closer to shore as the season progressed. The spatial distribution of groups with calves was dependent on the presence and number of escorts. Spatial segregation of groups with calves closer to shore is a key factor in understanding the overall distribution of whales in the area, suggesting that social strategies are affected by environmental factors, as seen in other wintering grounds. Small-scale studies from land-based stations, in areas such as this where there is no previous knowledge about the species, are cost effective. They provide information about the overall behavioural and spatial patterns while anthropogenic activity is still low, allowing habitat protection and management decisions before implementation and increase of human activities.

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