Linking trade-offs in habitat selection with the occurrence of functional responses for moose living in two nearby study areas

Abstract

A species may modify its relative habitat use with changing availability, generating functional responses in habitat selection. Functional responses in habitat selection are expected to occur when animals experience trade-offs influencing their habitat selection, but only a few studies to date have explicitly linked functional responses to the underlying trade-offs faced by the animals. We used data from 39 female moose fitted with GPS telemetry collars in two nearby study areas in Canada to investigate if moose (1) were faced with a food/cover trade-off in habitat selection, as typically acknowledged in the literature, and (2) showed a functional response in their use of food/cover-rich habitats. We also examined how habitat selection patterns varied seasonally, and between study areas. The occurrence of functional responses varied strongly between study areas, and could not always be related to a measurable food/cover trade-off. Functional responses were observed more often in the study area where the environmental conditions were more severe (colder temperatures, higher precipitations, and lower food availability). Selection coefficients were also less variable among individuals in that study area, suggesting that severe environmental conditions may constrain individuals to a few selection tactics and promote the development of functional responses. Moose reacted to the availability of different habitat types in different seasons, reflecting the changing trade-offs faced by the animals. We found considerable behavioral differences between individuals from two adjacent study areas, and therefore recommend caution when extrapolating habitat selection results. We advocate for the wider use of functional responses to identify critical habitats for a species from a management or conservation perspective.

Disentangling Woodland Caribou Movements in Response to Clearcuts and Roads across Temporal Scales

“…We found that although disturbances were essentially avoided, females nonetheless regularly moved through or in close proximity to roads and clearcuts, modifying their behaviour when doing so, confirming yet refocusing hypotheses A and B. Our results also further show that individuals modulate their response to disturbances on a daily and annual basis, especially in periods of significance for caribou ecology, supporting hypothesis C. The increased use of disturbed habitats noted during certain period was however unanticipated and expanded the scope of hypothesis C. We believe that these results could reflect an ability to adapt behavioural decisions temporally to compromise between risk avoidance and forage requirements to optimize their respective efficiency [6], [11], [13], [38]–[39].…”

“…Females preferentially increasing or decreasing their crossing rates suggest a vigilance-relocation response potentially related to the risk associated with local disturbance levels, a behavioural adjustment previously noted in elk [12]. As individuals typically avoid crossing clearcut edges and roads, a local increase in the presence of such features can be expected to impose greater alertness on individuals [9] and influence habitat selection patterns [11], [13]–[14]. Increased crossing rates may thus reflect relocation movements in an effort to access more secure areas [11], increasing the likelihood of edge and road crossings [10], [12].…”

Eurasian lynx habitat selection in human-modified landscape in Norway: Effects of different human habitat modifications and behavioral states

“…where β0 is the fixed-effect intercept, γ0j is the random intercept (i.e., the difference between the mean intercept β0 for all lynx and the intercept for lynx j), and γ1j is the random coefficient of covariate ×1 for lynx j (i.e., the difference between the mean coefficient β1 for all lynx and the coefficient for lynx j) (Mabille et al, 2012).…”

Habitat use and selection by male and female moose (Alces alces) in a boreal landscape.

“…Although there has been considerable study of range use by moose in other areas of Canada and Alaska (Dussault et al 2001, Dussault et al 2005a, b, Maier et al 2005, Gillingham and Parker 2009a, Mabille et al 2012, few studies have investigated habitat requirements and limiting factors o f moose in…”