The sunny, warm weather may be a pleasure for humans, but it is showing signs of negatively impacting local wildlife, a Midpeninsula Open Space District biologist said.

The current drought, which is one of the most severe in California history, has left breeding ponds for amphibians dry and could upset the life cycles of animals from frogs to deer, Cindy Roessler said.

Rain from recent storms only began to fill a pond on district land in the Santa Cruz Mountains in Palo Alto, and although she observed newts and frogs clamoring to lay eggs, many native animals may not come out of their burrows, missing a year of reproduction, she said.

"Some amphibians won't be able to reproduce. They need several months of water. There won't be a pond to reproduce in if there is no more rain," she said.

The effects are more than hypothetical. Newts that came out of their burrows after the second big rain emerged in late February, three months later than normal.

"For weeks they looked really skinny. You could see the vertebrae on their backs sticking up," Roessler said.

Last week, while out checking ponds in the area, Roessler was pleased to see fat newts in reproduction mode. But amphibian eggs, including those of frogs that currently line the pond, must hatch into tadpoles. They are at risk of dying if the ponds dry up too soon, she said.

Some mammals also seem affected, she said. The black-tailed deer have unusually thin coats. The deer change their coats twice a year, from reddish in summer to bluish in fall and winter.

"In spring the change starts at one end of the body to the other end. But they look bare -- even the yearlings. There's not much on their hips," Roessler said.

Roessler said she doesn't know what is causing the change, but speculated it could be the warm temperatures or nutritional deficiencies. Perennial plants deer depend on might not be growing fast enough to produce adequate forage, she said.