Sentences with phrase «prey abundance»

Changing water temperature also has an effect on the reproduction of cetaceans and pinnipeds, indirectly through prey abundance, either through extending the time between individual breeding attempts, or by reducing breeding condition of the mother (Whitehead, 1997).

Some species of marine mammals will be able to take advantage of increases in prey abundance and spatial / temporal shifts in prey distribution toward or within their primary habitats, whereas some populations of birds and seals will be adversely affected by climatic changes if food sources decline or are displaced away from regions suitable for breeding or rearing of young.

Regions were divided into relative prey abundance based on average number of small mammals caught per year per area, from an annual dataset (Australian Wildlife Conservancy, unpublished data).

Thus, a breeding pair produces one litter of pups each spring, but in areas of high prey abundance more than one female in a pack may give birth.

Influence of bait type, weather and prey abundance on bait uptake by feral cats (Felis catus) on Peron Peninsula, Western Australia.

They are effective predators that mainly hunt small or medium - sized vertebrates (Fitzgerald and Turner 2000), and while the density of feral cats is directly correlated with prey abundance (Genovesi et al. 1995; Edwards et al. 2001), the population density of free - ranging house cats is more reflective of human density (due to the provision of supplementary food) than that of their prey (Sims et al. 2008).

Instead, the researchers speculate that the birds were responding to movements of their aquatic prey timed to the spring - neap tide cycle, a hypothesis that could be confirmed through a study jointly tracking predator and prey abundance.

We hypothesize that increasing predator - prey size ratios reflect increases in prey abundance, prey nutrient content, and predation among predators.

Consequently, group living enables Neolamprologus obscurus to efficiently increase the prey abundance in their territory.

Not exact matches

«It could be that any time you have this mass abundance of prey,» he says, «we have supergroups and we just haven't seen them before.»

Based on a peatland model developed at the University of York and latest climate change predictions, the researchers warn that by 2051 - 80 the dunlin could see a 50 % decline in numbers, with the golden plover down 30 % and the red grouse down by 15 %, all driven by declining abundance of the birds» crane fly prey.

Mountain lions occur at far lower densities than deer, and so any loss of their prey can have disporportionate impacts on their reproductive rates and overall abundance.»

When Robert Paine introduced it in 1969, he envisioned its mechanisms as a dominant predator consuming and controlling the abundance of a particular prey species and a prey species competing with other species in its trophic class and excluding them from the community.

«Despite this, we have demonstrated that great differences in the abundance of predatory reef fish, and of their prey, can be attributed to humans,» Professor Kingsford says.

They then used the earlier observations of the changing abundances of the three pairs of predators and prey — leveraging data sets collected by other scientists — to show how the models would apply.

«A stable and healthy reef includes a high abundance and diversity of predatory fish and a relatively low number of herbivorous and small prey fish,» says study lead author April Boaden, a PhD student at the Coral CoE.

Prey diversity and abundance were marginally better in an urban environment.

Many of the bony fish species that are recorded in spectacular abundance from adjacent otolith assemblages in the Chagres Formation (File S2) may have formed a dominant portion of the prey resources for Isthminia, as they do for extant delphinids (see Kelley & Motani, 2015).

As a result of non-target species possibly being included in past research studies, it has been thought that snow leopards — who lack an abundance of natural prey — consume great numbers of small mammals such as marmots, hares and pika, as well as wild ungulates, which are larger hooved animals such as ibex.

ref In Kenya, experiments also indicated that urchin removal can benefit corals, but that this can be preceded by an initial increase in seaweed abundance, and must also be accompanied by protection of fishes that prey on urchins.

Individual traits, such as sex and social rank, and environmental effects, such as the amount of rainfall and the abundance of prey, also matter, but the ability of individuals to form and maintain social bonds in triads was key, according to the study, which appears today in the journal Ecology Letters.

The ability to see food on land might explain why our fish ancestors evolved, eventually growing limbs so they could stalk the abundance of prey on land.

Relationships with sea - ice variability, the Southern Annular Mode and prey and predator abundance all have the potential to modulate the annual breeding population.

A related concept, the mesopredator release hypothesis, predicts that the removal of apex predators leads to the irruption of mesopredators with concomitant declines in the abundances of their prey owing to elevated rates of predation by mesopredators [10].

What Olof Liberg wrote in his 1984 paper was this: «Most cats (80 - 85 percent) were house - based and obtained from 15 to 90 percent of their food from natural prey, depending on abundance and availability of the latter.»

When your cat consumes small prey animals they consume and abundance of soluble fiber.

Indeed, this was the case in the study from southern Sweden cited by USFWS: «Wild rabbits were the most important prey, and cats responded functionally to changes in abundance and availability of this prey.»

We argue that the behavioural capacity of feral cats to undertake long - distance excursions to exploit transient hunting opportunities results in significantly higher total predator pressure on prey, and helps to explain how low - density cat populations could have large impacts on small - mammal abundance at landscape scales.

Wild rabbits (Oryctolagus cuniculus) were the most important prey, and cats responded functionally to changes in abundance and availability of this prey.

Most cats (80 - 85 %) were house - based and obtained from 15 to 90 % of their food from natural prey, depending on abundance and availability of the latter.

Dr. Sarah Allen, Ocean and Coastal Resources Program Lead for the Pacific West Region of the National Park Service, believes this gathering of whales is due to an abundance of prey (primarily anchovies).

They thrived in their new homes when they first arrived because of the abundance of prey, including such delicacies as lizards and mice.

attributes both increases and decreases in penguin populations to changes in the abundance of their main prey, Antarctic krill.

The impacts from a changing climate also loom, from potentially shifting the abundance and distribution of essential prey species to melting previously ice - locked polar waters that will expose whales to even more human activity.

Across India, tiger abundance is strongly correlated with prey density [20] and both depend on strict controls on hunting.

Marine mammals, birds, cetaceans and pinnipeds (seals, sea lions and walruses), which feed mainly on plankton, fish and squid, are vulnerable to climate change - driven changes in prey distribution, abundance and community composition in response to climatic factors (Learmonth et al., 2006).