How much is enough? Landscape-scale conservation for the Florida panther

Recovery Action 1.1.4.2 in the Third Revision of the Florida Panther Recovery Plan calls for updating the Kautz et al. map every five years.

“Recovery Action 1.1.4.2. in the Third Revision of the Florida Panther Recovery Plan [1] calls for updating the Kautz et al. [7] map every five years.”

Kautz et al. identified areas consistently occupied by panthers for 20 years (Primary Zone), adjacent areas likely to be occupied by an expanding panther population (Secondary Zone), and areas that would best facilitate dispersal and population expansion north of the Caloosahatchee River (Dispersal Zone).

“Kautz et al. [7] identified areas that had been consistently occupied by panthers for 20 years (“Primary Zone”), adjacent areas that would be most likely to be occupied by an expanding panther population (“Secondary Zone”), and areas that would best facilitate dispersal and population expansion north of the Caloosahatchee River (“Dispersal Zone”).”

The majority of previous resource selection analyses for panthers in southern Florida were third-order selections (habitat within home ranges).

“the majority of these analyses were third order selections (habitat within home ranges) [4–9]”

Only Kautz et al. and Thatcher et al. attempted to analyze first-order selection (range within the region).

“only Kautz et al. [7] and Thatcher et al. [10] attempted to analyze the first order selection (range within the region).”

Three previous resource selection analyses were second-order selections (home ranges within the range).

“3 were second order selection analyses (home ranges within the range) [6, 7, 10]”

In south Florida, forested habitats have been shown to be important to panthers, although the region is topographically flat.

“and in south Florida forested habitats have been shown to be important to panthers [4–9, 38], although it is topographically flat [39].”

To the authors' knowledge, this is the first model to demonstrate the importance of forest edge and water depth in panther habitat use, although other studies have examined related factors such as forest patch size and water regime.

“To our knowledge, this is the first model to demonstrate the importance of forest edge and water depth in panther habitat use, although other studies have examined related factors such as forest patch size [5, 7, 9, 36] and water regime (duration of flooding) [10].”

Results from this study are consistent with Kautz et al. and Onorato et al. in that, related to forest patch size, the amount of forest edge was a highly predictive variable of adult panther presence.

“Results from our study are consistent with the latter in that, related to forest patch size, the amount of forest edge was a highly predictive variable of adult panther presence.”

The boundary of the panther Primary Zone as drawn by Kautz et al. was supported by the model, with a few notable exceptions.

“The boundary of the panther Primary Zone as drawn by Kautz et al. [7] was supported by our model, with a few notable exceptions.”

These areas probably are used by transient males and fit more closely to the definition of the Secondary Zone.

“These areas probably are used by transient males and fit more closely to the definition of the Secondary Zone [7].”

Upland forests ranked high in habitats selected within panther home ranges.

“However, upland forests ranked high in habitats selected within panther home ranges [6–9].”

The Secondary Zone of Kautz et al. is of little value to breeding panthers in its current state.

“The Secondary Zone of Kautz et al. [7] is of little value to breeding panthers in its current state (Fig 3).”

Kautz et al. estimated that the effective area of the Secondary Zone is about 34.5% of that in the Primary Zone.

“Kautz et al. [7] estimated that the effective area of the Secondary Zone is about 34.5% of that in the Primary Zone.”

Previous studies also found that panthers selected cypress swamps.

“Previous studies also found that panthers selected cypress swamps [6, 7].”

Of the available breeding habitat, approximately 5232 km2 (93.8%) is contained within the Primary Zone defined by Kautz et al., and 211 km2 (3.8%) is contained within their Secondary Zone.

“Of the available breeding habitat, approximately 5232 km2 (93.8%) is contained within the Primary Zone defined by Kautz et al. [7], and 211 km2 (3.8%) is contained within their Secondary Zone.”

Even if all adult habitat within southern Florida had the maximum adult density of 2.80 panthers per 100 km2 as reported in Quigley and Hornocker, the total population would remain below 240 adults and subadults, a population size thought necessary to maintain genetic viability and a high probability of persistence.

“Even if all of the adult habitat within southern Florida had the maximum adult density of 2.80 panthers per 100 km2 as reported in Quigley and Hornocker [44], the total population would remain below 240 adults and subadults, a population size thought to be necessary to maintain genetic viability and a high probability of persistence [7].”